Article

Assessment of soil structure in the transition layer between topsoil and subsoil using the profil cultural method

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Abstract

In France, agronomists have studied the effects of cropping systems on soil structure using a field method based on a morphological description of soil structure. In this method, called ‘‘profil cultural’’ or soil profile in English, the soil structure of the tilled layer is observed on a vertical face of a pit. Subsoil and more especially the transition layer between topsoil and subsoil have not always been given specific onsideration. However, these layers undergo the effect of cropping systems through soil compaction or smoothing/smearing. A more accurate quantification of earthworm macropores and cracks in the transition layer would enable a more precise evaluation of the agronomical potential of the soil, manifest in root development or water retention. Thus, the aim of this paper is to present the profil cultural method in detail, along with the improvements we have made to quantify the ability of roots to penetrate compacted zones in the transition layer. We propose two indicators: (i) number of earthworm burrows per m2 counted on a horizontal surface at the bottom of the transition layer in the soil pit (ii) cracking quantified by taking a 50-mm � 50-mm � 100-mm sample of soil from the transition layer and examining the number of cracks. Results from experiments on different tillage treatments are used to demonstrate why it is worthwhile to take into account cracks and earthworm activity. Soil profiles were examined in mouldboard ploughed and no tillage fields, and described using the profil cultural method and the new indicators. Root maps were also traced to observe the effect of soil structure on root growth. Preliminary results show that the classification of cracking and the quantification of the number of earthworm burrows per m2 can explain observed root development in subsoil. This first approach towards a better observation of subsoil structure and the effect it has on roots needs to be confirmed through further research, and especially via quantification and scoring of soil structure impact on roots.

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... The assessment of residue removal under NT solely in the topsoil may miss potential depletion of SOC in the subsoil layer, which have been found to rely on the exchanges to and from topsoil via plant root systems and soil fauna , and dissolved SOM by preferential flow (Rumpel and Kögel-Knabner, 2010). Under PT systems, assessment of soil physical conditions at the interface between the plow layer (cultivated soil layer) and the subsoil may also be important to determine whether the vertical exchange of SOC is not restricted (Peigné et al., 2013). ...
... Soil water retention related properties did not change significantly at the topsoil layer and across the soil profile, possibly due to the negative relationship between BD and SOM. The transition layer (18-to 30-cm depth) has been recognized as an important zone for soil physical assessment for root growth and water retention (Peigné et al., 2013). We found NT-Ret to maintain high AFP comparative to the surface layer indicating higher oxygen availability important for root growth (Table 5), whereas it was significantly lower under NT-Harv. ...
... However, we should also consider the accessibility of the subsoil by roots, which is dependent on the soil physical conditions at the transition layer (Peigné et al., 2013). We showed the removal of residue at the surface under NT to modify nutrient cycling below the conventional soil sampling depth, and the depletion of soil nutrients in the transition layer may make the roots concentrate at a shallow depth (Zhang and Barber, 1992). ...
Article
Both surface and subsoil layers can be a significant source of soil moisture and nutrients for crop growth, but the changes in subsoil properties due to management are rarely assessed. This study was conducted to determine tillage and residue management effects on soil nutrient availability, as well as soil biological and physical conditions throughout soil layers ranging from 0 to 60 cm. We utilized an experiment with 40-year long continuous maize (Zea mays L.) cropping under crossed plow-till (PT) vs. no-till (NT) and residue removed (Harv) vs. residue returned (Ret) treatments on a silt loam soil in Chazy, NY. We assessed soil properties that are indicative of soil processes important for crop growth. Soil physical indicators (texture, bulk density (BD), water stable aggregation (WSA), available water capacity (AWC), and air-filled porosity (AFP)), soil biological indicators (soil organic matter (SOM), permanganate oxidizable carbon, mineralizable carbon, and soil protein), and soil chemical indicators (pH and plant available nutrients) were measured at five depth increments (0–6, 6–18, 18–30, 30–45, and 45- to 60-cm depth). A novel statistical approach of marginal R² (R²m) was used to show percent variance of each measured soil indicator explained by tillage and residue management as well as the depth of soil sample. R²m was higher for soil biological indicators (0.66 < R²m < 0.91), compared to AWC and those nutrients that are not applied through fertilizer application (0.11 < R²m < 0.53). NT-Ret showed the highest concentration of majority of the measured soil nutrients, and higher accumulation of SOM related properties across depths. This was partly explained by favorable soil physical conditions indicated by BD, WSA, and AFP at the transition layer (18- to 30-cm depth) that allowed for the vertical exchange of soil water, nutrients, and SOM related properties between the topsoil and the subsoil layers. The PT treatments showed the absence of SOM transfer across the transition layer, whereas NT-Harv showed nutrient depletion at the transition and subsoil layers. This study revealed significant alteration of soil biological, chemical, and physical indicators depending on the treatment combinations, which can be ignored if surface sampling is solely used. Benefits of residue return appear more significant when combined with no-till for 1) providing better soil physical conditions and 2) maintaining adequate nutrient availability across a soil profile especially when considering subsoil properties.
... For instance, Sasal et al. (2006) and Boizard et al. (2013) propose distinguishing a platy soil structure from the F structure used in the "profil cultural" method (see below). Many authors have also outlined the importance of macropores due to soil biota activity in the dynamics of soil structure regeneration in reduced tillage (Capowiez et al., 2012;Piron et al., 2012;Silva et al., 2014) and developed their own system of description (Peigné et al., 2013;Piron et al., 2016submitted). In Brazil, Tavares Filho et al. (1999 have adapted the method for no-till situations in tropical soils (such as oxisols, which are considered to have a particular behaviour). ...
... The initial "profil cultural" method was developed by Manichon (1987) and is described in detail in Gautronneau and Manichon (1987), Peigné et al. (2013) and Roger-Estrade et al. (2004). The "profil cultural" concept was defined by Henin et al. (1969) as the part of the topsoil (i) whose structure is determined by tillage, compaction and weather conditions and (ii) where the main part of organic carbon, plant roots, soil biota and mineral nutrients are located. ...
... Similarly plant roots contribute to the maintenance or modification of pore space and can penetrate compacted zones (Unger and Kaspar, 1994;Gubiani et al., 2010). It is important to consider the action of these natural agents on modifications of soil structure through the creation of a macropore network and/or the deposition of casts because these modifications play an important role in soil functioning and root access to the subsoil (Ehlers et al., 1983;McKenzie et al., 2009;Peigné et al., 2013). ...
Article
In France, agronomists have studied the effects of cropping systems on soil structure using a field method that is based on a visual description of the soil structure. This "profil cultural" method was designed as a field diagnostic tool to identify the effects of tillage and compaction on soil structure dynamics. It is of great benefit to agronomists seeking to improve crop management and preserve soil structure and fertility.However, the "profil cultural" method was developed and has mainly been used in conventional tillage systems with regular ploughing. As there has been an increase in the use of various forms of reduced, minimum and no-tillage systems in many parts of the world, it is necessary to re-evaluate this method's ability to describe and interpret soil structure dynamics in no-till or reduced tillage. In these situations, changes in soil structure over time are mainly driven by compaction and by regeneration through natural agents (climatic conditions, root growth and macrofauna), therefore it is important to evaluate the effects of these natural processes on soil structure dynamics.These concerns have led to adaptations and amendments to the initial method based on field observations and experimental work in different cropping systems, soil types and climatic conditions. The description of crack types has been improved and a criterion of biological activity based on the visual examination of clods has been introduced.To test this modified method, a comparison with the initial method was undertaken and its ability to make diagnoses tested in five experiments in France, Brazil and Argentina. The adapted method allowed an improved assessment of the impact of cropping systems on soil functioning when natural processes were integrated into the description.
... Soil compaction develops under NT due to traffic pressure (Peigne et al. 2013) leading to higher soil bulk density and resistance (Gantzer and Blake 1978;Kay and VandenBygaart 2002;Soane et al. 2012;Javeed et al. 2013;Guan et al. 2014) (Fig. 2-12). ...
... In our study, the NT practice modified the soil bulk density by having higher values at 20-30 and 30-40 cm layers (Table 3-6). This is probably the transition layer compaction described in Peigne et al. (2013), which could partly explain the observation of lower primary and secondary RLDs under NT than under MP at 20-30 cm (Fig. 3-3). However, similar soil bulk densities of NT and MP in the upper layers were measured and were unable to explain the relative reduction of corn roots in NT in the upper layers. ...
... In addition, as the absence of soil disturbance under NT, the previous root channels could be preserved, resulting in more biological macro-porosity over the long-term (Peigne et al. 2013). This was reported by Messiga et al. (2011) at the experimental site. ...
Thesis
The no-till (NT) is gaining great attention for soil preparation. This practice modifies number of soil properties such as the distribution of phosphorus (P) in the soil profile. This work aims to analyze the impacts on the biogeochemical P cycle after decades of NT and incorporate those effects in an operational model. We used a long-term field experiment under corn-soybean rotation established on a clay loam soil (L’Acadie, Quebec, Canada). The design was a split-plot plan with 4 blocks under moldboard plough (MP) and NT, subdivided by 3 doses of P [0 (0P), 17.5 (0.5P), 35 (1P) kg P ha-1] applied in corn phase and localized to 5-cm deep and 5-cm from the corn row.The phosphate ion concentration in MP was relatively constant (0.08 mg P L-1) in the tilled layer (0-20 cm), slightly lower in 20-30 cm (0.05 mg P L-1) and much lower below (0.01 mg P L-1). In [NT, 0.5P] and [NT, 1P] plots, Cp was higher (0.28 et 0.19 mg P L-1) in the 0-10 cm layer compared to the tilled layer in MP, but decreased sharply with depth. This vertical stratification in NT was also observed for P-Olsen, P-M3 and other nutrients as C, N, and K. After 23- and 24-year of experimentation, maize roots tended to be fewer (-14%) under NT than MP, probably because of increased weed infestation under NT. For soybean, more roots accumulated in the 0-10 cm layer under NT (44% of total length) than MP (21%) and vice versa for the 10-20 cm layer. Those differences in root distribution under NT and MP corresponded to the stratification of N, P, and K.This set of data on the distribution of roots and phosphorus was used i) to develop a 1D model describing P dynamics over several decades in MP, ii) to test a method to assess the spatial P uptake distribution according local root length density and soil P availability, and iii) to develop a spatial 2D model describing P dynamic in NT. This model simulates the soil P availability dynamic on long term according soil properties and crop root distribution within soil profile for different soil preparation regime and different P fertilization rate. Although the model overestimates the P availability near the localized P fertilizer, it is able to predict the soil P stratification in NT treatment and its consequences on crop P uptake. This new model will be a useful tool to improve P fertilization management in context of no-till practices.
... Until recently, only field methods were used to describe burrows or the deposit of casts at the soil surface (Mueller et al., 2009;Peigné et al., 2013;Pérès et al., 1998). Casts at the soil surface are an interesting indicator of earthworm activities; however, their presence varies strongly over time as they result from seasonal biological activities and are altered by seedbed preparation. ...
... Consequently, although earthworms are important in restoring soil macroporosity by digging macropores after a soil compaction event (Capowiez et al., 2012), this method does not differentiate between the two D states with or without burrows. This results in an excessively severe assessment of soil structure under no-tillage, in which vertical pores have a major influence on the dynamics of soil structure and play an important role in soil functioning and root access to the subsoil (Ehlers et al., 1983;McKenzie et al., 2009;Peigné et al., 2013). Integrating a bioturbation indicator into VSSA appears necessary to describe the influence of earthworm bioturbation on soil-structure dynamics and to better predict consequences of earthworm activity on soil structure, plant growth, and hydric properties. ...
... Digging of burrows may be necessary for anecics, whose survival depends on access to both deeper soil layers and the soil surface. Type 1 bioturbation in continuous compacted soil structure, as in a plough pan (Fig. 5), has an important functional impact, since burrows increase water infiltration, gas exchange and root penetration (Langmaack et al., 2002;Peigné et al., 2013). In our study, Type 2 bioturbation was observed in both compacted and loosened soil structures (Table 4). ...
Article
Earthworm bioturbation, a biological process that strongly influences soil structure dynamics, is attracting more interest with the development of no-tillage farming. However, while methods for Visual Soil Structure Assessment (VSSA) are of great use to agronomists working to improve crop management and preserve soil structure, few methods have indicators that consider earthworm biostructures. One reason is that VSSA methods were initially created for conventional tillage systems, where tillage and compaction are the main drivers of soil structure over time, while bioturbation is a secondary driver. However, bioturbation is now recognised as an important process for soil functioning under no-tillage and reduced tillage systems. Among biostructures, the presence of burrows is one frequently-used indicator, but casts are rarely studied in the field, except in the “Soil-Structure Patterns” method (SSP), which provides a typology of soil structure that includes earthworm features. However the SSP typology appears complex (11 patterns), and implementing the method is time consuming. To improve VSSA methods, we identified patterns to define new indicators of earthworm bioturbation. We first assessed whether the patterns identified were useful for highlighting the real impact of bioturbation on the distribution of soil structures and the impact of tillage on earthworm activity. We then applied the pattern descriptions to the “profil cultural” method, which provides a detailed assessment of soil structure in the soil profile. This study was performed at two experimental sites in France experiencing different types of soil impacts (i.e. tillage, compaction). Identifying patterns in soil morphological units helped us to define four types of bioturbation: (1) type 0: no visible bioturbation; (2) type 1: presence of burrows; (3) type 2: presence of a few fresh cast aggregates; and (4) type 3: high presence of casts in different welded states. This new typology seemed relevant and complementary to typical indicators. When applied to the “profil cultural” method, these bioturbation indicators can improve the assessment of the soil structure usually provided by VSSA methods and provide more accurate information to agronomists and farmers about soil functioning, including biological activities.
... Le Profil Cultural, originally developed by H enin et al. (1960) and described by Manichon (1987), evaluates anthropogenic impacts (Roger-Estrade et al., 2004;Peign e et al., 2013). A soil pit, suitably wide to encompass likely structural variation and its spatial variability within a field, often corresponding to the width of a seed drill (3 m 9 1.5 m), is excavated perpendicular to tillage. ...
... Exploring profile faces with a knife reveals macro-pores (Ball et al., 2015), which can be highlighted with diluted paint (McKenzie, 1998). The quantification of earthworm burrows is also employed (Munkholm, 2000;Peign e et al., 2013). Mueller et al. (2009) found the VSA inter-aggregate porosity classification, assessed by examining an exposed face of a spade slice sample, correlated with dry q b . ...
... VESS Sq scores, for which assessment of intra-aggregate porosity on exposed aggregate faces is required, corresponded with porosity determined by CT imagery (Garbout et al., 2013;Munkholm et al., 2013). The classification of clods described in Le Profil Cultural, based on intra-aggregate porosity (Peign e et al., 2013), was justified with oedometer or consolidometer tests and significant differences between void ratios were reported (Roger-Estrade et al., 2004). Le Profil Cultural modified for tropical soils (Neves et al., 2003) was found to relate to microbial biomass carbon (da Silva et al., 2014). ...
Article
Soil structure forms a key component of soil quality, and its assessment by semi-quantitative visual soil evaluation (VSE) techniques can help scientists, advisors and farmers make decisions regarding sampling and soil management. VSE techniques require inexpensive equipment and generate immediate results that correlate well with quantitative measurements of physical and biochemical properties, highlighting their potential utility. We reviewed published VSE techniques and found that soils of certain textures present problems and a lack of research into the influence of soil moisture content on VSE criteria. Generally, profile methods evaluate process interactions at specific locations within a field, exploring both intrinsic aspects and anthropogenic impacts. Spade methods focus on anthropogenic characteristics, providing rapid synopses of soil structure over wider areas. Despite a focus on structural form, some methods include criteria related to stability and resiliency. Further work is needed to improve existing methods regarding texture influences, on-farm sampling procedures and more holistic assessments of soil structure.
... The increase of weed infestation and the limited availability of N mainly at the beginning of the growing season are probably the main problems that reduced tillage pose to organic farmers (Gadermaier et al., 2012;Peigné et al., 2007;Sans et al., 2011). On the other hand, reduced tillage is highly suited to conserve soil fertility and prevent erosion (Berner et al., 2008;Gadermaier et al., 2012) by enhancing soil organic carbon (SOC) content, microbial activity and soil structure Peigné et al., 2013). ...
... Other studies under Mediterranean conditions obtained similar results (López-Garrido et al., 2014). However, many studies from temperate regions reveal lower crop yields in systems with no soil layer inversion by chiselling (Cooper et al., 2016) because of a combination of a shortage of nutrients and competition from weeds Peigné et al., 2013). Indeed, the lower biomass of lentil in plots with reduced tillage can be explained by the higher weed biomass under these conditions. ...
... In organic arable cropping systems, the intensity of soil disturbance, the farmyard manure and green manure fertilization are overriding factors that determine the amounts of SOC and N and their pattern of distribution in the soil profile (Gattinger et al., 2012). Some authors have indicated that SOC is enhanced by reduced tillage practices after several years Peigné et al., 2013). However, other studies were unable to demonstrate such a positive effect (Berner et al., 2008). ...
Article
Conservation agriculture and organic farming are two alternative strategies that aim to improve soil quality and fertility in arable cropping systems through reducing tillage intensity, maintaining soil cover and increasing nutrient recycling, using farmyard and green manures. However, these practices can increase weed infestation or decrease nutrient availability. The objectives of this study were to evaluate the effects of tillage type (mould-board vs. chisel ploughing), fertilization and green manure on soil parameters (SOC, N, bulk density, carbon stocks, and soil microbial biomass C mic and N mic), weed abundance and crop yields in a four-year rotation of spelt, chickpea, winter wheat and lentil in the Mediterranean region (Catalonia, Spain). Tillage and green manure did not affect crop yields or weed biomass, although during the last year of the experiment, plots with mouldboard ploughing had less weed biomass and higher lentil biomass. Fertilization was the most important factor, increasing the cereal yields, SOC, N and soil microbial biomass (C mic and N mic) content of the soil. However, fertilization did not favour chickpea and lentil crops because weed competition limited legume crop growth. Overall, there was a loss of SOC and a reduction of carbon stocks over the four years of the trial in the soil because of the deep soil tillage (25 cm) and low crop productivity irrespective of tillage type. In contrast, N content increased in all of the plots and was enhanced by fertilization. The use of chisel plough stratified the distribution of SOC and N in the surface layers (0-10 cm). Both C mic and C mic /SOC ratio increased in fertilized treatments, suggesting an increased lability of SOC. The application of more stabilized organic matter may be a better practice to build up soil organic matter and to maintain crop yields in organic farming systems.
... Sasal et al. (2006) ont mis en évidence, dans les sols limoneux d'Argentine, l'importance d'une structure lamellaire apparaissant près de la surface du sol et empêchant l'infiltration d'eau dans des sols en semis direct. Comme évoqué précédemment, de nombreux chercheurs ont souligné l'importance des macropores d'origine biologique dans la dynamique de la régénération de la structure du sol en labour réduit (Capowiez et al., 2012 ;Peigné et al., 2013 ;Piron et al., 2012). Au Brésil, Tavares Filho et al. (1999) ont adapté la méthode, mais spécifiquement pour les sols tropicaux comme les oxisols. ...
... J'ai ainsi travaillé en collaboration avec des chercheurs français et internationaux dans le cadre de l'ISTRO (International Soil and Tillage Research Organisation), et plus particulièrement avec un groupe de chercheurs qui se réunissent autour de s méthodes d'observation visuelle des sols. Cela a donné lieu à un ouvrage collectif dans lequel j'ai co-écrit un chapitre , à une publication commune sur une nouvelle méthode d'observation du profil de sol, se rapprochant du scoring VESS (Ball et al., 2015) et à des issues spéciales du journal 'Soil and Tillage Research' où nous avons exposé nos travaux sur le profil cultural Peigné et al., 2013). ...
... Dans chaque maille nous avons compté le nombre de racines présentes. Le protocole est détaillé dans Peigné et al. (2013). La figure 35 présente, pour 2015 (dix ans d'essai) et à la floraison du blé, le pourcentage de mailles colonisées par des racines en fonction de la profondeur de sol pour les 4 traitements de travail. ...
Thesis
Full-text available
La majeure partie de mes travaux de recherche ont concerné la gestion de la fertilité de sols en agriculture biologique (AB). Plus largement ils s’inscrivent dans une perspective de contribution scientifique et opérationnelle à la transition écologique de l’agriculture. Pour lever les problèmes de fertilité des sols en AB j’ai posé l’hypothèse que la mise en œuvre en AB de pratiques de l’agriculture de conservation (AC) pouvait être une solution. L’AC s’est construite autour de trois principes : l’arrêt du labour, une couverture végétale du sol permanente et une rotation diversifiée des cultures. On prête à l’AC plusieurs intérêts agronomiques, environnementaux et économiques mais elle est consomme des herbicides pour maîtriser les adventices qui ne sont plus détruites par le labour. Ainsi, un certain nombre de spécificités de l’AB, comme l’interdiction d’utilisation d’herbicides, limitent la mise en œuvre en AB des principes de l’AC. Pour analyser et évaluer, dans une perspective d’amélioration de la fertilité des sols, les conditions et les limites de l’utilisation en AB des principes de l’AC j’ai développé plusieurs axes de recherche : la mise au point de méthodes pour observer la fertilité du sol, dont les effets interactifs entre les composantes biologiques et physiques du sol, (2) des essais sur les effets des pratiques de non labour et de labour agronomique (profondeur réduite, pas de rasette) en AB sur la fertilité du sol et sur les performances agronomiques, et (3) des travaux pour concevoir avec des agriculteurs des systèmes de culture sans labour en AB. L’apport majeur de mes travaux sur les méthodes d’observation du sol est l’amélioration du profil cultural comme outil permettant d’observer les interactions en propriétés physiques et biologiques des sols. En mobilisant une diversité de dispositifs expérimentaux mon travail a contribué à mieux comprendre des processus écologiques et plus particulièrement les interactions entre activité biologique (micro et macro) et la structure du sol. Ceci a été possible grâce à une mobilisation innovante de la méthode du profil cultural. J’ai ainsi apporté des réponses globales sur l’effet des techniques simplifiées de travail du sol en AB. La technique du labour agronomique ressort comme le meilleur compromis au labour profond, avec des niveaux de rendement et d’adventices similaires, mais avec une amélioration de la teneur en carbone dans l’horizon cultivé du sol. Pour les techniques sans labour, comme l’utilisation du chisel à différentes profondeurs de sol, les résultats sont très mitigés, avec une très forte variabilité des rendements et en moyenne une perte par rapport au labour profond. Cela est dû à un problème de contrôle des adventices, mais aussi à une dégradation de la fertilité du sol dans les horizons non travaillés du sol. Toutefois, l’horizon superficiel présente plus de matières organiques, point positif dans les sols sensibles à l’érosion. Dans un dernier axe de travail, j’ai mobilisé les connaissances acquises lors des essais, mais aussi celles d’agriculteurs pour concevoir des systèmes de culture innovants et intégrant des principes de l’AC. Mes travaux montrent que les systèmes de culture co-conçus ont ‘sur le papier’ mais aussi, selon les résultats des modèles d’évaluation actuels, plus de chances d’améliorer la fertilité des sols en AB que les systèmes actuels. L’enjeu d’évaluations en conditions réelles de ces systèmes co-conçus est fort et je poursuis dans cette voie par le suivi d’essais systèmes de longue durée. Les processus étudiés, les outils que j’ai contribué à développer ou à faire évoluer sont mobilisables au-delà de l’AB. Le fait de mieux comprendre un processus écologique et de pouvoir jouer dessus pour remplacer in fine une technique agricole, s’appuie sur un nouveau paradigme : l’agro-écologie. Ainsi, à la fin de ce mémoire, je présente les questions que je souhaite aborder dans la suite de mes travaux : (1) comment insérer des pratiques s’appuyant sur des principes agroécologiques dans les systèmes de culture ? et (2) comment aider les agriculteurs à mobiliser ces principes dans la transformation de leurs systèmes de culture ?
... However, according to soil and climate conditions, no-tillage could also increase topsoil density and may be unsuitable for poorly structured sandy soils and poorly drained soil (Soane et al., 2012). Compared with ploughing, penetration resistance measurements (Crittenden et al., 2015;Schulz et al., 2011), bulk density distribution (Krauss et al., 2017c (Supplement); Peigné et al., 2009) and morphological assessment of soil structure (Peigné et al., 2013;Vian et al., 2009) revealed similar densities in topsoils but denser soil layers below the new tillage layer till the former ploughing depth in conservation tillage systems for a range of soil textures. This seems to be a soil density increase due to the lack of tillage-induced loosening rather than compaction caused by heavy machinery that e.g. ...
... Subsoil non-inversion loosening with intensive secondary tillage (Munkholm et al., 2001) and deep rooting tap roots are approaches to remove plough pans and may help to improve porosity in lower soil layers (Kautz, 2015;Köpke et al., 2015). Applying no-tillage systems on a longer run also showed that plough pans can be remediated (Peigné et al., 2013). According to Soane et al. (2012) or Holland (2004), soil structure improves with no and reduced tillage after a transition period of several years. ...
... Different soil layers are marked with woolly yarn. Soil clods are marked with coloured dots (Peigné et al., 2013). Source: ISARA Lyon, Jean-François Vian. ...
... Another way of assessing the producer in his complex role of responding to the market and simultaneously assuming the need to conserve the environment is by measuring the effects on the state of the soil and water resources. Field or empirical methodologies have been very useful in many cases (Sullivan, 2007;Peigné et al., 2013;López-Santos et al., 2017). ...
... For example, Peigné et al. (2013) studied the effect of cultivation systems on soil structure by using field methods based on the edaphic profile called "cultural profile." To this end, the team focused on the agricultural areas with problems of compaction due to the passage of machinery. ...
... This is explained by noting that the relative weights of half of the categorical variables (CD, SM, KFWC, TO, HD, KWC, GH, KV, SFF, MT) attributed to producer decisions define direct actions that modify the magnitude of the calculated harvest (t ha −1 ) for each of the orchards sampled. In particular, the first two edaphic variables (CD and SM) that relate to modifications, whether intentional or not, of the upper layer of the soil turned out to be the most important in the MLP analysis and are consistent with other studies of visual assessment, similar to the technique used in the present study that was focused on evaluating soil fertility based on changes in its profile (Mueller et al., 2009;Peigné et al., 2013). ...
Article
The need to promote a sustainable land management (SLM) approach for land degradation neutrality (LDN) is a global challenge, and we must rely on local assessments of how rural participants are conducting their work. Therefore, the objectives of the present research are as follows: 1) evaluate the fruit culture of the guava producers (Psidium guajava, L.) in Calvillo, Aguascalientes, Mexico; and 2) to show whether it is possible to detect key variables in SLM by using an artificial neural network to improve productivity. The study unit (SU) was located in the community of San Tadeo (21.917 °N and 102.701 °W) in the municipality of Calvillo, Aguascalientes. We considered a total of 430 ha established with this fruit and nine orchards that consisted of 9.05 ha, which is equivalent to 2.09% of the total area. Each hectare was randomly sampled, with a significance of 95% (α ≥ 0.05). The information was collected by using empirical field techniques and a questionnaire sent to the producers. The results revealed that the productive success of the SU is based on the knowledge and ability of the fruit farmers to take advantage of bioclimatic and biophysical conditions for guava cultivation. It was demonstrated in approximately 90% of the analyzed cases that the producer's SLM was between regular and excellent. This result was confirmed by the index of edaphic adequacy (Iea), which was created by nine of thirteen variables measured in the field, that indicated in 47% of the orchards (OR), the edaphic condition is optimum (Iea = 0) or close to optimum (-0.2 ≥ Iea ≤ 0.2). In addition, by using a Multilayer Percetron (MLP), it was possible to detect two key aspects in the producers’ work: cava design (DC) and soil management (SM).
... Concern over subsoil structural degradation and associated impacts led to the development of SubVESS (Ball et al., 2015a) to compliment VESS and allow assessment of a soil profile to 1 m depth, using a simple flowchart and numeric scores (Ball et al., 2015a;Ball et al., 2017). As with other profile methods, SubVESS follows classical soil survey principles, though emphasises anthropogenic impact assessment, concentrating on the transition layer (Ball et al., 2015a), the zone between the topsoil and subsoil, often directly below the deepest, regular cultivation operation and particularly prone to compaction in arable soils (Peigné et al., 2013). SubVESS assesses features at particular sampling locations and for wider spatial coverage, for example, comparison between field areas, the excavation of multiple pits is required (Ball et al., 2015a). ...
... Le Profil Cultural (Hénin et al., 1960) assesses structural morphology in terms of the impact of cultivation processes by identifying structural zones and aggregate types (Roger-Estrade et al., 2004). Though recommended for deployment to ≈ 1-1.5 m and capable of evaluating entire soil profiles (Peigné et al., 2013), Le Profil Cultural might be used to assess just the topsoil and upper subsoil (Roger-Estrade et al., 2004), for example to 40 cm depth. ...
... Additionally, a technique, which is as straightforward and quick as VESS, but allows assessment to 40 cm depth (below the cultivation zone), or the upper sub-soil and readily deployable by farmers and advisors without full soil pit (to 1 m) excavation, may be desirable. Le Profil Cultural, which allows assessment to at least 1 m depth and specific transition layer evaluation (Peigné et al., 2013), is more suitable for expert use, time consuming and does not generate a final numeric score (Boizard et al., 2005). SOILpak is suitable for non-expert use, generates a numeric score and can be deployed to 40 cm depth (McKenzie, 1998). ...
Article
Visual soil evaluation (VSE) techniques, established in soil management and quality assessment are categorised into spade and profile methods. Both approaches have merits and limitations. For example, VESS, a widely used spade method, requires basic equipment and is quick, thereby enabling wide spatial deployment, but only gives a general indication of soil structural quality to 25 cm depth, potentially missing important features below the cultivation zone in arable soils. SubVESS, the profile equivalent of VESS, gives detailed information to ≈ 1 m at specific points but is time consuming, relatively expensive and cannot be deployed over wide areas. Despite giving more detailed information, full (to ≈ 1 m) profile methods may not always be desirable. Our aim was to compare possible management recommendations derived from soil structure, obtained by VESS, SubVESS and a new procedure that bridged both approaches, called the Double Spade method (DS). In-field and headland zones at 10 arable sites in Ireland under conventional tillage were surveyed using the methods, assessing to ≈ 25 (VESS), 40 (DS) and 80 (SubVESS) cm depth respectively. Results showed significant difference between field zones, indicating structural damage at headlands, occasionally to 80 cm depth. From the soils surveyed, VESS was not always sufficient for determining soil quality related management requirements. DS indicated that damage occurred below 20 cm depth. SubVESS gave additional information to the other VSE techniques regarding the extent of damage, in some cases only evident below 40 cm depth. Quantitative measurements showed significant difference only to 20 cm depth. It was concluded that the extra information obtained using DS was worth the time spent collecting the data. It is suggested that SubVESS may be appropriate to further investigate suspected issues as indicated by DS, but not for routine survey over large areas.
... The decrease in macropores was measured after four years of NT management, which indicates that these structural changes occurred over time. Similarly, a study of tillage effects on structural quality in the topsoil of a sandy loamy soil in Denmark carried out by Garbout et al. (2013) and research on sandy loams /silty soils (Peigné et al., 2009(Peigné et al., , 2013 showed a generally higher number of pore networks, branches and junctions under CT due to greater compaction under NT. The NT soil did however have a dominance of vertical macropores, which indicates the presence of anecic (vertically burrowing) earthworms (Peigné et al., 2009) that could potentially enhance the soil's ability to drain and transmit water (the hydraulic conductivity), affecting the infiltration rates of the soil. ...
... Topsoil compaction is often highlighted as one of the main challenges to NT systems, with the potential to significantly reduce infiltration rates, whereas in CT systems loosening of compacted topsoil layers is achieved by mouldboard ploughing. The absence of soil inversion in NT systems can create compacted clods (Peigné et al., 2009(Peigné et al., , 2013, also known as "NT pans". The work of Munkholm et al. (2003), where temporal and spatial effects of two different direct drilling techniques were assessed on a sandy loam in Denmark, supports this view, and found critically high penetration resistance and bulk density in their NT field. ...
... Soil pore structure, an important soil quality variable influencing chemical, physical and biological processes, was often found to be in a poorer state under NT practices than under CT (Garbout et al., 2013;Peigné et al., 2013;Abdollahi et al., 2014;Moncada et al., 2014;Rücknagel et al., 2017). The earthworm occurrence and macroporosity, caused by bioturbation in NT systems compared with CT, differed between studies, but the anecic species that are drilling deep vertical burrows were more abundant in NT systems (Peigné et al., 2009;Garbout et al., 2013), potentially affecting infiltration and water storage in deeper layers of the soil (Buczko et al., 2003). ...
Article
This review provides a comprehensive evaluation of no-till (NT) based on recent studies (post-2000) in NW Europe and evaluates the separate effect of the NT and other associated practices (e.g. cover crops, crop residue and crop rotations) individually and collectively on the water purification and retention functions of the soil. It also assesses the applicability of NT compared to conventional tillage (CT) systems with reference to a number of soil physical characteristics and processes known to have an important influence on water purification and retention functions. The literature search was carried out by a systematic approach where NT practices were assessed against soil structure, erosion, nutrient leaching/loss, water retention, infiltration and hydraulic conductivity (combinations of criteria = 40). Articles were selected based on their relevance in relation to the topic and location within NW Europe (n = 174). Results show that NT has large potential as an erosion mitigation measure in NW Europe with significant reductions of soil losses from agricultural fields, providing potential beneficial effects regarding inputs of sediment and particulate phosphorous (P) to water bodies. However, NT increased losses of dissolved reactive phosphorus (DRP) and had little effect on nitrogen (N) leaching, limiting the overall positive effects on water purification. Soil structural properties were often found to be poorer under NT than CT soils, resulting in decreased water infiltration rates and lower hydraulic conductivity. This was an effect of increased topsoil compaction, reduced porosity and high bulk density under NT, caused by the absence of topsoil inversion that breaks up compacted topsoil pans and enhances porosity under CT. However, several studies showed that soil structure under NT could be improved considerably by introducing cover crops, but root and canopy characteristics of the cover crop are crucial to the achieve the desired effect (e.g. thick rooted cover crops beneficial to soil structural remediation can cause negative effects in soils sensitive to erosion) and should be considered carefully before implementation. The contribution of NT practices to achieve Water Framework Directive (WFD) objectives in NW Europe is still uncertain, in particular in regards to water retention and flood mitigation, and more research is required on the total upscaled effects of NT practices on catchment or farm scale.
... However, according to soil and climate conditions, no-tillage could also increase topsoil density and may be unsuitable for poorly structured sandy soils and poorly drained soil (Soane et al., 2012). Compared with ploughing, penetration resistance measurements (Crittenden et al., 2015;Schulz et al., 2011), bulk density distribution (Krauss et al., 2017c (Supplement); Peigné et al., 2009) and morphological assessment of soil structure (Peigné et al., 2013;Vian et al., 2009) revealed similar densities in topsoils but denser soil layers below the new tillage layer till the former ploughing depth in conservation tillage systems for a range of soil textures. This seems to be a soil density increase due to the lack of tillage-induced loosening rather than compaction caused by heavy machinery that e.g. ...
... Subsoil non-inversion loosening with intensive secondary tillage (Munkholm et al., 2001) and deep rooting tap roots are approaches to remove plough pans and may help to improve porosity in lower soil layers (Kautz, 2015;Köpke et al., 2015). Applying no-tillage systems on a longer run also showed that plough pans can be remediated (Peigné et al., 2013). According to Soane et al. (2012) or Holland (2004), soil structure improves with no and reduced tillage after a transition period of several years. ...
... Different soil layers are marked with woolly yarn. Soil clods are marked with coloured dots (Peigné et al., 2013). Source: ISARA Lyon, Jean-François Vian. ...
... Soil compaction develops under NT due to traffic pressure (Peigne et al. 2013) leading to higher soil bulk density and resistance (Gantzer and Blake 1978;Kay and VandenBygaart 2002;Soane et al. 2012;Javeed et al. 2013;Guan et al. 2014) (Fig. 2-12). ...
... In our study, the NT practice modified the soil bulk density by having higher values at 20-30 and 30-40 cm layers (Table 3-6). This is probably the transition layer compaction described in Peigne et al. (2013), which could partly explain the observation of lower primary and secondary RLDs under NT than under MP at 20-30 cm (Fig. 3-3). However, similar soil bulk densities of NT and MP in the upper layers were measured and were unable to explain the relative reduction of corn roots in NT in the upper layers. ...
... In addition, as the absence of soil disturbance under NT, the previous root channels could be preserved, resulting in more biological macro-porosity over the long-term (Peigne et al. 2013). This was reported by Messiga et al. (2011) at the experimental site. ...
Thesis
La pratique du «sans labour» (NT) se développe dans le cadre de l’agriculture de conservation des sols. Cette pratique modifie nombre de propriétés du sol comme, par exemple, la répartition du phosphore (P) dans le profil du sol. L’objectif de cette thèse est d’analyser les impacts après plusieurs décennies du NT sur le cycle biogéochimique du P et d’intégrer ces effets dans un modèle de fonctionnement. Nous avons utilisé un essai au champ de longue durée sous maïs-soja (L’Acadie, Québec, Canada) implanté sur un sol argilo-limoneux. Le dispositif était un split-plot à 4 blocs avec mouldboard plough (MP) et sans labour (NT), subdivisés par 3 doses de fertilisation en P minéral [0 (0P), 17.5 (0.5P), 35 (1P) kg P ha-1] apportées sur le maïs et localisées à 5 cm de profondeur et à 5 cm du rang de maïs. La concentration des ions phosphates du sol (Cp) test était relativement uniforme dans la couche labourée (0-20 cm) (0.08 mg P L-1), puis baissait légèrement dans 20-30 cm (0.05 mg P L-1) et davantage au-delà (0.01 mg P L-1). Sous les traitements [NT, 0.5P] et [NT, 1P] traitements, le Cp était plus élevé dans la couche 0-10 cm (0.28 et 0.19 mg P L-1) que dans la couche labourée mais baissait rapidement avec la profondeur. Cette stratification verticale sous NT était également observée pour les teneurs en P-Olsen, P-M3 et autres nutriments comme C, N et K. Après 23 et 24 années d’essai, il y avait tendanciellement moins de racines du maïs sous NT (-14%) que sous MP, probablement à cause de la présence plus importante d’adventices sous NT. Pour le soja, il y avait beaucoup plus de racines dans la couche 0-10 cm sous NT (44% de longueur total) que sous MP (21%) et inversement dans la couche 10-20 cm. Ces différences de distribution des racines sous NT et MP correspondent à la stratification de N, P, et K. Cet ensemble de données sur la distribution des racines et du phosphore a été utilisé pour i) évaluer un modèle 1D décrivant la dynamique du P sur plusieurs décennies dans la couche labourée du sol, ii) proposer un mode d’estimation de la distribution du prélèvement dans le profil de sol, et iii) développer un modèle spatialisé 2D décrivant la dynamique du P pour le traitement sans labour. Ce modèle permet de simuler l’évolution de la disponibilité en P du sol sur le long terme quels que soient les modes de préparation du sol et le régime de fertilisation P. Même si le modèle surestime parfois la disponibilité en P à proximité de la zone fertilisée, il permet de prédire la stratification du P du sol en NT et ses conséquences sur le prélèvement de P en relation avec les propriétés du sol et le développement du système racinaire. Il pourra contribuer à améliorer le raisonnement de la fertilisation phosphatée dans le contexte du sans-labour.
... Concern over subsoil structural degradation and associated impacts led to the development of SubVESS (Ball et al., 2015a) to compliment VESS and allow assessment of a soil profile to 1 m depth, using a simple flowchart and numeric scores (Ball et al., 2015a;Ball et al., 2017). As with other profile methods, SubVESS follows classical soil survey principles, though emphasises anthropogenic impact assessment, concentrating on the transition layer (Ball et al., 2015a), the zone between the topsoil and subsoil, often directly below the deepest, regular cultivation operation and particularly prone to compaction in arable soils (Peigné et al., 2013). SubVESS assesses features at particular sampling locations and for wider spatial coverage, for example, comparison between field areas, the excavation of multiple pits is required (Ball et al., 2015a). ...
... Le Profil Cultural (Hénin et al., 1960) assesses structural morphology in terms of the impact of cultivation processes by identifying structural zones and aggregate types (Roger-Estrade et al., 2004). Though recommended for deployment to ≈ 1-1.5 m and capable of evaluating entire soil profiles (Peigné et al., 2013), Le Profil Cultural might be used to assess just the topsoil and upper subsoil (Roger-Estrade et al., 2004), for example to 40 cm depth. ...
... Additionally, a technique, which is as straightforward and quick as VESS, but allows assessment to 40 cm depth (below the cultivation zone), or the upper sub-soil and readily deployable by farmers and advisors without full soil pit (to 1 m) excavation, may be desirable. Le Profil Cultural, which allows assessment to at least 1 m depth and specific transition layer evaluation (Peigné et al., 2013), is more suitable for expert use, time consuming and does not generate a final numeric score (Boizard et al., 2005). SOILpak is suitable for non-expert use, generates a numeric score and can be deployed to 40 cm depth (McKenzie, 1998). ...
... If the soil in its natural condition is considered to be the 'genoform', then 'phenoforms' with differing soil indicators can subsequently develop according to management practice (Droogers and Bouma, 1997). Since compaction and tillage principally influence structure, emphasis is on the assessment of subsoil structure such as SOILpak for cotton growers (McKenzie, 1998), 'le profil cultural' for soil management (Peigné et al., 2013) and morphological descriptions for water management in wet soils (Mueller et al., 1994). Detailed tests of the potential of the soil for crop productivity already exist. ...
... In addition to cracking, Peigné et al. (2013) stressed the importance of quantification of earthworm macropores. McKenzie et al. (2009) buried a mesh layer horizontally in the soil so as to prevent root penetration to the subsoil. ...
... Continuous porosity through this zone is particularly important to allow root exploration and permeability to drainage water. A transition layer that is compacted or smeared can restrict the number of roots penetrating into it and below (Peigné et al., 2013). Roots in such layers are often thickened and distorted. ...
... types: (i) topsoil examination only such as the Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and the Visual Soil Assessment (VSA) drop test (Shepherd, 2009); (ii) subsoil only e.g. SubVESS ; (iii) topsoil and subsoil together such as SOILpak (McKenzie, 2013), 'Profil Cultural' (Peigné et al., 2013) and (iv) assessments that describe and measure more than soil structure such as the complete VSA analysis (Shepherd, 2009) and the Mueller Soil Quality Rating (M-SQR) (Mueller et al., 2013). A recent special issue of Soil & Tillage Research (Munkholm et al., 2013a) and book (Ball and Munkholm, 2015) summarised common methods of visual soil evaluation and their application to crop production, land appraisal, soil quality, soil compaction and the wider environment. ...
... Subsoil aggregation and porosity differ from those in the topsoil because of the decreased role of organic matter and tillage and the greater relative contribution of swelling and shrinking, freezing and thawing and biopore creation to structure formation. Subsoil examination begins below spade depth (typically c. 25 cm), usually just beneath the topsoil and often below any Ap horizon where there may be a critical zone or pan that has been compacted or smeared by machinery during tillage, planting or harvest and termed the anthropic 'transition layer' by Peigné et al. (2013). As with topsoil VESS, subsoil layers are first identified (usually between 2 or 4) and each layer is scored. ...
Article
Visual soil evaluation techniques have gained popularity and are increasingly used in agriculture and soil science for research, consultancy and teaching purposes. We describe recent applications, developments, opportunities and limitations, mainly of the Visual Evaluation of Soil Structure (for topsoil (VESS) and for subsoil (SubVESS)), and of the Visual Soil Assessment (VSA). Data are taken from experiments on compaction and from assessments made in farmer’s fields in the UK, Brazil and New Zealand. The methods are widely used to detect compaction and are well-suited for monitoring changes in compaction status, particularly in relation to weather extremes. VESS proved useful in distinguishing grazing vs wheel compaction in the UK and Brazil by permitting detection of layers at different depths within the topsoil zone. The depths of compact layers are important for scoring management decisions for soil improvement. However the use of scores as limiting thresholds in different soil types needs the support of further soil measurements and/or additional visual assessments of soil and crop. VSA and VESS were also used to estimate the risk of significant soil emissions of nitrous oxide where compaction damage was present and rates of mineral N fertiliser were high. Visual assessments also have the potential to assess the risk of surface water runoff and nutrient loss. The potential role of soil colour was shown for the further development of visual evaluation techniques for a soil carbon storage index. Visual soil evaluation techniques also provide a useful visual aid for improving soil awareness in groups of stakeholders, helping the exchange of knowledge and ideas for innovation in agriculture.
... types: (i) topsoil examination only such as the Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and the Visual Soil Assessment (VSA) drop test (Shepherd, 2009); (ii) subsoil only e.g. SubVESS ; (iii) topsoil and subsoil together such as SOILpak (McKenzie, 2013), 'Profil Cultural' (Peigné et al., 2013) and (iv) assessments that describe and measure more than soil structure such as the complete VSA analysis (Shepherd, 2009) and the Mueller Soil Quality Rating (M-SQR) (Mueller et al., 2013). A recent special issue of Soil & Tillage Research (Munkholm et al., 2013a) and book (Ball and Munkholm, 2015) summarised common methods of visual soil evaluation and their application to crop production, land appraisal, soil quality, soil compaction and the wider environment. ...
... Subsoil aggregation and porosity differ from those in the topsoil because of the decreased role of organic matter and tillage and the greater relative contribution of swelling and shrinking, freezing and thawing and biopore creation to structure formation. Subsoil examination begins below spade depth (typically c. 25 cm), usually just beneath the topsoil and often below any Ap horizon where there may be a critical zone or pan that has been compacted or smeared by machinery during tillage, planting or harvest and termed the anthropic 'transition layer' by Peigné et al. (2013). As with topsoil VESS, subsoil layers are first identified (usually between 2 or 4) and each layer is scored. ...
... The use and replication of VSE methods may be restricted when describing the soils of small plots due to soil disturbance, particularly the profile methods. The increasing awareness of the vulnerability of subsoils to compaction damage has led to the development of methods that include assessment of compacted subsoil layers (Peigné et al., 2013;. Generally the digging of pits and use of subsoil assessment methods are required when subsoil damage is suspected and the transition layer between topsoil and subsoil needs to be examined. ...
... agronomic potential of the soil and of the extent and depth of any loosening required (Peigné et al., 2013) (see Batey et al.,Chapter 2,this volume). This is especially important in no-tillage systems, where regular assessment of subsoil structure allows detection and remediation of compaction that could otherwise accumulate and restrict crop growth. ...
Chapter
This book with nine chapters describes the main methods for visual soil evaluation (VSE) of soil structure and soil-related properties. It includes clear visual images of the variation of soil quality and how these relate to soil productivity and environmental sustainability. Such images raise awareness and provide a measure of the soil degradation that is a looming threat to the viability of world agriculture. Emphasis is given to recognizing, protecting and restoring soil quality as these are of vital importance for tackling problems of food insecurity, global change and environmental degradation. The book shows how these aims can be achieved with VSE by describing tools that can readily be used by land users and environmental authorities to assess crop performance, soil improvement and soil productivity. VSE is also placed in the context of future sustainable intensification of agriculture including factors of soil loss, resilience, climate change, scarcity of water and other resources, nutrient retention and increased risk of degradation. This book is relevant not only to students, lecturers, scientists and advisors working directly with soils but also to policy makers, food security experts, environmentalists and engineers who have an interest in soils and sustainable agricultural production. Last, but not least, it is hoped that these simple VSE techniques will be used extensively in years to come as a tool to link soil specialists and non-specialists together with the mutual aim of developing sustainable soil management to advance global food security and improve the environment.
... Vakali et al. (2011) in their experiment in Römmershein, southwestern Germany, observed a lower crop biomass and higher wed biomass in case of barley under reduced tillage compared to conventional tillage while no difference between treatments in terms of yield was recorded under rye (Secale cereale) cultivation. Higher weed growth under reduced tillage in OF compared to plowing was also observed by Peigné et al. (2008Peigné et al. ( , 2013 in their long term trial performed in France. Cooper et al. (2016) in a meta-data analysis reported an increase of about 50% in weed pressure with conservation practices in OF than that of conventional plowing. ...
... Greater stratification of nutrients and organic matter in the surface soil might be the reason behind higher wheat biomasses in the beginning of the crop cycle compared to plowing. In all sites no yield reduction was noted in initial year but along the time weed pressure and soil compaction lowered the yield under reduced tillage (Peigné et al., 2008(Peigné et al., , 2013. Berner et al. (2008) in Frick (Switzerland), found about 14% and 8% reduction in Wheat (Triticum aestivum L.) and spelt (Triticum spelta L.) yield under reduced tillage while a 5% rise in sunflower (Helianthus annuus L.) yield was recorded in conservation practices over conventional one. ...
Chapter
Full-text available
Conservation agriculture (CA) is a resource-saving strategy encompassing three broad principles viz., minimum soil disturbance, diversified crop rotation and adequate soil cover through residue retention. Nowadays organic farmers are encouraged to adopt conservation practices to ensure soil quality and sustainability along with food security. In this chapter, we aimed to disseminate comprehensive knowledge regarding recent findings, advantages, drawbacks and opportunities of introduction of conservation practices in organic farming (OF). The possible potential benefits of adopting CA in OF are less soil erosion and degradation due to improved soil structure, rise in soil carbon stock, augmented biomass and diversity of macro- as well as micro-organisms, and reduced loss of nutrients through run-off and/or leaching. As CA and OF relies on principles of contrasting strategies of practices, introduction of CA in OF also poses challenges like difficulties in weed control, soil compaction, restricted nutrient availability due to slow mineralization rate and restricted choice of crops. Apart from these, some other constraints such as unavailability of suitable equipment, low incentives and funding from Governments and lack of organic market development strategies are also hindering the spontaneous adoption of CA by the organic farmers. Thus, practicing conservation techniques in OF strongly requires modification of traditional management practices into well optimized practices with some degree of flexibility depending upon pedo-climatic conditions, equipment availability and targeted objectives of farmers.
... The field days gave the participants access to different soils, crops and management systems, which permitted the demonstration of the various VSE methods under diverse scenarios and conditions. Five methodologies (VESS (Guimarães et al., 2011), VSA (Shepherd, 2009), SOILpak (McKenzie, 2001, SubVESS (Ball et al., 2015) and Profil Cultural − French and Brazilian versions, (Peigné et al., 2013;Tavares Filho et al., 1999)) were tested in Oxisols with contrasting textures. On the first day, the group visited a sugarcane field on an Oxisol with approx. ...
... This is especially relevant under no-tillage or reduced tillage systems with no or reduced possibilities for mechanical soil loosening. They combined the bioturbation indicator with the profil cultural method (Peigné et al., 2013), and demonstrated that this was a useful complement that allows a more detailed soil structure assessment and helps to derive soil management recommendations. Cherubin et al. (2017) showed that VESS was a robust tool to reveal changes in soil quality due to a land use conversion from native forest to pasture and then to sugar cane crop. ...
... They also successfully used the morphological data from the Profil Cultural with soil physical measurements as the inputs of a model that estimates soil structural dynamics in tilled soils. Peigné et al. (2013) introduced a modified version of the Profil Cultural that included the diagnosis of the subsoil with an emphasis on the examination of the number of earthworm burrows per m 2 in a horizontal plane and the quantification of cracking in the transition layer, as factors that can explain the root development in compacted subsoils. Several attempts to improve and adapt the method to specific conditions include a description of platy structure Sasal et al., 2017), and characterisation of earthworm activities . ...
... Well-described protocols are given by Peigné et al. (2013) and Boizard et al. (2017). Briefly, a pit of ~ 2-3 m wide and 0.8-1.5 m deep is dug to represent the spatial variation of soil structure and is vertically partitioned in layers. ...
Chapter
Soil structure is a complex and dynamic soil property that constitutes a key aspect of soil health. Soil structure assessment can be evaluated in the field by visual soil evaluation techniques. Development and improvement of these techniques/methods have been the focus of numerous soil scientists worldwide since the mid-20th century. Divided into topsoil and soil profile methods, they differ in principle and level of detail of the assessment. The development and protocols of selected methods are presented in this chapter in chronological order of development, to show differences in methodological approaches. The description given for each of the methods includes guidance for the appropriate selection of the method to be used by stakeholders. Two case studies are given as examples of i) how visual techniques can contribute to achieving the challenges for developing sustainable agricultural management focused on nurturing soil fertility, and ii) the use of visual techniques as tools to assess and monitor soil health in developing countries.
... SubVESS is useful for identifying subsoil compaction and is more suitable for crops with an effective root system extending below 30 cm and for soils susceptible to deep compaction through heavy machinery and harvesting under wet conditions. SOILpak (McKenzie) and le profil cultural (Peigné et al., 2013) can reveal soil quality for the whole profile; the latter shows the spatial variability of soil structure (see Chapter 2). Most of these methods have been developed under temperate conditions, although they have been shown to work well on tropical soils Guimarães et al., 2013;Moncada et al., 2014;Ball et al., 2015). ...
... Le profil cultural has also been developed under temperate conditions; however, studies such as Tavares Filho et al. (1999) have shown its adaptability to tropical soil conditions. Figure 8.8 shows the use of the le profil cultural and SubVESS methods to detect compacted layers, demonstrating the value of these methods in tracking soil degradation ( Tavares Filho et al., 1999;Peigné et al., 2013;Ball et al., 2015). ...
Chapter
This book with nine chapters describes the main methods for visual soil evaluation (VSE) of soil structure and soil-related properties. It includes clear visual images of the variation of soil quality and how these relate to soil productivity and environmental sustainability. Such images raise awareness and provide a measure of the soil degradation that is a looming threat to the viability of world agriculture. Emphasis is given to recognizing, protecting and restoring soil quality as these are of vital importance for tackling problems of food insecurity, global change and environmental degradation. The book shows how these aims can be achieved with VSE by describing tools that can readily be used by land users and environmental authorities to assess crop performance, soil improvement and soil productivity. VSE is also placed in the context of future sustainable intensification of agriculture including factors of soil loss, resilience, climate change, scarcity of water and other resources, nutrient retention and increased risk of degradation. This book is relevant not only to students, lecturers, scientists and advisors working directly with soils but also to policy makers, food security experts, environmentalists and engineers who have an interest in soils and sustainable agricultural production. Last, but not least, it is hoped that these simple VSE techniques will be used extensively in years to come as a tool to link soil specialists and non-specialists together with the mutual aim of developing sustainable soil management to advance global food security and improve the environment.
... Recientemente se ha demostrado que la actividad biológica del suelo depende del tipo de manejo agronómico que se realiza. Peigné et al. (2012) propusieron que la cero labranza induce una mayor cantidad de macroporos estables relacionados con la actividad biológica del suelo como consecuencia de una mayor producción de cementantes orgánicos para la agregación, mientras que en la labranza convencional, predomina la macroporosidad mecánica (sólo por la acción de la penetración de las raíces), la cual es propensa a una disrupción más rápida, debido a que se producen pocos cementantes orgánicos. Efecto bioquímico. ...
Article
Full-text available
El suelo es un componente de los sistemas terrestres que tiene un carácter multifuncional. Uno de los factores que más influye en las funciones del suelo es su estructura y el indicador más empleado para su estudio es la estabilidad de agregados. Existe una relación entre la estructura del suelo y el crecimiento de las plantas, en particular de sus raíces. La interacción de las raíces con el suelo, en especial con la estructura de éste, requiere de estudios a profundidad que ayuden a dilucidar los mecanismos de agregación en los que intervienen las raíces y la magnitud de estas interacciones. Contribuir a un mejor entendimiento de esa relación ayudará a implementar, mejorar y desarrollar técnicas de conservación y aprovechamiento sostenible del suelo. El presente trabajo tuvo como objetivo realizar una revisión de la producción científica de los últimos 50 años, cuyo tópico estuviera relacionado con los procesos por los cuales las raíces afectan la agregación del suelo. La conclusión de la presente revisión fue que la arquitectura de los sistemas radicales de distintas especies vegetales afecta de manera diferencial en el desarrollo de la estructura del suelo, incidiendo sobre la productividad de los agroecosistemas. Es necesario generar modelos que expliquen la magnitud y los mecanismos de la relación suelo-raíz de diferentes especies vegetales, así como las interacciones derivadas de las rotaciones de cultivos, con la finalidad de aumentar la producción de estos agroecosistemas, haciéndolos sistemas sostenibles.
... -the soil component: students are introduced to the characterisation of soil types (soil classification, origin) and the influence of these soil characteristics on crop growth and ecosystem services. As part of this instruction, the components of the soil profile (Peigné et al. 2013) are defined by the instructor and students learn to perform an auger test to describe the soil profile. -the water component: students' attention is brought to the fish ponds present on the studied farm and on infrastructures installed to manage water flow (e.g. ...
... In our study, the NT practice modified the soil bulk density by having higher values at 20-30 and 30-40 cm layers (Table 6). This is probably the transition layer compaction described in Peigne et al. (2013), which could partly explain the observation of lower primary and secondary RLDs under NT than under MP at 20-30 cm (Fig. 3). However, similar soil bulk densities of NT and MP in the upper layers were measured and were unable to explain the relative reduction of corn roots in NT in the upper layers. ...
Article
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Background and aims Relevant soil properties and nutrient distributions influencing crop root growth might be different under no-till (NT) and mouldboard plough (MP) management. The possible different root systems within different managements might have key impact on crop nutrient uptake and consequently crop production. Our objective was to assess the long-term combined effects of tillage and phosphorus (P) fertilization on corn (Zea mays L.) root distribution and morphology. Methods Corn root and soil samples were collected during the silking stage at five depths (0–5, 5–10, 10–20, 20–30 and 30–40 cm) and three horizontal distances perpendicular to the corn row (5, 15 and 25 cm) under MP and NT with three P fertilizations (0, 17.5, and 35 kg P ha−1) for a long-term (22 years) experiment in eastern Canada. Root morphology and soil properties were determined. Results NT practice decreased corn root biomass by −26 % compared to MP, mainly by decreasing the primary and secondary roots. Additionally, corn roots in NT tend to be more expansive on the surface layer with higher root length and surface densities for the depth of 0–5 cm at two sampling distances of 15 and 25 cm. The 35 kg P ha−1 rate increased the root biomass by 26 and 41 % compared to the 0 and 17.5 kg P ha−1 rates. Conclusions No-tillage practice and low rates of P fertilization reduce corn roots. This is probably caused by the weed competition in NT and the continued downward P status with low P rates over 22 years.
... Between 2003 and 2006, a drought affected the region and some crops were not harvested. In December 2005, the structure of the A horizon was analyzed using the visual structure evaluation (VSE) "le profil cultural" Manichon and Gautronneau, 1987;Peigné et al., 2013;Roger-Estrade et al., 2004). No P structure was present in the A horizon at the beginning of the experiment. ...
Article
In silty soils under no tillage (NT), platy (P) soil structure is widespread and constrains water infiltration. Our objectives were (i) to evaluate how traffic and the presence of crop residues influence P structure development in the field and (ii) to characterize changes in soil structure caused by alternation of wetting and drying (w-d) periods for two topsoil layers of a silty soil and two compaction levels in the laboratory. The five-year field experiment was carried out on a Typic Argiudoll under NT and the structure of the A horizon was analyzed using visual soil evaluation (VSE) both before and five years after two traffic levels were applied to four crop sequences. The laboratory experiment of w-d cycles was carried out with two disturbed layers of a Typic Argiudoll, which was repacked to achieve two different bulk densities, and the columns were subjected to 5, 10, or 15 w-d cycles. In the field experiment, the P structure was clearly identified by VSE and corroborated by shear strength and bulk density measurements. The proportion of P structure increased until about 50% of the A horizon after 5 years, irrespective of the traffic or presence of crop residues at the expense of the Φ structure proportion. In the laboratory, consecutive w-d cycles caused changes in soil volume, cracking of the soil surface, and formation of P structure of variable thickness up to 20 mm, confirming that alternation of w-d periods can cause structural modification of the silty soil, in particular horizontally oriented cracks. The number of w-d cycles increased the thickness of the P structure in the upper layer (R² = 0.55) and in the compacted treatment (R² = 0.81). The results obtained constitute important progress in the understanding of the evolution of P structure of silty soils under NT.
... , McKenzie (2001),Batey & McKenzie (2006), andPeigne et al. (2013). ...
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Since the 1970s a network of underground pipes, up to 1200 mm diameter, has been installed in the UK to transmit crude oil to refineries and gas from onshore terminals for distribution. Chosen routes are subject to significant constraints. Current techniques for pipe installation involve topsoil removal and storage. Trench depth is set to allow a cover of 1200 mm overburden after pipes have been installed. The heavy machinery involved results in severe compaction of exposed subsoil. Subsoil is loosened comprehensively and topsoil replaced. Existing field drains are reconnected, and, if necessary, new drains with gravel backfill installed. Pipe installation usually takes place between April and October. Preventative measures to limit compaction during installation are not a practical option. If subsequent arable crops or grass are poorer or drainage more defective than before disturbance, the loss is assessed and compensation paid. To determine the cause of the loss >60, investigations have been made throughout the UK. Soil physical properties were assessed in an open trench using visual and tactile methods. Consistently, severe compaction in the subsoil was identified as the cause of poor crop growth or drainage; it was not observed in the topsoil. Specific recommendations for remedial action were made based on location, depth and severity of the compaction. These included the installation of additional land drains, increasing the amount of gravel above the drains, or further subsoil loosening orientated to cross gravel backfill. After appropriate remedial action, net compensation for crop losses was frequently small or negligible.
... The most commonly used spade methods in research are the VSA method (Shepherd, 2009) and the VESS method developed from the Peerlkamp method Guimarães et al., 2011) (Munkholm and Holden, 2015). Among the soil profile methods, 'Profil Cultural' (Gautronneau and Manichon, 1987;Peigné et al., 2013), SOILpak (McKenzie, 1998 and, most recently, the numeric visual evaluation of subsoil structure methods (SubVESS) are used in research (Munkholm and Holden, 2015). These five spade and profile methods are described in detail by Batey et al. (2015). ...
Article
As the use of visual soil evaluation (VSE) methods has spread globally, they have been exposed to different climatic and pedological scenarios, resulting in the need to elucidate limitations, encourage refinements and open up new avenues of research. The main objective of this paper is to outline the potential of VSE methods to develop novel soil structure research and how this potential could be developed and integrated within existing research. We provide a brief overview of VSE methods in order to summarize the soil information that is obtained by VSE. More detailed VSE methods could be developed to provide spatial information for soil process models, e.g. compaction models. VSE could be combined with sensing techniques at the field or landscape scale for better management of fields in the context of precision farming. Further work should be done to integrate plant vigour, roots and soil fauna into VSE methods to provide general indicators of soil quality and for estimation of environmental risk factors related to soil C storage, GHG emissions and nutrient leaching, with particular reference to temporal changes. There is a great potential in combining (rather than comparing) VSE with measurements of soil structure, i.e. integrating VSE in soil structure and compaction research, as these methods provide spatial information that is difficult to obtain with other methods.
... Recientemente se ha demostrado que la actividad biológica del suelo depende del tipo de manejo agronómico que se realiza. Peigné et al. (2012) propusieron que la cero labranza induce una mayor cantidad de macroporos estables relacionados con la actividad biológica del suelo como consecuencia de una mayor producción de cementantes orgánicos para la agregación, mientras que en la labranza convencional, predomina la macroporosidad mecánica (sólo por la acción de la penetración de las raíces), la cual es propensa a una disrupción más rápida, debido a que se producen pocos cementantes orgánicos. Efecto bioquímico. ...
Article
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Soil is a multifunctional component of terrestrial systems. One of the factors that influence these functions is its structure and the indicator most commonly used for its study is aggregate stability. There is a close relationship between soil structure and plant growth. The way roots interact with soil properties, especially their structure, requires in-depth studies. A better understanding of this relationship will contribute to improving soil conservation and its sustainable use. To achieve this goal we carried out a review of the scientific literature of the past 50 years, with special emphasis on soil-root relationships reported in agricultural soils. We selected reports that mentioned at least one of the processes by which the roots affect soil aggregation. The conclusion of this review was that the architecture of the root systems of different plant species, differentially affects the development of soil structure, affecting the productivity of agroecosystems. It is necessary to build models that explain the magnitude and mechanisms of the soil-root of different plant species and interactions resulting from crop rotations to increase production of these agroecosystems and to make them sustainable.
... It is important to note that although conservation tillage can provide a number of benefits compared to conventional tillage, the effects are influenced by soil type, climate, and crop management practices (Palm et al. 2014). For example, depending on soil texture, conventional tillage might be more effective than conservation tillage in terms of addressing constraints such as soil compaction, and increasing crop performance (Peigné et al. 2013). ...
... These factors can be observed, especially in the areas of Forest, Capoeira and Pasture 4, which may be related to a greater presence of organic matter in the "A horizon" and increased Ma. The use of visual methods for evaluating soil quality has been shown to be effective in reducing subjectivity, especially in assessment of soil structure, compaction, root growth, among other features (McKenzie, 2013;Muphy et al., 2013;Peigné et al., 2013). In the present work, it was possible to establish field-based soil quality indicators sensitive to levels of degraded pastures, as well as to establish a practical method for the determining the levels of degradation in field with good accuracy. ...
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Developing techniques that are easily accessible to producers and extension agents would facilitate the assessment of pasture degradation in rural areas. The objective of this work was to evaluate the sensitivity of field-based indicators of soil quality at different levels of degraded pastures, validate these indicators with those determined in laboratory. Six areas were chosen: four areas of pastures in different gradients of degradation visually assessed (Degraded Pasture 1 - P1; Degraded Pasture 2 - P2; Degraded Pasture 3 - P3; and Degraded Pasture 4 - P4), in descending order of degradation; an area of Capoeira (natural vegetation of soil recovery); and a secondary Forest used as reference. The soil under all areas was an Ultisol clayey, and field determinations used were: soil coverage rate (SoilCov. Rt), depth of the root system (DRS) and "A horizon" thickness. Laboratory determinations were: soil density, total porosity (Tp), macroporosity (Ma), microporosity (Mi), Ca²⁺, Mg²⁺, Al³⁺, H+Al, P, K⁺, organic carbon (OC), base (BS) and aluminum saturation (AS). Also, the organic matter compartments such as particulate organic matter (POM), particulate organic carbon and carbon fraction associated with soil minerals were determined. Soil quality ranking were assigned to the different areas, and orthogonal contrasts were made to compare the stages of degradation. Subsequently, linear correlations were adjusted to test whether there were significant differences for the field and laboratory indicators among the areas of study. Soil quality ranking assigned represented the levels of degraded pasture visually observed in field, therefore allowing correlations with field indicators "A horizon" thickness (Rainy season r =0.71 and Dry season r =0.91) and DRS (Rainy season r =0.81 and dry season r =0.58). Similar correlations were found when the SoilCov. Rt was used, where correlations were observed with the "A horizon" thickness (Rainy season r =0.61 and Dry season r =0.75) and DRS (Rainy season r=0.76 and Dry season r =0.84). The field and laboratory determinations showed statistical differences between study areas, indicating that they were sensitive to levels of degradation. Through field determinations, it was possible to separate four groups of degradation: reference (Forest), low degradation (P4 and P3), under recovery (Capoeira) and high degradation (P1 and P2). The easily determined field-based quality indicators showed significant correlations with the laboratory values: BS, AS, Ma and POM, especially on the 0-5 cm surface layer, showing small variation between sampling periods and indicating the possibility of using these indicators to differentiate levels of degraded pastures with good accuracy.
... In the research context, the most used spade methods are the VSA (Visual Soil Assessment) [92] and the VESS (Visual Evaluation of Soil Structure) developed from the Peerlkamp method [90,93]. Among the soil profile methods, 'Profil Cultural' [94,95], SOILpak [96] and, most recently, the numeric visual evaluation of subsoil structure methods (SubVESS) [97] are used. Details of the methods have been published in a systematic review [98]. ...
Article
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The diffusion of tree crops has continuously increased during the last decades all over the world. The market boost has favored the adoption of intensive and highly mechanized cultivation, often triggering the degradation of the soil physical-hydrological qualities, mainly through enhanced soil erosion and compaction. Several papers have been published on soil degradation and restoration strategies in specific perennial crops and environments. This review paper collects such studies showing the sensitivity of soil under tree crops to the degradation of their physical-hydrological qualities. Then it reports the state of the art on the methodologies used for the evaluation of the physical-hydrological qualities in the field and in the laboratory, also suggesting an improved methodology for estimating the actual available water capacity. Some updated and promising experiences to recover the physical-hydrological qualities of soil are then illustrated. In particular, subsoiling and placement of drainages, spreading of organic amendments, compost, biochar, using of cover crops, and biological inoculants. A key point in applying the restoration practices is that they should not only be specific for the soil and tree rooting system, but also tailored according to the ecosystem functions that need to be improved besides plant health and yield.
... In recent years, some researchers have also set up a soil structure visualization model (SubVESS) to visually understand soil compaction, which set parameters that were sensitive to soil compaction as an evaluation index [20,21] . Peigné etc et al. [22] proposed a conception of a conversion layer between the topsoil and the deep soil and used comprehensive properties, such as the thickness, strength, and depth of the conversion layer, to judge the soil compaction. The process of soil compaction prediction evaluation is complicated, and there exists a series of problems such as large workload and sampling measurement error. ...
... The objective of this study is to present the adaptation of a profile method developed in arable land to the context of forest plantation. The cultivation profile method was developed by Hénin et al. (1969) and was fully described in Roger-Estrade et al. (2004), and Peigné et al. (2013). We will present the principle and the implementation of the method, use the method to describe the impacts of three MSP tools that were tested in experimental plantation sites and discuss the potential use and main limitations of the method in a forestry context. ...
Article
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Mechanical site preparation (MSP) is widely used in forestry to improve plantation success. Although it is known to alter soil properties, its direct effects on soil structure have rarely been described. The cultivation profile is a visual soil evaluation (VSE) method developed in agricultural research to analyse the impacts of cultivation practices on soil structure. The objective of the study was to adapt the method to forest plantations in order to analyse the effects of MSP on soil quality. Cultivation profiles were performed in six experimental plantation sites located in Northern France. The method made it possible to compare the impacts on soil structure of three MSP methods. It provided a schematic representation of the soil structural quality and a quantitative estimation of the volume of soil favourable to seedling root growth. It also highlighted unexpected negative effects of some MSP methods on soil structure, such as the creation of small cavities, the presence of compacted soil volumes due to wheel tracks or smeared soil volumes due to tool pass, and the pseudogleisation of soil zones due to changes in water circulation in the soil. The relevance and limitations of VSE methods in the context of forest plantation as well as the expected future development of the methods are discussed.
... Soil bulk density can be used as a measure of soil compaction and it therefore provides a useful indicator of soil physical condition. Previous studies of conservation tillage systems have found that soil compaction can become an issue if the soil surface is not regularly inverted through mouldboard ploughing Munkholm et al., 2003;Peigné et al., 2013). Soil bulk density on the Salle Park Estate was therefore monitored over the duration of the five-year cultivation trial to determine if there was any evidence of soil compaction on the conservation tillage Blocks L and P (Fig. 5). ...
Article
In 2010, the UK government launched the Demonstration Test Catchments (DTC) platform to evaluate the extent to which on-farm mitigation measures can cost-effectively reduce the impacts of agricultural water pollution on river ecology whilst maintaining food production capacity. In this paper, we compare the impacts on soil health of two types of conservation tillage (direct drill and shallow non-inversion) against conventional mouldboard ploughing after five years (2013–2018) of adoption within the River Wensum DTC. Across the 143 ha conservation tillage trial area, temporal changes in the physical, chemical and biological condition of the soils were examined through the analysis of 324 soil samples, whilst the impacts on soil water chemistry were assessed through the analysis of 1176 samples of subsurface field drainage. Riverine water pollution was also explored through high-resolution (30 min) hydrochemistry measurements generated by an automated, in-situ bankside monitoring station located 650 m downstream of the trial area. Results revealed that conservation tillage did not significantly alter the soil physical, chemical or biological condition relative to conventional ploughing during the first five years. In addition, conservation tillage did not reduce nutrient leaching losses into field drainage and did not significantly impact upon river water quality, despite the trial area covering 20% of the catchment. Economically, however, conservation tillage yielded net profit margins 13% higher than conventional ploughing after five years of practice due to a combination of operational efficiency savings and improved yields. Overall, the results of this study demonstrate that conservation tillage alone is ineffective at improving the short-term environmental sustainability of farming practices in this lowland intensive arable setting and indicates that a broader, integrated approach to conservation agriculture is required incorporating aspects of cover cropping, crop rotations and precision farming techniques. The improvements in farm business performance do, however, demonstrate land managers can make important financial gains by converting to a conservation tillage system.
... The M i component of STIC i was significantly correlated with direct indicators of soil structural quality; for example, higher soil BD values and lower K sat and total porosity in the topsoil were associated with more intensive machinery trafficking pressure (M i class, Tables 2 and 3), which is consistent with previous observations (Keller et al., 2013). More intensively managed sites (H-M i ) had lower K sat values (Tables 2 and 3) whereby increased trafficking pressure reduced soil structural quality as a result of an associated reduction in soil porosity and water conductivity (Ball et al., 2017;Peigné et al., 2013;Toivio et al., 2017). This in turn can have negative impacts on several soil functions, for example impeded plant root development, reduced nutrient and water uptake and ultimately reduced crop yields. ...
Article
Good soil structure provides multiple benefits for society but in grass based production systems is underpinned by trafficking management regime. For Irish soils, there is no soil trafficking intensity index that considers geo‐climatic variability or differences in drainage classes on soil compaction risk. Grazing and machinery activity data were compiled across 38 managed grasslands along with common soil structural quality indicators in order to develop and validate a “soil trafficking intensity index for compaction (STICi)”. Two component indices of STICi were developed: i. a grazing trafficking index (Gi, kg * yr ha‐1) and ii. a machinery trafficking index (Mi, kg * yr ha‐1). The average annual grazing trafficking pressure observed was 213,914 kg * yr ha‐1 and the average annual machinery trafficking pressure was 4,412 kg * yr ha‐1. These figures represent thresholds above which soils are at higher risk of compaction. Mi spanned a wider range (−2.1≤Mi≤2.8) compared to Gi (−1.32≤Gi≤ 1.06). STICi and components, when disaggregated by soil drainage class, were able to detect changes in direct indicators of soil structural quality, such as bulk density, total porosity, water holding capacity, water conductivity and visual soil assessment. STICi (Mi and, or Gi) were also related to indirect indicators, such as, soil carbon content, earthworms and microbial biomass. In general, poorly drained sites showed higher vulnerability to machinery trafficking intensity compared to grazing trafficking pressure. At national scale STICi can be utilised to identify “soils at risk of compaction”, and underpin targeted management advice for supporting sustainable grassland production.
... Probably, the surface application of amendments cannot modify soil structures below 10 cm depth, at least in the short term. Over a 2-year period under NT, Peigné et al. (2013) also found that main changes in the proportions of different soil structures took place in the first 10 cm soil. ...
Article
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The widespread degradation of the structure of silty soils under no till systems (NT) that has been observed in recent years is characterized by the presence of a platy structure (P) near the soil surface. Under these conditions, addition of organic and inorganic amendments could have beneficial effects on soil physical properties. We assessed structural regeneration following addition of amendments in an Argiudoll of Paraná, Argentina. Poultry litter (PL) and gypsum (G) were applied, providing an organic and inorganic amendment, respectively. Four treatments were tested: PL (7.5 Mg/ha), G (3 Mg/ha), the combination of PL + G (7.5 + 3 Mg/ha), and control (T) with no amendment. Description and quantification of the structural state of the soil profile was made using a Visual Soil Evaluation method: “Le profil cultural”. Aggregate stability, bulk density, total porosity, pore size distribution and soil shear strength for each soil structure and soil organic carbon (SOC) were determined at two depths. Twenty months after the amendment applications, both PL and PL + G treatments led to a significant increase of SOC in the upper 5 cm of soil. The proportion of Gamma (Γ) structure increased and P declined under PL and PL + G compared with G and T inn the A horizon. Treatments G and PL + G contributed to an increase in average diameter of aggregates in Γ only. The use of PL amendment alone or in combination with G could be a promising strategy to regenerate, in the short‐term, the degraded soil structure under NT.
... Some recent studies have matched the visual assessment of structure with soil physical and chemical properties (Murphy et al., 2013), crop yield (Mueller et al., 2009) as well as biological properties (Peigné et al., 2013). Soil structure assessment is also important in programs that reward farmers to maintain a good soil structure (McKenzie and Batey, 2006). ...
... The soil visual evaluation methods can be divided into the spade and profile methods (Emmet-Booth et al., 2016). All methods examine anthropogenic impacts on soil structure, however, profile methods such as the Whole Profile Assessment (Batey, 2000), SOILpak score (McKenzie, 2013) and Profil Cultural Method (Peigné et al., 2013) require considerable time and pedological knowledge to perform them in the field, since they evaluate soil depths of up to 1.5 m (Emmet-Booth et al., 2016). In contrast, some spade methods based on the evaluation of the surface layer of the soil (0.3 m), such as the Visual Evaluation of Soil Structure (VESS), proposed by Ball et al. (2007) under the name Visual Soil Structure Quality Assessment (VSSQA), which was improved and renamed by Guimarães et al. (2011), have been widely used for their simplicity . ...
Article
The Visual Evaluation of Soil Structure (VESS) method has been used frequently to evaluate the structural quality of soils from various parts of the planet, under different edaphoclimatic conditions and cultivation practices. In this context, this paper hypothesised that VESS is sensitive enough to detect differences between structural quality (Sq) scores of VESS from soils with different textural classes, submitted to distinct management and cultivation practices, under contrasting climates. To test this hypothesis, a systematic review and meta-analysis of global scope were conducted, with the objective of compiling and analysing all indexed scientific papers that utilised the method. Exclusion criteria were adopted with the intention of eliminating papers that did not meet the selection criteria for the meta-analysis, however, these papers were used in the systematic review. A sensitivity analysis was performed prior to the meta-analysis in order to evaluate the heterogeneity in the data set, thus increasing the scientific validity of the overall analysis. The results obtained through the systematic review showed that the number of studies using VESS has grown in recent years, not only in temperate regions, but also under diverse soil conditions and cropping systems in subtropical and tropical regions. The meta-analysis showed that temperate soils presented lower Sq scores compared to those observed in tropical and subtropical soils, whereas higher Sq scores were observed in clayey/silty soils compared to sandy soils, regardless of climate zone. Our findings also revealed that Sq scores differences induced by soil management and cropping systems were not detected by the meta-analysis. Thus, the VESS is an on-farm, practical and reliable tool for evaluating the structural quality of soils globally.
... The potential impact of this on soil processes (e.g. Peigné et al., 2013) warrant further investigation. Our results showed that decomposition occurs more slowly in the compacted soil of the tramlines at the crop-margin interface regardless of the litter type or the mesh size of the bags used in the experiment. ...
Article
Soil compaction is a major threat to agricultural soils. Heavy machinery is responsible for damaging soil chemical, physical and biological properties. Among these, organic matter decomposition, which is predominantly mediated by the soil biota, is a necessary process since it underpins nutrient cycling and the provision of plant nutrients. Understanding factors which impact the functionality of the biota is therefore necessary to improve agricultural practices. To better understand the effects of compaction on the soil system, we determined the effects of soil bulk density and soil penetration resistance on the decomposition rates of litter in three distinct field zones: a grass margin, sown at the edge of the field adjacent to the crop, tramlines in the crop:margin interface, and crop. Three litters of different quality (ryegrass, straw residues and mixed litter) were buried for 1, 2, 4 and 6 months in litter bags comprising two different mesh sizes (0.02 and 2 mm). Bulk density and soil penetration resistance were greater in the compacted tramline than in the margin or the crop. The greatest amount of litter remaining in the bags after 6 months was found in the tramline, and the least in the grass margin. Differences between treatments increased with burial time. No significant differences in mass loss between the two mesh sizes was detected before the fourth month, implying that microbial activities were the main processes involved in the early stages of decomposition. Decomposition in the tramline was clearly affected by the degradation of soil structure due to heavy compaction. This study shows that soil conditions at the edges of arable fields affect major soil processes such as decomposition. It also reveals the potential to mitigate soil degradation by managing the headland, the crop residues and the machinery traffic in the field.
... As relationships between visual soil quality characteristics and laboratory-measured soil parameters likely vary between soil types, use of VSE methods developed for a single soil type may lead to poor accuracy when it is applied on other soil types. Other VSEs that significantly correlate with soil physical measurements for various soil types are the visual evaluation of soil structure (such as such as SoilPAK (McKenzie, 2001), the Peerlkamp test (Ball et al., 2007;Mueller et al., 2009), Visual Evaluation of Soil Structure (Guimarães et al., 2013;Newell-Price et al., 2013;Pulido Moncada et al., 2014), CoreVESS (Johannes et al., 2017), and VSA soil structure (Mueller et al., 2009)), as well as the visual assessment of soil compaction using the French profil cultural method (Peigné et al., 2013). To the best of our knowledge no other VSEs have been related to soil physical measurements for several soil types. ...
Article
Visual soil evaluation (VSE) is a simple and fast method to assess soil quality in situ, and is becoming increasingly popular. Besides soil structure assessment, also other soil properties can be assessed such as grass cover, roots and earthworms. Yet, the full set of visual observations has not been properly evaluated for reproducibility and correlation with standard field or laboratory measurements, for several soil types. The objectives of this study were therefore to evaluate the reproducibility and the correlation of visual observations with closely related field or laboratory measurements. We used quantitative visual observations where possible, to enhance objectivity of VSE. The reproducibility and correlation of visual observations with standard measurements was evaluated for three soil types (sand, peat and clay) in the North Friesian Woodlands, The Netherlands. Reproducibility of quantitative visual observations was tested by comparing observations made by farmers and soil scientists, on the same soils. A linear mixed-effect model indicated that for all quantitative visual observations except for the depth of soil compaction, subjectivity due to the observers’ background (farmer or soil scientist) had no significant effect on the observations. For assessment of relative soil quality differences between sites, the results suggested that a single observer can make the visual observations, when assessing the fraction largest soil structural elements, earthworms, gley mottles and the depth of soil compaction. Spearman’s rank correlation coefficients indicated that visual observations of grass cover, root count, maximum rooting depth and the fraction largest soil structural elements correlated significantly with closely related field or laboratory measurements regardless of soil type. Maximum rooting depth, root count, soil colour, the fraction largest soil structural elements, and the degree of soil compaction only significantly correlated with field or laboratory measurements for specific soil types. Analyses showed that the correlation of visual observations with standard measurements were soil type dependent, suggesting that the evaluation of soil quality should also be soil type dependent.
... The main methods split between those involving a spade depth of soil, with a focus either on the topsoil, e.g. the Visual Evaluation of Soil Structure (VESS) (Ball et al. 2007) and the Visual Soil Assessment (VSA) (Shepherd 2009) or deeper soil profiles that include both topsoil and subsoil, e.g. 'Profil Cultural' (Peigné et al. 2013) andSOILpak (McKenzie 1998). Other, more detailed, soil description systems are exemplified by FAO (2006). ...
Article
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Globally soil quality and food security continue to decrease indicating that agriculture and the food system need to adapt. Improving connection to the soil by knowledge exchange can help achieve this. We propose a framework of three types of connections that allow the targeting of appropriate messages to different groups of people. Direct connection by, for example, handling soil develops soil awareness for management that can be fostered by farmers joining groups on soil-focused farming such as organic farming or no-till. Indirect connections between soil, food and ecosystem services can inform food choices and environmental awareness in the public and can be promoted by, for example, gardening, education and art. Temporal connection revealed from past usage of soil helps to bring awareness to policy workers of the need for the long-term preservation of soil quality for environmental conservation. The understanding of indirect and temporal connections can be helped by comparing them with the operations of the networks of soil organisms and porosity that sustain soil fertility and soil functions.
... To understand where and why soil compaction occurs, the soil structure was characterised on a morphological basis, on the observation face of a pit (1 m deep × 3 m wide) using a methodology called 'Soil profile' (Roger-Estrade et al., 2004;Peigné et al., 2012;Boizard et al., 2016). On each plot of the experimental trial, two pits were dug perpendicularly to the wheel tracks of soil cultivation machinery. ...
... c. The transition layer: this layer is just below the tilled layer (Peigné et al., 2013), whether tillage is shallow (harrow only -see next section) or deep (mouldboard plough or chisel plough). It is generally compacted by agricultural machinery (mostly traffic with heavy equipment) but not regularly tilled unless subsoiled. ...
Chapter
This book with nine chapters describes the main methods for visual soil evaluation (VSE) of soil structure and soil-related properties. It includes clear visual images of the variation of soil quality and how these relate to soil productivity and environmental sustainability. Such images raise awareness and provide a measure of the soil degradation that is a looming threat to the viability of world agriculture. Emphasis is given to recognizing, protecting and restoring soil quality as these are of vital importance for tackling problems of food insecurity, global change and environmental degradation. The book shows how these aims can be achieved with VSE by describing tools that can readily be used by land users and environmental authorities to assess crop performance, soil improvement and soil productivity. VSE is also placed in the context of future sustainable intensification of agriculture including factors of soil loss, resilience, climate change, scarcity of water and other resources, nutrient retention and increased risk of degradation. This book is relevant not only to students, lecturers, scientists and advisors working directly with soils but also to policy makers, food security experts, environmentalists and engineers who have an interest in soils and sustainable agricultural production. Last, but not least, it is hoped that these simple VSE techniques will be used extensively in years to come as a tool to link soil specialists and non-specialists together with the mutual aim of developing sustainable soil management to advance global food security and improve the environment.
Article
Legume crops are widely used in conservation agricultural systems, which are associated with minimum soil tillage, due to their nitrogen-fixing capabilities. However, tillage and fertilization regimes may affect the vertical distribution of legume roots and root traits, hence nutrient and water uptake by altering soil properties in the long term. This study aimed to investigate how tillage and P fertilization affect soybean (Glycine max, L.) root distribution and morphology in a long-term experiment.
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Conservation tillage includes a range of tillage practices, mostly noninversion, which aim to reduce soil erosion by leaving the soil surface covered by crop residues. Despite conservation tillage having been promoted in organic farming (OF) to improve inherent soil quality, several factors hinder its development such as weed control and soil compaction. Consequently, to enhance the adoption of conservation tillage in OF, long-term experiments were established several years ago in Europe. Different tillage techniques have been assessed from mouldboard ploughing to direct drilling under cover crops. In all cases, the effects of conservation vs. conventional tillage on soil fertility and weed and crop development were compared. Preliminary results show that the effects of conservation tillage are closely related to soil and climatic conditions, practices conducted in the field, and initial experimental conditions (level of weeds, previous crop, soil structure, etc.). Direct seeding under a cover crop or mulch remains a major challenge in OF, since weeds are not mechanically controlled, which thus affect crop performance. However, with other reduced tillage techniques, such as using a layer cultivator, weed development has had minimal effects with no impact on yields. In addition, to improved soil fertility, reduced tillage can increase crop yields. Most of the results of conservation tillage effects were obtained from experiments conducted for less than 10 years under OF management. Assessment over longer periods is needed and then shared with organic farmers to design new cropping systems. Introduction of new equipment and knowledge exchanges between conventional farmers practising conservation tillage and organic farmers could improve the adoption of conservation tillage in OF.
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The Twentieth Annual Research Review describes the ongoing research programme in the School of Biosystems Engineering at University College Dublin from over 79 researchers (10 academic staff, 2 technicians, 8 postdoctoral researchers and 59 postgraduates). The research programme covers three focal areas: Food and Process Engineering; Bioresource Systems; and Bioenvironmental Engineering. Each area is divided into sub-areas as outlined in the Table of Contents which also includes the name of the research scholar (in bold); the research supervisor(s); the title of the research; the nature* of the research programme; and the research sponsors. It also includes the noting of four awards for presentational excellence at the Twentieth Annual Biosystems Engineering Research Seminar held in University College Dublin on Thursday 12th March 2015. DOWNLOAD BOOK AT http://researchrepository.ucd.ie/handle/10197/6758
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Hyperspectral imaging (HSI) technique in the wavelength of 400−1000 nm was applied for the rapid and non-destructive measurement of external defects of potatoes. The hyperspectral images of seven potato types were obtained. Then the reflectance spectra of the interested areas of potato in these hyperspectral images were extracted and analysed. Five feature wavelengths (478, 670, 723, 819 and 973 nm) were selected based on principal component analysis. Principal component analysis was conducted again based on the five selected characteristic wavelengths. Potato external defects were identified through image processing methods, such as threshold segmentation, corrosion, expansion and connectivity analysis. The correct recognition rate of all the seven potato types using principal component analysis method of the characteristic wavelengths achieved 82.50%. The results showed that hyperspectral imaging technique was suitable for rapid and non-destructive assessment of external defects of potatoes.
Article
The aim of this study was to evaluate the effects of sludge compost (SC) in two rates and pig slurry (PS) on soil quality, in the framework of a field experiment (19-year-old) in a Mediterranean rainfed system. The treatments were compared with mineral fertilization (MF) plus a control treatment (no N fertilization). Soil microstructure and types of voids, earthworm community and its bioturbation were studied using micromorphological methods. Two earthworm species, Koinodrilus roseus and Nicodrilus trapezoides were identified; the latter was not present in the SC treatments. Earthworm abundance and biomass were not affected by fertilization. Pig slurry increased bioturbation associated with earthworm activity, improved soil microstructure (crumb type) and increased the biopore presence (compound packing voids). The control and MF plots showed a platy to massive microstructure with an absence of faunal chambers. In SC plots, non-mixed soil-organic materials were observed and soil vughs were not visible. Composition differences between SC and PS and the total amount of OM applied may have had an impact on the activity and species of earthworms; such changes can be an early indicator of further potential impacts on soil quality, however further contaminant studies are needed to validate this initial assessment. Abbreviations: CO: control; DM: dry matter; MF: mineral fertilizer; OM: organic matter; PS: pig slurry; SC: sewage sludge compost.
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A number of excellent textbooks on general ecology are currently available but‚ to date‚ none have been dedicated to the study of soil ecology. This is important because the soil‚ as the ‘epidermis’ of our planet‚ is the major component of the terrestrial biosphere. In the present age‚ it is difficult to understand how one could be interested in general ecology without having some knowledge of the soil and further‚ to study the soil without taking into account its biological components and ecological setting. It is this deficiency that the two authors‚ Patrick Lavelle and Alister Spain‚ have wished to address in writing their text. A reading of this work‚ entitled ‘Soil Ecology’‚ shows it to be very complete and extremely innovative in its conceptual plan. In addition‚ it follows straightforwardly through a development which unfolds over four substantial chapters. Firstly‚ the authors consider the soil as a porous and finely divided medium of b- organomineral origin‚ whose physical structure and organisation foster the development of a multitude of specifically adapted organisms (microbial communities‚ roots of higher plants‚ macro-invertebrates).
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Effects of tillage on soil morphology and porosity were investigated in plots planted to corn (Zea mays L.) for seven consecutive years. Micromorphometric analyses indicated that Ap horizons of no-till plots had approximately half the macroporosity (pores ≥ 200 μm equivalent circular diameter) of those of conventionally tilled plots. Loss of macroporosity was characterized by a decrease in mean pore size and a tendency for pores to become elongated, less tortuous, and oriented parallel to the soil surface. Obvious zoological activity, which consisted mainly of burrowing earthworms, resulted in two to nine times more bioporosity in a no-till pedon than in a conventionally tilled pedon. Earthworm activity also contributed to the formation of 5-cm-thick B & A horizon and a more uniform distribution of organic carbon than in the conventionally tilled pedon. These differences in morphology are reflected in the classification under Soil Taxonomy but not under the Canadian System. We speculate that zoological activity may serve to counteract the reduction in macroporosity in the Ap of the no-till pedon. Key words: Bioporosity, earthworms, micromorphometric analysis, zoological activity
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The compaction of soil alters its structure, increases its bulk density and decreases its porosity. These changes can be detected by careful and systematic visual and tactile examination directly in the field. These changes also reduce the permeability of soil to water and air and may alter the pattern of root growth. Further signs of compaction may be induced such as the creation of waterlogged zones or of dry zones caused by shallow rooting denying access to deeper reserves of water. Furthermore, there may be a reduction in nutrient uptake from dry soil. Under wet conditions anoxic pockets may form with associated biochemical changes, some of which are visible. Changes in mineral nitrogen may take place through denitrification and a reduction in nitrification. The criteria used to identify compaction in the field include patterns of crop growth, pale leaf colours, waterlogging on the surface or in subsurface layers above compaction, an increase in soil strength, changes to soil structure, soil colour and the distribution of roots and of soil moisture. Manifestation of soil compaction in crops is also dependent on the weather and is influenced by crop type and variety, and stage of growth. Many soil-borne diseases are made worse by stress to the crop which might be induced by compaction caused by drier or wetter conditions in the root zone. Where, when and how to identify compaction in the field are discussed and the techniques used are described. Specific examples of the identification of compaction are given, covering a wide range of situations.
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Modelling the architecture of the root system is a recent approach, since almost all such models have appeared during the last 10 years. In a short review of these architectural models, we define several steps in their evolution, which also correspond to different goals. The main basic idea was to translate and to combine morphogenetic rules, described at the root level, in order to produce a quantitative representation of the global object: the root system. The inclusion of stochastic processes appeared to be an economic way to simulate realistic root systems, staying at this organisation level, because of the unpredictable characteristics of some developmental processes, which lead to large variations from one root system to another. In several applications, these models were shown to be helpful for integrating knowledge at the root level regarding soil-root interactions. In the most recent works, a more integrated approach is proposed, in which the components of the root system appear according to a morphogenetic programme, and interact by contributing and responding to the endogenous context of resource availability. ((C) Inra/Elsevier, Paris.).
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Soil ecosystems support a plethora of intertwined biophysical and biochemical processes. Soil structure plays a central role in the formation and maintenance of soil biological activity by providing a diversified habitat for soil organisms and determining the movement and transport of the resources on which they rely. At the same time, the formation and preservation of soil structure and fertility is also strongly linked to soil biological activity through feedback loops. In most soil ecosystems, soil biological activity and associated processes are concentrated in the soil located around living plant roots and influenced by root activity, an environment known as the rhizosphere. Consequently, among the wide array of soil life forms, plants play a dominant role in the regulation of many soil processes. In this paper, we illustrate the functional complexity of soil ecosystems using specific examples of root-soil interactions and associated processes. Through examples taken from the literature, we examine the origins and variations in soil physical, chemical, and biological properties and their impact on root growth. Next, we consider how the response of root systems to their environment affects resource acquisition by plants. Finally, we describe how the concept of root functional architecture can improve the integration of research advances from fields operating as independent disciplines and improve our understanding of soil ecosystems.
Article
Potato plant reactions to soil compaction were studied in the field in the dry yr 1976. Irrigation was applied in some of the treatments. Strong compaction of topsoil resulted in shallow rooting, low water availability and relatively slow foliage and root growth in the first 60 days after emergence, compared with the non-compacted treatment. Compaction of the subsoil (formation of a plough pan) initially resulted in relatively rapid foliage growth, which was partly due to a high capillary flux from the water table; however the rate slowed down as vertical root elongation became inhibited by the plough pan. Topsoil compaction resulted in depressed tuber yields and severe induction of second growth compared to the non-compacted or irrigated treatments. At maturity, differences in total yields among treatments were small except for the treatment with a plough pan where the yield was low; soil compaction decreased marketable tuber yield. The quantity of available water for the crop, defined as the measured water uptake from the rooted zone and a calculated capillary flux to the rooting front was compared with potential evapotranspiration and significant differences thus obtained among treatments were well reflected by observed differences in vegetative growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Article
A morphological approach and soil porosity have been used to evaluate the effect of compaction and climate on the soil structure of a loamy soil in a reduced tillage system. The study was carried out between 2000 and 2006 as part of the long-term ‘‘cropping systems and soil structure’’ experiment conducted in Estrées-Mons in northern France. Soil hydraulic, mechanical and pore morphological properties were also measured to characterise the effects on soil structure dynamics. A complementary characterisation of the soil structure was conducted on a microscale. The method for morphological description of the soil macrostructure was well suited to studying soil structure dynamics in reduced tillage systems. Results showed that the soil structure in the layer without tillage depended in the first instance on compaction intensity. Structural porosity was partly preserved in the cropping system with little compaction. In contrast just one operation, such as the harvest of sugar beet (Beta vulgaris L.), was sufficient to reduce structural porosity for 5 years even though no further compaction occurred during this period. Morphological analysis revealed the evolution of highly compacted zones under the effects of weather conditions. Platy soil structures were systematically observed in the upper part of the highly compacted zones under the tilled layers, with cracking slowly penetrating deeper into the soil with time. The structure types observed corresponded to specific soil properties resulting from the transformation of the soil structure over time. A micromorphological assessment was performed to get detailed information about the network of cracks. The morphological characterisation showed that a visual morphological approach was insufficient for revealing the entire network of cracks.
Article
Compacted and well-structured sites, on a Vertisol used for irrigated cotton production, were compared using a range of procedures for assessing soil structural form. The techniques considered were: visual/ tactile assessment using the SOILpak score, shear strength, penetration resistance, core bulk density and air-filled porosity, clod shrinkage analysis, and image analysis. All of the methods under consideration distinguished compacted soil from well-structured soil, including core bulk density, which had previously been thought of as a poor measure of soil structure in Vertisols. The simple SOILpak scoring procedure was shown to have great potential as a tool for land managers. Soil factors known to directly affect root growth, mechanical impedance and aeration, correlated well with the indirect procedures. The cheaper methods (SOILpak score and core bulk density determination) related most strongly to shear strength at the reference water content (plastic limit). The SOILpak score was more strongly related to air-filled porosity than clod shrinkage analysis or image analysis; shear strength had the same predictive power as the SOILpak score for estimating air-filled porosity. However, an advantage of using resin-impregnated soil monoliths and the SOLICON image analysis system is that the samples are big enough to represent a large proportion of the root-zone. Staining of the soil with a Rhodamine dye solution provided images that were too coarse for the routine determination of SOLICON parameters, but it is a useful and rapid procedure for highlighting those macropores that are connected with the soil surface. Clod shrinkage parameters underestimated soil air-filled porosity where compacted aggregates were interspersed with finely aggregated soil.
Article
Agricultural land evaluation is hampered by inadequate procedures for assessing the severity of soil compaction. Therefore, the ‘SOILpak scoring procedure’ has been developed within the Australian cotton industry to allow semi-quantitative assessment of soil structural form. It allows compaction severity in Vertisols to be separated into as many as 20 categories on a scale of 0.0 (severely compacted) to 2.0 (excellent structure for root growth). The procedure is based upon visual assessment of soil samples in the field as they are pulled apart by hand. The SOILpak scoring system is well accepted by advisory staff because of its speed and simplicity. However, there have been some problems with operator bias, and an inability to deal with continuity of vertical macropores, degree of encroachment of under-furrow compaction into the ridges where cotton is planted, and the presence of thin smeared layers. This paper presents a modified SOILpak scoring procedure that addresses these problems. Also, the SOILpak scoring procedure has been integrated with terminology in the ‘Australian Soil and Land Survey Field Handbooks’ so that it can be used by soil surveyors in other areas.
Article
Macropore density is a key parameter to predict the leaching of contaminants from the root zone. The aim of this study was to assess the influence of intrinsic soil properties and earthworm characteristics on macropore density at different depths for five typical, Danish soil types under the same agricultural management (third year of pasture). Macropores were marked on a transparent sheet (0.7×1.0m) placed horizontally for the three main horizons of each soil type in eight plots along the local gradients in soil texture. Macropores were then counted on each sheet by digital image analysis. Particle size distribution was determined for the same soil horizons for each plot. The earthworm population was characterised for each plot by hand-sorting soil samples (0.5×0.5×0.3m). Results show that the macropore density: 1) was highest for the soil types developed on glacial deposits, which were the soils with the highest clay content, 2) in the topsoil (Ap horizon) was related to the fresh biomass of anecic earthworms across all soil types and textural gradients, 3) in the B horizon was related to the clay content, 4) in the C horizon, was directly related to the soil type, and 5) that for all soil types developed on moraines, the macropore density was highest in the B horizon, indicating an accumulation of macropores with time. Our results indicate that estimates of the macropore density in agricultural soils need to consider both short-term factors (agricultural management effects on the development of earthworm communities), and long-term factors (soil intrinsic properties). Further work is needed to estimate the risk of macropore flow.
Article
This study addresses the influence of three different land use systems (continuous maize, pasture/maize rotation, permanent pasture) on the relationships between earthworm populations and the number of earthworm burrows quantified in a soil profile. Quantified burrows were limited to those observable by the naked eye (i.e. >2mm in diameter) and enumerated earthworms were limited to those which could have created the observable burrows (i.e. >0.3g).The results were combined with data from the literature coming from different geographical regions. This study showed that earthworm abundance decreased with the increasing land management intensity (maize crop vs. pasture), while the number of burrows could be higher or similar under maize compared to pasture. Under maize, despite lower earthworm abundance and the annual destruction of the burrows by tillage, the number of burrows was almost as high as under pasture. This absence of a relationship between burrow numbers and earthworm abundance was observed in the soil profile and for each layer of the profile for each land use system. Furthermore, the burrow number/m−2 per earthworm strongly varied depending on land use and was far higher under maize when compared to pasture (74 vs. 7). Therefore, a power-law type relationship was clearly established between burrow number/m−2 per earthworm and earthworm abundance. This power type relationship was also observed when including data from the literature although it followed a different mathematical model. These results were explained by (i) increased earthworm burrowing activity (i.e. an increase in the number of burrows produced by each earthworm) under maize, and (ii) the dynamics of burrow number under pasture (i.e. decreased burrowing activity and burrow destruction process); both results of food accessibility combined with inter-individual competition. The results of the study suggest that farmers should not use the number of pores as an indicator of earthworm abundance, but as an indicator of earthworm activity, which could be integrated in an indicator of soil quality.
Article
Abstract Increased awareness of the role of soil structure in defining the physical fertility or quality of soil has led to the need for a simple assessment relevant to the environmental and economic sustainability of soil productivity. A test is required that is usable by farmer, consultant and researcher alike. Here an assessment of soil structure quality (Sq) is described which is based on a visual key linked to criteria chosen to be as objective as possible. The influences of operator, tillage and crop type on Sq value were tested. The test takes 5–15 min per location and enough replicates were obtained for statistical comparison of data sets. The assessments of individual operators were influenced to an extent by differences between fields, making the use of multiple operators desirable. Differences in soil management were revealed by the test and related to differences in soil physical properties (bulk density, penetration resistance and porosity) and crop growth. Indicative thresholds of soil management are suggested. The assessment should be viewed as complementary to conventional laboratory assessments of soil structure. Visual soil structure assessment can indicate to the soil scientist where to sample and what soil measurements are likely to be worthwhile.
Article
Quatre essais ont été conduits au champ pour étudier l’effet de l’état structural de la couche labourée sur l’enracinement. Dans chacun de ceux-ci les traitements expérimentaux sont les 3 états 0, B et C de la couche labourée présentés dans le le! article de cette série. La cinétique d’approfondissement du front racinaire a été affectée par les traitements, mais la profondeur maximale d’enracinement, atteinte après floraison, ne l’a pas été. La croissance de la masse racinaire a été différente entre traitements ; les rapports Masse racinaire/Masse aérienne + racinaire, calculés à la floraison sont cependant similaires dans toutes les situations. La croissance de l’ensemble des plantes, racines et parties aériennes, a donc été plus rapide dans le traitement 0 qu’en B et C. Les densités racinaires mesurées à la floraison sont nettement contrastées dans la couche labourée, où l’état structural est différent entre traitements, mais aussi dans les couches non travaillées où il ne l’est pas. Dans l’ensemble du profil la disposition spatiale des racines (verticale et horizontale) est fortement affectée par l’état structural de la couche labourée. Ceci est lié, dans la couche labourée, à la variabilité spatiale décimétrique de la résistance mécanique à la pénétration ; dans les couches non travaillées de C, l’irrégularité de la disposition des racines s’explique par des réductions localisées de la densité racinaire sous les obstacles situés dans la couche labourée (« effet d’ombre »).
Article
This paper aims to provide guidance for field practitioners on the vulnerability of different subsoils to compaction under different field conditions and on the tyre pressures necessary to reduce or avoid damage. It also indicates ways of identifying situations where some compaction alleviation may be necessary to improve subsoil conditions and methods for alleviating subsoil compaction problems, without increasing the risk of more extensive compaction damage in the future.
Article
In laboratory experiments, earthworms are often observed to burrow through compacted soil layers, leading to the general assumption that these animals play a significant role in regenerating compacted soils in agricultural plots. To demonstrate this role under field conditions, the abundance of earthworm macropores inside compacted zones was estimated on plots under reduced (RT) or conventional tillage (CT). Then, different types of compacted zones typically found in CT (plough pan and compacted clods) and RT plots (compacted volume under wheel tracks) were experimentally simulated in wooden boxes, buried in the field and inoculated with different earthworm species. After 6weeks of incubation, the number of macropores inside the compacted zones was examined. Field observations showed that approximately 10% and 30% of the compacted zones were colonised by at least one macropore in CT and RT plots, respectively. A significantly greater number of anecics was found in RT plots, but we could not conclude that this ecological type of earthworm plays a more major role in the regeneration process in these plots since there were fewer compacted zones and these covered a smaller area in CT. The semi-field experiment provided evidence that earthworm-mediated regeneration of compacted zones is possible and its nature varies between ecological types of earthworm. Lumbricus terrestris, which makes individual burrows that are vertical and deep, was the main species to cross through the plough pan. The other three earthworm species (Aporrectodea giardi, A. caliginosa and A. rosea) did burrow inside the other types of compacted zones (“wheel tracks” and “compacted clods”). In every case, however, macropore density was far greater in non-compacted zones, illustrating that avoidance of compacted soil by earthworms is important and should be taken into account when extrapolating results from laboratory studies.
Article
Biopores are tubular soil macropores left by plant roots after their decay or burrowed by soil animals, which provide channels for deep rooting and improve crop access to water and nutrients. The density of biopores, number of biopores per unit area, and proportion of biopores occupied by roots were measured on horizontal soil profiles at 30, 50, and 70 cm in depth in a fine-texture subsoil of Andosol (Light clay, a volcanic ash of the Kanto loam type) at the mature stage of wheat and maize. Images of 0.1 mm resolution from the pictures of cleaned profile surfaces were examined on a computer display. Dark spots with a circular and smooth boundary were regarded as biopores. The density of biopores larger than 1 mm in diameter ranged from 500 to 2,000 m-2. The percentage of biopores occupied by roots was more than 30% of biopores larger than 1 mm and increased with depth. Roots were accumulated in biopores. The proportion of biopores (> 1 mm) with roots increased with depth. It was 28-35% in the wheat plot and 14-20% in the maize plot. This suggested that thinner wheat roots easily entered a biopore and remained in it. The possible influence of biopores on the spatial distribution of roots was discussed.
Article
To understand how earthworms could improve soil porosity in no-tillage organic farming systems, the aim of our study was to compare the effect of different tillage systems on earthworm populations, from conventional (traditional mouldboard ploughing, MP and shallow mouldboard ploughing, SMP) to conservation tillage (reduced tillage, RT, direct drilling or very superficial tillage, NT) in three organic arable systems in France (sites A–C). In a second stage, the effect of earthworm activity on soil porosity under the four tillage systems was assessed at sites A and B. Earthworm abundance, biomass and diversity were measured over a 2–3-year period at the 3 sites. During the same period, soil structure (soil profile description and soil bulk density) and open worm burrows in the soil were assessed at sites A and B. After 3 years of experiments, it was found that at 2 sites earthworm abundance and biomass were higher in NT than with ploughing or reduced tillage. The increase of earthworms in NT is mainly due to anecic species increase. Earthworm abundance and biomass tend to decrease regardless of the tillage techniques employed at sites with a ley, and conversely, tend to increase in NT and RT at sites initially ploughed. In the short term, the increase of anecic species in NT has no effect on soil porosity evolution: NT soils were more compacted than those which were ploughed. A long-term experiment is required to assess the effect of biological activity on the physical components of soil in organic farming.
Book
Soil ecology is the study of interactions between the soil physico-chemical components (minerals and soil solution) and the soil biota. These creatures range in size from microscopic to those visible to the naked eye. They live within the pore spaces between solid particles and contribute vitally to plant nutrition, in symbiotic association with roots or by releasing essential nutrients into the soil solution around roots. The breakdown of plant and animal residues, as well as many synthetic chemicals, is catalyzed by soil microorganisms and facilitated by soil animals. Soil pedogenesis involves the mixing of organic material and mineral particles by soil fauna such as collembola, enchytraeids, mites and earthworms. Soil bacteria and fungi produce binding substances that stabilize aggregates, building a soil structure that allows for root penetration, water infiltration, chemical buffering and gas exchange. Humans are highly reliant on the soil ecosystem, which provides food, fiber, fuel and other ecological services such as water filtration/purification and the recycling of atmospheric gases. Yet, the development of deep soil profiles underlying most terrestrial ecosystems takes thousands of years or longer. Since soils form so slowly, they are considered to be a non-renewable resource that merits careful attention and protection. At the present time, we are experiencing unprecedented global change, largely induced by anthropogenic activities such as fossil fuel burning and land use change. Food and fuel insecurity, as well as environmental pollution and ecological degradation, are tremendous societal challenges for the 21th century. As scientists, we believe that understanding the functions and dynamic nature of the soil ecosystem are crucial for predicting and mitigating the long-term consequences of present-day actions. In this way, we can make recommendations and decisions today that will sustain our soils for the future. This modular textbook is intended to provide an overview of the soil ecosystem, soil organisms and their functions, as well as the impact of human-induced management and global change. It is meant for advanced undergraduates, beginning graduate students and practicing scientists from diverse disciplines. Some of the scientific literature and internet sources relevant to soil ecology are provided for further reading. The first section of the book provides the context for understanding the soil ecosystem. Physical, chemical and biological components and their interactions are reviewed, with a view towards a holistic approach and interpretation of soil functions. Section II examines the diversity of life found within our soils, from microscopic to macroscopic organisms. Methods for collecting and enumerating soil organisms, including emerging molecular approaches, are introduced. The concept of the soil foodweb is introduced and trophic interactions (feeding relationships) are discussed. The third section gives an overview of the major ecological and pedological functions of soil organisms, including primary production, decomposition and carbon cycling, nutrient cycling (nitrogen, phosphorus and sulfur), soil structure and biological. This section is meant to give the reader a sense of what organisms do in soils, and at what temporal and spatial scales their activities affect ecosystem processes. Section IV discusses the impact of human-induced management on the soil foodweb in agricultural, grassland and forest ecosystems. Finally, we consider the effect of global changes on the diversity and function of the soil foodweb, as well as the consequences for sustainable soil use.
Article
Lack of water is a major limitation to crop production, particularly where roots of cereal crops are not able to access water stored in the subsoil. One way that roots penetrate the subsoil to access water is by following natural biopores - paths created by roots from previous crops, or as burrows from soil fauna. Burying a mesh layer horizontally in the soil can prevent root penetration to the subsoil. We used this technique with the novel modification that the mesh was punctured to create a defined number of holes per unit area; controlling access to the subsoil and to the water therein. The holes were of similar size to biopores. Five barley genotypes were late sown and grown during a dry summer. Monitoring of crop performance included plant height, leaf area and Normalized Difference Vegetation Index (NDVI). Crops grown with unrestricted access to the subsoil outperformed crops with limited or no access to the subsoil. Crops grown with controlled, limited access to the subsoil performed better than those with no access and the performance was generally related to amount of access. Changes in soil water content were in line with the amount of root access to the subsoil; confirming the association between subsoil water and crop growth and development in drought conditions. While there were no significant interactions between the genotypes and treatments used here, the method offers promise for studying some aspects of cereal ecophysiology and could be used to identify promising germplasm that may be of interest in plant breeding. Further testing is required to adapt the method for a wider range of crop types and soil conditions and testing for crops grown to maturity.
Article
Characterisation of soil structure within the tilled layer of cultivated fields is crucial because the importance of this soil characteristic on the biological, chemical and physical properties of the soil and its repercussions on water cycle, root growth and functioning. We present in this paper a method for field characterisation of soil structure. This method, practised since the 1970s, was designed for field diagnosis of the effects of cropping systems on soil structure. It is based on a stratification of the observation face of a pit dug perpendicular to the direction of tillage and traffic: spatial compartments are distinguished, according to the nature of the mechanical stresses they have been submitted to during tillage and crop management. Characterisation of soil structure is performed on a morphological basis, using two criteria, each of them addressing a specific organisation level of the soil: firstly, clods size distribution, proportion of fine soil and the way the clods are brought together are considered; then, secondly, the clods are classified in three types, on the basis of the importance and the origin of their internal structural porosity. Physical measurements (bulk density, compaction test, and water retention) are presented, which demonstrate that physical behaviour is different between clod types. These results justify the use of the method to model changes with time in soil structure, under the effects of the main factors affecting soil structure dynamics in tilled fields: compaction, fragmentation, climate and biological activity. A model which simulates at the field scale the changes over time of the proportion of compacted clods within the tilled layer is presented. In this model, the tilled layer is represented as a set of 1 cm2 pixels, regularly located on a square grid. Each pixel is defined by its co-ordinates and a specific structure, compacted or non compacted. The pixel co-ordinates are modified during ploughing, for which the model calculates the lateral and vertical displacement of the soil. The structure of any individual pixel can be changed, depending on the soil condition and the operation type. This model was evaluated by comparing its outcomes to measurements obtained from a long term field experiment designed to study soil structure dynamics.