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Promising Agricultural Management Practices and Soil Threats in Europe and China
Abstract
Advising farmers on the best agricultural management practices (AMP) to be adopted in order to Sustain agricultural productivity while improving soil quality is mandatory to assure future food production. Some promising AMPs have been suggested over the time to prevent soil degradation. These practices have been
randomly adopted by farmers but which ones are mostly used by farmers and where they have been applied remains unclear. As part of the iSQAPER project—Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience—we (1) mapped the current distribution of previously selected 18 promising AMPs in several pedoclimatic regions and farming systems along Europe and China, based on ten and four study site areas (SSA), respectively; and (2) identified the soil
threats occurring in those areas. In each SSA, farmers using promising AMPs were identified and questionnaires were used to assess farmer’s perception on soil threats in their fields. For this study, 138 plots/farms were identified in Europe (112) and China (26). Results show that most widely used promising AMPs in Europe are crop rotation (15%), manuring and composting (15%), and min-till (14%), whereas in China are manuring and composting (18%), residue maintenance (18%), and integrated pest and disease
management (12%). In Europe, soil erosion is the main threat in agricultural Mediterranean areas, while soil-borne pests and diseases are more frequent in the SSAs from France and the Netherlands. In China, soil erosion, SOM decline, compaction, and poor soil structure are among the main farmers’ concerns. This
research provides relevant information for policy-makers and the development of strategies to support and promote agricultural management practices with benefits for soil quality.
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Sampling and analysis or visual examination of soil to assess its status and use potential is widely practiced from plot to national scales. However, the choice of relevant soil attributes and interpretation of measurements are not straightforward, because of the complexity and site-specificity of soils, legacy effects of previous land use, and trade-offs between ecosystem services. Here we review soil quality and related concepts, in terms of definition, assessment approaches, and indicator selection and interpretation. We identify the most frequently used soil quality indicators under agricultural land use. We find that explicit evaluation of soil quality with respect to specific soil threats, soil functions and ecosystem services has rarely been implemented, and few approaches provide clear interpretation schemes of measured indicator values. This limits their adoption by land managers as well as policy. We also consider novel indicators that address currently neglected though important soil properties and processes, and we list the crucial steps in the development of a soil quality assessment procedure that is scientifically sound and supports management and policy decisions that account for the multi-functionality of soil. This requires the involvement of the pertinent actors, stakeholders and end-users to a much larger degree than practiced to date.
Because of the increasing pressures exerted on soil, below-ground life is under threat. Knowledge-based rankings of potential threats to different components of soil biodiversity were developed in order to assess the spatial distribution of threats on a European scale. A list of 13 potential threats to soil biodiversity was proposed to experts with different backgrounds in order to assess the potential for three major components of soil biodiversity: soil microorganisms, fauna, and biological functions. This approach allowed us to obtain knowledge-based rankings of threats. These classifications formed the basis for the development of indices through an additive aggregation model that, along with ad-hoc proxies for each pressure, allowed us to preliminarily assess the spatial patterns of potential threats. Intensive exploitation was identified as the highest pressure. In contrast, the use of genetically modified organisms in agriculture was considered as the threat with least potential. The potential impact of climate change showed the highest uncertainty. Fourteen out of the 27 considered countries have more than 40% of their soils with moderate-high to high potential risk for all three components of soil biodiversity. Arable soils are the most exposed to pressures. Soils within the boreal biogeographic region showed the lowest risk potential. The majority of soils at risk are outside the boundaries of protected areas. First maps of risks to three components of soil biodiversity based on the current scientific knowledge were developed. Despite the intrinsic limits of knowledge-based assessments, a remarkable potential risk to soil biodiversity was observed. Guidelines to preliminarily identify and circumscribe soils potentially at risk are provided. This approach may be used in future research to assess threat at both local and global scale and identify areas of possible risk and, subsequently, design appropriate strategies for monitoring and protection of soil biota.
The idea of offsetting anthropogenic CO2 emissions by increasing global soil organic carbon (SOC), as recently proposed by French authorities ahead of COP21 in the 'four per mil' initiative, is notable. However, a high uncertainty still exits on land C balance components. In particular, the role of erosion in the global C cycle is not totally disentangled, leading to disagreement whether this process induces lands to be a source or sink of CO2 . To investigate this issue, we coupled soil erosion into a biogeochemistry model, running at 1 km(2) resolution across the agricultural soils of the European Union (EU). Based on data-driven assumptions, the simulation took into account also soil deposition within grid cells and the potential C export to riverine systems, in a way to be conservative in a mass balance. We estimated that 143 out of 187 Mha have C erosion rates <0.05 Mg C ha(-1) yr(-1) , although some hot-spot areas showed eroded SOC >0.45 Mg C ha(-1) yr(-1) . In comparison with a baseline without erosion, the model suggested an erosion-induced sink of atmospheric C consistent with previous empirical-based studies. Integrating all C fluxes for the EU agricultural soils, we estimated a net C loss or gain of -2.28 and +0.79 Tg yr(-1) of CO2 eq, respectively, depending on the value for the short-term enhancement of soil C mineralization due to soil disruption and displacement/transport with erosion. We concluded that erosion fluxes were in the same order of current carbon gains from improved management. Even if erosion could potentially induce a sink for atmospheric CO2 , strong agricultural policies are needed to prevent or reduce soil erosion, in order to maintain soil health and productivity. This article is protected by copyright. All rights reserved.
Soil erosion by water is one of the major threats to soils in the European Union, with a negative impact on
ecosystem services, crop production, drinking water and carbon stocks. The European Commission’s Soil
Thematic Strategy has identified soil erosion as a relevant issue for the European Union, and has
proposed an approach to monitor soil erosion. This paper presents the application of a modified version
of the Revised Universal Soil Loss Equation (RUSLE) model (RUSLE2015) to estimate soil loss in Europe for
the reference year 2010, within which the input factors (Rainfall erosivity, Soil erodibility, Cover-
Management, Topography, Support practices) are modelled with the most recently available pan-
European datasets. While RUSLE has been used before in Europe, RUSLE2015 improves the quality of
estimation by introducing updated (2010), high-resolution (100 m), peer-reviewed input layers. The
mean soil loss rate in the European Union’s erosion-prone lands (agricultural, forests and semi-natural
areas) was found to be 2.46 t ha-1 yr-1, resulting in a total soil loss of 970 Mt annually.
A major benefit of RUSLE2015 is that it can incorporate the effects of policy scenarios based on land-
use changes and support practices. The impact of the Good Agricultural and Environmental Condition
(GAEC) requirements of the Common Agricultural Policy (CAP) and the EU’s guidelines for soil protection
can be grouped under land management (reduced/no till, plant residues, cover crops) and support
practices (contour farming, maintenance of stone walls and grass margins). The policy interventions
(GAEC, Soil Thematic Strategy) over the past decade have reduced the soil loss rate by 9.5% on average in
Europe, and by 20% for arable lands. Special attention is given to the 4 million ha of croplands which
currently have unsustainable soil loss rates of more than 5 t ha-1 yr-1, and to which policy measures
should be targeted.
Healthy soils are critical to agriculture, and both are essential to enabling food security. Soil-related challenges include using soils and other natural resources sustainably, combating land and soil degradation, avoiding further reduction of soil-related ecosystem services, and ensuring that all agricultural land is managed sustainably. Agricultural challenges include improving the quantity and quality of agricultural outputs to satisfy rising human needs, also in a 2 degrees world; maintaining diversity in agricultural systems while supporting those farms with the highest potential for closing existing yield gaps; and providing a livelihood for about 2.6 billion mostly poor land users. The greatest needs and potentials lie in small-scale farming, although there as elsewhere, trade-offs must be negotiated within the nexus of water, energy, land and food, including the role of soil therein.
Development of improved weed management systems requires more knowledge on how various weed species respond to changing agronomic practices. A long-term study was conducted to determine weed population responses to various tillage intensities and crop rotations in a winter wheat (Triticum aestivum L.) dominated cropping system. Weed density and species composition differed with tillage, rotation, year, and date of sampling within years. Weed community dynamics were most affected by year-to-year differences in environmental conditions, followed by crop rotation, and then tillage intensity. Russian thistle (Salsola iberica Sennen & Pau) and kochia [Kochia scoparia (L.) Schrad.] densities increased in years of low rainfall and above average temperatures. Winter annual weeds such as downy brome (Bromus tectorum L.) and flixweed [Descurainia sophia (L.) Webb ex Prantl], as well as the perennial weed dandelion (Taraxacum officinale Weber in Wiggers), increased in years where higher than average rainfall was received in fall or early spring. Continuous winter wheat facilitated a dense downy brome infestation to develop over time. Trifluralin is not efficacious on stinkweed (Thlaspi arvense L.) or Canada thistle [Cirsium arvense (L.) Scop.] and its use in canola resulted in an increase in these species in a winter wheat-canola rotation. Total weed densities were often greater in zero tillage than in either minimum or conventional tillage. Russian thistle, downy brome, kochia, and redroot pigweed (Amaranthus retroflexus L.) were associated with zero tillage while wild buckwheat (Polygonum convolvulus L.), lamb's-quarters (Chenopodium album L.), flixweed, and wild mustard (Sinapis arvensis L.) were associated with conventional tillage. Perennials such as dandelion and perennial sowthistle (Sonchus arvensis L.) were associated with zero tillage but Canada thistle was associated with conventional tillage. Information will be utilized to implement more effective weed management programs in winter wheat production systems.
Feeding the world population, 7.3 billion in 2015 and projected to increase to 9.5 billion by 2050, necessitates an increase in agricultural production of ~70% between 2005 and 2050. Soil degradation, characterized by decline in quality and decrease in ecosystem goods and services, is a major constraint to achieving the required increase in agricultural production. Soil is a non-renewable resource on human time scales with its vulnerability to degradation depending on complex interactions between processes, factors and causes occurring at a range of spatial and temporal scales. Among the major soil degradation processes are accelerated erosion, depletion of the soil organic carbon (SOC) pool and loss in biodiversity, loss of soil fertility and elemental imbalance, acidification and salinization. Soil degradation trends can be reversed by conversion to a restorative land use and adoption of recommended management practices. The strategy is to minimize soil erosion, create positive SOC and N budgets, enhance activity and species diversity of soil biota (micro, meso, and macro), and improve structural stability and pore geometry. Improving soil quality (i.e., increasing SOC pool, improving soil structure, enhancing soil fertility) can reduce risks of soil degradation (physical, chemical, biological and ecological) while improving the environment. Increasing the SOC pool to above the critical level (10 to 15 g/kg) is essential to set-in-motion the restorative trends. Site-specific techniques of restoring soil quality include conservation agriculture, integrated nutrient management, continuous vegetative cover such as residue mulch and cover cropping, and controlled grazing at appropriate stocking rates. The strategy is to produce "more from less" by reducing losses and increasing soil, water, and nutrient use efficiency.
Land use and management influence the magnitude of soil loss. Among the different soil erosion risk factors, the cover-management factor (C-factor) is the one that policy makers and farmers can most readily influence in order to help reduce soil loss rates. The present study proposes a methodology for estimating the C-factor in the European Union (EU), using pan-European datasets (such as CORINE Land Cover), biophysical attributes derived from remote sensing, and statistical data on agricultural crops and practices. In arable lands, the C-factor was estimated using crop statistics (% of land per crop) and data on management practices such as conservation tillage, plant residues and winter crop cover. The C-factor in non-arable lands was estimated by weighting the range of literature values found according to fractional vegetation cover, which was estimated based on the remote sensing dataset F cover. The mean C-factor in the EU is estimated to be 0.1043, with an extremely high variability; forests have the lowest mean C-factor (0.00116), and arable lands and sparsely vegetated areas the highest (0.233 and 0.2651, respectively). Conservation management practices (reduced/no tillage, use of cover crops and plant residues) reduce the C-factor by on average 19.1% in arable lands. The methodology is designed to be a tool for policy makers to assess the effect of future land use and crop rotation scenarios on soil erosion by water. The impact of land use changes (deforestation, arable land expansion) and the effect of policies (such as the Common Agricultural Policy and the push to grow more renewable energy crops) can potentially be quantified with the proposed model. The C-factor data and the statistical input data used are available from the European Soil Data Centre.
Biodiversity loss, an important consequence of agricultural intensification, can lead to reductions in agroecosystem functions and services. Increasing crop diversity through rotation may alleviate these negative consequences by restoring positive aboveground-belowground interactions. Positive impacts of aboveground biodiversity on belowground communities and processes have primarily been observed in natural systems. Here, we test for the effects of increased diversity in an agroecosystem, where plant diversity is increased over time through crop rotation. As crop diversity increased from one to five species, distinct soil microbial communities were related to increases in soil aggregation, organic carbon, total nitrogen, microbial activity and decreases in the carbon-to-nitrogen acquiring enzyme activity ratio. This study indicates positive biodiversity-function relationships in agroecosystems, driven by interactions between rotational and microbial diversity. By increasing the quantity, quality and chemical diversity of residues, high diversity rotations can sustain soil biological communities, with positive effects on soil organic matter and soil fertility.
© 2015 John Wiley & Sons Ltd/CNRS.
Human activities, especially conversion and degradation of habitats, are causing global biodiversity declines. How local ecological assemblages are responding is less clear[mdash]a concern given their importance for many ecosystem functions and services. We analysed a terrestrial assemblage database of unprecedented geographic and taxonomic coverage to quantify local biodiversity responses to land use and related changes. Here we show that in the worst-affected habitats, these pressures reduce within-sample species richness by an average of 76.5%, total abundance by 39.5% and rarefaction-based richness by 40.3%. We estimate that, globally, these pressures have already slightly reduced average within-sample richness (by 13.6%), total abundance (10.7%) and rarefaction-based richness (8.1%), with changes showing marked spatial variation. Rapid further losses are predicted under a business-as-usual land-use scenario; within-sample richness is projected to fall by a further 3.4% globally by 2100, with losse
Introduction A framework is developed to link major soil functions to ecosystem services assessment. Provisioning soil functions—with primary linkages to ecosystem services—are evaluated on a continental scale in Europe. Methods We defined major provisioning soil functions combining the approaches proposed by the Millennium Ecosystem Assessment and the Thematic Strategy for Soil Protection of the European Union. Soil productivity was evaluated by three main land use types (cropland, grassland, forest) using a validated expert model called SoilProd. Models include soil, climate and topographic criteria. Raw material provision capacity of soils was assessed on the basis of (i) organic carbon content and (ii) availability of soil materials for construction. Results A coherent system of soil function-based ecosystem services was compiled, taking into account major soil functions. We also produced new data on soil-based provisioning ecosystem services, including productivity and raw material availability. The attempts to cover the main human activities requiring materials of soil origin and to map the locations where those materials are available on a continental scale provide new insight to this field of research. Conclusions Soil-based ecosystem services can be assessed by the evaluation of soil functions which play a role in the production of these services. Quantitative analysis and comparison of the spatial distribution of the investigated soil functions were performed. While crop productivity showed a general trend to increase in a northward and westward direction, local soil quality in most regions—except in the Mediterranean—can compensate for climatic handicaps to a great extent. Comparison of areas with potential for providing ecosystem services by individual soil functions highlights the complexity of decision-making for resource utilization but also the possibilities for optimization and more conscious management.
Mineable phosphorus reserves are confined to a handful of countries.
Reductions in wastage could free up this resource for low-income,
food-deficient countries.
MANY tropical soils are poor in inorganic nutrients and rely
on the recycling of nutrients from soil organic matter to maintain fertility.
In undisturbed rainforests such nutrients are recycled via the
litter1; 'slash-and-burn' agriculture, meanwhile, depends on the
mineralization of organic nutrients from the plant remains2,3 or
on (short-lived) inputs from ash4. This dependence on organic
nutrients in tropical soils has the result that tests of soil quality which
only give isolated measures of inorganic nutrient status are
unreliable5, and that the effects of fertilization can be
inconsistent because of leaching or fixation of inorganic nutrients. Here we
attempt to quantify the role of organic matter in sustaining the fertility of
soils from three different climate zones. We estimate rates of carbon turnover
from ecological measurements and 14C dating, and determine its
relation to the soil carbon and nutrient budgets. We find that agriculture
without supplementary fertilization was economical for 65 years on temperate
prairie and for six years in a tropical semi-arid thorn forest. An extremely
nutrient-poor Amazonian soil showed no potential for agriculture beyond the
three-year lifespan of the forest litter mat, once biological nutrient cycles
were interrupted by slash-burning. These observations suggest that
quantification of organic-matter cycling may provide an important guide to the
agricultural potential of soils.
A doubling in global food demand projected for the next 50 years poses huge challenges for the sustainability both of food production and of terrestrial and aquatic ecosystems and the services they provide to society. Agriculturalists are the principal managers of global useable lands and will shape, perhaps irreversibly, the surface of the Earth in the coming decades. New incentives and policies for ensuring the sustainability of agriculture and ecosystem services will be crucial if we are to meet the demands of improving yields without compromising environmental integrity or public health.
1] Past land use changes have greatly impacted global water resources, with often opposing effects on water quantity and quality. Increases in rain-fed cropland (460%) and pastureland (560%) during the past 300 years from forest and grasslands decreased evapotranspiration and increased recharge (two orders of magnitude) and streamflow (one order of magnitude). However, increased water quantity degraded water quality by mobilization of salts, salinization caused by shallow water tables, and fertilizer leaching into underlying aquifers that discharge to streams. Since the 1950s, irrigated agriculture has expanded globally by 174%, accounting for $90% of global freshwater consumption. Irrigation based on surface water reduced streamflow and raised water tables resulting in waterlogging in many areas (China, India, and United States). Marked increases in groundwater-fed irrigation in the last few decades in these areas has lowered water tables (1 m/yr) and reduced streamflow. Degradation of water quality in irrigated areas has resulted from processes similar to those in rain-fed agriculture: salt mobilization, salinization in waterlogged areas, and fertilizer leaching. Strategies for remediating water resource problems related to agriculture often have opposing effects on water quantity and quality. Long time lags (decades to centuries) between land use changes and system response (e.g., recharge, streamflow, and water quality), particularly in semiarid regions, mean that the full impact of land use changes has not been realized in many areas and remediation to reverse impacts will also take a long time. Future land use changes should consider potential impacts on water resources, particularly trade-offs between water, salt, and nutrient balances, to develop sustainable water resources to meet human and ecosystem needs.
Although sustainable land management (SLM) is widely promoted to prevent and mitigate land degradation and desertification, its monitoring and assessment (M&A) has received much less attention. This paper compiles methodological approaches which to date have been little reported in the literature. It draws lessons from these experiences and identifies common elements and future pathways as a basis for a global approach. The paper starts with local level methods where the World Overview of Conservation Approaches and Technologies (WOCAT) framework catalogues SLM case studies. This tool has been included in the local level assessment of Land Degradation Assessment in Drylands (LADA) and in the EU-DESIRE project. Complementary site-based approaches can enhance an ecological process-based understanding of SLM variation. At national and sub-national levels, a joint WOCAT/LADA/DESIRE spatial assessment based on land use systems identifies the status and trends of degradation and SLM, including causes, drivers and impacts on ecosystem services. Expert consultation is combined with scientific evidence and enhanced where necessary with secondary data and indicator databases. At the global level, the Global Environment Facility (GEF) knowledge from the land (KM:Land) initiative uses indicators to demonstrate impacts of SLM investments. Key lessons learnt include the need for a multi-scale approach, making use of common indicators and a variety of information sources, including scientific data and local knowledge through participatory methods. Methodological consistencies allow cross-scale analyses, and findings are analysed and documented for use by decision-makers at various levels. Effective M&A of SLM [e.g. for United Nations Convention to Combat Desertification (UNCCD)] requires a comprehensive methodological framework agreed by the major players. Copyright © 2010 John Wiley & Sons, Ltd.
This study was aimed to determine the patterns as well as the effects of biological, anthropogenic, and climatic factors on
plant invasions in China. About 270 volumes of national and regional floras were employed to compile a naturalized flora of
China. Habit, life form, origin, distribution, and uses of naturalized plants were also analyzed to determine patterns on
invasion. Correlations between biological, anthropogenic and climatic parameters were estimated at province and regional scales.
Naturalized species represent 1% of the flora of China. Asteraceae, Fabaceae, and Poaceae are the dominant families, but Euphorbiaceae
and Cactaceae have the largest ratios of naturalized species to their global numbers. Oenothera, Euphorbia, and Crotalaria were the dominant genera. Around 50% of exotic species were introduced intentionally for medicinal purposes. Most of the
naturalized species originated in tropical America, followed by Asia and Europe. Number of naturalized species was significantly
correlated to the number of native species/log area. The intensity of plant invasion showed a pattern along climate zones
from mesic to xeric, declining with decreasing temperature and precipitation across the nation. Anthropogenic factor, such
as distance of transportation, was significantly correlated to plant invasions at a regional scale. Although anthropogenic
factors were largely responsible for creating opportunities for exotic species to spread and establish, the local biodiversity
and climate factors were the major factors shaping the pattern of plant invasions in China. The warm regions, which are the
hot spots of local biodiversity, and relatively developed areas of China, furthermore, require immediate attentions.
KeywordsAnthropogenic factor-Biodiversity-Biogeographic pattern-China-Climate-Plant invasion-Taxonomic pattern
We investigated conservation and cycling of N under oat–oat and lupine–oat rotations in disturbed and undisturbed soil, when
roots or roots plus aboveground residues were retained. Crop residues were labelled with 15N in Year 1, and differential soil disturbance was imposed after harvest. In Year 2, plant growth, N transfer from residue
into the various sinks of the second crop (plant, soil, and residual residues), and changes in microbial activity and numbers
were determined. Oat biomass was greater after lupine than after oat due to differences in supply of N from these residues.
Buried residues of both crops appeared to decompose faster than when left on the soil surface. Lupine residues decomposed
faster than oat residues. Oat biomass was not affected by soil disturbance if grown after lupine but decreased when oat straw
was buried in the soil. More residue N was recovered from soil than from the crop. Most 15N was recovered from disturbed soil, which also had greater dehydrogenase activity and more culturable fungi. At the end of
the oat–oat rotation, 20 and 5kg N ha−1 were derived from the roots of the first crop in undisturbed or disturbed soil, respectively. Equivalent values for the lupine–oat
rotation were 18 and 44kg N ha−1. Returning aboveground residues provided an extra 52–80kg N ha−1 for oat and 61–63kg N ha−1 for lupine relative to treatments where they were removed. Over a year, lupine contributed 9 to 20kg N ha−1 more to the agroecosystem than did oat.
Agriculture plays a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide, and methane. From
1991 to 1999, we measured gas fluxes and other sources of global warming potential (GWP) in cropped and nearby unmanaged ecosystems.
Net GWP (grams of carbon dioxide equivalents per square meter per year) ranged from 110 in our conventional tillage systems
to −211 in early successional communities. None of the annual cropping systems provided net mitigation, although soil carbon
accumulation in no-till systems came closest to mitigating all other sources of GWP. In all but one ecosystem, nitrous oxide
production was the single greatest source of GWP. In the late successional system, GWP was neutral because of significant
methane oxidation. These results suggest additional opportunities for lessening the GWP of agronomic systems.
With humans having an increasing impact on the planet, the interactions between the nitrogen cycle, the carbon cycle and climate are expected to become an increasingly important determinant of the Earth system.
The intensification of agricultural practices to increase food and feed outputs is a pressing challenge causing deterioration of soil quality and soil functions. Such challenge demands provision of empirical evidence to provide context-sensitive guidance on agricultural management practices (AMPs) that may enhance soil quality. The objectives of this study are: (i) identify the most promising AMPs (and their combinations) applied by farmers with the most positive effects on soil quality and (ii) evaluate the sensitivity of the soil quality indicators to the applied AMPs. The impact of selected AMPs on soil quality was assessed using a Visual Soil Assessment (VSA) tool in a total of 138 pairs of plots spread across 14 study site areas in Europe and China covering representative pedo-climatic zones. The inventory and scoring of soil quality was conducted together with landowners. Results show that 104 pairs show a positive impact of AMPs on soil quality. Higher impact of the AMPs was observed in lower fertile soils (i.e. Podzols and Calcisols) as opposed to higher fertile soils (i.e. Luvisols and Fluvisols). For the single use applications, the AMPs with positive impacts were crop rotation, manuring & composting and no-tillage, followed by organic agriculture and residue maintenance. Cluster analysis showed that the most promising combinations of AMPs having a positive impact on soil quality are composed of crop rotation, mulching and min-till. The agreement between scientific skills and empirical knowledge in the field identified by the farmers confirm our findings and ensures their applicability.
Core ideas: Impact of agricultural management practices on soil quality was assessed. Selected AMPs have high positive effects on soil quality in low fertile soils. Selection of visual soil indicators was confirmed by the farmers' knowledge.
iSQAPER project - Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience - aims to develop an app to advise farmers on selecting the best Agriculture Management Practice (AMPs) to improve soil quality. For this purpose, a soil quality index has to be developed to account for the changes in soil quality as impacted by the implementation of the AMPs. Some promising AMPs have been suggested over the time to prevent soil degradation. These practices have been randomly adopted by farmers but which practices are most used by farmers and where they are mostly adopted remains unclear.
This study is part of the iSQAPER project with the specific aims: 1) map the current distribution of previously selected 18 promising AMPs in several pedo-climatic regions and farming systems located in ten and four study site areas (SSA) along Europe and China, respectively; and 2) identify the soil threats occurring in those areas. In each SSA, farmers using promising AMP's were identified and questionnaires were used to assess farmer's perception on soil threats significance in the area.
138 plots/farms using 18 promising AMPs, were identified in Europe (112) and China (26).Results show that promising AMPs used in Europe are Crop rotation (15%), Manuring & Composting (15%) and Min-till (14%), whereas in China are Manuring & Composting (18%), Residue maintenance (18%) and Integrated pest and disease management (12%). In Europe, soil erosion is the main threat in agricultural Mediterranean areas while soil-borne pests and diseases is more frequent in the SSAs from France and The Netherlands. In China, soil erosion, SOM decline, compaction and poor soil structure are among the most significant. This work provides important information for policy makers and the development of strategies to support and promote agricultural management practices with benefits for soil quality.
Soil biodiversity is increasingly recognized as providing benefits to human health because it can suppress disease-causing soil organisms and provide clean air, water and food. Poor land-management practices and environmental change are, however, affecting belowground communities globally, and the resulting declines in soil biodiversity reduce and impair these benefits. Importantly, current research indicates that soil biodiversity can be maintained and partially restored if managed sustainably. Promoting the ecological complexity and robustness of soil biodiversity through improved management practices represents an underutilized resource with the ability to improve human health.
The long-term effects of cropping systems and management practices on soil properties provide essential information for assessing sustainability and environmental impact. Field experiments were undertaken in southern Spain to evaluate the long-term effects of tillage, crop rotation and nitrogen (N) fertilization on the organic matter (OM) and mineral nitrogen (Nmin) contents of soil in a rain-fed Mediterranean agricultural system over a 6-year period. Tillage treatments included no tillage (NT) and conventional tillage (CT), crop rotations were of 2 yr with wheat (Triticum aestivum L.)-sunflower (Helianthus annuus L.) (WS), wheat-chickpea (Cicer arietinum L.) (WP), wheat-faba bean (Vicia faba L.) (WB), wheat-fallow (WF), and in addition, continuous wheat (CW). Nitrogen fertilizer rates were 50, 100, and 150 kg N ha−1. A split-split plot design with four replications was used. Soil samples were collected from a depth of 90 cm at the beginning of the experiment and 6 yr later. Soil samples were also collected from a depth of 30 cm after 4 yr. These samples, like those obtained at the beginning of the experiment, were subjected to comprehensive physico-chemical analyses. The soil samples that were collected 6 yr later were analyzed for OM, NH4+N and NO3−N at the 0–30, 30–60 and 60–90 cm soil depths. The tillage method did not influence the OM or Nmin contents of the soil, nor did legume rotations increase the OM content of soil relative to CW. A longer period may have been required for differences between treatments to be observed owing to the small amount of crop residue that is returned to soil under rain-fed conditions of semi-arid climates. The WF rotation did not raise the Nmin content of the soil relative to the other rotations. The consistent significant interaction between tillage and crop rotation testifies to the differential effect of the management system on the OM content and N status of the soil. The ammonium levels clearly exceeded those of NO3−N throughout the soil profile. The high Nmin content of the soils reveals the presence of abundant N resources that should be borne in mind in establishing N fertilization schemes for crops under highly variable climatic conditions including scant rainfall such as those of the Mediterranean region.
Under semiarid Mediterranean climatic conditions, soils typically have low organic matter content and weak structure resulting in low infiltration rates. Aggregate stability is a quality indicator directly related to soil organic matter, which can be redistributed within soil by tillage. Long-term effects (1983–1996) of tillage systems on water stability of pre-wetted and air dried aggregates, soil organic carbon (SOC) stratification and crop production were studied in a Vertic Luvisol with a loam texture. Tillage treatments included conventional tillage (CT), minimum tillage (MT) and zero tillage (ZT) under winter wheat (Triticum aestivum L.) and vetch (Vicia sativa L.) rotation (W–V), and under continuous monoculture of winter wheat or winter barley (Hordeum vulgare L.) (CM). Aggregate stability of soil at a depth of 0–5 cm was much greater when 1–2 mm aggregates were vacuum wetted prior to sieving (83%) than when slaked (6%). However, slaking resulted in tillage effects that were consistent with changes in SOC. Aggregate stability of slaked aggregates was greater under ZT than under CT or MT in both crop rotations (i.e., 11% vs. 3%, respectively).
The soil nematode fauna was assessed as a potential ecological index for the progressive stages of degradation, as well as the possibilities of restoration of a Calcic Haploxeralf in a semi-arid environment in Spain. With this aim in mind, soil characteristics and nematode populations were compared in a virgin ecosystem (evergreen oak forest) and in a closely associated area subjected to intensive cereal cultivation. In addition, in the latter area, the effects of different tillage systems, local soil compaction and crop rotations were evaluated over a 3 year period. Nematode populations were compared in experimental plots subjected to three contrasted situations: (i) no-tillage versus conventional tillage, (ii) soil compacted by tractor traffic versus undisturbed by traffic, and (iii) barley monoculture versus barley-vetch or barley-sunflower rotations.The soil with a virgin ecosystem had the greatest number and diversity of fungivorous (Tylenchus) and omnivorous predator (mononchids and dorilaimids) nematodes, whereas the values for endoparasites (Heterodera avenae and Pratylenchus) nematodes increased in tilled soil. The population of bacterial-feeding nematodes (rhabditids) was the same in virgin and cultivated areas. The greatest density and diversity in the no-tillage system occurred in the bacterial-feeding, fungivorous and omnivorous predator groups. A favorable effect of crop rotation was that the population of plant parasites (pathogenic) remained below crop damage concentrations. The effect of traffic on soil compaction was reflected conspicuously by the vertical distribution of soil nematodes within the soil profile. The population of plant parasites increased with depth, whereas the opposite occurred with the bacterial-feeding and omnivorous predator groups.
Soil organic phosphorus plays a significant role in phosphorus (P) nutrition of crops especially in high-P-fixing soils of the tropics. Soil management practices, which favour the accretion of organic P, would, therefore, help in improving soil P fertility over time. In a six-year field experiment with soybean–wheat rotation on a Vertisol, the effects of continuous additions of four rates of animal manure (0, 4, 8 and 16 t ha−1 yr−1) with and without fertilizer P (22 kg P ha−1) on crop yields and soil organic P were examined. Soybean and wheat yields, and P uptakes increased significantly with the addition of manure and fertilizer P. For the similar amount of P input, the yield increases were larger with manure P than with fertilizer P. Combined use of manure and fertilizer P resulted in a greater crop yield and P uptake than their solitary application. Irrespective of the treatment, P content in different organic P fractions followed the order: moderately-resistant organic P (MROP) > moderately-labile organic P (MLOP) > highly-resistant organic P (HROP) > labile organic P (LOP), with their relative proportion being in the ratio of 22:8:5:1. Continuous annual application of manure increased the content of all the soil organic-P fractions, except the HROP, over the control. Addition of fertilizer P together with manure promoted the accretion of soil organic P. Generally the increases in organic P fractions due to manure additions were strongly associated with a concomitant increase in the soil organic carbon. Cropping without manure and fertilizer P depleted soil organic P, while regular additions of manure and fertilizer P favoured its accumulation. The magnitude of depletion/build-up was strikingly larger in MLOP and MROP fractions compared to others, indicating that these two fractions are major sources and sinks for plant-available P in soil.
Human activities over the last three centuries have significantly transformed the Earth's environment, primarily through the conversion of natural ecosystems to agriculture. This study presents a simple approach to derive geographically explicit changes in global croplands from 1700 to 1992. By calibrating a remotely sensed land cover classification data set against cropland inventory data, we derived a global representation of permanent croplands in 1992, at 5 min spatial resolution [Ramankutty and Foley, 1998]. To reconstruct historical croplands, we first compile an extensive database of historical cropland inventory data, at the national and subnational level, from a variety of sources. Then we use our 1992 cropland data within a simple land cover change model, along with the historical inventory data, to reconstruct global 5 min resolution data on permanent cropland areas from 1992 back to 1700. The reconstructed changes in historical croplands are consistent with the history of human settlement and patterns of economic development. By overlaying our historical cropland data set over a newly derived potential vegetation data set, we analyze our results in terms of the extent to which different natural vegetation types have been converted for agriculture. We further examine the extent to which croplands have been abandoned in different parts of the world. Our data sets could be used within global climate models and global ecosystem models to understand the impacts of land cover change on climate and on the cycling of carbon and water. Such an analysis is a crucial aid to sharpen our thinking about a sustainable future.
Global food demand is increasing rapidly, as are the environmental impacts of agricultural expansion. Here, we project global demand for crop production in 2050 and evaluate the environmental impacts of alternative ways that this demand might be met. We find that per capita demand for crops, when measured as caloric or protein content of all crops combined, has been a similarly increasing function of per capita real income since 1960. This relationship forecasts a 100-110% increase in global crop demand from 2005 to 2050. Quantitative assessments show that the environmental impacts of meeting this demand depend on how global agriculture expands. If current trends of greater agricultural intensification in richer nations and greater land clearing (extensification) in poorer nations were to continue, ~1 billion ha of land would be cleared globally by 2050, with CO(2)-C equivalent greenhouse gas emissions reaching ~3 Gt y(-1) and N use ~250 Mt y(-1) by then. In contrast, if 2050 crop demand was met by moderate intensification focused on existing croplands of underyielding nations, adaptation and transfer of high-yielding technologies to these croplands, and global technological improvements, our analyses forecast land clearing of only ~0.2 billion ha, greenhouse gas emissions of ~1 Gt y(-1), and global N use of ~225 Mt y(-1). Efficient management practices could substantially lower nitrogen use. Attainment of high yields on existing croplands of underyielding nations is of great importance if global crop demand is to be met with minimal environmental impacts.
Consequences of changing biodiversity
- F S Chapin
- E S Zavaleta
- V T Eviner
Consequences of changing biodiversity. Nature
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405:234-42. https://doi.org/10.1038/35012241
opportunities-for-soil-sustainability-in-europe/. Date 696 of last access
EASAC (2018) Opportunities for soil sustainability in
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Europe.
https://easac.eu/publications/details/
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opportunities-for-soil-sustainability-in-europe/. Date
696
of last access: 28 May 2019
The state of the world's land and water 708 resources for food and agriculture-Managing sys-709 tems at risk
- Fao
FAO (2011) The state of the world's land and water
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resources for food and agriculture-Managing sys-709
tems at risk. http://www.fao.org/3/a-i1688e.pdf. Date
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of last access: 28 May 2019
Soil threats in Europe: Status, methods, drivers and effects on ecosystem services
- J Stolte
- M Tesfai
- L Øygarden
The state of the world’s land and water resources for food and agriculture-Managing systems at risk
- Fao
Threats to soil quality in Europe
- G Tóth
- L Montanarella
- E Rusco
Soil organic matter and its role in crop production
- F Allison