Leibniz Centre for Agricultural Landscape Research

Arctic soils are the largest pool of soil organic carbon worldwide. Temperatures in the Arctic have risen faster than the global average during the last decades, decreasing annual freezing days and increasing the number of freeze-thaw cycles (temperature oscillations passing through zero degrees) per year as the temperature is expected to fluctuate more around 0 °C. At the same time, proceeding deepening of seasonal thaw may increase silicon (Si) and calcium (Ca) concentrations in the active layer of Arctic soils as the concentrations in the thawing permafrost layer might be higher depending on location. We analyzed the importance of freeze-thaw cycles for Arctic soil CO2 fluxes. Furthermore, we tested how Si (mobilizing organic C) and Ca (immobilizing organic C) interfere with the soil CO2 fluxes in the context of freeze-thaw cycles. Our results show that with each freeze-thaw cycle the CO2 fluxes from the Arctic soils decreased. Our data revealed a considerable CO2 emission below 0 °C. We also show that pronounced differences emerge in Arctic soil CO2 fluxes with Si increasing and Ca decreasing CO2 fluxes. Furthermore, we show that both Si and Ca concentrations in Arctic soils are central controls on Arctic soil CO2 release, with Si increasing Arctic soil CO2 release especially when temperatures are just below 0 °C. Our findings could provide an important constraint on soil CO2 emissions upon soil thaw, as well as on the greenhouse gas budget of high latitudes. Thus we call for work improving understanding of freeze-thaw cycles as well as the effect of Ca and Si on carbon fluxes, as well as for increased consideration of those factors in wide-scale assessments of carbon fluxes in the high latitudes.

Agroforestry systems (AFS) upscaling has the potential to integrate sustainability and resilience objectives into agriculture. However, this is a daunting task requiring multi-actor collaboration across public and private sectors at multiple governance levels, coupled with innovative approaches to jointly managing AFS knowledge. Understanding such multi-actor interactions from a network perspective may help to unravel how social structures, created by relational patterns enhance or hinder AFS upscaling. Our paper aims to comparatively explore the role of regional actor-networks on AFS upscaling for a selected farming system. By conducting semi-structured interviews, we collected information about the ties of 86 actors supporting cacao agroforestry systems (CAFS) across two regions of Colombia. We use social network analysis (SNA) to comparatively visualize and understand the general structure of these networks, find relational patterns between the diverse categories of actors involved, and identify a set of key players bridging the majority of the actors within these networks. We find highly centralized networks that connect multiple actors by a low number of mostly non-reciprocal ties. Within these networks, we identify a predominance of bridging ties over bonding ties, homophily patterns among research and education institutions, and heterophily configurations among farmer-based organizations. We also find that the composition of the sets of key actors and the platforms where they converge varies substantially from region to region due to decentralized agricultural policies and differing characteristics across regions. Our approach provides key entry points for promoting multi-actor coalitions that can effectively expand the benefits of AFS in tropical agricultural systems.

Fungi of the genus Alternaria are ubiquitous in the environment. Their mycotoxins can leach out of contaminated plants or crop debris into the soil entering the plant via the roots. We aim to evaluate the importance of this entry pathway and its contribution to the overall content of Alternaria toxins (ATs) in wheat plants to better understand the soil-plant-phytopathogen system. A hydroponic cultivation system was established and wheat plants were cultivated for up to two weeks under optimal climate conditions. One half of the plants was treated with a nutrient solution spiked with alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA), whereas the other half of the plants was cultivated without mycotoxins. Plants were harvested after 1 and 2 weeks and analyzed using a QuEChERS-based extraction and an in-house validated LC-MS/MS method for quantification of the ATs in roots, crowns, and leaves separately. ATs were taken up by the roots and transported throughout the plant up to the leaves after 1 as well as 2 weeks of cultivation with the roots showing the highest ATs levels followed by the crowns and the leaves. In addition, numerous AOH and AME conjugates like glucosides, malonyl glucosides, sulfates, and di/trihexosides were detected in different plant compartments and identified by high-resolution mass spectrometry. This is the first study demonstrating the uptake of ATs in vivo using a hydroponic system and whole wheat plants examining both the distribution of ATs within the plant compartments and the modification of ATs by the wheat plants.

Most food insecurity studies in developing countries, including Ethiopia, use a single food security indicator to determine the food insecurity status, thus overlooking the multidimensional nature of food security. Using cross-sectional data collected from 408 households in three districts of East Hararghe Zone, Ethiopia, this study combined two food security indicators namely calorie intake and Food Consumption Score (FCS) so as to gain more insights on the multidimensional nature of food security and to categorise households into different food insecurity groups. The study further sought to identify factors influencing the households’ food insecurity status. The research findings based respectively on the per capita calorie intake and the FCS indicate that 36.03 and 49.02 percent of the sampled households were food insecure. However, the findings reveal that when the two indicators were combined, 22.06 and 40.93 percent of the households were completely food insecure and transitory food insecure respectively. These findings also suggest that the 40.93 percent (26.96 and 13.97 percent) of households categorised as food secure based on single indicators (i.e., per capita calorie intake and FCS respectively) was unrealistic. Furthermore, findings from the bivariate probit model indicate that food insecurity incidences decreased with the adoption of soil and water conservation, access to irrigation, livestock, access to fertilisers, and household income. It increased with the age of the household head, the household size, and the coping strategy index. Therefore, policies and strategies combating food insecurity should consider a combination of food security indicators.

Organic carbon and aggregate stability are key features of soil quality and important to consider when evaluating the potential of agricultural soils as carbon sinks. However, we lack a comprehensive understanding of how soil organic carbon (SOC) and aggregate stability respond to agricultural management across wide environmental gradients. Here we assessed the impact of climatic factors, soil properties and agricultural management (including land use, crop cover, crop diversity, organic fertilization and management intensity) on SOC and the mean weight diameter of soil aggregates, commonly used as indicator for soil aggregate stability, across a 3,000 km European gradient. Soil aggregate stability (-56%) and SOC stocks (-35%) in the topsoil (20 cm) were lower in croplands compared to neighboring grassland sites (uncropped sites with perennial vegetation and little or no external inputs). Land use and aridity were strong drivers of soil aggregation explaining 33% and 20% of the variation, respectively. SOC stocks were best explained by calcium content (20% of explained variation) followed by aridity (15%) and mean annual temperature (10%). We also found a threshold-like pattern for SOC stocks and aggregate stability in response to aridity, with lower values at sites with higher aridity. The impact of crop management on aggregate stability and SOC stocks appeared to be regulated by these thresholds, with more pronounced positive effects of crop diversity and more severe negative effects of crop management intensity in non-dryland compared to dryland regions. We link the higher sensitivity of SOC stocks and aggregate stability in non-dryland regions to a higher climatic potential for aggregate-mediated SOC stabilization. The presented findings are relevant for improving predictions of management effects on soil structure and C storage and highlight the need for site-specific agri-environmental policies to improve soil quality and C sequestration.

In this article, we propose an agenda promoting the development of a new integrated assessment toolkit (theory-based toolkit) of environmental governance in overlooked ecosystems of grasslands and savannahs in the Global South. To explore the complexity of social-ecological and governance systems, a growing number of systems-thinking approaches provide academics/practitioners with numerous analytical frameworks, theories, and methodologies that are potentially useful for unveiling institutional aspects along with their causal variables for the access, use and management of natural resources. Yet, we argue that achieving a comprehensive understanding of environmental governance systems only by using one single framework or theory is limiting. Further, there is a growing need of more social science knowledge and grassland and savannah context-specific frameworks that are tailored and applicable to policy settings. Therefore, by building on the five approaches of the political ecological framework of community-based governance (CBG) relating to key environmental governance frameworks, such as the community-based natural resource management (CBNRM) and the institutional and development framework (IAD), we propose a theory-based toolkit that would review, synthesize, connect, relate and test multiple core principles in a way that more fully accounts for social-ecological interactions in focal ecosystems. We are convinced that future empirical analysis/research following our agenda and the toolkit approach can generate hypotheses that are testable in real-life contexts. To this end, we suggest guiding research questions, research methods, as well as comparable cases and their rationales.

We investigated an already existing agri-food network connect-ing ten regional community-supported agriculture farms with a food hub in the city of Berlin. The overall aim of the study was to conduct an agroecological characterization of the farms by using the Agroecology Criteria Tool and focusing on the role of knowledge (co-)creation and sharing. We conducted walking interviews with ten farmers and applied participatory research techniques. We found that, first, the farmers either have already transformed the farm into an advanced agroecological model (level 3) or are transitioning from organic to agroecological (level 2–3). Second, the interactions between the farms and regional agri-food system actors foster the reconnection between eaters and regional growers (level 4). The actors of this transfor-mation belong, thus, to grassroots self-organized and solidarity- based initiatives, which have built an agroecology-based regional agri-food network. And third, the diversity of activities and for-mats identified for engaging a broad range of stakeholders pro-vides resources for redefining power relationships and co- creating knowledge. However, there are important barriers that must be addressed to scale this network, such as the lack of structures, platforms and collaborations fostering the knowledge (co-)creation and sharing, access to affordable and secure land, and the lack of governmental support.

Arctic soils store large amounts of organic carbon and other elements, such as amorphous silicon, silicon, calcium, iron, aluminum, and phosphorous. Global warming is projected to be most pronounced in the Arctic, leading to thawing permafrost which, in turn, changes the soil element availability. To project how biogeochemical cycling in Arctic ecosystems will be affected by climate change, there is a need for data on element availability. Here, we analyzed the amorphous silicon (ASi) content as a solid fraction of the soils as well as Mehlich III extractions for the bioavailability of silicon (Si), calcium (Ca), iron (Fe), phosphorus (P), and aluminum (Al) from 574 soil samples from the circumpolar Arctic region. We show large differences in the ASi fraction and in Si, Ca, Fe, Al, and P availability among different lithologies and Arctic regions. We summarize these data in pan-Arctic maps of the ASi fraction and available Si, Ca, Fe, P, and Al concentrations, focusing on the top 100 cm of Arctic soil. Furthermore, we provide element availability values for the organic and mineral layers of the seasonally thawing active layer as well as for the uppermost permafrost layer. Our spatially explicit data on differences in the availability of elements between the different lithological classes and regions now and in the future will improve Arctic Earth system models for estimating current and future carbon and nutrient feedbacks under climate change (https://doi.org/10.17617/3.8KGQUN, Schaller and Goeckede, 2022).

Increasing global food demand will require more food production without further exceeding the planetary boundaries, while at the same time adapting to climate change. We used an ensemble of wheat simulation models, with sink-source improved traits from the highest-yielding wheat genotypes to quantify potential yield gains and associated N requirements. This was explored for current and climate change scenarios across representative sites of major world wheat producing regions. The sink-source traits emerged as climate neutral with 16% yield increase with current N fertilizer applications under both current climate and mid-century climate change scenarios. To achieve the full yield potential, a 52% increase in global average yield under a mid-century RCP8.5 climate scenario, fertilizer use would need to increase fourfold over current use, which would unavoidably lead to higher environmental impacts from wheat production. Our results show the need to improve soil N availability and N use efficiency, along with yield potential.

Given the accelerated global shifts and disruptions to agrifood value chains, an approach is required that reveals multiple drivers, recognizable patterns, and behaviors that can be understood and navigated towards value chain resilience. This research shares roots with and builds further on resilience approaches, the concept of upgrading in global value chains and innovation to contribute to the study of agrifood value chain resilience. The analysis is based on narratives extracted from interviews with local actors in the chain. Narrative, as formed from a combination of temporal succession and causality, helps us track the chain’s historical trajectory, identify critical historical and contemporary drivers of change and actors’ adaptations to historical events, the latest being the Covid-19 pandemic. Our study finds that main drivers, such as natural hazards, market dynamics, actors’ organization, and digital and technological innovation, have been key to Covid-19 adaptation. These constitute crucial areas for policy action and management of systemic risk. For example, previous experience with the fungal disease Foc TR4 one year before the Covid-19 pandemic has been perceived as a key factor in easing Covid-19 adaptation. The analysis shows that some shocks may be challenging to predict, while others may result from the chronic build-up of vulnerabilities, such as the impacts of climate change or the spread of transboundary diseases. As observed in this study, the backbone of overall agrifood value chain resilience and Covid-19 adaptation lie in experiential learning and build on the past; hence, identifying lessons from past innovations is crucial to finding solutions in novel contexts and to deriving opportunities for agrifood value chain development.

Increasing soil organic carbon (SOC) stocks in agricultural soils removes carbon dioxide from the atmosphere and contributes towards achieving carbon neutrality. For farmers, higher SOC levels have multiple benefits, including increased soil fertility and resilience against drought-related yield losses. However, increasing SOC levels requires agricultural management changes that are associated with costs. Private soil carbon certificates could compensate for these costs. In these schemes, farmers register their fields with commercial certificate providers who certify SOC increases. Certificates are then sold as voluntary emission offsets on the carbon market. In this paper, we assess the suitability of these certificates as an instrument for climate change mitigation. From a soils' perspective, we address processes of SOC enrichment, their potentials and limits, and options for cost-effective measurement and monitoring. From a farmers’ perspective, we assess management options likely to increase SOC, and discuss their synergies and trade-offs with economic, environmental and social targets. From a governance perspective, we address requirements to guarantee additionality and permanence while preventing leakage effects. Furthermore, we address questions of legitimacy and accountability. While increasing SOC is a cornerstone for more sustainable cropping systems, private carbon certificates fall short of expectations for climate change mitigation as permanence of SOC sequestration cannot be guaranteed. Governance challenges include lack of long-term monitoring, problems to ensure additionality, problems to safeguard against leakage effects, and lack of long-term accountability if stored SOC is re-emitted. We conclude that soil-based private carbon certificates are unlikely to deliver the emission offset attributed to them and that their benefit for climate change mitigation is uncertain. Additional research is needed to develop standards for SOC change metrics and monitoring, and to better understand the impact of short term, non-permanent carbon removals on peaks in atmospheric greenhouse gas concentrations and on the probability of exceeding climatic tipping points.

Extensive pastoral livestock systems in Central Europe provide multiple ecosystem services and support biodiversity in agricultural landscapes but their viability is challenged by livestock depredation (LD) associated with the recovery of wolf populations. Variation in the spatial distribution of LD depends on a suite of factors, most of which are unavailable at the appropriate scales. To assess if LD patterns can be predicted sufficiently with land use data alone at the scale of one federal state in Germany, we employed a machine learning supported resource selection approach. The model used LD monitoring data, and publicly available land use data to describe the landscape configuration at LD and control sites (resolution 4km*4km). We used SHapley Additive exPlanations to assess the importance and effects of landscape configuration; and cross-validation to evaluate the model performance. Our model predicted the spatial distribution of LD events with a mean accuracy of 74%. The most influential land use features included: grassland, farmland and forest. The risk of livestock depredation was high if these three landscape features co-occurred with a specific proportion. A high share of grassland, combined with a moderate proportion of forest and farmland, increased LD risk. We then used the model to predict the LD risk in five regions; the resulting risk maps showed high congruence with observed LD events. While of correlative nature and lacking specific information on wolf and livestock distribution and husbandry practices, our pragmatic modelling approach can guide spatial prioritization of damage prevention or mitigation practices to improve livestock-wolf coexistence in agricultural landscapes.

This study investigates the major environmental and socio-economic impacts of an increase in the area of rubber plantations and the changing patterns of drivers of land use changes by combining geospatial technologies and socio-economic methods. Using a combination of geospatial techniques and socio-economic methods, we mainly analysed the rate of increase in area under rubber plantations, major impacts of land use changes and the changing drivers of land use changes. Our results shows that the area under rubber plantations has increased significantly within the study area, with the area under rubber plantations increasing from 30–74% of the total area within five decades. Impact assessment of land-use changes based on household surveys showed significant improvement in socio-economic conditions of the farmers however at the expense of severe environmental degradation. Our results also indicate that while areas under rubber plantations continue to increase, the drivers of land use changes have changed over time. Furthermore, it has been observed that in the past many interventions prioritized social and economic development and placed less emphasis on the ecological stability of the region. Perceptions of farmers revealed that the effects of ecological fragility already affected the economic robustness of the whole area. Therefore, we conclude that government interventions to support additional rubber cultivation should also focus on ecosystem stabilization in order to minimize the risk of an ecological catastrophe that would significantly affect the economic prosperity of the region.

Plant monocultures growing for extended periods face severe losses of productivity. This phenomenon, known as ‘yield decline’, is often caused by the accumulation of above- and belowground plant antagonists. The effectiveness of plant defences against antagonists might help explaining differences in yield decline among species. Using a trait-based approach, we studied the role of 20 physical and chemical defence traits of leaves and fine roots on yield decline of 18-year old monocultures of 27 grassland species. We hypothesized that yield decline is lower for species with high defences, that root defences are better predictors of yield decline than leaf defences, and that in roots, physical defences better predict yield decline than chemical defences, while the reverse is true for leaves. We additionally hypothesized that species increasing the expression of defence traits after long-term monoculture growth would suffer less yield decline. We summarized leaf and fine root defence traits using principal component analysis and analysed the relationship between defence traits mean as a measure of defence strenght and defence traits temporal changes of the most informative components and monoculture yield decline. The only significant predictors of yield decline were the mean and temporal changes of the component related to specific root length and root diameter (e.g. the so called collaboration gradient of the root economics space). The principal component analysis of the remaining traits showed strong trade-offs between defences suggesting that different plant species deploy a variety of strategies to defend themselves. This diversity of strategies could preclude the detection of a generalized correlation between the strength and temporal changes of defence gradients and yield decline. Our results show that yield decline is strongly linked to belowground processes particularly to root traits. Further studies are needed to understand the mechanism driving the effect of the collaboration gradient on yield decline.

Regional assessments of the wind erosion risk are rare and differ due to the used methods and the available data to be included. The adaptation of existing methods has the advantage that the results can be compared directly. We adopted an already successfully applied methodology (ILSWE ‐ applied in East Africa), to investigate the spatio‐temporal variability of the wind erosion risk between 2005 and 2019 in southern Africa. The approach integrates climatic variables, a vegetation index and soil properties to describe the potential impact of wind erosion at the landscape scale. The annual and seasonal variability is determined by the vegetation cover, whereas droughts and strong El Niño events having only regional effects. We estimated that 8.3% of the study area experiences a moderate to elevated wind erosion risk over the 15‐year period with annual and inter‐annual fluctuations showing a slight upward trend. In general, the desert and drylands in the west have the highest proportion of risk areas, the moist forests in the east are characterized by a very low risk of wind erosion, while the grasslands, shrublands and croplands in the interior most likely react to changes of climatic conditions. The validation process is based on a comparison with the estimated frequency of dust storms derived from aerosol optical depth and angstrom exponent and revealed an overall accuracy of 65%. The results of this study identify regions and yearly periods prone to wind erosion to prioritize for further analysis and conservation policies for mitigation and adaption strategies. This article is protected by copyright. All rights reserved.

Many ecological restoration projects overlook social perspectives, resulting in unsuccessful restoration outcomes within Forest Landscape Restoration (FLR). The factors that influence an individual's or group's decision to adopt innovations, ranging from social-ecological approaches to specific restoration practices, are still poorly understood. This article examines those drivers determining the adoption of innovations in the context of FLR. Our work, based on a systematic literature review, points to the need for meaningful stakeholder inclusion in social-ecological restoration projects and emerging use of the concept of social-ecological restoration in the research projects. Thus, this article specifically focuses on adoption theory and social-ecological restoration frameworks. We derived a balanced framework that comprises seven drivers and strategies of social-ecological restoration built on the degree of restoration actors’ involvement, particularly local community participation across restoration scales. In developing countries, establishing social groups that share savings and credit structures within neighboring households can be a sustainable approach. Further studies should focus on comparing different studies at local scales within which restoration field trials span different aspects of social-ecological restoration and how it is linked to social cohesion.

The solubility and mobility of copper (Cu) in soil is strongly influenced by the presence of dissolved organic carbon (DOC); however, the interactions between Cu and DOC are complex and not yet fully understood. In this study, Cu and DOC concentrations were measured monthly for two years in leachates from self-constructed lysimeters installed at inter-and intra-row vineyard hilltop, backslope, and footslope areas at the SUPREHILL Critical Zone Observatory, Croatia. The aim was to quantify Cu and DOC leaching from the hilltop towards the backslope and the footslope. The assumed strong relationship between Cu and DOC in the leachates was statistically analyzed and explained using chemical equilibrium software. Leachates were analyzed for pH, EC, DOC, Cu, and major ion concentrations. The highest Cu concentrations found in leachates from the intra-row foot-slope suggested Cu downhill transport. Although not strong, a significant positive correlation between Cu and DOC in footslope leachates confirmed the relevance of Cu complexation by DOC. Speciation confirmed that more than 99.9% of total Cu in leachates was found as a Cu-DOC complex. Data implied the role of soil water flow pathways in explaining Cu downhill transport. Critical timing for applying Cu fungicides at sloped vineyards was highlighted.

Nutrient leaching from agricultural soils presents an economic loss for farmers and can degrade the quality of the surrounding environment. Thus, leachates from 18 in situ wick lysime-ters, installed at 40 cm soil depth at the vineyard hilltop, backslope, and footslope intra-and inter-row area (SUPREHILL Critical Zone Observatory, Croatia) were collected monthly over two years and analyzed for major plant nutrient ions. Our objectives were to quantify nutrient losses via leach-ing from the hilltop towards the backslope and to the footslope, and to compare leaching from vine plant rows (intra-row) with grassed areas between vine rows (inter-row). We found that the concentrations of nitrate, orthophosphate, and potassium were significantly higher in leachates collected at the footslope as compared to the hilltop and backslope only at intra-and not at inter-row positions, while ammonium was independent of the slope and row positions. The vineyard intra-row is identified as the probable spatial origin of nutrient leaching along the slope, thus confirming spatially different contributions of overall hillslope to major plant nutrients leaching. The experimental field scheme used in this study, which separately analyses vineyard intra-and inter-row, was confirmed to be an adequate approach for optimizing vineyard management practices.

Background Land Tenure Formalization (LTF) is long advocated as a policy prescription that fosters growth and reduces poverty in developing countries. However, the empirical evidence on LTF effects is mixed and inconclusive, proving unclear implications for policy. A set of possible conceptual and methodological flaws arising from treating LTF as a dichotomy between formalized and non-formalized alongside potential selectivity biases are amongst the main explanations for the mixed and inconclusive results. Using Tanzania’s National Panel Survey data from the 2014/2015 wave and employing a Selectivity Corrected Multinomial Endogenous Switching Regression, this study models the development outcomes of LTF with clear distinction of LTF between customary and statutory land tenure systems in Tanzania. Findings The study finds that possession of formal land tenure certificates [Certificate of Customary Right of Occupancy (CCRO) or Certificate of Granted Right of Occupancy (CGRO)] improves perceived land tenure security, but the effect is relatively larger and more significant for CGRO holders than CCRO holders especially in economically high potential areas, where land is becoming more individualized and commoditized. With regard to credit access, our results show variations in the effects between general, formal, and informal credit access. While there is no significant effect of LTF on general access to credit, possessing a CGRO significantly reduces the uptake of informal credit and appears to improve access to formal credit. With regard to land investments, our results show positive and significant effects of LTF on organic and inorganic fertilizer use as well as trees and permanent crops investments, but only for CGRO plots. Conclusions The study concludes that the effects of LTF differ significantly between the land tenure systems, thus, treating LTF as a dichotomy between formalized and non-formalized is an oversimplification that could potentially mislead policy decisions. Therefore, the study recommends that the design, implementation and evaluation of LTF programs should recognize this distinction for greater clarity about LFT effects and more meaningful policy messages. The study, further, recommends strategic land policy interventions that aim to enhance land tenure security, especially in high potential areas for more socio-economically optimal outcomes of the interventions.

The rapid transition of livestock husbandry in the 20th century involved a broad adoption of slurry-based livestock housing systems that resulted in farm economic benefits, but also in societal debate related to the environment and animal welfare. In this article, we apply the method of topic modeling to four major German newspapers to identify thematic emphases and changes in coverage around “slurry”. We considered more than 2300 articles published between 1971 and 2020. Our results show that reporting encompasses economic, environmental, and social topics in which slurry is represented mostly critically (“poisonous substance”), occasionally neutrally (“scent of countryside”), or rarely positively (“input for the bioeconomy”). Three meta-themes overarch the majority of issues and reflect public discourse on agriculture: (i) the dichotomy of agricultural industrialization and family farming; (ii) contrasting actualities of factory farming and animal welfare; and (iii) the responsibility of policy for the emergence, existence and solution of livestock and slurry-related problems. A more balanced recognition of mutual values and constraints by the media could contribute to a discursive reconciliation of public and private interests.