Thomas Döring

University of Bonn | Uni Bonn · Institute of Crop Science and Resource Conservation (INRES)

To promote and maintain health in agricultural and food systems, appropriate criteria are needed for the description and assessment of the health of soils, plants, animals, humans and ecosystems. Here we identify the concept of resilience as a universally applicable and fundamentally important criterion of health in all relevant areas of agricultur...

In the face of increasingly frequent droughts threatening crop performance, ecological theory suggests that higher species diversity may help buffering productivity by making systems more resistant through resource complementarity and more resilient through higher response diversity. However, empirical evidence for these diversity effects under dro...

Soil-borne plant diseases are a major source of crop losses. Biologically active soils have the ability to suppress pathogenic infections of plants, but little is known how this essential soil function might be affected by abiotic stresses. Using a model system with pea and its fungal pathogen Pythium ultimum we studied how the sup-pressiveness of...

High stability of crop yields is a key objective in crop production and breeding, especially under the conditions of a changing climate. Reliable indices are therefore needed for quantifying yield stability. Recently it was shown that some frequently used indices of yield stability, such as the coefficient of variation (CV) may be wrongly interpret...

Inoculating crops with specifically designed microbial consortia (MC) is increasingly discussed as an instrument for sustainably promoting arable crop growth. While some promising results were achieved in laboratory, climate chamber, and greenhouse experiments, field applications of microbial inoculants under temperate climate conditions have been...

Weed management in organic farming needs to integrate a wide range of preventive tools. Here we tested the stale seed bed technique in field experiments with organic lemon balm. In a two‐factorial trial, four intensities of stale seedbed after either autumn or spring ploughing were tested in 2019/2020 and 2020/2021 on alluvial loams of the research...

Aims. Intercropping cereals and grain legumes has the potential to increase grain yield in comparison to the respective sole crops, but little is known about mixture effects at the early crop developmental stage. In cereal legume mixtures, the cereal is usually the dominating partner. We aimed to find out when domination starts, which factors may e...

This presentation gives an overview of some basic aspects to consider in planning and implementing field trials in agronomy.

Aphids are economically and ecologically important herbivorous insects. A critical step in their life cycle is the visually guided host finding behaviour. To elucidate the role of colour in host finding of aphid spring migrants we conducted large colour trap experiments in the field and analysed aphid catch data, using trap spectral reflectance dat...

Ground beetles (carabids) constitute an important functional component of biodiversity in agroecosystems, mainly because of their role as predators of pests, but also as consumers of weed seeds and as prey to other organisms. Over the past few decades, there has been a marked and continuous decline of ground beetles in Europe, and many species of t...

Purpose Mixtures of cover crops are gaining importance in farming systems. While complementarity between species is a potentially important mechanism underlying mixture benefits, there is little quantitative evidence about complementarity of root growth. Therefore, we aimed to gain detailed knowledge about mixture effects of specific root traits....

The use of microbial consortia (MC) with complementing features is considered to be a promising method of sustainable crop intensification, potentially trumping the limited performance of single-strain applications. We assessed the effect of two novel MC on early wheat growth and litterbag microbial activity in heated and unheated soil. Pot experim...

Cropping system diversification through annual intercropping provides a pathway for agricultural production with reduced inputs of fertilizer and pesticides. While several studies have shown that intercrop performance depends on the genotypes used, the available evidence has not been synthesized in an overarching analysis. Here, we review the effec...

Compensation can be defined as a process by which a system is able to regain its normal state in response to losing a part of its structure. From genes to individuals to communities, compensatory processes ensure functionality, stability and resilience. While there is a rich literature on compensation in natural and semi-natural communities, as wel...

Different methods have been proposed for in situ root-length density (RLD) measurement. One widely employed is the time-consuming sampling of soil cores or monoliths (MO). The profile wall (PW) method is a less precise, but faster and less laborious alternative. However, depth-differentiated functions to convert PW RLD estimates to MO RLD measureme...

For several decades, farmers have been mixing rock powders with livestock slurry to reduce its NH3 emissions and increase its nutrient content. However, mixing rock powders with slurry is controversial, and there is currently no scientific evidence for its effects on NH3 and greenhouse gas (GHG) emissions or on changes in its nutrient content due t...

Exploring potential to use new technologies in agriculture for diversification

Soil nutrient depletion threatens global food security and has been seriously underestimated for potassium (K) and several micronutrients. This is particularly the case for highly weathered soils in tropical countries, where classical soluble fertilizers are often not affordable or not accessible. One way to replenish macro- and micronutrients are...

In the face of a changing climate, yield stability is becoming increasingly important for farmers and breeders. Long-term field experiments (LTEs) generate data sets that allow the quantification of stability for different agronomic treatments. However, there are no commonly accepted guidelines for assessing yield stability in LTEs. The large diver...

Societies’ calls for addressing the urgent problems of climate change, biodiversity loss and other environmental crises are becoming ever louder. Responding to this, and to the growing severity of global threats to agricultural and food systems, national and international research funders are increasingly demanding that funded projects achieve real...

While intercropping is known to have positive effects on crop productivity, it is unclear whether the effects of mixing species start at the early plant stage, that is, during germination. We tested whether the germination of two legume species, alsike clover and black medic, characterized by a contrasting response to water availability and tempera...

Current use of mineral nitrogen (N) fertilizers is unsustainable because of its high fossil energy requirements and a considerable enrichment of the biosphere with reactive N. Biological nitrogen fixation (BNF) from leguminous crops is the most important renewable primary N source, especially in organic farming. However, it remains unclear to which...

Poppy seed production is susceptible to abiotic and biotic stress and weed infestation, which introduces the risk of total crop failure. For the purpose of risk minimization, poppy was grown in additive intercropping systems with early and late sown white clover and spring barley sown at three different densities in a three year field trial to asse...

In the face of a changing climate, yield stability is becoming increasingly important for farmers and breeders. Long-term field experiments (LTEs) generate data sets that allow the quantification of stability for different agronomic treatments. However, there are no commonly accepted guidelines for assessing yield stability in LTEs. The large diver...

While intercropping is known to have positive effects on crop productivity, it is unclear whether the effects of mixing species start at the early plant stage, that is, during germination. We tested whether the germination of two legume species, alsike clover and black medic, characterized by a contrasting response to water availability and tempera...

Ecological management of insect pests in agricultural crops through manipulation of host finding behaviour - Lecture at Federal University of Santa Catarina - Florianópolis-SC - Brazil

Yield stability is important for food security and a sustainable crop production, especially under changing climatic conditions. It is well known that the variability of yields is linked to changes in meteorological conditions. However, little is known about the long-term effects of agronomic management strategies, such as the supply of important n...

Many benefits of cover crops such as prevention of nitrate leaching, erosion reduction, soil organic carbon enhancement and improvement of soil structure are associated with roots. However, including root characteristics as a criterion for cover crop selection requires more knowledge on their root growth dynamics. Seven cover crop species (crimson...

Many benefits of cover crops such as prevention of nitrate leaching, erosion reduction, soil organic carbon enhancement and improvement of soil structure are associated with roots. However, including root characteristics as a criterion for cover crop selection requires more knowledge on their root growth dynamics. Seven cover crop species (crimson...

Diversifying rotations with grain legumes could contribute to the resilience of agricultural systems for adapting to climate change. Yield stability is an important goal in agricultural production and is particularly relevant in Europe-grown grain legumes. Their yields tend to be more variable than yields of some other crops and there is some evide...

Organic amendments can reportedly sustain and increase lowland rice productivity in smallholder systems. Few studies have assessed locally-available substrates in hydrologically variable floodplain environments. We investigated the effects of green and farmyard manures on rice yields, and total soil C and N in the Kilombero floodplain, Tanzania. At...

To meet the growing rice demand in Africa, gaps between actual and attainable yields have to be reduced. In Tanzania, this particularly concerns smallholder rain-fed production systems in the floodplains. After quantifying the existing yield gaps, key contributing factors need to be analyzed to improve site-specific management. Field experiments we...

Elsalahy et al., 2020_Supplementary materials_Crop Resilience to Drought With and Without Response Diversity

Most of our crops are grown in monoculture with single genotypes grown over wide acreage. An alternative approach, where segregating populations are used as crops, is an exciting possibility, but outcomes of natural selection upon this type of crop are not well understood. We tracked allelic frequency changes in evolving composite cross populations...

Weed suppression is a potential benefit of cover crop mixtures, as species diversity may allow for combining early and late-season competition with weeds. Here, we studied if this is possible for only-legume mixtures containing species with different growth rates, by testing two legumes, alsike clover (AC; Trifolium hybridum L.) and black medic (BM...

Weed suppression is a potential benefit of cover crop mixtures, as species diversity may allow for combining early and late-season competition with weeds. Here, we studied if this is possible for only-legume mixtures containing species with different growth rates, by testing two legumes, alsike clover (AC; Trifolium hybridum L.) and black medic (BM...

In East Africa, smallholder farmers produce rainfed lowland rice mainly in floodplains. Low nitrogen contents of the predominant Fluvisols and highly variable hydrological conditions result in low yields and large yield variations, and hence, result in high production risks for farmers. We investigated crop management strategies aimed at increasing...

Allelopathic root exudates affect natural and managed grasslands in various contexts such as weed control, reseeding, overseeding and crop rotation by causing autotoxicity and/or heterotoxicity. In this study, we investigated the allelopathic effect of two species of legumes, Alsike clover (Trifolium hybridum; AC) and Black medic (Medicago lupulina...

Allelopathic root exudates affect natural and managed grasslands in various contexts such as weed control, reseeding, overseeding and crop rotation by causing autotoxicity and/or heterotoxicity. In this study, we investigated the allelopathic effect of two species of legumes, Alsike clover (Trifolium hybridum; AC) and Black medic (Medicago lupulina...

Most of our crops are grown in monoculture with single genotypes grown over wide acreage. An alternative approach, where segregating populations are used as crops is an exciting possibility, but outcomes of natural selection upon this type of crop are not well understood. We tracked allelic frequency changes in evolving composite cross populations...

Electromagnetic induction (EMI) data are often used to investigate spatial and temporal patterns of soil texture, soil water content, and soil salinity. We hypothesized that the EMI methodology might thus also offer potential to detect agricultural legacy effects originating from fertilizer application and irrigation of different fields. Therefore,...

Organic farming is often subject of heated scientific and public debates. This raises the question: How can scientists working in organic farming research achieve being impartial while simultaneously sharing enthusiasm about organic farming and promoting it as a solution to many of the problems of agricultural and food systems? Science needs to be...

In the face of a changing climate and the need to improve global food security, temporal yield stability is gaining increasing attention, and is often considered as important as mean yield itself. Analysis of yield stability is particularly relevant in European-grown grain legumes which produce high quality protein for food and feed and provide a r...

Plant breeding and genetics play an important role in organic agriculture. Well‐rehearsed examples include plant breeding for resistance against plant diseases and pests, genetic improvement in terms of nutrient use efficiency and the selection for a better ability of crops to compete with weeds. However, beyond this view of plant genetics as a way...

Grain legumes produce high quality protein for food and feed, and potentially contribute to sustainable cropping systems, but they are grown on only 1.5% of European arable land. Low temporal yield stability is one of the reasons held responsible for the low proportion of grain legumes, without sufficient quantitative evidence. The objective of thi...

Flaxseed is the economically most important medicinal plant in Germany. It is cultivated on an area of over 2500 ha. Its pollen and/or nectar are a potential foodresource for insects in intensively used agricultural landscapes. To test this hypothesis insects on flowering flaxseed plants and the flowering environment were collected and the species...

Organic potato cultivation requires a whole system perspective, with particular focus on rotation design. Producing organic potatoes relies strongly on indirect, preventive and long-term strategic measures for both plant nutrition and plant protection. This chapter examines all aspects of the process of cultivating organic potatoes, including rotat...

Here we propose a method to adjust the standard CV to account for the systematic dependence of σ² from μ. This adjusted CV can be used as a stability index that is expressed in units that are equivalent to the standard CV, as a percentage of the mean, and can therefore be used in agronomic studies that aim to provide guidance for farmers and adviso...

The size of the arable land is constantly decreasing all over the world due to severe anthropogenic disorders. Plant production therefore has to be adapted to changing environmental conditions along with the proper selection of crop varieties and the application of sustainable environmental technologies which also consider economic aspects. The inv...

This year, organic farmers, advisors and researchers in the West of Germany celebrate the 25th anniversary of the foundation of an organic research and demonstration network. Established to support and improve organic farming systems, the network is funded by the federal state of North Rhine-Westphalia and is organized around 30 participating pilot...

Grain legumes produce high quality protein for food and feed, and provide ecosystem services contributing to sustainable cropping systems. Yet yield instability is perceived to be high, resulting in low adoption by farmers in Europe, where grain legumes were cultivated on only 1.5% of the arable land in 2014. The objective of this study was to asse...

Abstract Numerous studies have demonstrated that crop mixtures may be higher yielding than monocultures; in addition, mixtures may also have the potential to increase weed suppression. Legumes are considered as a key component in many mixtures because of their essential role in fixing nitrogen1. Optimizing mixtures of only-legume for a particular...

Vorwort zur 1. Auflage: Die Ökologische Landwirtschaft hat sich zu einer stark wissensbasierten Wirtschaftsweise entwickelt. Für eine erfolgreiche Beschäftigung mit und in ihr braucht es neben dem Spezialwissen der Boden-, Pflanzenbau-, Nutztier-, Wirtschafts- und Sozialwissenschaften auch Kenntnisse über die Querbeziehungen zwischen diesen Gebiet...

This article concerns the organic movement's aim to promote health across the entire farm system as outlined by the IFOAM Principle of Health (IFOAM 2005). It discusses the implementation of Health by organic farmers in Austria, Germany and the UK. Results from an international survey and a series of workshops on health promoting strategies and pri...

The project 'Developing best practice networks of health in organic agricultural systems' aimed to create an international network of farmers and scientists to jointly develop new and interdisciplinary approaches to health measurement and research in ecological agriculture. The project identified personal philosophies and statements of best practic...

Rhizobia play important roles in agriculture owing to their ability to fix nitrogen through a symbiosis with legumes. The specificity of rhizobia-legume associations means that underused legume species may depend on seed inoculation with their rhizobial partners. For black medic (Medicago lupulina) and lucerne (Medicago sativa) little is known abou...

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Introduction In comparison to monocultures, mixtures of different plant species often exhibit a range of benefits, including increased biomass yield and efficient weed suppression (Storkey et al., 2015). Legume species are considered as a key component in many mixtures because of their role in fixing nitrogen (Döring et al., 2013). Optimizing mixtu...

In comparison to monocultures, species mixtures often exhibit a range of benefits, including increased biomass yield and efficient weed suppression (Döring et al., 2013). Legumes are considered as a key component in many mixtures because of their role in fixing nitrogen (Storkey et al., 2015). Optimizing mixtures of legume species depends on determ...