Newest publications
Urban waste fertilizer: effects on yield, nutrient dynamics, and potentially toxic element accumulation
(2025) Reimer, Marie; Möller, Kurt; Magid, Jakob; Bruun, Sander; Reimer, Marie; Department of Agroecology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark; Möller, Kurt; Institute of Crop Science, Fertilization and Soil Matter Dynamics (340i), University of Hohenheim, Fruwirthstr. 20, 70593, Stuttgart, Germany; Magid, Jakob; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark; Bruun, Sander; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
Recycling nutrients contained in urban wastes to agriculture is essential in a circular economy. This study simultaneously compares different recycled fertilizers (household waste compost, sewage sludge, human urine) with mineral fertilization and animal manures. Tested were their long-term effects on yield, nutrient budgets, potentially toxic element (PTE) accumulation, and nitrogen (N)/carbon (C) cycle (among others N efficiency, N losses, soil C). Therefore, data from a long-term field trial and predictions from the soil–plant-atmosphere model Daisy were evaluated. Based on trial data, human urine performed similar to the mineral fertilization for yield, N efficiency (mineral fertilizer equivalent (MFE) = 81%), and nutrient budget, while sewage sludge and compost were comparable to animal manures in terms of having lower yields, N efficiencies (MFE 70% and 19% respectively) and higher nutrient imbalances, especially P and S surpluses. Compost and sewage sludge applications resulted in net PTE inputs. Yet, plant uptake and soil accumulation seemed neglectable. Model outputs predicted N losses of 34–55% of supplied N. Losses were highest for compost, followed by deep litter, manure, sewage sludge, human urine, mineral fertilization, and slurry. Nitrate leaching was the main loss pathway (14–41% of N input). Within the compost and straw-rich manure fertilization, about 25% of applied N was stored in the soil which was accompanied by an increase in soil C. The study suggests substitution of established fertilizers with recycled ones is feasible. Thereby each fertilizer has advantages and disadvantages and thus should be utilized according to its strength or in mixtures.
Market-based instruments for biodiversity in agricultural landscapes: An evaluation of quality criteria in a German case study
(2025) Streit, Lea; Feuerbacher, Arndt; Röhl, Markus; Streit, Lea; Nürtingen-Geislingen University of Applied Science, Institute for Landscape and Environment, Hechinger Str. 12, 72622, Nürtingen, Germany; Feuerbacher, Arndt; University of Hohenheim, Ecological-Economic Policy Modelling Research Group, Institute for Agricultural Policy and Markets, Schwerzstr. 46, 70599, Stuttgart, Germany; Röhl, Markus; Nürtingen-Geislingen University of Applied Science, Institute for Landscape and Environment, Hechinger Str. 12, 72622, Nürtingen, Germany
Market-based instruments (MBIs) for the protection and promotion of biodiversity have gained significant importance in recent years. The success of MBIs depends largely on the transparent presentation of their actual effects, which rely on the quality of implementation. Quality criteria can be used to evaluate this. To date, few studies have examined whether and how these criteria are applied. This study seeks to address this gap, by using MBIs in the German agricultural landscape as a case study. Quality criteria were defined on the basis of a literature review; then applied to MBIs identified through an internet search and finally analyzed. Quality criteria related to methodological approaches (implementation, maintenance, used seed mixtures) and quality control (monitoring, localization) are presented less frequently than information on rights and obligations or the use of financial funds. Among the 151 MBIs analyzed, 70% lack control mechanisms and monitoring systems, indicating unverified effectiveness. Additionally, MBIs financed through program approaches are more likely to have control mechanisms and include perennial measures than MBIs funded by direct payments of sponsors or consumers purchasing a product. The development of MBI offerings suggests that there is persistent and growing demand, as some programs have been running for several decades. However, without ecological monitoring, it is not possible to ascertain whether these measures benefit biodiversity. To establish standardized methods for comparing MBIs for biodiversity, policymakers must consider official guidelines and, where appropriate, implement regulatory frameworks.
Rapid cycling genomic selection in maize landraces
(2025) Polzer, Clara; Auinger, Hans-Jürgen; Terán-Pineda, Michelle; Hölker, Armin C.; Mayer, Manfred; Presterl, Thomas; Rivera-Poulsen, Carolina; da Silva, Sofia; Ouzunova, Milena; Melchinger, Albrecht E.; Schön, Chris-Carolin
Key message: A replicated experiment on genomic selection in a maize landrace provides valuable insights on the design of rapid cycling recurrent pre-breeding schemes and the factors contributing to their success. Abstract: The genetic diversity of landraces is currently underutilized for elite germplasm improvement. In this study, we investigated the potential of rapid cycling genomic selection for pre-breeding of a maize ( Zea mays L.) landrace population in replicated experiments. We trained the prediction model on a dataset (N = 899) composed of three landrace-derived doubled-haploid (DH) populations characterized for agronomic traits in 11 environments across Europe. All DH lines were genotyped with a 600 k SNP array. In two replications, three cycles of genomic selection and recombination were performed for line per se performance of early plant development, a major sustainability factor in maize production. From each cycle and replication, 100 DH lines were extracted. To evaluate selection response, the DH lines of all cycles and both replications (N = 688) were evaluated for per se performance of selected and unselected traits in seven environments. Selection was highly successful with an increase of about two standard deviations for traits under directional selection. Realized selection response was highest in the first cycle and diminished in following cycles. Selection gains predicted from genomic breeding values were only partially corroborated by realized gains estimated from adjusted means. Prediction accuracies declined sharply across cycles, but only for traits under directional selection. Retraining the prediction model with data from previous cycles improved prediction accuracies in cycles 2 and 3. Replications differed in selection response and particularly in accuracies. The experiment gives valuable insights with respect to the design of rapid cycling genomic selection schemes and the factors contributing to their success.
Nematode community structure suggests perennial grain cropping cultivation as a nature‐based solution for resilient agriculture
(2024) Förster, Alena; Hohberg, Karin; Rasche, Frank; Emmerling, Christoph; Förster, Alena; Department of Soil Science, Faculty of Regional and Environmental Sciences, Trier University, Trier, Germany; Hohberg, Karin; Senckenberg Museum of Natural History Görlitz, Görlitz, Germany; Rasche, Frank; Department of Agronomy in the Tropics and Subtropics, Institute of Agricultural Sciences in the Tropics (Hans‐Ruthenberg‐Institute), University of Hohenheim, Stuttgart, Germany; Emmerling, Christoph; Department of Soil Science, Faculty of Regional and Environmental Sciences, Trier University, Trier, Germany
Introduction: Conventional agricultural land‐use may negatively impact biodiversity and the environment due to the increased disturbances to the soil ecosystem by tillage, for example. Cultivation of the perennial grain intermediate wheatgrass ( Thinopyrum intermedium , IWG, Kernza®) is a nature‐based solution for sustainable agriculture, improving nutrient retention mainly through its extensive root system. Nematodes serve as sensitive bioindicators, detecting early changes in the soil food web, reflecting in changes in their community structure. Materials and Methods: IWG and annual wheat sites in South France, Belgium and South Sweden were investigated in April 2022 for two depths (5–15 cm; 25–35 cm) to evaluate the difference in nematode community structure among the cropping systems. Results: Sites with IWG cultivation held an accumulation of structure indicators (c‐p 3–5 nematodes) compared to sites with annual wheat cultivation. A generalised linear mixed model revealed significantly more root feeders, especially for the subsoil, under IWG as a result of the perennial cultivation. The maturity index, plant‐parasitic index, channel index and structure index were greater for IWG sites. The enrichment index was greater for annual wheat sites due to the dominance of bacterivores and enrichment indicators (c‐p 1 nematodes). The nematode community structure (weighted faunal profile analysis) indicates IWG sites as being a generally undisturbed system with efficient nutrient cycling and balanced distribution of feeding types, as well as higher metabolic footprint values for root feeders (including plant‐parasitic nematodes) and fungivores. Annual wheat sites, on the other hand, held indicators of a disturbed system with increased occurrence of opportunistic species and a more bacterial driven pathway. The topsoil had an increased occurrence of structure indicators in both cropping systems. Conclusion: IWG creates favourable conditions for a diverse food web, including improved nutrient cycling and a heterogeneous resource environment, regardless of climatic conditions, establishing it as a stable and resilient agricultural management system.
Degrowth attitudes among entrepreneurs hinder fast venture scaling
(2024) Hinderer, Sebastian; Kuckertz, Andreas; Hinderer, Sebastian; Entrepreneurship Research Group, University of Hohenheim, Stuttgart, Germany; Kuckertz, Andreas; Entrepreneurship Research Group, University of Hohenheim, Stuttgart, Germany
The degrowth paradigm has gained popularity in the sustainability discourse in recent years. Questioning the absolute decoupling of economic growth from environmental degradation, degrowth proponents suggest downscaling production and consumption to reduce resource extraction and energy consumption. However, this seems to be at odds with conventional wisdom about entrepreneurship. Thus, our research aims to shed light on the implications of the degrowth discourse on entrepreneurship. We answer how degrowth attitudes among (sustainable) entrepreneurs are associated with decision‐making on scaling strategies for their ventures. Differentiating between scaling fast and scaling slow strategies, we show that a degrowth attitude is negatively associated with scaling fast strategies, whether entrepreneurs consider themselves sustainable or not. However, sustainable entrepreneurship is positively associated with scaling slow strategies. Furthermore, we show that the development level of the economy an entrepreneur is active in is an essential factor in the decision‐making on scaling strategies.