Impact of Diverse Production Systems on Yield Stability and Environmental Adaptability of Wheat and Barley: A Study Based on Long-Term Field Experiments

• Applicant: Professorin Dr. Janna Macholdt
• Subject Area: Plant Cultivation, Plant Nutrition, Agricultural Technology
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 420210236

The objective of this project is to contribute to the fundamental understanding of the impacts that a diverse array of production systems have on the grain yield stabilities of wheat and barley. In particular, this project will provide new insight into the complex genotype x environment x management factor (GxExM) interactions prevailing in production systems with a focus on the long-term effects of management factors such as crop rotation and fertilisation. Based on the results of four long-term field experiments (LTFEs), the following hypotheses will be tested:1. Preceding wheat and barley with leaf crops, especially legumes, leads to higher yield stability and environmental adaptability than using a cereal as the preceding crop. (Verification of different preceding crops: sugar beet, oilseed rape, maize, clover, field bean, wheat, rye, oat)2. Production systems with higher mineral nitrogen fertilisation show more stable wheat and barley yields and better environmental adaptability than systems with lower mineral nitrogen supply. (Comparison of different mineral nitrogen fertilisation levels: 0%, 50%, 100%)3. Additional organic fertilisation results in higher yield stability and better environmental adaptability when applied to wheat and barley than mineral fertilisation alone. (Verification of different organic fertilisers: farmyard manure, green manure, sugar beet leaves, cereal straw, pea/field bean straw)4. Different genotypes of wheat and barley react similarly to differences in preceding crops, the mineral nitrogen supply and additional organic fertilisation. (Verification of the wheat and barley cultivars used in the 4 LTFEs).To jointly answer the hypotheses, three work packages (WPs) are designed. The first WP comprises the compilation of the experimental database, which consists of one organic LTE conducted at the University of Copenhagen (Denmark) and three conventional LTEs conducted at the Justus Liebig University Giessen (Germany). The second and core WP of this project comprises the stability analysis of the experimental databases mentioned above. Here, the impact of the management factors (mineral and organic fertilisation as well as crop rotation and, in particular, the effects of the preceding crops) on the yield stability of wheat and barley cultivars in diverse production systems and multiple environments will be determined. Due to the time that has passed since the experiments were established, it will be possible to compare the long-term management effects on yield stability of wheat and barley over a sufficient number of years. The third WP is about modelling the environmental adaptability of wheat and barley in diverse production systems. Based on a system model approach, wheat and barley yield reactions subjected to different selected management strategies and weather driving factors will be analysed, and simulations regarding the sensitivity to environmental stress under future climate scenarios will be performed.

• DFG Programme: Research Grants