Exploring rhizosphere processes in diversified plant cultures – implications on nutrient use efficiency and stress tolerance in legume-based cropping systems

Exploring rhizosphere processes in diversified plant cultures – implications on nutrient use efficiency and stress tolerance in legume-based cropping systems

Legumes provide valuable inputs of symbiotically fixed N, to the benefit for the legume itself as well as for associated and succeeding plants, but the reliance of legume-derived N in cropping systems is often compromised by legume sensitivity to stressful conditions causing low yield stability. This project will test the hypothesis that increased within- and between-species diversity improves both nutrient and water use efficiency and yield stability in legume - cereal intercrops. Novel insights about N and P dynamics in the combined rhizospheres of co-cultivated faba bean and spring wheat will be obtained by chemical and biochemical analyses of rhizosphere and bulk soil sampled with high resolution. Analyses of resource use efficiency will be based on yield and quality parameters in cultures of varied faba bean varietal diversity subject to both P and water limitation. Legume varietal mixtures represent an innovative strategy to improve yield stability, which is evaluated in new field experiments at the proposed home department. The collaboration between the home (SLU Alnarp) and host (University of Toronto, Canada) departments and the combination of field and greenhouse experiments provide unique possibilities to link mechanistic information at the rhizosphere level with processes at the cropping system level. The obtained knowledge will be important for the possibilities to optimize N and P use efficiency and minimize yield variability in legume cropping systems.

Publications:

- Bargaz et al. 2017. Species interactions enhance root allocation, microbial diversity and P acquisition in intercropped wheat and soybean under P deficiency. Applied Soil Ecology 120: 179-188.  DOI: 10.1016/j.apsoil.2017.08.011

- Bargaz et al. 2016. Nodulation and root growth increase in lower soil layers of water-limited faba bean intercropped with wheat. Journal of Plant Nutrition and Soil Science 179, 537-546. DOI: 10.1002/jpln.201500533