Biogeochemistry of Agroecosystems

Back to the Roots: Fostering Sustainable Nutrition in Africa

Sustainable food production in developing countries is challenged not only by exponential population growth, but also by insufficient crop yields due to land degradation, nutrient scarcity and water limitation. Future development requires an increase in crop productivity and yield stability while avoiding depletion of natural resources. Whereas industrialized countries benefited from novel high-yield cultivars, breeding of varieties adapted to the multiple resource limitations common in sub-Saharan Africa, where drought is combined with insufficient fertilization, was mainly disregarded. This project targets the rhizosphere, the key hotspot where plants overcome water and nutrient scarcity, which was widely ignored in prior breeding efforts. In close collaboration with African researchers, the productivity of local varieties of wheat, maize, sorghum and millet will be compared with modern cultivars under various limitations. Rhizosphere mechanisms involved in overcoming multiple resource limitations will be identified by a cutting-edge multiple isotope labeling approach (D2O, 15N, 33P, and 13C) combined with molecular marker analysis, which permit the tracing of nutrient and water fluxes in the rhizosphere in-situ. Finally, the most effective varieties will be tested under extreme droughts in field experiments to determine the potential of the identified rhizosphere traits to overcome future challenges of sustainable crop production. Breeders will be provided with these key rhizosphere traits, paving the way for sustainable food supplies in drought-affected areas worldwide.