The objectives of WP2 are to:
- Identify architectural and functional root traits relating to the root-soil interface geometry and functioning that contribute the most to genotypic variation in N and P acquisition under topsoil drought conditions.
- Evaluate the plasticity of root responses in presence of heterogeneous distributions of nutrients (N and/or P) and water (topsoil drying) in the soil, and determine their effect on plant performance.
- Determine the role of soil biota (with particular focus on mycorrhizal fungi) in root acquisition of N and P undersuch heterogeneous conditions of nutrients and water.
The variation in root traits present in genotypes of a single species, both a crop and a model, maize will be used to determine which of these traits are important for optimum nutrient and water acquisition from heterogeneous soils. We will do this by:
- Comparing genotypes differing in lateral root density, rooting depth, root elongation rate, root:shoot ratio, andother morphological/physiological properties, in how they perform in conditions of high/low soil P or N, combinedwith drought, in plants grown either in soil containers/rhizotrons or in field experiments;
- Exploring the role of mycorrhizal fungi and other soil biota in (N and) P acquisition under such conditions;
- Determining changes in nutrient acquisition/plant development when the genotypes described above are exposed to homogeneous vs. topsoil high nutrient conditions, combined with topsoil drying.
Root responses of soil-grown plants to N or P deficiency, combined with water limitation, will be studied with contrasting genotypes, both by comparing nutrient-rich versus nutrient-poor soil and by comparinghomogeneous vs. heterogeneous soil.
A list of deliverables for this workpackages is available here