WP2 Root-soil interactions affecting N and P

The objectives of WP2 are to:

  1. 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.
  2. 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.
  3. 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.

Maize root heavily infected with mycorrhiza

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