• Efficiency;
  • heterogeneity;
  • nitrogen source;
  • nutrient and temperature gradients;
  • root-surface activity


Interest in mineral nutrition during the last 20 years has centred increasingly on its dynamic aspects. This has led to a consideration of temporal variation, both diurnal and seasonal, and of spatial patterns as they affect nutrient supply. The response of plants to such variations are reviewed in the light of distribution and survival. Although all plants require the same small number of mineral elements, there is evidence of fine tuning in relation to soil heterogeneity. This allows a large number of nutritional options which in turn may influence coexistence and change. Selected examples for nitrogen and phosphorus are given and attention drawn to the need for further study, not only of nutrient interactions, of the energy costs of different nutrient pathways and of messenger functions of key nutrients (e.g. N and P linking activities of both root and shoot), but also of activities around the root surface; the micro-environment produced and the involvement of microflora and fauna.