The International Plant Nutrition Colloquium in Hannover was the 14th in a series that started in 1954. This volume is a compilation of the plenary lectures presented at this Colloquium. These papers include two lectures which address the role of plant nutrition in the sustainability of agro-ecosystems and the production of enough high quality food to feed the growing world population. Advances in plant nutrition are reviewed in the 11 papers presented in each of the symposia including: genetics and molecular biology of plant nutrition; nutrient functions; the role of the apoplast in mineral nutrition; plant quality and plant health; salinity and plant-soil-water relations; mineral element toxicity and resistance nutrient acquisition; soil organisms/plant interactions; fertiliser use in relation to optimum yield and environment, nutrient dynamics in natural and agro-ecosystems, and plant nutrition and sustainable development.