This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends sustainable plant nutrition as a means of increasing food production. It further recommends developing suitable institutional mechanisms for policy formulation to monitor and guide the implementation of integrated plant nutrition programmes through an interactive process involving farmers, research, extension services and other sectors of society.
UN Food and Agriculture Organization's (FAO) Plant Nutrition Programme promotes activities at the farm level for sustainable nutrient management based on the entire cropping cycle. The Programme helps farmers to combine plant nutrient systems, establishing the best association of biological (manure, crop residues), mineral and naturally occurring nutrients to achieve a balanced supply while controlling losses and enhancing labour productivity.
Applying integrated approaches to plant nutrition, which enhance soil productivity through a balanced use of mineral fertilizers combined with organic sources of plant nutrients, is detailed in an FAO document titled 'Guide to efficient plant nutrition management'. As crops are harvested, the nutrients taken up from the soil are removed and if they are not replaced, this leads to £soil nutrient mining', which gradually impoverishes the land. Although the recycling of available organic material (plant and animal residues) is a desirable feature of all farming systems, helping to retain moisture and build soil structure, it is now fully recognized that recycling alone does not provide adequate nutrient value for sustained, productive cropping.