During the next decades global population will increase to about 9 billion. Most of the additional people will live in the South. To enhance food security, additional food will have to be produced there. Already nowadays about 1.4 billion people live in risk-prone areas in the South, where farming systems as yet have not much benefited from mainstream agricultural technologies. Their agroecosystems are usually located in areas too marginal for intensive agriculture and remote from markets. Food insecurity is often directly related to insufficient food production.
Depletion of soil fertility is a major cause of low food production in these areas. Farmers have limited access to chemical fertilizers because of high prices. Alternative nutrient sources have been sought in local natural resources and improved fallows, using agroforestry, biomass transfer, rock phosphate, and animal manure. So far, results of these investigations are diverse, with both promising and disappointing messages. The alternative sources have a limited availability, are labour and knowledge intensive, and nutrient use efficiency is often low.
Optimising nutrient use efficiency in tropical agroecosystems is key to both securing food production and to protecting the wider environment. Higher nutrient use efficiency is necessary to save scarce natural resources and to minimize nutrient losses. It has been reported that an efficiency gain by a factor 2 to 4 is needed worldwide to avoid large scale eutrophication and ecosystem simplification.
This symposium will provide scientists and policy makers a forum to discuss current insights and research results on optimisation of crop nutrient management in tropical agroecosystems. It is organised on the occasion of the retirement of Bert Janssen, who has spent his whole research career on nutrient management in tropical agroecosystems.
Location: Vakschool Wageningen, Marijkeweg 20, 6709 PG Wageningen