Use of phosphate rocks for sustainable agriculture
Extensive research on the agronomic potential and actual effectiveness of phosphate rocks (PRs) as sources of phosphorus has been carried out in Africa, Asia, Latin America and elsewhere. A wealth of information is available, but it is scattered among meeting proceedings, technical reports and scientific and other publications. This bulletin gives comprehensive coverage of the key topics regarding the utilization of PRs in agriculture, including the latest information on PR research, and provides guidelines for the direct application of PR (DAPR) to the acid soils of the tropics and subtropics. The selected topics include: world PR deposits; characterization of PR sources; evaluation methodologies of PR sources for direct application; analysis of the biophysical and farming factors that affect the agronomic effectiveness of PR sources, together with an analysis of the socio-economic factors that influence the use and adoption of PR technologies as a capital investment to trigger agricultural intensification; development and use of decision-support systems for DAPR; soil P testing for PR application; available technologies for enhancing the agronomic effectiveness of indigenous PR sources; environmental issues; legislation guidelines; and future research areas and priorities.