Fertilizers and the environment

Soil fertility decline is occurring over large parts of the world, particularly the developing world. It occurs mainly through intensive cultivation and the inadequate application of replacement nutrients, and through deforestation and clearance of vegetation on sandy soils. Large amounts of soil nutrients are also lost to the terrestrial ecosystems through wind and water erosion. Low soil fertility is considered as one of the most important constraints on improved agricultural production. To sustain the future world population more fertilizers are required, which may become an environmental hazard, unless adequate technical and socio-economic measures are taken. It is estimated that, by the year 2020 at a global level, 70% of plant nutrients will have to come from fertilizers. Fertilizers are thus indispensable for sustained food production, but excessive use of mineral fertilizers has roused environmental concerns. Chief among these concerns are eutrophication of fresh water bodies, global warming and stratospheric ozone depletion, proliferation of algal blooms in coastal waters and contribution towards acid rain.