It’s a strange world that still seems to require scientific evidence to show that synthetic fertilizers slowly poison the soil’s health though they may increase farm productivity in the short term.
One large study done by the Indore Agriculture College in 504 villages found 70 per cent soil samples deficient in sulphur and 50 per cent deficient in zinc after use of synthetic fertilizers.
Overuse and erroneous use of synthetic fertilizers caused the deficiency. The major crop in the region, soyabean, needs sulphur but the manner of application of fertilizers did not fulfill this need. As a result, crops absorbed more sulphur from the soil depriving it of the vital nutrient.
Farmers have been using large doses of DAP (Di ammonium Phosphate) before sowing soyabean. DAP supplies only 2 nutrients – nitrogen and phosphorus. So the soil becomes deficient in potash and other nutrients.
Mechanized farming has also led to disappearance of organic farmyard manure which improves soil structure and increases its water holding capacity. This in turn enhances microbial activity and raises nutrient availability.
A complete shift to organic compost is also not advised as it may not contain sufficient quantities of nutrients to meet commercial farming targets. The best solution is to combine organic compost with proper application of synthetic fertilizers with on-soil test results and accompanying recommendations.