Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu
Continuous cropping and manuring in a typical black soil increased the level of nitrogen and carbon in all the plots during a three-year period. Accumulation of organic C was the highest in the plots fertilized with 100 per cent of the optimum soil test-based dose of NPK plus farmyard manure and it was the least in the unmanured control plots. The same was true for total N. Increase in organic C in soil was due to incorporation of organic matter in the form of farmyard manure or crop residues.
Organic carbon, total N in soil, continuous rotational cropping
