Long term influence of organic and inorganic fertilizer on some chemical properties of calciorthents under rice-wheat cropping system

Abstract

To study the effect of long term fertilizer on pH, electrical conductivity, cation exchange capacity, free calcium carbonate, total-N, P, K and S in calcareous soil. A long term field experiment was conducted during rabi 1988-89 at RAU, Pusa farm in split plot design with NPK levels in main plot and organic sources in sub-plot treatment under rice-wheat cropping system. After increasing doses of fertilizers and with the incorporation of compost and crop residue. Electrical conductivity increased with increase in NPK levels and decreased with the incorporation of organic sources. Cation exchange capacity of soil increased significantly with application of NPK fertilizer as well as incorporation of organic sources whereas compost and crop residue either alone or in combination with different levels of NPK fertilizer decreased the amount of free CaCO3 of the soil. There was a buildup of total N, P K and S with conjoint use of chemical; fertilizers with compost and crop residue in soil.