Sulphur nutrition of crops with and without organic manures under intensive cropping

A field experiment Was conducted during pre-rainy season, rainy season (kharif) and winter season (rabi) of 1989-90 and 1990-91 to evaluate the productivity and fertility building under intensive cropping of rice (Oryzasativa L)-potato (Solanum tuberosum. L)-sesame (Sesamum indicum L). The productivity of rice and potato was maximum where these crops were fertilized 'With 75% (N, P and K@ 45, 10 and 19 kg/ha for rice; 7S, 33 and 62 kg/ha for potato) of the recommended doses of N, P (through single superphosphate) and K (60,13 and 25 kg/ha for rice; 100,44 and 83 kg/ha for potato) it) conjunction with farmyard manure @ 10 tonnes/ha. Sesame grown on residual fertility recorded maximum seed yield (1.4 tonnes/ha) in the treatment receiving 75% of the reoommended fertilizer applied to both rice and potato along with incorporation of crop residues of each crop in the sequence. Exclusion of single superphosphate having 12% S either from potato or from rice reduced the productivity of all the 3 crops. Nutrient uptake was maximum where both rice and potato were fertilized with 100% of the recommended doses of N, P (as single superphosphate) and K Total N. and the available P, K and S status oCthe soil improved when both rice and potato were fertilized with 75% of the recommended fertilizer along with farmyard manure@ 10 tonnes/ha or incorporation of crop residues. Negative· balance of S was recorded under the treatments receiving no single superphosphate, farmyard manure or crop residues. Application.of farmyard manure @ 10 tonnes/ha to both rice and potato in conjunction with 75% (N. P and K @ 45, 10 and 19 kg/ha in rice; 75,33 and 62 kg/ha in potato) of the recommended fertilizer was more remunerative than that of 100%.