EVALUATION OF PYRITE AND GYPSUM AS A SOURCE OF SULFUR IN INDIAN MUSTARD (BRASSICA-JUNCEA) RICE (ORYZA-SATIVA) CROPPING SEQUENCE

An experiment was conducted during winter (1988-89 and 1989-90) and ra iny seasons (1989-90 and 1990-91) to evaluate pyrite and gypsum as a s ource of sulphur in indian mustard [Brassica juncea (L.) Czernj. & Cos son]-rice (Oryza sativa L.) cropping sequence. The sulphur application @ 40 kg/ha gave significantly higher seed (2.10 tonnes/ha) and oil yi elds (0.80 tonne/ha) of indian mustard. The residual effect of S @ 80 kg/ha to indian mustard reflected in maximum grain yield (3.22 tonnes/ ha) of succeeding rice. The uptake of nutrients (N, P, K, S and Fe) al so increased significantly with increase in S level; maximum being (11 5.30, 17.16, 87.82, 35.48 and 1.16 kg/ha N, P, K, S and Fe respectivel y) under 40 kg S/ha by indian mustard and 80 kg S/ha by the succeeding rice crop. Both the sources of sulphur (gypsum and pyrite) were equal ly effective in increasing the yield and yield components as well as u ptake of nutrients by indian mustard and succeeding rice. However, app lication of pyrite to the preceding indian mustard significantly incre ased the uptake of Fe by succeeding rice compared with that of gypsum.