Response of gobhi sarson (Brassica napus subsp. Oleifera var. annua)soybean (Glycine max) sequence to phosphorus and sulphur

Abstract

An experiment was conducted during 1993-94 and 1994-95 to study effect of P levels (0, 30, 60 and 90 kg P,O$ha), and patterns of its application (residual, direct and cumulative) in combination with sulphur (0, 20 and 40 kg St ha) on gobhi sarson [Brassica napus (L.) subsp. oleifera D.C. var. annua L.] and soybean [Glycine max (L.) Merr.] cropping sequence at Ludhiana. Both gobhi sarson as well as soybean responded to direct application of P up to 60 kg P,05/ha. Both the crops grown on residual phosphorus yielded significantly less as compared to direct application of P. Total productivity of gobhi sarsom soybean cropping system was also higher when both the crops were directly fertilized with P @ 60 kg P,O,/ha. Application of P to soybean alone in the system gave higher agronomic efficiency than its application to gobhi sarson. Application of 60 kg P,O$ha to either of the crops gave lower physiological efficiency than application of 30+30 kg P,OJha to both the crops. Both crops responded to sulphur application only up to 20 kglha.