Management options for judicious use of phosphatic fertilizers in a rice (Oryza sativa)-based cropping system

Abstract

A field experiment comprising rice (Oryza sativa L.)-rapeseed [Brassica campestris (L.) var brown sarson] crop rotation was conducted during 1990 to 1995 with 3 P20, levels and 6 phases of its application at Shalimar. Application of phosphorus recorded significant increase in grain yields with increase in P205 levels from 30 to 90 kg ha, the effect being more pronounced in rice than rapeseed. Phosphorus applied @ 60 kglha every year to both crops proved superior to other phases (frequencies) of application which was also reflected in rice yield equivalent (RYE). Kharif applied P,05 (to rice) registered maximum overall RYES as compared to rabiapplied P,O, (to rapeseed). Higher P rates and its repeated application every year resulted in higher P build up in soil. Though long term application every year resulted in higher P build up in soil.