Abstract

Flold experiments were conducted on milllsols at Pantnagar to study the officacy of two nitrophosphate grades differing In P solubility vis-a-vis urea + triple super- phosphate (TSP) in rice-wheat sequence. Grain, yield response of rice to both the nitrophosphate grades was similar but its magnitude was less than the reponse to uroa TSP. The relative agronomic effectiveness of nitrophosphate decreased with Increasing level of application. Total N and P uptake by rico was also loss in the plots fertilized with either grade of nitrophosphate as compared to urea + TSP plots. The residual effects of nitrophosphates on wheat were however more or less similar to urea TSP when additional N was adequately supplied.

Keywords: Nitrophosphatos, Rice-wheat sequence, Grain yield.