Abstract
A greenhouse experiment was conducted lo elucidate the influence of Nand P fertilisation on various soil K fractions andto investigate yield and plant uptake of K in rice. Application of 100 kg N ha-1 significantly (P < 0.05) increased number of tillers, plant height, straw yield and grain yield. Without P, application of 200 kg N ha! significantly (P<0.05) depressed plant height, straw yield and grain yield and increased sterility. Maximum grain and straw yield and plant height was noted for 100 and 50 kg ha! Nand P, respectively. Potassium concentration in plants decreased by 40% at higher levels of 200 kg N ha-I and 100 kg P ha-I. Following N and P fertilisation, initial level of 17 mg kg-I soluble and 67 mg kg-I slowly available K decreased to 8 to 11 and 28 to 52 mg kg-I, respectively. Post-harvest exchangeable K in soil ranged from 38 to 42 mg kg-I.
