Phosphorus and Zinc Requirement of Rice under Saline Condition

Abstract

A green house experiment was conducted for two consecutive years to study the phosphorus and zinc requirement of rice, irrigated with saline water. Three levels of water salinity viz. control (S0), 8.0 (S1) and 16.0 (S2) dSm−1 electrical conductivity (EC), three levels of phosphorus 40 (P1), 80 (P2) and 120 (P3) kg ha−1 and four levels of zinc sulphate (ZnSO4) viz. control (Zn0), 25 (Zn1), 50 (Zn2) and 75 (Zn3) kg ha−1 were tested in a factorial completely randomized design. Saline water having EC 16 dSm−1 decreased the plant height, number of tillers plant−1 and grain yield by 18.2, 24.0 and 52.3% during 1st year and 18.73, 22.13 and 51.63%, respectively during 2nd year of experimentation. Phosphorus application @ 80 kg ha−1 increased grain yield to extent of 19.12 and 29.02% during 1st and 2nd years over 40 kg ha−1 dose of phosphorus while ZnSO4 @ 50 kg ha−1 increased grain yield by 46.29 and 43.33% during 1st and 2nd year over control, respectively. On the basis of grain yield, positive interaction indicated that 95.10 kg ha−1 phosphorus and 60.68 kg ha−1 zinc sulphate were found to be optimum doses for getting higher yield of rice under salt stressed condition on sandy loam soils. The N, P, K, Ca, Na and Zn uptake by grain significantly increased up to 50 kg ha−1 ZnSO4 application. The electrical conductivity of saturated extract of soil after experimentation remarkably increased but pH was not affected with water salinity levels. Irrigation with saline water adversely affected the growth and yield of rice and nutrient uptake.