STUDIES ON THE WATER USE EFFICIENCY AND NUTRIENT UPTAKE BY RICE UNDER SYSTEM OF INTENSIFICATION

Abstract

All the growth and developmental parameters viz. plant height, leaf area index, crop growth rate (CGR), panicle m^-2, grain weight per panicle, grain and straw yield, NPK content in grain and straw as well as nutrient uptake were better influenced by 2.5 cm irrigation 0 days after disappearance of ponded water (DAD) over 6 DAD but were at par with 3 DAD. The test weight was not influenced by irrigation levels. Water-use efficiency (WUE) was favourably influenced by 2.5 cm irrigation 3 DAD over 0 DAD but was at par with 6 DAD. Final soil fertility status (N, P₂O₅ and K₂O ha^-1) decreased with increasing levels of irrigation. All the growth and development parameters, grain and straw yield, WUE, NPK content in grain and straw, nutrient uptake , were favourably influenced by  10 t FYM ha^-1 +  120 kg N, 60 kg P₂O₅  and 40 kg K₂O ha^-1 (F₂) over all the nutrient levels. Both the gross and net return were significantly higher at 0 DAD over 6 DAD but were at par with 3 DAD while, F₂ was significantly higher over all the nutrient levels. The highest return per rupee of investment was recorded at 2.5 cm irrigation 3 DAD while, it was significantly higher at F₁ (120 kg N, 60 kg P₂O₅ and 40 kg K₂O ha^-1) over all the nutrient levels but was at par with F₂ level.