Changes in nutrient availability and uptake in transplanted rice under shallow and deep submergence

Abstract

Field experiments were conducted to study the changes in electro-chemical properties and nutrient availability in soil and soil solution in transplanted rice during kharif and rabi season under deep (20 cm) and shallow (10 cm) submergence, respectively. The pH of soil and soil solution increased up to 30 days after transplanting (DAT), then decreased and again increased slightly at 50% flowering stage. Redox potential of soil decreased rapidly during kharif season while during rabi season, the values increased up to 30 DAT and thereafter stable values were recorded. Concentration of nutrients in soil and soil solution decreased with crop growth except in the case of soil P during kharif season and soil solution Ca during both the seasons. Availabilit y of nutrients in soil and soil solution except for P and Mg was more during kharif season, while the nutrient uptake was higher during rabi season. Application of P and K during rabi season was effective in areas where P and K were applied once in two seasons. Significant difference in yield was obtained only during rabi season.