Water and potassium fertilization management for irrigated rice cultivation

Irrigation water levels and timing of potassium fertilization is extremely important for the use of lowlands for irrigated rice (Oryza sativa L.) cult ivation in crop rotation. A field experiment was conduced for three consecu tive years in Inceptisol to study the effects of water management (WM1 - co ntinuous flooding and WM2 - intermittent flooding followed continuous flood ing) and mode of potassium fertilizer application (K-1 - at sowing; K-2 - f ractional application and K-3 - fractional application of half levels) on g rain yield and yield components of irrigated rice. Water management present ed expressive effect on rice performance as compared to potassium fertiliza tion. Continuous flooding during whole growing cycle of crop had higher gra in yield as well as higher values of yield components and grain quality. Fr actional potassium fertilization increased its utilization efficiency. Pota ssium fertilizer management affected differently rice crop performance acco rding to forms of water management.