Modelling the effects of soil and water management practices on the water balance and performance of rice

Rice is a major food grain crop of the world. However, its sustainability in major rice growing areas is being threatened by water and energy related constraints. With these constraints in view, a 2 year field study was conducted to assess the effects of soil and water management practices on crop growth and water balance components in rice on sandy loam and silty clay loam soils of a semiarid subtropical environment of north India. Treatments included two irrigation regimes — continuous submergence (I1) and intermittent submergence 2 days after drainage (I2) in main plots, and three puddling intensities — no puddling (P0), two discing+one planking (P2), and four discing+one planking (P4) in subplots. Increase in puddling intensity significantly increased depth of puddle and decreased saturated hydraulic conductivity (Ks) of the puddled layer in both the soils. Increase in puddling intensity from P0 to P2 or P4 significantly increased leaf area index and dry matter production. There was no difference in these parameters in P2 and P4. However, grain yield increased significantly with increase in puddling intensity.