Effect of integrated nitrogen management and varieties on seed yield, quality and water saving under aerobic rice (Oryza sativa L.)

A field experiment was undertaken during the Kharif seasons of 2009 and 2010 at ICAR-IARI, New Delhi to evaluate the effect of integrated nitrogen management and varieties on seed yield, its quality and water saving under aerobic rice. The experiment conducted in split plot design including two rice varieties viz. ‘Pusa Basmati 1’ and ‘Pusa Basmati 1121’ and eight integrated nitrogen management (INM) practices viz. N control (N0P60 K40); 100% RDN (recommended dose of N i.e., 120 kg N/ha through urea); 75% RDN+ 25% N through farmyard manure (FYM); 75% RDN+ 25% N through Sesbania green manuring; 75% RDN+ 25% N through Azotobacter biofertilizers; 75% RDN+ 25% N through vermicompost; 100% N through FYM+GM+BF+VC and 100% N through FYM+GM+BF+VC+ ZnSO4. The results showed that rice variety ‘Pusa Basmati 1’ showed higher panicle length, filled grains/panicle, spikelet fertility, grain yield, seed yield, harvest indices and germination percentage as compared to ‘Pusa Basmati 1121’. However, ‘Pusa Basmati 1121’ gave higher effective tillers, 1000 seed weight, straw yield, shoot length, root length, seedling dry weight and vigour index than ‘Pusa Basmati 1’. Application of RDN through INM significantly enhanced the yield attributes, seed quality parameters and grain as well straw yield. Treatment with 100% N by FYM+GM+BF+VC+Zn showed highest yield attributes, seed quality parameters, grain and straw yield as compared to other INM treatments and it was followed by the treatments having 100% N by FYM+GM+BF+VC and 75% RDN+25%VC. Significantly higher amount of water was used in flooded transplanted rice than aerobic rice by both the rice varieties resulting in 59.5 to 63% irrigation water saving in aerobic rice. In flooded transplanted and aerobic rice a total of 1529.2 to 1725.2 mm and 929.2 to 1225.2 mm water was used to produce one kg of rice. Thus there was a total saving of 28.4 to 39.6% water in both the rice varieties under aerobic cultivation.