Alternative tillage and crop residue management in wheat after rice in sandy loam soils of Indo-Gangetic plains

A 3-year field study was conducted to evaluate the effect of three tillage practices (conventional, zero and reduced/strip) with two nitrogen levels (120 and 150 kg N ha(-1)) applied in primary strips and three crop residue management practices (removal, burning and incorporation) in secondary strips in wheat after rice. Reduced tillage resulted in significantly higher overall mean wheat yield (5.10 Mg ha(-1)) compared to conventional (4.60 Mg ha(-1)) and zero tillage (4.75 Mg ha(-1)). Residue incorporation resulted in highest mean yield (5.86 Mg ha(-1)) during third year. Maximum mean yield (6.1 Mg ha(-1)) was obtained in reduced tillage followed by conventional tillage (5.8 Mg ha(-1)) under residue incorporation in third year. The weed dry weight recorded at 30 days after sowing was highest (0.3 Mg ha(-1)) under zero tillage and lowest under conventional tillage (0.16 Mg ha(-1)). Among crop residue management practices, the highest dry weight of weeds (0.22 Mg ha(-1)) was recorded under residue incorporation. The highest infiltration rate (1.50 cm h(-1)) was recorded in residue incorporation followed by residue burning (1.44 cm h(-1)) whereas; the lowest (0.75 cm h(-1)) in zero tillage. Soil bulk density was the highest (1.69 Mg m(-3)) under zero tillage and the lowest in residue incorporation (1.59 Mg m(-3)). There were no changes in soil available P and K after each crop sequence in relation to tillage practices during first 2 years. Higher organic carbon (5.1-5.4 g kg(-1)) was measured under zero tillage compared to other treatments. Residue incorporation increased soil organic carbon and available P while higher available K was monitored in burning treatment during the third year. These results suggest that reduced tillage and in situ incorporation of crop residues at 5 Mg ha(-1) along with 150 kg N ha(-1) were optimum to achieve higher yield of wheat after rice in sandy loam soils of Indo-Gangetic plains of India. (c) 2005 Elsevier B.V. All rights reserved.