EFFECT OF INCORPORATION OF LEGUME STRAW ON SOIL PROPERTIES AND CROP YIELD IN A MAIZE-WHEAT SEQUENCE

A field experiment was conducted on Samana sandy loam soil (Typic Usto chrept) for six years to evaluate the effect of summer moong straw (SM S) incorporation on crop yield and soil properties. After harvesting p ods, SMS was incorporated seven days before sowing maize in summer moo ng maize - wheat sequence. Five levels of N (0, 50, 75, 100, and 125 k g N ha(-1)) and two levels of N (80 and 120 kg N ha(-1)) were applied to maize and wheat, respectively. Mineral N content was substantially higher in plots with SMS than without SMS during early growth of maize . SMS incorporation increased the N content of 60-day-old maize plants by 20%. Organic C, mineral N, and 0.5 M NaHCO3 extractable P were 27, 12, and 16%, respectively, higher in SMS-amended plots than unamended plots after six years. SMS incorporation increased infiltration rate of 1.4 times and available water by 2 cm in the 180-cm-depth of soil p rofile. It decreased resistance to soil penetration. SMS incorporation resulted in significant increase in grain yield of maize at all level s of N. It decreased the number of barren plants and increased the num ber of cobs plant(-1), grain weight cob(-1), and 1000-grain weight. A residual effect of SMS incorporation on the succeeding wheat crop was also observed for all six years at the 80 kg N ha(-1) level and in the later three years at the 120 kg N ha(-1) level.