Effects of green manure crops and tillage practice on maize and rice yields and soil properties

Improper tillage with no manure may cause a range of undesirable processes (destruction of soil structure, accelerate erosion, depletion of organic matter and fertility). A field experiment was conducted to observe the change in soil properties after incorporation of green manure crops and to find out the residual effect of green manure crops along with tillage on maize and rice yields during 2010-2011 and 2011-2012 at grey terrace soil (poorly drained, grey and clay loam). Three kinds of tillage practices and four types of green manures were tested in a split-plot design with three replications. Tillage practice was assigned in the main plot and green manure crop in the sub-plot. The test crops were maize and transplanted rice (T. aman rice). Three kinds of tillage practices were: T1 (Minimum tillage), T2 (Tillage depth up to 10-12 cm), and T3 (Tillage depth up to 20-25 cm). Four types of green manures were: G1 (Sesbania aculeata), G2 (Mimosa invisa), G3 (Vigna radiata) and G4 (Control, no green manure crop). The results showed that green manure has significantly increased soil organic matter, soil health and crop growth. The S. aculeata produced more biomass and was superior to other two green manure crops. Soil densities, porosity, texture, field capacity and soil moisture were influenced due to the green manure crops and tillage practices. The lowest bulk density (1.45 g cm) and particle density (2.48 g cm) were found in S. aculeata and deep tillage practice. The highest porosity (41.73%) and field capacity (24.24%) were also observed in S. aculeata and deep tillage practice. The incorporation of S. aculeata and deep tillage practice also showed the highest yield of T. aman and maize. Therefore, application of S. aculeata and deep tillage practice may be recommended as green-manure cultivation strategy in T. aman (O. sativa) and maize (Z. mays) cropping to maintain soil health and sustainable crop production.