Minimum tillage:
Minimum tillage is aimed at redducing tillage to the minimum necessary for ensuring a good seed bed, rapid germination, a satisfactory stand and favourable growing conditions. Minimum tillage has certain advantages: improved soil conditions due to decomposition of plant residues in situ, higher infiltration caused by the vegetation present on the soil and channels for med by the decomposition of dead roots, less resistance to root growth due to Improved structure, less soil compaction by reduced movement of heavy tillage vehicles and less soil erosion compared to conventional tillage. However, these advantages are evident on coarse and medium –textured soils and appear after two to three years of practicing minimum tillage. In minimum tillage, more nitrogen has to be added as rate of decomposition of organic matter is slow. Sowing/planting operations are difficult with ordinary equipment. Further, continuous use of herbicides cause pollution problems and dominance of perennial problematic weeds. Three to four times greater wind erosion with tractorization of tillage than with the traditional country plough (Venkateswarlu, 1994). In contrast, conservationtillage favoured organic carbon enrichment of soils (also known as carbon sequestration) (Lal, 1999).