Changes in physico-chemical and biological properties of soil under conservation agriculture based pearl millet – mustard cropping system in rainfed semi-arid region

Poor soil health and low soil water content during crop growing period are major factor for low productivity of pearl millet - mustard rotation under rainfed semi-arid regions. The authors evaluated five different tillage and residue management practices for improving physico-chemical and biological properties of soil. Results showed that conservation agriculture (CA) practice (zero tillage (ZT) with 4 t ha(-1) residue retention) exhibited higher proportion of soil macro-aggregate. It also increased infiltration rate of about 15.2% over conventional tillage without residue but ZT increased soil penetration resistance in surface soil layer. In the residue applied plots, similar to 2-4% (w/w) higher soil water content was maintained throughout the season than the no-residue plots. CA practice had the highest soil organic carbon (4.96 g kg(-1)) and microbial biomass carbon (188.3 mu g g(-1) soil). Significant and positive correlation was also found between soil organic carbon with infiltration rate (r = 0.73**), mean weight diameter (r = 0.80**) and microbial biomass carbon (r = 0.86**). Thus, this study suggests that ZT with residue retention can be advocated in pearl millet - mustard rotations for improving, productivity, soil health and maintaining higher soil water content in rainfed semi-arid regions.