Review of Various Studies of Tillage Practices on Some Soil Physical and Biological Properties

The objective of this paper was to review the various studies of tillage practices effects on some selected soil physical and biological properties from 2000 to 2021 and summarise the findings. The findings of the review indicated that generally, No-tillage (NT) systems have greater benefits than the conventional tillage systems under various soil, environmental, and management conditions. These benefits include using fewer machines, reducing fuel cost, reducing soil loss due to improved aggregate stability, improved soil temperature, and minimal soil erosion due to the protective effect of crop residues left on the soil surface. Furthermore, NT soils possess lower soil bulk density (BD), higher porosity, greater infiltration rate and water retention. Even though some studies reported NT to have higher soil BD and cone index and lower moisture content compared to conventional tillage, however, the studies show no significant crop yield difference after long years of practice. In addition, the presence of the crop residues on the surface leads to higher microbial biomass, which improves the soil through burrowing and creates more soil pores, thereby improving the soil hydraulic conductivity as compared to conventional tillage practices irrespective of the soil type. Conclusively, the NT system improves soil properties in both short- and longterm duration under various soil types as compared to conventional tillage. NT is therefore recommended for soil and water conservation purposes which would lead to higher crop yield.