Effect of crop management and weed control systems on the native soil microbial population

The soil quality in a paddy field is the most crucial element for the supply and the production of rice in India. However, the pressure on the paddy field creates a challenge for preventing soil degradation. Soil microflora are most vulnerable to soil pollution, and a decrease or increase of the soil bacteria may reflect the health of soil. In this study, we try to understand the effect of crop management and weed control systems on the native soil bacterial colony. Our study consists of three types of crop management systems, such as zero-tillage, the system of rice intensification (SRI), brown manuring, and three types of weed removal processes, i.e. chemical, integrated and mechanical. In the chemical and integrated treatment, two herbicides were used for weed removal, but in mechanical weeding, a conoweeder was used. The colony forming unit (CFU) of different soil bacteria (nitrogen fixing and phosphate solubilizing) were measured during different stages of the crop growth. It was observed that the mechanical weeding has the least impact for both soil bacteria, but the chemical treatment showed a decrease of PSB count in all three systems. Whereas, the integrated treatment produced a better result in crop management and soil microbial population.