Evaluation of tillage and weed management systems on rhizosphere microflora under rice-wheat cropping system

摘要

A field study was conducted in an Inceptisol with rice-wheat cropping system during 2006 and 2007 to evaluate the effect of different tillage systems vis-à-vis different weed control practices on the population of fungi, total bacteria, actinomycetes, Rhizobium and Azotobacter in rhizosphere soil of rice and wheat. Four types of tillage systems and two methods of weed control practices were evaluated. Among weed control methods hand weeding and recommended herbicidal application (Butachlor as pre emergence and fenoxaprop ethyl + ethoxysulfuron as post emergence in Kharif and pendimethalin as pre emergence and Metsulfuron as post emergence in rabi) were compared. The study revealed that maximum microbial population in crop rhizosphere was found in conventional-conventional tillage system in both the seasons. However, conventional-zero and zero-conventional tillage systems were in second order in Kharif and Rabi season, respectively. Pre-emergence herbicides suppressed the microbial population between 0 and 10 days after sowing of crop, whereas application of post emergence herbicides did not show any significant inhibition in microbial population after their application. Among weed control practices, hand weeding was found most suitable for microbial population enhancement in soil followed by herbicide application. However, weedy check did not support the microbial population in soil in comparison to hand weeding practice.