Effects of different tillage systems and herbicide on soil microflora of Lablab bean rhizosphere

A long term field study was conducted at the Agronomy Farm, Department of Agronomy, Dr. B.S. KKV, Dapoli (Maharashtra) in Rabi season lablab bean crop to evaluate the effect of different tillage systems visa-vis different weed control measures on the survival and growth of total bacteria, total fungi, total free living nitrogen fixers and total phosphate solubilizers in rhizosphere soil. Four types of tillage systems were evaluated, viz. (i) Conventional-conventional (ii) Conventional-zero (iii) Zero-conventional and (iv) Zero-zero tillage systems. Among weed control measures, comparative effects of hand weeding and recommended herbicides application (oxadiargyl as pre-emergence) were tested along with weedy check. The results of the investigation revealed that tillage systems didnot significantly influence microbial population. The marginal growth of different microorganisms was observed in conventional-conventional tillage system, whereas minimum was in zero-tillage system. There were no adverse effects of herbicide use on all the estimated microbial population at all the stages of the crop. In short use of recommended herbicide oxadiargyl at 0.12 kg/ha had no long term adverse effects on rhizosphere microflora of lablab bean crop.