Influence of Glufosinate Ammonium on Some Soil Properties and Rhizospheric Micro-organisms of Tea Crop (Camellia sinensis L.) in Eastern Himalayan Region of India

The effect of Glufosinate Ammonium 13.5% SL on soil physico-chemical properties and microflora population on tea soil of Darjeeling, West Bengal, India was investigated over two years (2014 and 2015). Effect of herbicides on bulk density, water holding capacity, moisture content, soil pH, organic matter content, electrical conductivity, as well as total nitrogen, available phosphorus and available potassium contents were analyzed along with microflora population of rhizosphere soil (total bacteria, actinomycetes and fungi). The experiment was laid out in randomized complete block design with three replications. The treatments comprised of POE application of Glufosinate Ammonium 13.5% SL at 300, 375, 500, 750 g ha-1 along with standard check Basta (Glufosinate Ammonium 13.5% SL) at 375, 500 g ha-1, hand weeding (at 25 and 45 DAA ) beside untreated control plot. Result revealed that, no significant changes in soil physico-chemical properties were observed due to application of tested herbicides. Herbicidal treatments recorded a decreasing trend on soil microbial counts immediately after application up to 20 DAA. Then the microflora population increased gradually after completion persistency period of Glufosinate Ammonium. Overall there was no long term adverse effect of Glufosinate Ammonium 13.5% SL on the microbial population in Rhizosphere soil of Tea crop.