Rhizosphere enzyme activities as influenced by age of seedlings, weed management practices and humic acid application under system of rice intensification

Field experiments were conducted during two consecutive kharif seasons of the years 2006 and 2007, to study the rhizosphere enzyme activities under System of Rice Intensification. The results revealed that increased enzyme activities were noticed by transplanting 14 days old seedlings with pre emergence application of pretilachlor at the rate of 0.75 kg a.i. ha⁻¹ + one mechanical weeding at 30 DAT and combined application of humic acid as seedling dip (0.3 per cent humic acid) + foliar spray (0.1 per cent humic acid) twice at 30 and 45 DAT.