EFFECT OF ORGANIC NUTRIENT MANAGEMENT ON NUTRIENT UPTAKE BY CROP, NUTRIENT DEPLETION BY WEEDS AND ECONOMICS OF RAPESEED

An experiment was carried out at the Instructional-cum Research Farm, Assam Agricultural University during the rabi season of 2018-19 in order to assess the effect of organic nutrient amendments on nutrient uptake by crops, depletion by weeds and the economics.The experiment was laid out in randomized block design (RBD) with eleven different treatments of organic management along with one control plot.Results revealed that the maximum nutrient uptake by crop was observed under the treatment receiving vermicompost 2.5 t/ha + poultry manure 2.5 t/ha + mustard oil cake 1 t/ha (54.450N kg/ha, 12.230 P kg/ha and 24.397K kg/ha) being statistically at par with the treatment of FYM 5 t/ha + poultry manure 2.5 t/ha + mustard oil cake 1 t/ha (52.403N kg/ha, 11.783 P kg/ha and 24.427K kg/ha).Considerably, the highest nutrient depletion by weeds were observed under the control plots (1.213 N kg/ha, 0.740 P kg/ha and 1.113 K kg/ha) over all the treatments.In terms of economics, the treatment vermicompost 2.5 t/ha + poultry manure 2.5 t/ha + mustard oil cake 1 t/ha recorded the highest gross return (Rs.108880/ha) while the net return was maximum under FYM 5 t/ha + poultry manure 2.5 t/ha + mustard oil cake 1 t/ha (Rs.55660/ha), both being closely followed by each other.Contrarily, the highest benefit-cost ratio (B: C) was observed under FYM @10 t/ha (2.600).