Nutrient content, uptake and oil content of rapeseed as influenced by reduced tillage, mulching and INM practices

Abstract

A field study was carried out to evaluate the effect of reduced tillage, mulching and INM practices on nutrient content, nutrient uptake and oil content of rapeseed under rainfed condition at Assam Agricultural University, Jorhat, Assam during the rabi seasons of 2016-17 and 2017-18. The experiment was laid out in a split-plot design with three replications. The main-plot treatments comprised of two tillage practices (P1: conventional tillage and P2: reduced tillage) and two mulching practices (M1: No mulching and M2: mulching with paddy straw) and the sub-plot treatments comprised of four nutrient management practices viz., N1:100% RDF (Recommended Dose of Fertilizer), N2: 50 % RDN (Recommended Dose of Nitrogen) through chemical fertilizer + 50% N through FYM, N3: 50% RDN through chemical fertilizer + 50% N through Vermicompost and N4: 50% RDN through chemical fertilizer + 50% N through Enriched Compost. The treatment receiving 50 per cent recommended dose of nitrogen through chemical fertilizer and rest 50 per cent through FYM (N2) recorded significantly highest N, P and K contents in seed and stover. Reduced tillage (P2) brought an average of 7.4%, 8.0% and 7.8% higher uptake of N, P and K, respectively over conventional tillage (P1). Similarly, mulching (M2) brought 12.0%, 12.9% and 11.8% higher N, P and K uptake, respectively and significantly higher seed oil content over no-mulching (M1). Integrated use of 50 per cent recommended dose of nitrogen through chemical fertilizer and rest 50 per cent through FYM (N2) resulted an average of 18.4%, 18.5% and 16.5% higher N, P and K uptake, respectively and significantly higher seed oil content over 100% RDF (N1).