Effect of varieties, fertilizers and agrochemicals on nutrient uptake of mustard, Brassica juncea and soil nutrient balance

A field experiment was carried out during the winter season of 2004–05 and 2005–06 at Udaipur, Rajasthan on clay loam soil to study the effect of 4 balanced fertilizations (60 kg N + 40 kg P₂O₅ + 40 kg K₂O (NPK), NPK + 40 kg S/ha (NPKS), NPK + 5 kg Zn/ha (NPKZn and NPKSZn) and 3 agrochemicals (water, brassinosteroid 0.4 ppm and thiourea 1000 ppm foliar sprayed at branching and flowering) on 2 mustard, Brassica juncea (L) Czern and Coss varieties (Bio-902 and Vasundhra). Amongst varieties variety Bio-902 accumulated significantly higher N, P, K, S and Zn in seed stover and total compared to Vasundhra. The addition of S, Zn and S + Zn with NPK significantly improved content and uptake of these nutrients over application of NPK alone. The highest values of N, P, K, S and Zn uptake in seed and stover thereby of total by mustard were recorded with the conjoint application of NPKSZn which was significantly higher over NPK, NPKZn and NPKS. The magnitude of increase in total uptake of N, P, K, S and Zn due to NPKSZn application was to the tune of 42.4, 51.2, 40.6, 52.1 and 72.1 per cent respectively over NPK. The foliar spray of brassinosteroid recorded significantly higher nutrient uptake of N, P, K, S and Zn in seed, stover and total in mustard over water and thiourea spray. The combined application of NPKSZn in balanced amount resulted in higher net gain of nutrients in soil which helped in maintaining soil fertility.