Effect of nitrogen and sulphur levels on mustard (Brassica juncea L.) yield and post-harvest soil fertility

Abstract:

Indian mustard (Brassica juncea L.) is an important rabi oilseed crop whose productivity is strongly affected by balanced nitrogen (N) and sulphur (S) nutrition. A field experiment was conducted during rabi 2025–26 at the AICRP Mustard Research Farm, College of Agriculture, Nagpur, Maharashtra, on black cotton soil to evaluate three nitrogen levels (50, 65 and 80 kg N ha⁻¹) and three sulphur levels (15, 30 and 45 kg S ha⁻¹) in a factorial randomized block design with three replications. Mustard variety TAM-108-1 was grown at 45 × 10 cm spacing. Growth and yield observations included plant height and days to 50% flowering, number and weight of siliquae plant⁻¹, seed yield and stover yield. Post-harvest soil was assessed for pH, electrical conductivity (EC), organic carbon, calcium carbonate, available N, P and K, and DTPA-extractable Fe, Mn, Zn and Cu. Nitrogen increased plant height, siliqua number, siliqua weight and seed yield, while sulphur generally improved these traits. Plant height at 50% flowering reached 137.42 cm with 80 kg N ha⁻¹ and 130.94 cm with 45 kg S ha⁻¹. The highest seed yield among individual N levels was 18.27 q ha⁻¹ at 80 kg N ha⁻¹, while 45 kg S ha⁻¹ produced 18.51 q ha⁻¹. The N × S interaction produced the highest seed yield (18.97 q ha⁻¹) and stover yield (55.28 q ha⁻¹) with 80 kg N + 45 kg S ha⁻¹. Post-harvest pH and EC were not significantly altered. Organic carbon, available N and P and several micronutrients increased with higher nutrient levels. Overall, balanced N and S nutrition improved mustard productivity and maintained a favorable post-harvest soil fertility status.