Effect of sowing window, planting geometry and nutrient-management on yield, nutrient uptake and economics of Indian mustard in Vertisols of south-eastern Rajasthan

A field experiment was conducted during the winter (rabi) seasons of 2017–18, 2018–19 and 2019–20 at Agricultural Research Station, Agricuture University, Kota, India, to find out suitable nutrient-management levels, planting geometry and sowing window for Indian mustard Brassica juncea (L.). The treatments comprised sowing window, viz. 10 October, 20 October and 30 October, in main plots; planting geometry, viz. 30 cm x 10 cm and 45 cm x 10 cm and nutrient-management levels, viz. 100% recommended dose of fertilizer (RDF) N₈₀ + P₄₀ + K₃₀ + S₄₀ + Zn₅ kg/ha), 125% RDF and 150% RDF, in subplots were laid out in split-plot design with 3 replications. Application of 125% RDF N₁₀₀ + P₅₀ + K_37.5 + S₅₀ + Zn_6.25 kg/ha had significance influence on plant height (215.39 cm), dry matter/plant (54.83 g), primary and secondary branches/plant (5.99 and 14.17), siliquae/plant (184.89), seeds/siliqua (15.59), 1,000-seed weight (5.01 g), seed yield (2.67 t/ha), oil content (38.42%) and oil yield (1011.72 kg/ha), protein content (21.10%), net returns (₹87,570/ha) and benefit: cost ratio (3.06), total nutrient uptake by crop NPKS (108.44, 27.39, 164.22 and 14.77 kg/ha, respectively) and available nutrients in soil NPKS (299.0,49.8,467.5 and 10.3 kg/ha, respectively) and zinc (1.36 mg/kg) over 100% RDF and at par with 150% RDF. The crop-sowing period extended from 10 to 30 October were found optimum and had non-significant effect on yield attributes, seed yield and economics, However, significant improvement in dry-matter/plant (58.63 g), primary and secondary branches/plant (6.09 and 14.50), siliquae/plant (202.66), seeds/siliqua (15.64), 1,000-seed weight (5.18 g), seed yield (2.62 t/ha and benefit: cost ratio (3.05), protein content (21.06%), available nutrients in soil and total nutrient uptake by crop were observed at planting geometry of 45 cm x 10 cm over 30 cm x 10 cm. Thus, extent of sowing window from 10 to 30 October, planted at 45 cm x 10 cm crop geometry and fertilized with 125% RDF (N₁₀₀ + P₅₀ +K_37.5 + S₅₀ + Zn_6.25 kg/ha) proved beneficial for obtaining high seed yield and net returns of Indian mustard in Vertisols of south-eastern Rajasthan.