Nitrogen Management in Rabi Sunflower (Helianthus annuus. L) in Relation to Different Tillage Practices Imposed during Kharif

A field experiment was conducted during rabi 2011 at Research farm, Regional Agriculture Research Station (RARS), Bijapur on a deep black soil under rainfed condition to study the effect of different tillage practices imposed during kharif and different nitrogen sources on rabi sunflower growth and yield. Tillage practices had no significant effect on growth and yield of sunflower crop. Yield components like number of seeds per head (1068.6) and seed weight per head (55.1 g) were significantly higher with the minimum tillage while tillage practices did not show significant influence on seed yield and stalk yield. Sunflower fertilized with 100% recommended dose of fertilizer (RDF) recorded significantly higher germination percentage, plant height, number of leaves, leaf area index, dry matter production than rest of the treatments. Yield attributes viz. head diameter (10.6 cm) and number of seeds per head (1174.8) were significantly higher with 100% RDF (35:50:35 N: P₂O₅: K₂O kg ha ⁻¹) but on par with in- situ sunnhemp green manure incorporation @ 2.5 t ha ⁻¹+ 50% recommended dose of nitrogen through urea and in -situ sunnhemp green manure incorporation @ 5 t ha ⁻¹. Seed yield (1187 kg ha ⁻¹) and stalk yield (2484 kg ha ⁻¹) of sunflower were significantly higher with 100% RDF over farmers’ practice (24:30:0 N:P₂O_5:K₂O kg ha ⁻¹) but was on par with rest of the treatments. Reducing the tillage intensity did not significantly influence yields and substituting 50% nitrogen through organic sources produced yields comparable to that of inorganic source of nitrogen application.