Yield and nutrient uptake of rainfed sunflower as influenced by humic acid under nutrient management practices in Alfisols

Abstract

A field experiment on rainfed sunflower was conducted during kharif 2014 at College agriculture farm, College of Agriculture, Rajendranagar, Hyderabad to study the effect of humic acid under nutrient management practices on dry matter accumulation, yield attributes, yield and nutrient uptake of rainfed sunflower. The experiment was laid out in Split plot design with eigthteen treatments (Six main and three sub-treatments and replicated thrice). The six main treatments consisted of M1-Absolute control, M2 - compost @ 2.5t/ha, M3-Compost @ 5t/ha, M4- RDF alone (60-60-30 kg N, P2O5,K2O/ha), M5- RDF+ compost @ 2.5t/ha and M6- RDF+compost @ 5t/ha and three sub-plot treatments consisted of application of varying levels of humic acid granules (basal) viz., S1 - 5.0kg/ha, S2- 10.0 kg/ha and S3- 15.0kg/ha. The results revealed that among all the nutrient management practices maximum dry matter accumulation, seed, oil yield (1859 and 741kg/ha) and nutrient uptake (N, P and K) at all the crop growth stages were recorded with the combined application of RDF (60-60-30 N, P2O5, K2O kg/ha) + Compost @ 5t/ha and the lowest growth parameters, yield attributes and yield were observed under absolute control. The effect of varying levels of humic acid was found to be significant only on dry matter accumulation at harvest and nitrogen uptake at 60DAS. The interaction effect was found to be non-significant