Response of seed yield, nutrient uptake and nitrogen use efficiency to different sources of vermicompost and inorganic fertilizer in sunflower ( Helianthus annuus L.) cultivation

Abstract

Field experiment was carried out at the Annamalai University, Experimental Farm, Department of Agronomy, Annamalai Nagar, Tamil Nadu to study the response of seed yield, nutrient uptake and nitrogen use efficiency to different sources of vermicompost and inorganic fertilizer in sunflower cultivation during February – May 2013. The experiment was laid out in randomized block design (RBD) with eleven treatments includes control, recommended dose of fertilizer, graded dose of fertilizer along with different sources of vermicompost + foliar application of boron and zinc on different dates (20 and 40 DAS). The treatments were replicated thrice. The results revealed that crop raised with pressmud vermicompost registered higher seed, stalk yield and harvest index. The vermicompost treatments had significant influence on the nutrient uptake, nitrogen use efficiency (NUE), Agronomic Efficiency (AE), Apparent nitrogen recovery (ANR), Physiological efficiency (PE) and Internal efficiency (IE) over control and recommended dose of fertilizer by the crop at harvest. Among the treatments, pressmud vermicompost@ 2.5 t ha-1 along with 75% RDF (recommended dose of fertilizer) + foliar spray of ZnSO4 @ 0.5 % + Borax @ 0.2% on 40 and 60 DAS to sunflower hybrid registered the higher NPK uptake, nitrogen use efficiency ( NUE), Agronomic Efficiency (AE), Apparent nitrogen recovery (ANR), Physiological efficiency (PE) and Internal efficiency (IE) values at harvest. From the above experimental results, it could be concluded that with application of pressmud vermicompost @ 2.5 t ha-1 along with 75% RDF + foliar spray of ZnSO4 @ 0.5 % + Borax @ 0.2% on 40 and 60 DAS not only resulted in higher seed yield but also superior in respect of nutrient uptake and nitrogen economy under sunflower cultivation.