Effect of Integrated Nutrient Management in Sunflower ( Helianthus annuus L.) on Alluvial Soil

Sunflower, an important oil seed crop, needs a balanced nutrition for its optimum growth and thorough maintenance of soil health. A field experiment was conducted to study the impact of integrated use of organic, inorganic and biofertilizers on soil fertility, soil organic carbon fractions, soil microbiological and biochemical parameters as well as yield of sunflower (cv. GK 2002) in alluvial soil at Agricultural Experimental Farm, University of Calcutta, Baruipur, India, during 2013–14 and 2014–15. There were ten different treatments with three replications. After analysis, the data clearly showed significant difference among treatments in sunflower yield and a prominent impact of integrated use of organic, inorganic and biofertilizers was found under the treatments. Microbial biomass carbon, basal soil respiration, activities of soil enzyme and different carbon fractions showed higher values for those treatments where only organic inputs were given. The best possible combination for higher seed yield was recorded in T₁₀/T₆ treatment (vermicompost 2.5 t ha^–1 or FYM (5 t ha^–1) with phosphate solubilizing bacteria @ 8 kg ha^–1 soil application + Azotobacter @ 8 kg ha^–1 soil application + 50% recommended dose of chemical fertilizers + foliar spray (2% urea)). T₁₀/T₆ treatment is thus recommended for sunflower cultivation in alluvial soil considering the soil quality and seed yield of sunflower.