Effect of organic and inorganic nutrient sources on growth, yield, nutrient uptake and economics of fodder cowpea [Vigna unguiculata (L.) walp.]

An experiment was conducted to evaluate the varying organic and inorganic nutrient sources on fodder cowpea [Vigna unguiculata (L.) Walp.] in the kharif of 2017 at ICAR-NDRI, Karnal. The result revealed that application of 100% RDF (N, P, K) along with biofertilizers (rhizobium, PSB, potassium and zinc solubilizer bacteria) (T₆) gave significantly (P<0.05) higher in plant height (204.6 cm), primary branches (6.1), root length (24.47 cm), green matter yield (334.5 q ha⁻¹), CGR (8.13 g m⁻² day¹), RGR (4.68 g g⁻¹ day¹), K content (1.45%) in plant, P uptake (23.01 kg ha¹) and K uptake (86.04 kg ha¹) and available Zn status (0.465 ppm) in soil, after harvesting of the crop. However, N content (2.93%) in plant, N uptake (172.51 kg ha⁻¹) and Zn uptake (192.03 g ha⁻¹) was maximum with the application of 66.67% RDF along with biofertilizers consortium (T7). Application of 100% RDF along with PSB (T3) recorded highest number of nodule (33), P content in plant (0.389%) and available P status (24.76 g ha⁻¹) in soil, after harvest. Further studies that, available N status (208.03 kg h¹), K status (221.27 kg ha¹) in soil, after harvest and Zn content (33.31 ppm) in plant were significantly higher with these treatments like T8–15 N, 60 P₂O₅, 40 K₂O kg ha⁻¹ along with rhizobium, T4–100% RDF along with K solubilizer and T₁₁-FYM 5 t ha ⁻¹ with biofertilizers, respectively. In context of the economics of fodder cowpea production, highest gross return (Rs. 53525 ha⁻¹) was obtained from T6 while maximum net return (Rs. 31351 ha⁻¹) and benefit-cost ratio (1.45) were worked out maximum with the treatment T,.

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