Comparative effect of organic and inorganic nutrient sources on cowpea under grain amaranth (Amaranthus hypochondriacus)–cowpea (Vigna unguiculata) cropping sequence in Inceptisols of western India

The field experiment was conducted for 2 years 2016–17 and 2017–2018 with grain amaranth in rabi and cowpea in summer seasons at College Farm of N. M. College of Agriculture, Navsari Agricultural University, Navsari, Gujarat, to study the effect of integrated nutrient management on grain amaranth- cowpea cropping sequence. There were six treatments, viz. T₁, RDN₁₀₀ CF; T₂, RDN₇₅ CF + RDN₂₅ FYM; T₃, RDN CF + RDN₂₅ BC; T₄, RDN₅₀ CF + RDN₅₀ FYM; T₅, RDN₅₀ CF + RDN₅₀ BC and T₆, RDN₅₀ FYM + RDN₅₀ BC applied to grain amaranth and each plot of rabi grain amaranth was equally divided into four sub plot with four levels of recommended dose of fertilizers, viz. F₁, RDF₀₀ F₂, RDF₅₀ F₃, RDF₇₅ and F₄, RDF₁₀₀ to cowpea. Growth, physiological growth indices, development, yield and quality of cowpea crop was appreciably influenced by direct and residual effect of various combination of organics and chemical fertilizers. Significantly highest plant height, number of branches/plant, plant spread, crop growth rate, net assimilation rate, seed and stover yields as well as protein content and yield were noted under treatment RDN₅₀ FYM + RDN₅₀ BC (T₆). Direct application of RDF levels to cowpea in summer season is concerned and treatment RDF₁₀₀ recorded significantly higher values of all parameters.