Effect of various cow-based bio-enhancers and botanicals on soil fertility after harvest, nutrient content and uptake by organic cowpea (Vigna unguiculata L.)

Abstract

An experiment was conducted on medium black calcareous clayey soil to evaluate some cow-based bio-enhancers and botanicals for organic cultivation of cowpea (var. GC-6) during summer-2019 at Junagadh Agricultural University, Junagadh. The experiment comprising randomized block design with twelve treatments and three replications. The results revealed that next to 100% RDF, application of FYM @ 4 t/ha + Biofertilizers (Rhizobium @ 30 ml/kg seed + PSB @ 3 L/ha + KSB @ 3 L/ha) and Panchagavya as foliar spray @ 3% at 30 and 45 DAS + FYM @ 2 t/ha found significantly higher in terms of P content in seed, NPK content in stover and NPK uptake by organic cowpea. Whereas, the content of N and K in seed were significantly higher under FYM @ 4 t/ha + Biofertilizers (Rhizobium @ 30 ml/kg seed + PSB @ 3 L/ha + KSB @ 3 L/ha), followed by RDF through chemical fertilizers, Panchagavya as foliar spray @ 3% at 30 and 45 DAS + FYM 2 t/ha and Jeevamrut @ 500 L/ha with irrigation at sowing, 30 and 45 DAS + FYM 2 t/ha. While higher organic carbon and available NPK after harvest of the cowpea were recorded under the treatment of FYM @ 4 t/ha + Biofertilizers (Rhizobium @ 30 ml/kg seed + PSB @ 3 L/ha + KSB @ 3 L/ha), followed by FYM @ 4 t/ha and Jeevamrut @ 500 L/ha with irrigation at sowing, 30 and 45 DAS + FYM 2 t/ha.