Nutrient management in summer cowpea (Vigna unguiculata (L.) Walp.) through natural farming practices

Abstract

A field experiment entitled “Nutrient management in summer cowpea (Vigna unguiculata (L.) Walp.) through natural farming practices” was conducted during the summer 2022 at the College of Agriculture, Vijayapura, Karnataka on medium deep black soil of the Northern Dry Zone of Karnataka. The experiment was laid out in a Complete Randomized Block Design (RCBD) with three replications and thirteen treatments, including ghanajeevamrutha and jeevamrutha concentrations. The results revealed that soil application of ghanajeevamrutha @ 2000 kg ha-1 combined with a foliar application of jeevamrutha @ 20% during the flowering and pod development stages, significantly enhanced seed yield (1625 kg ha-1), haulm yield (3432 kg ha-1), and other yield attributes such as the number of pods per plant (24.93) and length of the pod (18.07 cm) compared to other treatments. This treatment also significantly improved nutrient uptake, with values of 134.12 kg N ha-1,18.79 kg P2O5ha-1 and 73.42 kg K2O ha-1 and increased soil enzyme activities such as dehydrogenase (5.87 μg TPF g-1 soil day-1) and urease (16.95 μg NH4 -N g-1 soil hr-1) at flower initiation stage. Economically, this treatment combination provided significantly higher gross returns (`81,266 ha-1) and net returns (`56,366 ha-1), which was ghanajeevamrutha jeevamrutha followed by application of 5 t FYM along with 25 kg N,50 kg P2O5 , 25 kg K2O, 20 kg S and 25 kg ZnSO4ha-1,which resulted ingross returns of `76,400 ha-1 and net returns of `49,290 ha-1. It concludes, the soil application of ghanajeevamrutha @ 2000 kg ha-1along with a foliar application of jeevamrutha @ 20% concentration offers an effective and sustainable approach to enhance cowpea yields, soil fertility and improve overall economic returns of farmers.