Response of rainfed black gram to phosphorus and potassium nutrition with composted coirpith

Abstract

To study the effect of phosphorus and potassium levels along with composed coirpith (CCP) on growth, yield and uptake of rainfed black gram, field experiments were conducted in TNAU farm during rabi season of 2001 with the following treatment combinations T, = 12.5:25:0 NPK Kg ha-1; T, = 12.5:25:12.5 NPK Kg ha-1; T, = 12.5:25:25 NPK Kg ha-1; T, = 12.5:25:25 NPK kg ha-1+ Composted Coir Pith (CCP) @ 12.5 t ha-1; T, = 0:25:0 NPK kg ha-1+ CCP 12.5 t ha-1. Organic nitrogen, KMnO,- N and Olsen's phosphorus content in the post harvest soil samples were more in 12.5:25:25 NPK + CCP @ 12.5 t ha-1 treated plots whereas NH,OAc extractable potassium content was more in 12.5:25:12.5 NPK treated plots. Phosphorus and potassium application along with CCP did not show any significant effect on root and shoot length, but their application showed significant effect on yield attributing characters like number of pods, number of grains / pod, filled grain and 100 seed weight. Application of 25 kg ha potassium and 12.5 t ha-1 CCP along with normal recommended dose of nitrogen and phosphorus recorded maximum nutrient uptake in black gram grains.