Nutrient uptake and yield of rice (Oryza sativa L.) as influenced by coal-derived potassium humate and chemical fertilizers

Abstract

Experiment were conducted for two years to investigate the influence of potassium humate and chemical fertilizers on yield and nutrient uptake of rice. Potassium humate was applied at the rate of 0 (PH₀), 5 (PH₅) and 10 (PH₁₀) mg kg^-1 soil along with 75 and 100% recommended dose of nitrogen, phosphorous and potassium (NPK). Two doses of zinc, 0 (Zn₀) and 12.5 (Zn_12.5) mg kg^-1 were also applied in the form of zinc sulphate. The above treatments were arranged in a Factorial Complete Randomized Design (FCRD) with three replications. Two years experimental results showed that sole and combined application of 10 mg kg^-1 potassium humate along with 100% NPK and 12.5 mg kg^-1 zinc sulphate was significantly superior in increasing the yield and nutrient uptake by rice over 75 and 100% of NPK alone.Application of 10 mg kg^-1 potassium humate along with 100% NPK and 12.5 mg kg^-1 zinc sulphate recorded highest N, P, K, S and Zinc uptake by straw and grain of rice. Thus integrated use of humic acid along with chemical fertilizers is beneficial for increasing productivity and soil health.