Effect of potassium application on yield and quality of green gram (Vigna radiata L.) on coarse textured soils of southern Haryana

Abstract

Crops need large quantity of potassium for enhancing their yield as well as quality. Pulses are important crops grown in India but their productivity is low. Among production inputs, recommendations for N and P fertilizers are made in most states with no K application resulting in imbalanced nutrient supply and lower crop yields.To quantify optimum dose for green gram ( Vigna radiata L.), a series of field experiments were conducted at Regional Research Station, CCS HAU, Bawal, Haryana, to assess the response of green gram to fertilizer potassium on coarse textured (Typic Haplustepts) soils of southern Haryana. After completion of research trials, crop was tested on farmer’s field through demonstrations and on farm trials (OFTs) to evaluate the response and adoptability of green gram as per the fertilizer potassium doses concluded in research experiment. Five levels of fertilizer potassium (0, 10, 20, 30 and 40 kg K2O ha-1) were evaluated for the response of green gram in randomized block design replicated thrice. The results of research trials revealed that the yield, protein content and growth parameters of green gram increased significantly with the application of fertilizer potassium @20 kg K2O ha-1. Significantly higher yield of green gram was recorded (5.87, 16.29, 19.23 and 22.36 %) due to application of 10, 20, 30 and 40 kg K2O ha-1, respectively over control. The total K uptake by green gram increased significantly with the incremental doses of potassium application which helped to prevent the depletion of available soil K and build-up its content in the soil. The mean K use efficiency varied from 38.30 to 54.15 and maximum (54.15 %) was recorded with the application of 20 kg K2O ha-1. The benefit cost ratio was also increased with the application of potassium and reflected in terms of additional returns per rupee (Rs. 10.94, 15.63, 12.17 and 10.72) invested on application of K @ 10, 20, 30 and 40 kg K2O ha-1, respectively. The farmer’s field trial results with 0 and 20 kg K2O ha-1 revealed that application of 20 kg K2O ha-1 increased the yield of green gram by 10.87% over control.