Soil test crop response based gradient experiment of rice (Oryza sativa L.) with NPK fertilizers in alluvial soil of Varanasi

Abstract

Soil Test Crop Response (STCR) studies are very useful for balanced fertilizer recommendation in farmers’ field. But before conducing STCR experiment, a gradient experiment is requisite. For that a gradient experiment was conducted in a farmer’s field at Varanasi during kharif 2017. The experiment was conducted in three strips (I, II and III) in which three varying doses of NPK fertilizers were applied [low (0, 0, 0), medium (120, 60, 60) and high (240, 120, 120) kg ha-1 of N, P2O5 and K2O], respectively. Rice (var. HUR105) was grown as exhaust crop. After harvest, grain and straw yields of rice were recorded and plant samples were collected and analyzed for NPK uptake determination. We noticed significant difference on NPK uptake, grain and straw yields, and post-harvest soil test values of rice crop which was the reflection of graded levels of NPK fertilizer application. Fertility gradient was created and the field was ready for further advancement of STCR experiment for fertilizer recommendation.