Chandra Shekhar Azad University of Agriculture and Technology, Kanpur-208002, Uttar Pradesh
Under pot studies, eight important pedogenic groups of soils of Uttar Pradesh exhibited widely varying soil test values for N, P and K determined by different methods. These nutrients were maximum in montmorillonitic rich Mar soils but minimum in gravelly Aravali and Rakar soils.
Almost all the soils moderately responded to N and P applications with the exceptions of Mar and Tarai which gave higher benefits from the former and lower from the latter nutrient. Highest response to K was recorded by Aravali and Rakar soils.
Nitrogen by alkaline permanganate and Prince's methods correlated significantly with yield responses as well as its uptake at the tillering stage. Yield responses and uptake of P at tillering and dough stages gave significant correlations with P extracted by Olsen's method. Potassium evaluated by Morgan's method also showed significant correlations with yield responses and its uptake values at the tillering stage.
Soil tests for available N, P and K, uptake, correlation studies, soils of U. P
