Published Paper Details:

A Field experiment was conducted during spring 2009-10 in an Aquic Hapludoll at Norman E Borlaug Crop Research Center of the G.B Pant University of Agriculture and Technology., Pantnagar, as per technical programme of All India Coordinated Research Project on Soil Test Crop Response Correlation. The experiment was conducted in two phases. In the first phase soil fertility gradient was developed by dividing field into three strips and applying graded doses of fertilizers in them, (Strip I: No fertilizer, Strip II: 100, 100 and 100 kg N, P2O5 and K2O/ha and strip III: 200, 200 and 200 kg N, P2O5 and K2O/ha and growing of exhaust crop oat (var Kent). In the second phase i.e. test crop Cowpea (var Pant lobia-1) was grown by dividing each strip in 24 plots having 23 fertilizer treatments and one control plot. Response of selected combinations of three levels of farmyard manure, four levels of nitrogen, four levels of phosphorus and four levels of potassium at different levels of cowpea was studied. The values of the organic carbon, alkaline KMnO4 extractable nitrogen, Olsen�s phosphorus and neutral normal ammonium acetate extractable potassium in the experiment field ranged between 0.72-1.16 per cent, 112.30-200.60 kg/ha, 13.00-24.24 kg/ha and 101.90-245.30 kg/ha, respectively. In the present investigation the total straw yield ranged from 13.07-24.94 q/ha and total grain yield ranged from 9.00-18.20 q/ha. The nutrient requirement for production of one quintal of cowpea grain was found to be 5.71 kg of nitrogen, 0.90 kg of phosphorus and 3.72 kg of potassium. Per cent contribution of nitrogen, phosphorus and potassium was 62.00, 59.00 and 32.00, from soil, whereas from other sources as FYM was 7.00, 29.00, 10.00; chemical fertilizer 30.00, 14.00 and 30.00 and conjoint use of chemical fertilizer with FYM was 30.00, 17.00, 27.00 in terms of NPK respectively. With the help of these data fertilizer recommendation at different yield targets and soil test value can be calculated. Coefficient of quadratic multiple regression (R2) was found highly significant (0.898**) between grain yield, soil test values, added fertilizers and FYM. Organic carbon, alkaline KMnO4-N, Olsen�s P and AB-DTPA P and Ammonium acetate K and AB DTPA K methods of available N, P and K, respectively were at par for the cow pea grown in Mollisol of Uttarakhand. Findings from present study can successfully be utilized for the larger parts of Tarai region of Uttarakhand as effective guide for efficient and balanced fertilizer recommendations.