Effect of Long Term Application of Fertilizer and Manure on Establish Relationship between Soil Organic Carbon Fractions with Yield of Maize and Wheat Crops under Maize-Wheat Sequence in Heplustepts

A field study entitled “Effect of long term application of fertilizer and manure on Establish Relationship Between soil Organic Carbon Fractions with yield of maize and wheat crops under maize-wheat sequence in Heplustepts” was conducted during Kharif 2013-14 and 2014-15 in the Long Term Fertilizer Experiments initiated in Kharif, 1997 at the Instructional Farm of the Rajasthan College of Agriculture, Udaipur. The soil of the experimental site was sandy clay loam in texture, slightly alkaline in reaction, medium in available nitrogen and phosphorus, while high in potassium and zinc. The treatment consisted of control, 100 % N, 100 % NP, 100 % NPK, 100 % NPK + Zn, 100 % NPK + S, 100 % NPK + Zn + S, 150 % NPK, 100 % NPK + Azotobacter, FYM 10 t ha-1 + 100 % NPK (-NPK of FYM), 100 % NPK + FYM 10 t ha-1 and FYM 20 t ha-1. The application of farm yard manure also increased the passive and active soil organic carbon like humin, humic acid, fulvic acid, soil microbial carbon, water soluble carbon, water soluble carbohydrate and carbon mineralization. The significant positive correlation was found of organic carbon fraction with yield of maize and wheat crops. The regression of maize grain and stover yield, wheat grain and straw yield with its forms explains the variation in forms up to 92%, 99%, 99% and 98%, respectively.