Effect of protracted fertilization and manuring on changeable pools of soil organic matter in four different soil types with wheat-based cropping systems of India

Abstract

Long term effect of manuring and fertilization on the SOM fractions e.g. hot water extractable C (HWEOM-C) and hot water extractable N (HWEOM-N) pool of SOC were studied in four major soil groups of India. The soil samples were collected in the year 2015 to a depth of 0–15 cm and 15-30 cm from the fields of All India Coordinated Project (AICRP) on Integrated Farming System continuing since 1983. The treatments comprised of control, 100%NPK, 50%NPK+50%N–FYM, 50%NPK+50%N–CR and 50%NPK+50%N–GM and green manuring crops like Sesbania (Sesbania aculeate L. in Ludhiana), Green gram (Vigna radiata L. in Pantnagar), Sunhemp (Crotalaria juncea L. in Jabalpur), Karanj (Pongamia pinnata L. in Ranchi). The results indicated that Hot water extractable carbon (HWEOM-C I, II) was highest in 50%NPK+50%N-FYM in both the soil depths for Pantnagar (Mollisol), Jabalpur (Vertisol) and Ranchi (Alfisol) but in Ludhiana (Inceptisol), HWEOM-C I was highest in 50%NPK+50%N-FYM and HWEOM-C II in 50%NPK+50%N-GM in both the soil depths. Hot water extractable nitrogen (HWEOM-N) was highest in 50%NPK+50%N-GM for all soil orders in both the soil depths.