Long-term substitution of synthetic fertilizer by cattle manure: Effects on carbon footprint, carbon sequestration, and yield in a double rice system

The greenhouse gas (GHG) flux from rice crops under inorganic or organic fertilization has accumulated considerable interest due to ongoing agricultural intensification. However, impacts of substituting inorganic fertilizer with cattle manure or combining both on net greenhouse gas emissions (NGHGE), carbon footprint (CF), carbon sequestration, soil enzymes and sustainable grain yield in paddy soils are poorly understood. Treatments were CK (no fertilizers), NPK (synthetic fertilizers), M (full substitution of synthetic fertilizers by cattle manure), and NPKM (combined synthetic fertilizers with cattle manure). Results showed that M increased yield by 25.64 % in early rice and 27.24 % in late rice. The enzymatic activity like Acid phosphatase (AP), and β-1, 4-N-acetylglucosaminidase (NAG) increased in NPKM fertilization compared to M treatment. Carbon…