Saprotrophic Fungi, Bacterial Life Cycle and Organic Nutrient Management Practices Variations Impacts Soil Carbon Pools and Fractionations Dependability

Due to soil organic carbon, agricultural soil has the ability to absorb carbon from the atmosphere. Adopted management techniques and cropping systems have an impact on sequestering carbon. Here, we looked into the fundamental physiochemical characteristics of the soil, the components of SOC, and the microbiological characteristics in five cropping systems namely Maize- black gram, Maize- rice, Maize-soybean, Maize-mustard, Maize- buckwheat and Maize- Vegetable pea. The SOC pool was significantly (P < 0.001) enlarged by the cropping system. Changes in the SOC pool and stability were seen in soil microbial communities, and the main causes were the persistence of saprotrophic fungal dominance and the change in bacterial life-history strategy from K- to R-strategy. SOC fractions were increased via modifications to the agricultural system and microbial community dynamics. Active carbon pools (Mg ha(- 1)) in soils in 0-15 cm layers of different cropping system was significantly higher in Maize-soybean (10.27) followed by Maize- Vegetable pea (10.12), Maize- black gram (9.53), Maize- buckwheat (9.30), Maize- rice (8.99) and lowest in Maize -mustard (8.57). The carbon pool index was also higher in Maize-soybean (1.18) followed by Maize- Vegetable pea (1.14), Maize- black gram (1.13), Maize- buckwheat (1.11), Maize- rice (1.08) and lowest in Maize -mustard (1.04). Finally, the carbon management index was higher in Maize-soybean (193.54) followed by Maize- Vegetable pea (184.92), Maize- black gram (178.02), Maize- buckwheat (172.77), Maize- rice (165.99), Maize -mustard (136.48). Among the different cropping system, Maize-soybean had greater amount of total soil organic carbon, carbon pool index, lability index and higher carbon management index and hence, considered the best cropping system to sequester carbon in the Sikkim Himalaya. The second and third position was achieved by Maize- Vegetable pea and Maize- black gram with respect to carbon management index. Thus, the study recommended that in the Indian Himalayan study region, maize-soybean farming be encouraged for effective land resource management planning.