Soil Organic Carbon and Feeding the Future: Basic Soil Processes

Abstract

Soil organic carbon (SOC) is an essential component of the global carbon (C) cycle, profoundly impacting the sustainability and resilience of agroecosystems under changing climate conditions. Soil functions, such as climate change mitigation and food production, are regulated by different properties of individual SOC pools, which are fractionated depending on their decomposability and stability. This chapter reviews literature and provides empirical evidence on the functions of fractionated SOC pools and their management strategies to mitigate climate change impacts and ensure food security. We briefly cover different SOC pools such as dissolved organic matter, soil microbial biomass, particulate organic matter, and mineral-associated organic matter. These specific SOC pools have distinct characteristics and can be measured using various fractionation methods. We document how different SOC pools affect C sequestration, nutrient supply, water retention, and crop productivity. In the last section, we review current knowledge on how soil management strategies (conservation agriculture, agroforestry, organic amendments, and biochar application) impact SOC, total nitrogen, soil porosity, and crop production compared with conventional practices. Overall, this review enhances our scientific understanding of the roles and management of SOC pools, leading to climate change mitigation and food security.