Soil organic matter (SOM) dynamics, encompassing the processes of accumulation, decomposition and transformation of organic materials in the soil, play a crucial role in soil health, nutrient cycling and overall ecosystem sustainability. The depletion of SOM, often resulting from intensive agricultural practices and land degradation, poses significant challenges to soil fertility, productivity and the environment. In contrast, the enhancement and maintenance of SOM stocks contribute to improved soil structure, water holding capacity, nutrient availability and carbon sequestration. Therefore, studying SOM dynamics is vital for developing strategies that mitigate soil degradation, optimize crop production and mitigate climate change impacts.
Farming approaches prioritizing the enhancement and maintenance of SOM are the cornerstone to sustainable agriculture. For example, organic farming principles, such as the avoidance of synthetic fertilizers and pesticides, the promotion of biodiversity and the use of organic amendments, contribute to the accumulation of SOM and its beneficial effects on soil and environment quality. As organic matter is continuously added to the soil through practices such as crop residues incorporation, cover cropping, crop rotation, and the use of organic fertilizers, organic farming systems can effectively increase SOM stocks. Moreover, understanding the implications of SOM dynamics in sustainable farming approaches extends beyond individual farm boundaries. Sustainable agriculture practices that promote SOM enrichment can contribute to mitigating climate change by sequestering atmospheric carbon dioxide and reducing greenhouse gas emissions associated with synthetic inputs. Additionally, sustainable farming systems can improve soil resilience, water infiltration and nutrient cycling, thereby reducing environmental pollution and enhancing overall ecosystem health.
This chapter sheds light on the mechanisms driving SOM dynamics and emphasizes the importance of sustainable
soil management practices. It provides an overview of the approaches and methods used to monitor the changes of SOM, including identifying relevant processes describing and estimating its decomposition, lability and humification for sustainable management. By improving our understanding of these dynamics, we can develop strategies that promote soil health, enhance agricultural productivity, and contribute to long-term environmental sustainability.
