Soil Organic Matter Dynamics
Maintaining and increasing the organic matter content of our soils is essential for retaining and supplying nutrients and water to agricultural crops and forests and increasing beneficial microbial activity. However, all soil organic matter is not the same. Organic matter that is stuck on or within minerals or trapped inside mineral micro-aggregates stays around much longer than organic matter that is free. Increasing these mineral associated organic matter (MAOM) forms is the key to maintaining higher organic matter in soils. The mechanisms and processes that control the amount of mineral associated organic matter are under dispute so soil scientists cannot currently advise farmers and land managers on the best amendments or practices to increase MAOM in their soils. A UGA research group focuses on unraveling these mechanisms through a focus on iron minerals and iron cycling in soils. Their primary research on mineral associated organic matter has shown that the complexities of soil iron cycling can both generate or destroy MAOM depending on the conditions. Their work has generated new theories of soil organic matter behavior and influenced how organic matter is represented in global carbon cycling models.