BIOGEOCHEMISTRY OF SOIL ORGANIC MATTER: RESOURCES AND PERSPECTIVES

Sugarcane is a semi-perennial grass species belonging to the genus Saccharum, with C4 photosynthetic metabolism, which grants it greater efficiency in utilizing light, water, and nitrogen compared to plants with C3 photosynthetic metabolism. The crop was introduced in Brazil around 1532, and one of its main products is ethanol, a biofuel that has been used as an alternative to fossil fuels. Today, Brazil is the world's largest producer of sugarcane, with an estimated production of over 600 million tons harvested from a planted area of approximately eight million hectares. In Brazil, there are two sugarcane-producing regions: the Northeast and the Center-South, with the latter accounting for about 90% of the country's production. Various production systems can be adopted for sugarcane cultivation. The main systems are conventional cultivation and, more recently, organic cultivation. A characteristic of conventional sugarcane farming is the harvesting method, which may involve the use of fire. Conservationist management requires increasing organic matter in the soil. Soil organic matter (SOM) is the primary indicator of soil quality and can serve as a parameter for evaluating the sustainability of production systems. Additionally, SOM provides substantial and direct benefits to soil fertility, such as increased nutrient availability and enhanced soil cation exchange capacity (CEC). In this context, several studies in the literature discuss techniques for analyzing SOM in production systems.