Soil Organic Matter

Soil consists of different materials. Even if the main frac-tion is mineral, the organic matter in soil plays a critical role in the functions of a healthy soil. The main functions (Schulte et al.,2014) in soil, such as primary productivity, water purification and regulation, carbon sequestration and regulation, biodiversity and nutrient cycling are all highly dependent on soil organic matter (SOM). The or-ganic fraction in soil consists of approximately 58% car-bon, which was mostly removed from the atmosphere through the photosynthetic activity of plants. Therefore, the level of SOM is not only critical for the soil and the farmer, but also for climate, environment and society as a whole. Depending on the type of soil, most organic matter levels in arable and vegetable production are between 1 to 6% of total soil mass. Even with such a small proportion, soil organic matter has a huge impact on most physical, chemical and biological characteristics of the soil.