Soil Oxygen—Soil Organisms and Plants Can't Live Without It Custom Search Soil oxygen is necessary for almost all soil organisms. These organisms decompose organic matter and make nutrients available to plants. In well-drained soil, oxygen is available at the root zone, which encourages good root health. The amount of oxygen in the soil is affected by microbial use of oxygen, and by factors that decrease the air exchange between the atmosphere and the soil. When soils become waterlogged from too much rain or overwatering, oxygen is forced out of the soil after about 48 hours of saturation. The absence of oxygen also creates ideal conditions for root rot microorganisms. Compacting soil also forces oxygen out, since there is less room between soil particles. Fertilizing with compost or other organic matter will open up the soil, allowing oxygen into the soil and keeping the soil from becoming waterlogged. The most efficient way to alleviate compaction and add oxygen is a procedure called core aeration, which is often called plugging. |