Organic soil is soil that contains more than 30 percent of decayed organic material from dead leaves, stems and animals, and this material gives the soil a rich color and fibrous texture. Organic soil also receives and retains moisture, which makes it highly supportive for plant growth. According to the Regents of the University of Minnesota, "Soil organic matter, and the soil organisms that live on it, are critical to many soil processes. It allows high crop yields and reduced input costs."
The decayed material that breaks down in the soil and is recycled within it to support new plant growth actually improves the texture of the soil. The organic materials, when mixed with sandy soils, make the soil heavier and give it a root-supporting consistency. When mixed with heavier clays, the organic material loosens it up and makes it more penetrable to water and oxygen.
As stated by Colorado State University Extension, "Organic materials, also known as organic amendments, break apart tight clays and hold water and nutrients in loose sands. Organic materials include compost, peat and manure."
Enhancing soil with organic matter and using organic soils promote a natural balance in the soil that increases the activities of worms and beneficial microorganisms in further enriching the soil and in fighting off plant diseases. When supported with the rich nutrients found in organic soil, the microorganisms proliferate and crowd out any harmful microorganisms. Reducing the amount of chemical fertilizers and gardening products also support this healthy soil balance.
Organic Soil Types
Organic soil preparations are formulated for specific uses, and this is determined by the amount of organic matter that is mixed into the soil. Organic soil for pots has a higher ratio of compost to soil. This soil type is light and loose and very water-absorbent to support the moisture and nutrition requirements of a potted plant.
Organic soil for gardening has a slightly lower ratio of compost to soil in its composition since it must have more weight and body to it to withstand natural rain, winds and the rooting system of plants growing in the ground. This type of soil however is still light and loose for water absorption and retention and increased oxygen to the soil and the plant roots.
Organic soil is also used to restore areas that have been excavated for construction. In the absence of chemical additives and fertilizers, organic soil mixes into the existing soil and reaches balance with it much faster than non-organic soils.
Organic Soil Improvements
Maintain the composition of your organic soil by adding organic materials to it annually. Peat moss, bone meal and organic compost will replenish the nutrient levels of the soil from the previous year's harvest. Make your own compost from leaves, lawn and garden debris and non-meat kitchen scraps for use the following year. This is an eco-friendly way of reducing trash by using these things to build a soil amendment.
Organic soil supports the growth of healthy fruits and vegetables. Animals benefit from the organic soil—they feed on its produce, and birds feed on the worm population in the soil. The ability of organic soil to stabilize the root systems of plants prevents runoff, thereby preventing the pollution of nearby water supplies.