What Does Compost Do?
What Does Compost Do?
- Improves Soil Structure
Improved soil structure creates passageways in the soil for air and water. In heavy clay soils, the addition of compost enhances the physical make-up of soil which improves soil structure, porosity and bulk density to create a better environment for plant growth. - Supplies Slow-Release Nutrients to Plants without using fertilizers
Compost is a good source of nutrients including nitrogen, phosphorus, potassium, sulfur, and microorganisms essential for plant growth. Since compost is made of relatively stable organic matter, nutrients are slowly made available for root uptake and. In this way, nutrients are less likely to be lost through leaching. - Holds Moisture and Reduces Erosion
Compost has a large capacity to hold water - many times its own weight. This reduces water loss and leaching in soil. The soil-binding properties of compost result from its humus content which acts like a glue, holding soil particles together, making soil resistant to erosion and improving moisture retention. - Immobilizes and Degrades Pollutants
Compost has the ability to bind heavy metals, pesticides, herbicides and other contaminants, reducing both their leachability and absorption by plants. The soil microorganisms that compost supports also help break down pesticides, fertilizers and hydrocarbons. This same binding effect allows compost to be used as a filter for storm water and other runoff. - Provides Organic Matter
Compost supplies organic matter to the soil which increases the presence of microorganisms. The activity of microorganisms promotes root development and assists in the extraction of nutrients from the soil. It also encourages the growth of earthworms and other macro-organisms, whose tunneling increases water infiltration and aeration. - Suppresses Soil-Borne Diseases and Plant Pathogens
Plant disease is influenced by both the level and type of organic matter as well as the microorganisms present in soil. Detrimental organisms like root-eating nematodes, a number of specific plant diseases and several lawn diseases are suppressed by microorganisms found in compost.
How good is the compost?
The quality of the compost used for soil enhancement is important. Commercial compost should have a sweet, earthy smell. Compost should meet the Washington Department of Ecology’s guidelines for “Grade A” compost.
Source - King County, WA Composting and Waste Prevention Programs. Visit their website - http://dnr.metrokc.gov/swd/resrecy/index.asp
