Compost is the product resulting from the controlled biological decomposition of organic material that has been sanitized through the generation of heat and stabilized to the point that it is beneficial to plant growth. Compost bears little physical resemblance to the raw material from which it originated. Compost is an organic matter resource that has the unique ability to improve the chemical, physical, and biological characteristics of soils or growing media. It contains plant nutrients but is typically not characterized as a fertilizer.

Thanks to its many attributes, compost is extremely versatile and beneficial in many applications. Compost has the unique ability to improve the properties of soils and growing media physically (structurally), chemically (nutritionally), and biologically. Although some equate the benefit of compost use to lush green growth, caused by plant-available nitrogen, the real benefits of using compost are long-term and related to its organic matter content.

Improves the soil structure, porosity, and density, thus creating a better plant root environment.

Increases infiltration and permeability of heavy soils, thus reducing erosion and runoff.

Improves water holding capacity, thus reducing water loss and leaching in sandy soils.

Supplies a variety of macro and micronutrients.

May control or suppress certain soil-borne plant pathogens Supplies significant quantities of organic matter.

Improves cation exchange capacity (CEC) of soils and growing media, thus improving their ability to hold nutrients for plant use.

Supplies beneficial microorganisms to soils and growing media. Improves and stabilizes soil pH.

Can bind and degrade specific pollutants.

Compost can greatly enhance the physical structure of soil. In fine-textured (clay, clay loam) soils, the addition of compost will reduce bulk density, improve friability (workability) and porosity, and increase its gas and water permeability, thus reducing erosion. When used in sufficient quantities, the addition of compost has both an immediate and long-term positive impact on soil structure. It resists compaction in finetextured soils and increases water holding capacity and improves soil aggregation in coarse-textured (sandy) soils. The soil-binding properties of compost are due to its humus content. Humus is a stable residue resulting from a high degree of organic matter decomposition. The constituents of the humus act as a soil ‘glue,’ holding soil particles together, making them more resistant to erosion and improving the soil’s ability to hold moisture.