Compost acts as a natural soil enhancer, loosening clay soils, increasing moisture retention in sandy soils, and balancing soil pH, as well as providing needed plant nutrient. Work compost into the soil before planting, or use it as a top dressing for fertilization during the growing season. Another way to use compost is as a liquid fertilizer. Compost tea gives newly planted seedlings a good start through regular fertilizer applications or as a spray, which allows nutrients to be absorbed directly through the leaves.
Compost Provides Nutrients
Soil is naturally replenished with the three main nutrients (nitrogen, phosphorus and potassium), secondary nutrients and minerals that plants need, from decaying plant matter, which happens over long periods. Compost is made from the same plant matter, but it is already broken down so that nutrients are available to your plants now. Compost is one of the most well-balanced fertilizers and soil amendments, containing all of the three main nutrients and many of the secondary nutrients and minerals required for healthy plant growth.
Compost Enhances Soil
Soil texture refers to the fineness or coarseness of the mineral matter, and affects water retention, fertility, and air circulation within the soil. The ideal soil is a garden loam that is about equal parts sand, clay and humus, (organic material that provides nutrients for beneficial micro-organisms in the soil). One of the best sources of organic matter is compost. Good soil structure will have a loose, granular structure. Adding organic matter improves the soil structure, which should be amended before planting each year.
Compost and pH
The pH in compost depends on the materials used to make it. Finished compost tends to be slightly acidic, and adding compost to a slightly alkaline soil will bring it toward neutral. Most garden plants favor a slightly acid to neutral soil of pH 6.5 to 7. Compost acts as a chemical buffer, increasing the plants' tolerance to a broader pH range of 6 to 8.
Compost should be dug into the soil during bed preparation and as a top dressing to replace nutrients that have been used up or leeched from the soil throughout the growing season. It can also be added to planting holes when making new additions to an existing bed. Sterile compost can also be mixed with peat moss to create a potting mix that is satisfactory to get seedlings started. Make compost sterile by baking at 180 degrees Fahrenheit for 30 minutes.
Compost tea is a liquid fertilizer made by steeping compost in water, combined with aeration to activate beneficial microorganisms and nourish plants. Compost tea is high in nitrogen and is very beneficial, producing strong, healthy plants. It can be applied through the soil, to be absorbed through the root system, or via a foliar spray, which allows plants to absorb nutrients directly.