Compost 101: Nutrients & Usage

By May 10, 2014posts

From Judy Elliott, DUG Community Empowerment & Education Coordinator
This article was originally published in the 2009 Spring edition of The Underground News. 

Compost is generally thought of as a soil ‘amendment’, not fertilizer.  That being said, its beneficial use in the garden is ‘greater that the sum of its parts’.  As it feeds the soil, it stimulates the growth of beneficial microorganisms, binds together the large pores inherent in sandy soils, physically creates air spaces in tightly packed particles of clay soils, can decrease your watering by almost 30%, promotes disease resistance in veggies, herbs, flowers, turf, shrubs and trees, and, perhaps most important, provides a ‘slow release’ of all major (N: nitrogen, P: phosphorous, K: potassium), minor and trace elements needed for plant growth.  Most Colorado soils are deficient in nitrogen, but adding compost, rather than additional fertilizer is often sufficient for healthy crop growth. Any supplemental fertilizer needs can be provided by foliar feeding of seaweed (liquid kelp) and fish emulsion on all crops several weeks after they have been transplanted (or, are  up and growing, if seed-planted) and again, during their mid-season growth.

Our supplier of compost for the 2010 season produces an excellent product, that is made from decomposed landscape material, has undergone the necessary ‘maturation’ process, is in a stable form and provides a balanced source of nitrogen, phosphorous and potassium. It has undergone rigorous soil testing and analysis to insure its uniformity of product, is fairly neutral in pH and low in soluble salts.

Use it by spreading on the top of garden beds & digging it uniformly into the top 2-3” of soil, rather than leaving it on to op as mulch.  Cultivate weekly around all actively growing crops, prior to watering, to maintain soil porosity and promote deep rooting patterns for all crops. As the soil warms, light layers of straw mulch around cool season crops (peas, salad greens, radish) will extend their growing season.  Several weeks after warm or hot season crops are up and growing, provide that same mulch.  This not only cools the root-growing area, but will add to the organic content of the soil as it slowly decomposes.