Many home gardeners are concerned about the health of soil because soil is the key to a garden’s productivity. Healthy soil produces healthy, nutritious food. Soil is depleted by natural growth processes and needs continual nutrient replenishment. Soil erodes from lack of organic content; the U.S. currently loses 7 tons per acre of topsoil per year. Inorganic fertilizers have been in widespread use since World War II, while organic fertilizer use continues to grow. There are many sources of research and comparison to study the differences between the two approaches to gardening and agriculture.
Read websites such as The Sustainable Table (see Resources), which is a nonprofit organization that gives education on the relationship between soil fertility and food nutrition. Understanding how soil productivity issues are related to health issues helps in determining which agricultural approach to take. The International Fertilizer Industry Association (see Resources) provides educational materials on the use of synthetic fertilizers.
Study the benefits of incorporating organic material into soil as fertilizer. Adequate organic content in soil is essential for healthy plant growth. Washington State University provides a fact sheet to educate home gardeners on the reasons to recycle yard wastes into compost that can be used as a soil amendment (see Resources). Soil is regenerated slowly by the continual application of organic matter. The National Resources Conservation Service reports that “plant deficiency diseases usually are less severe in soils that are well supplied with organic matter.”
Read labels. Inorganic fertilizers have an N-P-K label that describes the percentage content of nitrogen, phosphorus and potassium. Nitrogen is the element that is needed in the largest amount for plants to grow, and it is available from both synthetic and organic sources. Some manufacturers of organic fertilizers also use the well-known N-P-K label system, even though their products contain many other nutrients. Organic fertilizer labels list other ingredients that provide essential nutrients. These may include cottonseed meal, alfalfa meal, blood and bone meal, feather meal, animal manure and seaweed ingredients.