Chemical fertilizers and pesticides have been a mainstay for home gardeners for decades. When used in home gardens, plant growth results are immediate and chemical pesticides effectively eradicate insects. Organic fertilizers feed soil biological processes and do not add chemicals to the environment. Chemical fertilizers feed plants but do not feed soil microorganisms. Health of the soil is the major focus of organic growing.
Fritz Haber, a German scientist in the early 20th century, invented the process for turning nitrogen into liquid ammonia, which is the basis for chemical fertilizer. Chemically created nitrogen became the basis for artificial fertilizers, the world's primary source for increasing food production since World War II.
Commercially made organic fertilizer is derived from natural sources such as cottonseed meal, blood and bone meal, bat guano, seaweed, fish waste products and feathermeal. Organic compost fertilizer is created from kitchen scraps, yard clippings, grass clippings, dry leaves and newspaper or office paper. Chemical fertilizers are identified by the industry standard label known as N-P-K, or nitrogen, phosphorus and potassium. These are macronutrients which are needed in the largest amounts by growing plants.
Methods of Use
Nitrogen in chemical fertilizer is available directly to plants but does not feed the living organisms in soil. Organic soil amendments feed living organisms, which produce nutrients in the soil. Soil organisms are the mechanism by which plants gain nutritional value, according to the Natural Resources Conservation Services.
The Environmental Protection Agency has determined that many chemical pesticides are a health risk. "The health effects of pesticides depend on the type of pesticide. Some, such as the organophosphates and carbamates, affect the nervous system. Others may irritate the skin or eyes. Some pesticides may be carcinogens, others may affect the hormone or endocrine system in the body. Integrated Pest Management is the method used in sustainable agriculture and home organic gardening to reduce insect damage to crops. This includes companion planting, use of beneficial insects--such as ladybugs and praying mantises--and biologically based insect sprays.
Chemical fertilizers have increased crop yield and industrial farm profitability but they are also responsible for the increase of atmospheric nitrogen to a dangerous level, according to the World Resources Institute. Nitrogen levels have doubled since 1940, distorting the natural biological life cycles in soil, plants, water and air. Sustainable agricultural practices use organic fertilizers, soil amendments and integrated pest management.These practices and products are designed to increase soil fertility and crop yield with the use of nature-based materials.