Soil nutrient analysis has become important as knowledge of the decline in nutrient content of vegetables and fruit has increased. Tomatoes grown on nutrient-rich organic soil have been shown to be nutritionally superior, according to the University of California at Davis. Alternative soil nutrient analysis tests emphasize the total nutrient content of soil and the health of the soil food web.
Optimum Soil Health
Plants need 17 nutrients for survival, according to the Utah State University Extension. Carbon, oxygen and hydrogen are available from air and water. Nitrogen, phosphorus and potassium are nutrients needed in the largest amounts. Calcium, magnesium and sulfur are the next elements in demand.
Essential Trace Minerals
Trace minerals are essential to soil health in smaller amounts and they include boron, manganese, copper, zinc, chlorine, nickel, cobalt and molybdenum. The same trace minerals are essential for human health. Soil samples can be sent for nutrient analysis to private and public laboratories, such as university agricultural extension offices.
Soil Food Web
All 17 nutrients are essential for soil food web health. The Natural Resources Conservation Service defines the soil food web as "the community of organisms that live all or part of their life in the soil." Soil organisms "support plant health as they decompose organic matter, cycle nutrients, enhance soil structure, and control the populations of soil organisms including crop pests." Human nutrition vitality depends on soil food web.
Standard soil nutrient analysis concentrates on nitrogen, phosphorus and potassium content and gives fertilizer recommendations for these. Alternative soil testing labs analyze soil for its total nutrient content and its total microbiological functioning. Microbiological organisms produce nutrients that are absorbed into vegetables and fruit.
Improve Nutrient Content
Soil nutrient content is improved by adding organic matter such as compost. Elaine Ingham of the Natural Resources Conservation Service says "Organic matter is the storehouse for the energy and nutrients used by plants and other organisms." Compost is alive with billions of tiny organisms that cycle nutrients into vegetables and fruit. Home gardeners can significantly improve the soil nutrient analysis by using backyard composting techniques.