Colorado State University routinely analyzes soil samples for pH, soluble salts, organic matter, nitrate nitrogen, phosphorus, potassium, zinc, iron, copper, manganese, lime and soil texture. A standard soil test typically includes the following:
--Texture--estimated by the hand-feel method;
--Organic matter--reported as a percent of the total soil. Note: about 2/3 of a pound of nitrogen per 1,000 square feet will be released (mineralized to nitrate) during the growing season for each 1 percent organic matter present;
--pH;
--Lime--CaCO3 reported by percent. Note: on soils with free lime, sulfur will not effective lower the pH;
--Soluble salts--reported in mmhos/cm;
--Nutrients--reported in parts per million (nitrate nitrogen, phosphorus, potassium, copper, iron, manganese, zinc).
Additional tests could be run for special needs like lead content or sodium problems. Fertility evaluation of soils for organic matter, nitrate, available phosphorus, potassium, zinc, iron, copper and manganese are determined on a routine basis. Five nutrients (nitrogen, phosphorus, potassium, zinc and iron) may be deficient in Colorado soils. Other nutrients have not been found to be deficient in Colorado except under unusual or special conditions. When field experiments show the need for additional tests, they will be included in the routine list. In addition to the above tests, pH and soluble salts are determined. When salts are high, leaching requirements are suggested. Good soil drainage is a must for reclamation of salt-affected soils. Included in a report from the Colorado State University Soil Testing Laboratory are interpretations that relate results to fertilizer and management suggestions. Soil pH, determined by the 1:1 soil:water method, indicates the acidity or alkalinity of soil based on a scale of 0 to 14. On the pH scale, 7.0 is neutral, values below 7.0 are acid, and those above are alkaline. Most Colorado soils are alkaline, having a pH between 7.0 and 8.0. A pH value above 8.5 indicates that the soil may contain excess sodium.
Also ask a local Cooperative Extension Agent to go over the test with you. See this link for addresses and phone numbers: Colorado Cooperative Extension Offices. ***

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