Soil testing that determines needed fertilizer will measure nitrate in the soil, but tests don’t sufficiently account for soil microbes, which mineralize organic nitrogen and make more of it available to a crop. As a result, farmers often apply more fertilizer than necessary.
Richard Haney, a U.S. Department of Agriculture soil scientist in Temple, Texas, has developed soil test that replicates some of the natural processes that occur in a field and accounts for microbial activity, along with measuring nitrate, ammonium (NH4) and organic nitrogen.
The new soil test is known as the Soil Health Tool. It involves drying and rewetting soil to mimic the effects of precipitation. It also uses the same organic acids that plant roots use to acquire nutrients from the soil. The testing tool measures organic carbon and other nutrients, accounts for the effects of using cover crops and no-till practices and works for any crop produced with nitrogen or other types of nutrient fertilizer. For more information visit http://www.ars.usda.gov/is/pr/2014/140710.htm
This article appears in the September 2014 issue of Acres U.S.A.