Discovery could cut use of fertilizer by farmers
July 10, 2014
• Uses a more accurate soil test
• Can save money and help environment
A discovery by a scientist with the USDA Agricultural Research Service could help farmers use less fertilizer, saving money and helping the environment.
Richard Haney, a U.S. Department of Agriculture soil scientist in Temple, Texas, has developed a soil test that replicates some of the natural processes that occur in a field and accounts for that microbial activity, along with measuring nitrate, ammonium (NH4), and organic nitrogen.
Current soil testing measures nitrate in the soil, but doesn’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 they need.
The new soil test has been dubbed the “Soil Health Tool” and 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 tool measures organic carbon and other nutrients, accounts for the effects of using cover crops and no-till practices, and will work for any crop produced with nitrogen or other types of nutrient fertilizer.
Mr. Haney has made it available to commercial and university soil testing laboratories and has worked with farmers to promote it. Growers who use it receive a spreadsheet that shows the amounts of nitrogen, phosphorus, and potassium available to crops.
On average, they reduce fertilizer costs by about $10 to $15 per acre. With less fertilizer applied, there is less of it running off into surface water.
Tests have found that the tool reduces fertilizer use by 30 percent to 50 percent and reduces fertilizer costs by up to 39 percent. The enhanced testing methods had little effect on corn production profits, but increased profits by 7 to 18 percent in wheat, oat, and sorghum fields.