Using an integrated approach, Agricultural Research Service scientists in the Cropping Systems and Water Quality Research Unit (CSWQ) at Columbia, Mo., are determining which combinations of precision agriculture methods work best.

Using data collected between 1991 and 2003, researchers Newell Kitchen, Robert Lerch and Ken Sudduth determined that topsoil loss from field erosion significantly reduced agricultural productivity. They also discovered that elevation and soil electrical conductivity, which measures how easily soil allows an electrical current to flow through it, were extremely helpful in identifying different management zones. In fact, zone maps created with this information were more accurate predictors of crop yield than maps made with traditional soil surveys.

In addition, the CSWQ team developed two site-specific management approaches to help growers identify the fertilizer needs of specific areas within a field, allowing for more accurate application. The first method assesses nitrogen deficiency by measuring crop canopy reflectance. The second method, still in development, relies on an automated soil sample collection and analysis system, which could quickly and economically predict the soil's nitrogen-supplying capacity.

During the next five years, the researchers hope to show that their methods decrease nutrient and sediment losses, increase profitability and improve soil quality. Above all, they hope to demonstrate that precision agriculture can be an economically viable tool for farmers.

Read more about the research in the March 2007 issue of Agricultural Research magazine.

SOURCE: USDA news release.