Farmers Encouraged to Take Advantage of Heavy Rains

After days of heavy rains, the side of a hill completely gave out in Pottawattamie County.

May 9, 2007

In the first few days of May 2007 much of southern and western Iowa received between three and ten inches of rain. Iowa State University is estimating those heavy rains have caused parts of 22 counties in Iowa to experience an exceptionally high soil loss of more than seven tons per acre.

High soil losses can eventually reduce crop yields. Loss of topsoil reduces soil quality and can lower productivity. The resulting silt can fill roadside ditches and impair drainage systems reducing performance or requiring costly clean-up.

To make the best of a bad situation, experts are urging producers to look at their land for erosion problems. USDA’s Natural Resources Conservation Service State Agronomist Barb Stewart recommends landowners tour their fields now. Stewart says, "Especially check waterways and terraces to see if recent rains have damaged them. Look for small gullies that have formed in the fields and large silt fans that have accumulated at the base of a slope. If problems are found, they need to be quickly repaired before more damage is done.”

Greg Mathis, NRCS district conservationist in eastern Pottawattamie County, notes fields that have been consistently no-tilled have held the soil much better. On steeper slopes in his district surrounding Oakland, terraces are used to slow water runoff and help keep soil in place. “Because of the heavy rains, there are a lot of terrace breaks,” says Mathis. “However, there are a lot more terraces that didn't break and they are doing their job holding water and sediment.”

Wayde Ross, NRCS district conservationist in Ringgold County along the Missouri border says, “A lot of people are saying they have not seen any rains like this for 10 years. Many of our terraces need attention. Terraces are expected to last 20 years with minimal maintenance under normal conditions. After that time they may need to be completely cleaned out and rebuilt to continue functioning properly. Very few landowners think about that until something like our recent heavy rain happens.”

In eastern Pottawattamie County, terraces were also blowing out, allowing water to flow over the top, causing erosion.

Ringgold County’s moderately to steep rolling hills and silty clay loam soils are difficult to keep in place. Ross says no-till helps, but even on some of the steeper slopes no-till is not enough. They need to be seeded in permanent cover. Add the rains of last week, and the soil losses from some tilled fields were in excess of 20 tons per acre.

Conservationists say a yearly soil loss of three tons per acre in Ringgold County is generally acceptable.

Hilly Shelby County in western Iowa has highly erodible loess soils. Angela Biggs, NRCS district conservationist, said, “The four to seven inches of rain that drenched many parts of the county caused more than a year’s worth of soil loss in many farm fields in just one day.”

If landowners discover problems with soil loss they are encouraged to contact NRCS at their local USDA service center. NRCS and its partner agencies offer landowners free technical assistance and programs that can help solve erosion problems.

Photo Gallery of Shelby County Rain Damage

-30-

http://wepp.mesonet.agron.iastate.edu/index.phtml

Contact:
Dick Tremain, Public Affairs Specialist
USDA Natural Resources Conservation Service
Phone: (515) 323-2736

<Back to 2007 News Releases