What About No-Till?

Intense thunderstorms in the area that brought some very heavy rains in a short period of time just magnified the impact no-till cropping systems have on soil erosion. In driving through southeast Nebraska following these rains, the tilled fields showed significant signs of erosion, with ditches cut through the soil and topsoil accumulations at the bottom of hills. While some of the no-till showed erosion in the soybean stubble fields, the stalk fields held the soil much better. The past year we have had some very intense thunder storms with the prediction of more severe weather this spring.

In the fall of 2006 Randy Prior, Extension Educator in Saline County and I measured water infiltration rates on tilled and no-till fields in Nemaha and Richardson Counties. These measurements were taken after a period of substantial rainfall, so in general soil moisture conditions were very good. Throughout the summer though, the crops had experienced some dry stressful conditions which impacted crop yields. In one comparison, a field had been no-tilled for 6 years. Water infiltration rates were 5.70” per hour compared to 4.14” per hour for the neighboring tilled field. While this area received little rain during the growing season, the no-till field still yielded 150 bushels per acre, with the tilled field yielding less than 100 bushels per acre. We were also able to penetrate a steel rod down 6’ in the no-till field, but only 3’ in the tilled field. In a comparison of tilled and no-tilled fields at another site, infiltration rates were actually higher on the tilled field, although the steel rod penetrated 6’ for the no-till compared to 4’ for the tilled field. Soybeans also yielded 54 bushels per acre for the no-till compared to 44 bushels per acre for the tilled. This field has been 15 years no-till.

While these are just observations made at two sites in one year, there are some farmers that have been practicing some form of no-till for 10-20 years and are very satisfied with it. If you are not practicing no-till it may be worth trying, at least on some of your acres.

Farmers that have practiced continuous no-tilled for years have seen some increases in organic matter in the soil. The addition of manure over the long-term has also increased organic matter in soils. Research at the University of Nebraska has shown that for each percent organic matter in the soil up to 3%, 31 pounds of nitrogen will be mineralized (made available) to a corn crop. So if your soil was 2% organic matter you would credit 62 pounds of nitrogen from your soil and 93 pounds if it was 3 percent. In the long-term, no-tilling may help save on fertilizer costs as well.

While presently it is too wet to get much field work completed, this may not be the case in 2-3 months from now. Soil moisture can be a very important factor in determining crop yields. Each tillage operation dries out the soil. Warm weather and strong winds dry the soil out fairly rapidly. Residue on the surface in the no-till environment helps conserve soil moisture and reduces the amount of water lost from evaporation. In mid-summer we may need every inch of water available for the growing field crops.

If you have questions feel free to contact me at (402) 274-4755 at the Nemaha County Extension office.