On droughty soils in the southeastern region of the country, agronomists are suggesting a continuous double-crop no-till rotation. Many growers plant small grain followed by soybeans and then rotate to corn or cotton the following year.
Instead, Virginia Polytechnic Institute agronomist Dan Brann suggests a double dose of double-cropping may be better on soils too droughty to consistently produce good summer crop returns. His suggestion is a year of small grains and double-crop soybeans followed by small grains and double-cropped corn.
Until now, double-cropped corn historically produced poor yields in Virginia due to insect damage in late-planted corn. But this problem can be solved with Bt corn hybrids, says Brann, who conducted double-crop corn tests last year.
In addition, a Virginia farmer harvested 150-bushel, double-crop corn behind 127-bushel barley. The farmer irrigated three times with 3/4-inch water each time. His top five corn hybrids were Bt hybrids.
Brann planted in mid-June with 75- to 115-day corn variety maturities behind barley. A plot at Warsaw, Va., was conventionally tilled and received 150 pounds of nitrogen per acre. Plots at Corbin Hall, Va., were no-tilled and received 125 pounds of nitrogen per acre.
While Brann normally recommends splitting nitrogen on corn to avoid losing nitrogen due to leaching, all of the nitrogen was applied to the double-cropped corn at one time. He found the corn grows so fast that it takes up nitrogen before it can leach away.
Due to warm temperatures and adequate moisture following barley…