Monday, November 5, 2007 - 11:45 AM
53-9

Rotation Effect from Soybean Will Maximize Corn Productivity.

Palle Pedersen, Department of Agronomy, Iowa State University, 2104 Agronomy Hall, Ames, IA 50011-1010

The use of modern soybean cyst nematode (SCN; Heterodera glycines) resistant soybean [Glycine max L. (Merr.)] cultivars and European corn borer [(Ostrinia nubilalis (Hübner)] and/or corn root worm (Diabrotica ssp.) resistant corn (Zea mays L.) hybrids may give growers the opportunity to plant more corn on corn or soybean on soybean to fill the demand from the rapid growing biofuel industry. The objective was to evaluate cultivar and hybrid effects in conventional and no-tillage systems with different rotation sequences involving 1st-, 2nd-, 3rd-, 4th-year corn or soybean, alternate corn and soybean, and continuous corn or soybean. Experiment was initiated in 2003 at two locations in Iowa. At each location, a field that previously had been in the alternate corn and soybean rotation was used and a new rotation sequence was then added every year. All the rotation sequences have been planted after the 2007 growing season. The experiment was a randomized complete block in a split-split plot arrangement with four replications. Main plots were no-tillage and conventional tillage systems, the sub-plots consisted of the 12 rotation sequences involving corn and soybean, and the sub-sub plots were three different soybean or corn cultivars. Two soybean cultivars with different sources of SCN-resistance (PI88788 and Hartwig) and a susceptible SCN cultivar were used. Isogenic corn hybrids with and without resistance to corn root worm and/or European corn borer were used. Data from the 2004 through 2007 growing season will be presented.