Starter Fertilizer Research Update

Harvesting corn silage in Pennsylvania

Greg Roth
Department of Crop and Soil Sciences
Penn State
January 2000

As part of our contribution to a regional cropping systems project sponsored by the Foundation for Agronomic Research, we have been evaluating various liquid starter fertilizers for corn. We compared five alternatives to two fairly common programs: 10-30-0 and 10-30-10 per acre on high P testing soils. Three of the alternatives were higher N starters consisting of UAN and a UAN/10-34-0 blend to give us a 50-0-0, 50-30-0, and a 30-30-0 treatment. Another alternative was a 30-30-0-10S program that was composed of 10-34-0 and 8-0-0-9. The last alternative was not to use any starter. This year we conducted two trials, one in Centre County and one near Hershey in Dauphin County. Both trials were no-tilled into soybean stubble. The results of both trials were different. At Centre County, there was little consistent visual differences among the treatments in height or color. The best yields in this trial (140 bu/acre) occurred with either no starter or 10-30-10. At Hershey, three of the starters (30-30-0-10S, 10-30-0, and 10-30-10) resulted in slightly taller and darker green corn. At harvest yield differences were not significantly different, but these three had the highest yields. We did not see any stand reduction in either trial. The take home message- starter responses on high P soils is not that great, especially in a warm dry season. We also did not see much benefit of the higher N starters at either site. These starters have been found to be advantageous on high P soils in several other studies in other states. Still other research seems to suggest the need for K is most critical even on high testing soils. Our results tend to support the latter. We plan on continuing our effort again next year.

We also looked at how hybrids respond to starter fertilizer again this year. Last year we found that three of the six hybrids we evaluated responded to starter and the other three did not. This is similar to what a Kansas State University researcher has found for the last three years. This year we found yield differences to starter that were generally similar to last year with the same hybrids tending to show higher yields with starter. This year, though, with all the drought stress, our yield differences were not different statistically. We'll continue this research again next year.