Source: Missy Bauer, field agronomist, The Andersons, Fluid Journal, Fluid Fertilizer Foundation
In the Eastern Corn Belt, 10-34-0, at rates of 10 to 15 gal/A, has been a common starter fertilizer in a 2 x 2 band placement. However, 10-34-0 prices have increased nearly threefold since April of 2007, leaving many growers asking the question, "How much do I really need to apply." In addition, with supplies being tight, the prospect of growers cutting back is real.
We need to keep in mind what the goal of starter fertilizer is and not sacrifice yield or profitability as changes are made. The purpose of starter fertilizer is to enhance early nutrient uptake, increase early plant and root growth and increase yields.
Starter is most beneficial when crops are planted into cool wet soils in early spring. Reduced-till conditions, earlier planting, and the goal of increasing corn yields continue to drive starter fertilizer use. If rates of 10-34-0 in the 2 x 2 band are reduced, yield can be maintained by increasing the rate of nitrogen (N) in the band. For example, using a starter fertilizer with a 1:1 N:P ratio by blending 10-34-10 and UAN (28 percent) has been shown to maintain yields. A study was conducted in 2006 on a sandy loam soil at The Andersons Agronomic Land Lab in Tekonsha, Mich., to evaluate a high N starter in comparison with 10-34-0. Starter fertilizer placed in a 2 x 2 band at 15 gal/A resulted in 196.7 bu/A for 10-34-0 and 198.6 bu/A for 19-17-0. Starter fertilizer blends with 50 percent UAN and 50 percent 10-34-0 are working well in the Eastern Corn Belt and can give growers a viable alternative to running straight 10-34-0.
As the pressures of tight supply and costs continue to escalate, growers are wondering what else they can do to improve efficiency of their starter fertilizer programs. The addition of low salt popup placed in-furrow can provide some added efficiency and improved early growth. The combination of a 2 x 2 band placement and a low rate (3 to 5 gal/A) of a low salt popup in-furrow has improved early growth and yield. In a study conducted on a sandy loam soil at The Andersons Agronomic Land Lab in Tekonsha in 2007, a 2 x 2 placement of starter fertilizer, plus 3 gal/A of 6-24-6 low salt in-furrow compared to 2 x 2 alone, resulted in an average plant height of 2.86 inches taller at the V6 growth stage. Figure 1 shows the visual difference in the plants early in the growing season. In 2005, a study near Butler, Indiana, evaluating four different Pioneer hybrids, resulted in yields gains ranging from 2.9 to 9.2 bu/A by adding popup fertilizer in-furrow in combination with 2 x 2 versus 2 x 2 alone. As phosphorus (P) rates in the 2 x 2 band are reduced, adding low rates of popup in-furrow may help to maintain early growth and yield.
Figure 1. Starter fertilizer 2x2 band placement + popup in-furrow in comparison to 2x2 only. 2007, M. Bauer.