The higher price of inputs this season puts even more pressure on maximizing corn silage yields, points out Chad Lee, University of Kentucky Extension grain crops specialist. Here are his guidelines for putting silage corn in the best position to reach high yields:
- Soil test and fertilize accordingly. Many silage fields in Kentucky have two crops, wheat and corn, both for silage. Good yields of both crops can pull more than 300 lbs of potassium and 150 lbs of phosphorus from the soil, says Lee. Those nutrients must be replaced. Applying nutrients according to soil test will help identify exactly what is needed and where.
- Select good hybrids. Based on the Kentucky Silage Corn Hybrid Performance Report: 2010, hybrid yields differed by as much as 6 tons/acre and milk yields by as much as 8,500 lbs/acre. Find as much data on hybrids as possible before buying them. Obviously, forage yield data is the best, but grain yields are an indicator of overall tonnage and can be useful as well. Finding no data on a hybrid is not a good sign. Stay away from hybrids with no track record.
- Plant on time. Corn planting is recommended from April 1 to May 1 in western and central Kentucky and April 15-May 15 in eastern Kentucky. Many silage fields are planted after those dates, which most likely results in some yield losses. Planting corn in time means wheat must be harvested earlier. That will reduce wheat yields, but those yield losses will be more than offset by the increases in corn yield from timely planting. The wheat yield loss will also be offset by improved wheat silage quality.
- Increase the planting rate on good soils. When corn is grown for silage, generally about 2,000-3,000 more seeds per acre should be planted than when it’s grown for grain. On good soils with 30” rows, recommended planting rates on corn for grain are about 30,000-33,000 seeds per acre. That means silage seeding rates could go as high as 36,000 seeds per acre on very productive fields. Drop back planting rates for less productive soils or wider row widths.
- Avoid micronutrients, except for zinc. Soils with proper pH and adequate phosphorus may be low in zinc. Most other micronutrients on most soils in Kentucky have not been shown to increase yields. If you are applying manure to fields, you are supplying a lot of micronutrients anyhow. Some weathered soils in the Russell County area have shown yield increases to boron. However, these yield increases appear to be specific to one soil type.
- Check your planters to make sure discs, seed meters, press wheels, closing wheels, etc. are in good working order. Each planter should deliver seed at the desired amount, the desired depth (1.5”), and the desired uniform spacing. A planter that does not do these three things well could result in erratic stands, which could lead to erratic yields. Any planter that sat outside over the winter is very likely to have some rust in areas that will hinder seed delivery. Remove the rust before planting begins in earnest.
“Finally, appoint someone to have priority for the corn crop,” says Lee. “Dairy producers must focus on the cow above all else. The cow takes priority in logistics of the dairy farm. By having someone solely responsible to the corn crop, that person can better achieve timely management of the corn crop.”
For more information about corn for silage, review Producing Corn for Silage.