Integrated Crop Management

Time is running out for planting an "emergency" forage crop

Weather events or unusual circumstances will sometimes lead to the decision to produce an "emergency" forage crop. The forage crop chosen often is a warm-season annual grass harvested one to three times during the growing season. The choice of crop species depends primarily on how the crop will be stored or used (hay, silage, or grazed), the type of animal being fed, and the yield expectations.

Harvest as silage provides the widest range of species choices. Foxtail, Japanese, and hybrid pearl millets and sudangrass and sorghum-sudangrass hybrids can all be planted as late as mid-July and still produce a harvestable crop. All of these also could be considered as grazed forage too. Foxtail millet, sudangrass, and the sorghums should not be used for horse pasture. It is probably too late in the season to plant forage sorghum and expect a normal forage sorghum yield silage crop, and forage sorghum is not generally recommended as a grazing crop.

Choices for an emergency crop for harvest as dry hay are more limited. The best choice is probably foxtail millet. It is the most "grassy" of the millets and the best suited for drying and safe storage as dry hay. Sudangrass and Japanese millet also are possible choices for a hay crop but somewhat less desirable because of coarse stems and less uniform field curing.

Planning for and choosing an emergency forage crop may not be sufficient. For a successful midsummer planting, there needs to be adequate soil moisture to germinate the seed and a regular rainfall pattern for the remainder of the growing season to keep the crop growing.

Though often not considered, you may already have an emergency forage crop growing. Corn silage or soybeans harvested during early pod fill also are possible and viable forage choices; however, their value as grain must be weighed against their value and need for forage.

Livestock producers need to be aware of late summer nitrate toxicity risk with many grass forages growing during dry summer months. They also should be aware that hydrocyanic acid (Prussic acid) needs to be considered when managing sudangrass and the sorghums as pasture.

Stephen K. Barnhart is a professor of agronomy with extension, teaching, and research responsibilities in forage production and management.

This article originally appeared on page 220 of the IC-498(18) -- July 9, 2007 issue.


Source URL:
http://www.ipm.iastate.edu/ipm/icm//ipm/icm/2007/7-9/forage.html