Following wheat harvest producers have the opportunity to develop additional grazing and forage resources using summer annuals. Pearl millet, sorghum-sudangrass, sudangrass and certain forage brassicas can be seeded after wheat and grazed 60 days later. These forages are adapted to growing during the hot periods of the summer unlike cool-season grasses which make up most permanent pastures.

Grazing summer annual pastures during late August and September allows producers to rest and stockpile cool-season pastures for late fall and winter grazing. Wheat fields seeded with summer annuals unsuitable for grazing due to lack of fence or water can be hayed. While haying does not provide a rest area for permanent pastures, feeding the hay during early fall can provide a rest period suitable for stockpiling.

Prussic acid can be a concern for sorghum-sudangrass and sudangrass pastures. To avoid this potentially deadly problem wait until these forages are 24 inches tall before grazing or cut them for hay. The drying process of haying allows the toxic compound to dissipate. Pearl millet does not contain the compound causing prussic acid poisoning so it may be grazed later into the fall. For more information and to view a presentation on prussic acid poisoning visit http://ilift.traill.uiuc.edu/pasture/training/index.cfm.

Seed, equipment and nitrogen costs can make summer annuals an expensive forage source compared to perennial forages. Nonetheless producers should consider the management opportunities summer annuals offer to the entire forage supply when evaluating this enterprise. Opportunities include emergency forage supply, longer rest period for existing pasture rotations, alternative grazing locations while stockpiling cool-season pastures, as well as spreading land cost over the wheat and grazing enterprises.

Justin Sexten, 618-242-9310, sexten@uiuc.edu
Date: June 9, 2006