Considerations for Late Summer-planted Forage Crops
August 10, 2012
Most row crop acres will be harvested early this year, and many dryland acres are being harvested for silage or hay. Irrigated crops are maturing early and silage and grain harvest will be two or more weeks earlier than average. This may be an opportunity to double crop for forage production.
Ground left bare may need to be planted to a cover crop to maintain adequate ground cover. Since forage is scarce and values high, a cool season forage crop could be planted to graze or harvest mechanically. What should you plant?
Before planting anything, review your herbicide history. Prior use of contact herbicides like glyphosate won’t cause any problems, but some herbicides have a long soil residual effect that could prevent successful establishment of some crops.
Double crop choice is likely to be different for rainfed and irrigated conditions. One ton (dry weight) of forage production is likely to use 4-5 inches of water. For rainfed conditions, a crop that will winter kill is preferred in order to accumulate soil water from snow melt and spring rainfall for the next crop. For irrigated conditions, forage production will be more with a crop that survives winter and is spring harvested—although irrigation for the forage and following crop will likely need to be increased compared with no double cropping.
Determine when the forage crop is to be harvested and how it will be used. For fall-harvested hay or silage, oats or other spring cereals will outyield all other options. Plant about 100 lb of seed per acre. Various legumes like hairy vetch, field peas, or winter peas can be added to increase protein concentration a percentage point or two, but they are unlikely to increase dry matter yield; the forage from the cereal alone will meet most cattle protein needs. Also be wary of spending more for the seed than the extra protein might be worth. For grazing this fall and winter, turnips and oats (separately or in a mixture) usually will provide the most feed.
Early planting and emergence (irrigation or soil moisture must be available immediately) is essential for successful fall forage. Plantings after Labor Day rarely produce sufficient growth for mechanical harvest in the fall and the amount of fall grazing becomes negligible for plantings made after mid-September. Even earlier planting dates may be needed for sites north of the Platte River. Later plantings should consist of winter cereals. Also, the chances for successful establishment are low unless soil is sufficiently moist to at least an eight-inch depth at time of planting.
For spring forage, the winter cereals rye, triticale, and wheat tend to be the best choices. Rye is your best choice for early spring pasture and produces much growth before being terminated for timely planting of a row crop. Some rye varieties also provide enough fall growth for some light grazing if planted early enough. Rye also may be the most reliable crop when planted under stressful conditions. Rye has some drawbacks. It turns stemmy and matures much earlier than triticale or wheat, with a loss in feed value and palatability, although this should not be an issue if harvest ends in time for spring planting of a row crop. Also, it should not be used in fields that will be used to grow grain wheat due to potential contamination that could lead to discounts/dockage when wheat grain is sold.
Triticale holds on to its feed value best into late spring. This makes it well suited for hay and silage, or for stretching grazing well into June if grazing begins two or three weeks later than it could begin with rye. Triticale often is more susceptible to winter injury than rye and wheat.
Winter wheat will provide very little grazing for fall. During spring, forage quality and acceptance is very high but forage yield is less than rye and triticale. It can be grazed and then allowed to produce grain if grazing ends when plants begin to joint and elongate.
Mixtures often can be desirable and can be designed for individual needs. For example, an early planting of 30 lb of oats plus 75 lb of winter rye per acre may provide both fall grazing from the oats and spring grazing from the rye.
Extension Forage Specialist
Extension Soil Nutrient Management Specialist