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Forage sorghum has 92% of the digestible nutrients of corn silage and 85% of the feed value.

April 28, 2020

3 Min Read
Landscape view of deer feeding on corn silage in a field
BLOCKING A BUFFET: Deer like corn silage. In fact, in Pennsylvania, deer feeding damage is a big problem in cornfields. Forage sorghum can be a good replacement in places with heavy deer damage, or you can mix it in with your silage acres.Andrew Frankenfield

Corn silage is one of the most common forages fed to livestock in Pennsylvania, and with good reason.

Proper management and variety selection can lead to great yields of a high-quality product that easily meets the nutritional needs of some of our highest-producing livestock. But corn silage is also highly attractive to wildlife.

Deer feeding damage makes up a significant portion of yield loss in cornfields across Pennsylvania. There are several options for alternative forages that can fit well in your production system while providing less temptation to those pesky deer.

Variety selection

Both annual and perennial forages can supply adequate yield and forage quality to replace corn silage acreage.

When selecting perennial forages, it’s important to note that deer like to graze some species over others. In fields with heavy deer pressure, it would be best to avoid seeding legumes such as alfalfa and clover, as these species will be selectively grazed over grasses.

Forage sorghum, sudangrass and millets can provide significant yields with a demonstrated reduction in deer feeding and damage.

Forage sorghum closely matches the yield and nutritional value of corn silage with significantly less deer feeding. The yield of digestible nutrients of properly managed sorghum is around 92% of corn silage, and the feeding value is estimated at around 85% of corn silage.

Management considerations

Forage sorghum should be planted between 1 inch and 1.5 inches deep once soil temperatures reach 65 degrees F. This often occurs about two weeks after the ideal planting date for corn in your area.

A seeding rate between 5 pounds and 8 pounds an acre should result in an adequate stand.

A routine soil test will provide soil fertility recommendations, but an estimate of 150 pounds of nitrogen, 75 pounds of phosphorus and 75 pounds potassium is adequate in the absence of soil fertility recommendations.

Pest management

Forage sorghum has little insect pressure in Pennsylvania, so the routine use of insecticides is not recommended.

Forage sorghum can be more sensitive to herbicides used in corn production, so control of weeds may be more difficult. A weed management program should start with adequate burndown — either with tillage, herbicides or a combination of both. With adequate fertility and seeding rates, forage sorghum emerges quickly enough to outcompete weeds, so a later herbicide application is not often necessary.

Harvest management

In shorter-season areas of Pennsylvania, it is important to select a hybrid with an earlier maturity so that it reaches the proper moisture content before frost. Forage sorghum, as well as many other annuals, can accumulate prussic acid after a frost, so it is ideal to harvest prior to frost to avoid quality degradation and animal toxicity.

Sorghum maturity is rated as full, medium and early, so your seed dealer can help you select what maturity is the best fit for your growing conditions.

Forage sorghum should be harvested for silage when the grain is at the soft-to-medium dough stage. At this stage, whole-plant moisture is most likely to be in the proper range for safe ensiling and fermentation.

Forage utilization

Yield and forage quality of forage sorghum is comparable to corn silage and can even exceed that of corn silage in droughty fields or those with heavy deer pressure.

Additionally, forage sorghum can be established for a fraction of the cost, decreasing the financial risk of crop establishment.

Forage sorghum can also be grown in mixtures with corn silage or as a barrier around cornfields to mitigate deer feeding pressure.

Source: Penn State Extension, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.

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