By Leanna Duppstadt and Justin Brackenrich
There are lots of reasons to need an alternative forage: ever-changing environment of forage management, herbicide and fertilizer prices, unpredictable weather, winter killed or damaged cereal crops, and so on. If during the planting season you fall behind or things get too dry, what are my alternatives? You just want to have more grazing options for the summer slump of your cool season pastures? Rather than have these questions go unanswered, or hope things will work out on their own, it is important to start with a plan and know what options exist.
Options for Spring
As winter let's up and we move into spring, the first available options we have, for planting, are establishment of either cool-season annual or perennial forages. An example of a cool-season annual would be oats and peas, while red clover and smooth brome grass could serve as a perennial option.
One good thing about summer annuals, like an oat pea mix, is that you can produce a forage in a quick turnaround, and still have time in the late summer or fall to produce another summer crop or seed into a perennial forage as an annual. Other grains, like barley, wheat, or rye can be used to provide forage too, but are usually planted in the subsequent fall and not as useful as an emergency feed. Research conducted by South Dakota State in 2007 showed that early planted (April) and early harvested (June) could yield 2.0 tons/ acre. Adding peas would decrease tonnage, but increase digestibility, crude protein, and RFV. For more information on Oats and Peas as a forage, read Oat and Pea Forage Combinations by Michigan State University.
When establishing perennial forages in the spring, management and forage availability differ, when comparing them to fall seeded stands. Typically, perennial forages should be established until legumes flower or grasses reach boot before harvest. This can be moved up if weeds encroach but harvesting too early can reduce stands success and should be used only when necessary. These stands will be susceptible to drought stress and moisture issues during the hot summer months and adding a nurse crop to these seedings can increase this risk. Yes, the nurse crop can reduce weed competition and increase forage production, but it is another crop competing for nutrients and water. Before establishing perennial forages in the spring/summer, consider soil fertility testing and prior weed management treatments. Planting clean will be your best defense but be aware that prior herbicides may limit success of these stands. Review Agronomy Guide Table 1.8-6 for seeding recommendation and rates. For other information on spring forage seeding types, read Spring Seeding of Forages by The Ohio State University.
Another option for spring seeding a perennial forage is frost seeding clover into small grains, like wheat or barley. Frost seeding red clovers will allow the clover to establish and grow after the small grain is harvested. This practice is most effective when seeding on a "good" wheat stand, as a thin stand will allow the red clover to establish too fast and overtake the grain. If herbicides are typically used as a part of small grain management, this practice may not be most effective, as herbicides are limited once the clover is seeded. For more information about frost seeding in small grains, read Frostseeding Clovers Into Small Grains .
Options for Summer
In Pennsylvania, a few summers annual alternatives options exist. They all have their pros and cons, so make sure you understand each before deciding what to plant.
The big question- what forage are we replacing? Is this a situation where we are replacing a high nutrition, bulk forage like corn silage? Are we needing dry matter as a winter feed, so replacing something like hay? Do we just want to find a way to need less preserved forage, and extend our grazing season? Some good choices as alternatives to corn silage would be species like forage sorghum or sorghum-sudangrass hybrids, which can often give similar nutritive qualities to corn silage but will grow better in dry conditions. Other summer forage options could include teff grass, forage crabgrass or pearl millet, which could be used for fall forage as well.
Forage sorghum
Forage sorghum is a suitable alternative to corn silage, as it is best suited for silage. Yields are typically in the range of 8-10 tons, but grows better in droughty conditions and is subject to less deer damage. When using quality varieties and hybrids, nutritive value can be 89-90% of corn sileage. If used as a silage, there is less concern of prussic acid or nitrate issues due to dissipation during storage and the dilution of using the entire plant as compared to the selective nature of grazing animals. Fertility and liming are similar to that of corn; 150-75-75 would be sufficient for crop production. Seed should be planted at a depth of 1.0"-1.5" in 7.5" or 15" rows. Sorghum prefers warmer soils for germination and growth; therefore, it should be planted about 14 days (about 2 weeks) after corn planting temperatures are reached. Common planting rates are 5 to 8 lbs per acre.
Sudangrass / Sorghum-sudangrass hybrids
Sudangrass presents a substantial risk for prussic and nitrate poisoning issues. Newer low prussic acid varieties are available, but the risk remains. Grazing plants less than 24", grazing directly after a drought ends or a frost, and some susceptible sudangrass hybrids, can increase the risk of prussic acid issues. Sudangrass has narrow stems and leaves, making it a good option for grazing, chopping, and even hay, if conditions allow. Sorghum x sudangrass hybrids will typically yield more, when compared to sudangrass or sudangrass hybrids, but have higher prussic acid levels. Sorghum x sudangrass has the best utility when used for green chop or sileage, since the larger stems will make drying for hay difficult. Nitrogen levels must be monitored with these crops. Applying a large amount of N upfront can lead to not only wasted resources, but nitrate accumulation in the plant. Split applying N, so that 50 lbs is applied after the first cutting will provide the best opportunity for growth. Sudangrass and sorghum x sudangrass should be planted at a depth of 1.0"-1.5". As with sorghum, these verities prefer warmer soils for germination and growth; therefore, it should be planted about 14 days (about 2 weeks) after corn planting temperatures are reached, until mid-July. Rates are variable, depending on the variety.
Read Reducing the Risk of Nitrate and Prussic Acid Poisoning in Livestock for more on Nitrate and Prussic acid issues.
Millets
Pearl millet is a close second to our sorghums and sorghum-sudangrass hybrids in terms of total yield. Millets often grow 40" in 2 to 3 months. Some varieties, like Pearl, will regrow after harvest, while other varieties, like Foxtail, will not. Since it tolerates cooler temperatures better than the other warm season annual grasses, it is also a good option to stockpile for fall grazing. Even though millets have a lower yield than the other options, like sorghum or sudangrass, millets do not accumulate toxic levels of prussic acid, making them an excellent option for grazers. This crop can be produced with a simple fertility program, planting after corn through mid-July.
Teff Grass
Teff is a warm season annual grass that is adapted to a variety of growing conditions including droughty or waterlogged soils. It can be planted in mid-summer and used as an emergency summer forage as pasture, hay, or silage. If planning to graze teff, consider harvesting the forage mechanically first, then grazing the second harvest. Teff's shallow and thin root system is susceptible to grazing damage. When managed properly, it can produce over 3 tons per acre, with a crude protein content of 15-16%. Teff should not be seeded until the threat of frost has passed. Teff seed is very small, so careful considerations need to be made to ensure a seed depth of 1/8 to 1/4 of an inch, on a firm seedbed.
Soybeans
Soybeans can be considered as a forage alternative if alfalfa or clover will be in short supply, whether that be thinning stands, winter-kill, or drought conditions. Traditional soybean crops can be harvested for this purpose, as emergency silage. This is also an option if the soybean was damaged and isn’t viable for grain harvest. There are limited herbicides labeled for harvest soybeans as a forage, so this should be taken into consideration if making the decision to harvest grain soybeans as an emergency forage.
Forage soybean varieties are available. They are taller than traditional soybeans and are harvested around 28-36 inches tall. It can be grazed, greenchopped, or used for silage. It can produce 2 to 4 tons of dry matter per acre (soybeans planted later in the year as emergency forage will have lower yields) with a crude protein content between 14-19%. For more information regarding the management of soybeans for forage, please reference this article from Wisconsin University, Soybeans for Hay or Silage.
Stockpiling and Summer Grazing
If your objective with the alternatives is to increase grazing, either during the summer or fall months, species selection is paramount. Many of the species we graze during the summer will be much different than fall species. Some even carry health risks when grazed later in the year. Often, we can plant an annual grass, like millet, and brassica, and clover, after a small grain to have a nice early fall grazing area. For more on extending the grazing season and species selection, read Extending the Grazing Season with Plant Diversity.
Brassicas
Brassicas planted in May through early June can be grazed late summer and brassicas planted in July through early August can be used in the fall to extend the grazing season. Their high cold tolerance could mean that they are available as late into the year as December, as long as ground conditions are favorable for grazing. They are highly productive and can vary in protein levels from 15 to 25% in the aboveground foliage depending on nitrogen fertilization and weather conditions. Brassicas should be planted in well drained soils. They can also pose some animal health risks if not grazed properly so be sure to introduce animals to them slowly and they should not make up more than 75% of the animals diet, so supplement with dry hay or grass pasture.
Tall Fescue
Tall fescue is a cool-season perennial and an excellent option for stockpiling because it retains its quality late into the fall and early winter. This is because of a waxy layer on the leaf that helps to shield it from cooling temperatures and frost damage. Proper management is still needed to encourage maximum growth and yields in the fall months. Start to stockpile in late July – early August, roughly 60 days before the first frost. Mow or graze down to 3-4 inches and then make a 40-60 lb nitrogen application for optimal forage accumulation. Strip grazing is the best method for forage removal, to get the most use out of the forage while minimizing waste.
Cereal Grains/Triticale/ Oats/Rye)
Oats planted in late July can be ready in the fall. They are also a good companion with brassicas like radish or turnips. Triticale or rye planted in September can provide spring forage and can be removed in time for any spring planting.
Growing a diverse selection of forages in combination with a field cropping system can pose challenges with pesticide and/or manure restrictions so always be sure to check the label before planting. Also, remember to choose the forage that will be best suited for your operation in terms of the nutrient needs of your livestock as well as your management practices and capabilities to establish, harvest, or maintain these species.
Penn State Forage Variety Trial Reports are available that summarize data collected from ongoing forage trials at two locations in PA. When selecting species, be sure to pick ones that will be adapted to your area.
Many universities have excellent resources, which were used in the writing of this article, to compare management and usage of different annual options. Summer Annual Forage Grasses by University of Nebraska, Summer- Annual Grasses for Supplemental or Emergence Forage by Penn State Extension, and Sorghums, Sudangrass, and Sorghum-Sudan Hybrids by The University of Wisconsin. For harvesting and feeding information, read Harvesting and Feeding Warm-Season Annuals for Forage . For price comparisons of annuals and corn silage, review Annual Forage Alternatives to Corn Silage .
Source : psu.edu