Seed these in case of emergency

The U.S. Drought Monitor is starting to light up again as several states show signs of struggling with inadequate soil moisture. As drought conditions develop across the northern tier of the U.S. and the Midwest, fingers point to a lack of snowfall last winter as a major culprit.

Then there are regions of the South where farmers joke that they are always only days away from a drought, regardless of previous rainfall. It’s during these stretches of high heat and limited moisture that perennial pasture systems could benefit from additional tonnage and forage quality that warm-season annuals can bring to the table.

In a recent University of Georgia Beef Tips N’ Advice newsletter, Lisa Baxter, Taylor Singleton, and Jennifer Tucker offer recommendations for planting, fertilizing, and harvesting warm-season annuals like pearl millet, sorghum-sudangrass, and sudangrass. Although seeding these species comes with additional costs, the extension specialists advocate for extra summer forage to supplement perennial grass production.

“The first key to drought management is preparedness, and being prepared means having the right tools ready,” writes Tucker, a beef and forage specialist. “Planting summer annual forage grasses is yet another tool in our toolbox to extend the grazing season and provide forage during environmental stressors.”

Stagger planting dates

Baxter, Georgia’s state forage specialist, and Singleton, an extension sustainability specialist, recommend seeding warm-season annuals when soil temperatures reach and maintain 65ºF at a 2-inch depth. In the Coastal Plains, this can occur anytime between April and June. They warn that planting late can result in yield drag and may hinder a return on investment. Late plantings are also more prone to suffer from drought stress; however, having multiple planting dates may be helpful.

“These forages grow much faster than perennials, so consider staggering your planting dates to extend the summer forage supply,” they add. “Two plantings made approximately four weeks apart can provide good-quality forage throughout the summer.”

For grazing purposes, they encourage applying 40 to 60 pounds of nitrogen per acre after seedlings emerge, as well as 50 to 60 pounds of nitrogen per acre per month during the grazing season. For hay production, they suggest applying 40 pounds of nitrogen per acre at planting, 60 pounds per acre after establishment, and an additional 60 pounds per acre after each cutting. Splitting nitrogen applications can mitigate nitrate toxicity.

“Many forages have the potential to accumulate nitrates, but millets, sorghums, and sudangrass are especially prone to this issue,” the specialists assert.

Fill the gaps

Tucker reiterates that warm-season annuals are highly tolerant to drought and heat, and they emerge quickly and grow fast. In fact, these species can be available to graze 35 to 45 days after planting. Moreover, warm-season annuals can have relatively high forage quality compared to perennial forages under the same summer conditions in the South.

With that said, she does not recommend relying on warm-season annuals as the backbone of a forage system. A strong perennial base is paramount, she writes, but there are at least five situations in which warm-season annuals will help fill forage gaps.

• To gain emergency forage when on-farm forage supplies are low and a fast-growing forage option is needed

• In a double-crop system, to cover the soil after harvesting a winter annual crop or between cropping seasons

• To salvage fertilizer applications that were applied to a failed row-crop stand

• During pasture renovations when other hay or grazing acres are limited

• In annual forage systems

Tucker notes utilizing warm-season annuals during pasture renovations can provide grazable or harvestable acres when land that would otherwise be available is not. It’s also common to use these species as the smother crop of the spray-smother-spray method of tall fescue pasture renovation.

Graze carefully

Though these situations allow the option to hay or graze summer forage, Tucker suggests the latter may be more practical since warm-season annuals can be a challenge to dry down in humid climates. Even so, these species require different grazing management than perennials like bermudagrass and bahiagrass.

Tucker recommends waiting to turn animals out on warm-season annuals until plants are 20 to 24 inches tall. Then, rotate livestock to a new paddock when plants are 8 to 10 inches tall. Allow 10 to 20 days for adequate rest and recovery.

“Grazing these species down to a nice, clean turf will result in significant injury for the plant and can be detrimental to our cattle health, thus continuous grazing is not recommended,” she advises.

Instead, strip graze or limit graze. For the former approach, allocate a strip of a forage with temporary fence and advance animals forward through the paddock as they graze plants down to 8 to 10 inches. For limit grazing, give animals access to warm-season annuals for a specific period — a few hours per day or on alternating days — before returning them to a perennial pasture or feeding area for the majority of the time.

“These methods allow for the most efficient use of summer annual grasses,” Tucker says. “Remember that when managed properly, summer annuals grasses provide a large amount of material very quickly, thus stocking density and rotation speed will need close attention for optimum utilization.”

Is it economical?

Assessing planting and fertilizer costs and potential forage yields raises the question: Is it economical to grow warm-season annuals? It depends. Tucker encourages farmers to take inventory of feed supplies and calculate expected forage availability, comparing that to what they think their livestock will need this summer.

She suggests grazing dairy cattle on warm-season annuals is almost always justifiable, whereas grazing beef cows on these species is most cost-effective in emergency forage situations. In stocker systems, the efficacy of summer annual forage production is highly dependent on the cattle market.

With that said, it may pay to be prepared in any situation, especially in the South. “After almost 10 years in Georgia, I can confirm that the common saying rings true: We are always one day away from a drought,” Tucker concludes.