Sorghum forages are continuing to flourish in North Dakota as NDSU data shows sorghums have a fit in the livestock forage ration, especially if producers hit the yield/nutrient compromise.
“2023 and 2022 were really good sorghum years for us. We had really good success with the sorghums, but one kick against the sorghums has been that while they yield really well, forage quality has been an issue in terms of nutrient content,” said James Rogers, NDSU Extension forage crops production specialist at NDSU’s North Central Research Extension Center (NCREC), during 2023 field days in Williston, N.D.
Rogers has been working with sorghum-sudan forages and sorghum mixes for North Dakota producers partly because they are a warm season annual forage, and they work well in terms of prevent plant acreages because they enjoy hot humid days, which fit after June 30.
New rules concerning prevent plant acres have encouraged more producers to plant forages on those acres because they can utilize that forage several ways.
“There has been changes in the rules concerning prevent plant acres that allow producers to plant a crop that can be utilized as a forage crop without affecting payments. It can be grazed, we can put it into silage, or we can hay it and put it in a bale,” Rogers said.
There are a lot of traits to find in sorghum-sudan forages, from dwarfism to brown mid-rib, male sterile plants, and photosensitivity.
“Do you need all those traits? When you’re feeding a beef cow, you really don’t. You just need to make sure that you’re getting her adequate nutrient content with enough forage mass to meet her needs,” he said.
Rogers has conducted variety trials on the sorghums to help with decision-making.
Because sorghum-sudangrass is a relatively new forage in the state, producers may be unsure of the right date to plant and harvest sorghum and other forages in order to obtain the most quality/nutrient content with the highest yield.
“All our forages go through a period of high quality when they’re in the very vegetative stage, and then as they mature, that quality goes down depending upon the forage and the rate of that decline varies depending on the forage,” he said.
“What we want to do is be able to hit that yield quality compromise. We want to be able to produce enough yield that’s going to justify putting it into a bale, putting it into silage, or grazing it. But we also don’t want to compromise our quality. We want enough quantity with enough quality to meet livestock nutrient demands.”
Of course, variations in weather conditions from year-to-year influence forage crop planting and harvest dates, dry matter (DM) yield, and nutrient content.
Rogers began the first year of a four-year planting date trial in 2023 on loamy soil at NCREC. There were 12 forage treatments, including cool/warm season annual forages planted as monocultures and/or mixtures, with three planting dates: May 10, June 12, and July 26.
Rainfall varied from May to October, but from August to October, the center received above average rainfall in 2023.
DM yield and forage nutrient content were evaluated for each planting date.
“Understanding how planting date affects forage yield and nutrient content is important in determining forage crop selection, so we examined planting date effect on forage DM yield and nutrient content of these annual forages,” Rogers said.
Since 2023 was only the first year of the multi-year trial, no firm conclusions can be made just yet, but Rogers says he did find an effective planting date for yield. The June and July planting dates had higher forage yields than the May planting date of about a thousand pounds of dry matter.
The forages in the treatments were sorghums and other forages as monocultures, as well as two-way and three-way mixes.
The forages were the mixes sorghum-sudan/Derry (forage soybean), rye/Derry, rye/sorghum-sudan/Derry. oat/sorghum-sudan, rye/sorghum-sudan, rye/oats, oat/sorghum-sudan/Derry, oat/Derry and the monocultures of Dylan rye, forage oats, Derry forage soybean and sorghum-sudan.
Four of the treatments included Derry forage soybeans. Rogers said he wanted to find a legume that would be compatible with sorghum-sudangrass.
“I thought of forage soybeans, so I sent for a southern-type forage soybean seed developed by the USDA-ARS in the 1990s called Derry forage soybean,” Rogers said. “Derry has really found its niche as a component in wildlife food plots. It’s used a lot there. It really has a very tall upright growth habit and has a lot of leaves on it. It actually did pretty well here.”
The problem that Rogers had with Derry forage soybeans was the deer, which affected some of their yields. In fact, on some of the monoculture plots of Derry forage soybean, Rogers didn’t get a yield because the deer ate the entire plot.
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“We have a pretty nice little deer population here at the center and they absolutely loved it,” he said.
After emergence, the annual grasses received 50 pounds of urea. No nitrogen was applied to those treatments containing any forage soybeans.
With forages planted on May 10, 2023, the highest dry matter yield was the mixture of rye/sorghum-sudan/Derry forage soybean at 4,401 pounds per acre, followed by sorghum-sudan at 4,162 pounds per acre and a mix of sorghum-sudan and Derry at 3,643 pounds per acre.
With forages planted on June 12, 2023, the highest dry matter yield was sorghum-sudan at 6,273 pounds per acre, followed by sorghum-sudan/Derry forage soybean at 4,990 pounds per acre and a mix of oats and Derry at 4,529 pounds per acre.
With the sorghum-sudangrass at 6,273 pounds per acre, the nutrients were: percent crude protein, 16.7; percent total digestible nutrient (TDN), 65.2; percent lower acid detergent (ADF), 29.7; percent neutral detergent fiber (NDF), 57; and percent dry matter intake (DMI), 2.11.
“For comparison purposes, premium quality grass hay contains crude protein (CP) greater than 13 percent; good is 9-13 percent and fair is 5-9 percent, according to NDSU,” Rogers said.
With forages planted on July 26, 2023, the highest dry matter yield was oats at 5,675 pounds per acre, followed by a mix of oats and rye at 4,671 pounds per acre and a mix of oats and Derry at 4,529 pounds per acre.
CP rose with planting date, so the July 26 date had the highest CP at 19.2 percent.
Other details from the trial include:
• Forage soybean performed well in combination with sorghum-sudan with no difference in yield compared to sorghum-sudan with fertilizer regardless of planting month.
• Initial economic evaluation indicated with hay valued at $82 per bale, the highest net return is sorghum-sudangrass ($80.19 per acre) followed by sorghum-sudangrass/forage soybean ($70.75 per acre). This order could change with more years of data.
• In 2024, forage barley will be included as an additional treatment.
During field days, Rogers said he wanted to take more of a systems approach with the sorghum-sudangrass and the seed mixes that can be planted together with the sorghums to provide the kind of forage livestock producers need.
“We also want to begin to integrate crops into this system, and work toward having a living root in the soil as many days as we can year-round,” he said.
Rogers pointed to winter rye, a forage planted alone or in mixes. The rye did not add to the forage mass this year, but it will overwinter and provide a crop next spring.
“Think about what the cereal rye is doing. I’ve already got a crop established there that’s going to go through the winter period, and I’m probably going to be able to harvest it next spring. With one planting, I’m getting two seasonal crops out of it, and I am very interested in that,” Rogers said.
At the Williston field days, Rogers explained that when sorghum-sudangrass gets really big, it produces a very high amount of biomass that can be difficult to dry down because it produces such a large amount of mass.
The dry stalk trait that is in some sorghum-sudan varieties does help with dry down, he pointed out.
“It will have a big stalk, but it tends to have a little bit less moisture content, which is going to speed drying,” he said.
Rogers said another variety they grew at NCREC and Williston Research Extension Center was a forage sorghum, with a dwarfism trait.
“When they put the dwarfism trait in it, what it does is it reduces the inter-nodal length from leaf to leaf in the plant, so it will have the same number of leaves as a non-dwarf type plant, but in a shorter statute,” he said. “You are going to get the quality, but you’re not going to have the bulkiness – the mass of all that additional stalk in order to help you dry it down.”
His goal with these sorghums and combining them with other mixes is to not only help producers get the most from their forages and find varieties and types of forages that will work on their farms and ranches, but to have a living root growing all year long for soil health.
“My ultimate goal is to have some type of crop growing out there 365 days of the year. That is going to be a challenge here in North Dakota, but it’s something that we can definitely look for,” Rogers said.
This year at some NDSU field days, Rogers will update producers with his several trials that he is conducting with sorghum-sudan and other forages.