Reduced lignin alfalfa: Quantity and quality considerations

Alex Rocateli, Oklahoma State University associate professor and Extension specialist for forage systems, said when he finally got to Oklahoma, he found his experience with forage sorghum and switchgrass wasn’t something producers were looking for. Instead, they were wanting winter grass, wheat and alfalfa information. Rocateli spoke at the Feb. 22 Alfalfa U event in Dodge City, Kansas.

“I just realized you don’t have much information needs in this area,” he said. “I don’t see much in Kansas, in New Mexico, or Oklahoma, even Texas.”

It was at this point Rocateli started getting interested in reduced lignin alfalfa, and after a couple years of planning and securing funding, he was finally able to start researching and planted variety trials in 2019. Even with his partial data, he could only assume so much.

“I think that we have some take home messages and some points that we can discuss,” he said. “And I hope that in two or three more years, I can have more solid things.”

Rocateli likes to stay simple when it comes to looking at the data he’s collected. He’s still got some work to do on it and believes the stands won’t be as stable as he likes until years three to five.

When it comes to reduced lignin alfalfa and what it can produce, Rocateli compared whole milk and skim milk and how one has more protein than the other, despite being a less concentrated version of the original. That’s accomplished mathematically, and it can be analogous to reduced lignin compared to conventional alfalfa.

“Definitely the plant is producing more protein because you are reducing your lignin mathematically,” he said. “Your crude protein will increase, but the increment in crude protein you’re talking about 0.25 units—one, no more than 2%.”

How does that impact the quality of the forage? Not much really. But if the ADF (acid detergent fiber) or digestibility of the alfalfa goes up, that translates to quite a difference.

“Now when you decrease 1% or 2% of ADF of lignin that translates into 10% to 15% higher digestibility,” Rocateli said. “So that has a huge impact.”

When it comes the other half of the story—how much forage is produced—in Rocateli’s trials, over the course of a season, it all depends on how much rain was received and if harvest intervals were appropriate.

“Giving up on that tonnage and getting a more digestible forage that will translate the more milk, that will translate more beef or (higher priced hay),” he said. “That’s why these two need to correlate.”

Rocateli said the economics need to make sense.

“And when we don’t know I think that is the most exciting part,” he said.

In the end Rocateli sees the potential in reduced lignin alfalfa in the High Plains.

“It really can produce quality forage, but you need to sacrifice a little bit of yield,” he said. “And when you talk about the economics here, we need to see exactly why it is better to give up 10% of the yield for 10% to 15% higher digestibility.”

Management must be taken into consideration and a manager needs to have more flexibility in addition to the water use efficiency.

Kylene Scott can be reached at 620-227-1804 or [email protected].