The group published their work in the Agronomy Journal.
One goal of their research was the establishment of an emergency plan for producers who have forage challenges, said Scott Wells, corresponding author and assistant professor at the University of Minnesota.
“It’s a Band-Aid, or the first aid kit – a program to generate forage immediately,” he told FeedNavigator. “There are cases when it could work really well – that’s why there’s the economic piece of it.”
Winter-kill of alfalfa (Medicago sativa L.) causes substantial yield losses in northern environments, requiring alternative forages to meet livestock needs.
Wells said the research project was informed by several years of poorer alfalfa production from inclement weather including wildfire and drought. “[What happens] if the alfalfa looked great in March and then died? This is what got us to think about it."
Wells et al’s study explored the forage yield, nutritive value, and nitrogen response of seven annual forage species and one grass–legume biculture, no-till planted into spring-terminated alfalfa. Those tested were harvested in 30-day intervals.
Ryegrass was picked to be one of the replacement forages because the department had worked with it previously, said Wells.
“You have to set up the ones you know are going to work,” he said.
Consistent return from ryegrass
Although teff and sudangrass were among the highest-yielding plants tested, the annual ryegrass had the most consistent greatest net return, they said.
The ryegrass can be planted and cut three and possibly four times in a growing season, said Wells.
“By the time you make the third cut, you’d be pushing into August and I would hesitate to say tear that up and plant alfalfa,” he said. “I would plant a cool season cover crop that could be a forage or [let the field] go fallow and plant corn silage.”
The project also examined the potential of planting an alternative forage in a no-till manner on top of the killed alfalfa, he said.
“It’s really situational,” he said. “If you had first-year production and you lost the alfalfa I’d probably take the risk and replant it – the need for forage is greater than the poorer plants we might get.”
It is not recommend to plant a new crop of alfalfa over old strand alfalfa because of the potential for auto-toxicity, said Wells.
However, there are other steps that a producer would need to make the alternative forage work in a ration, he said.
“This is not an alfalfa replacement,” he said. “The crude proteins are good … but they won’t provide the level of protein that alfalfa would bring.”
One concern when starting the project was if dairy nutritionists would be able to formulate rations using the alternative forages, he said.
The initial focus was on providing an alternative for dairy producers, said Wells. However, the forages also would work for beef production.
“It would work fine for beef – you don’t need quite the hot forage ration going in,” he said.
It also could be an option for a grazing situation if needed, he added.
Source: Agronomy Journal
Title: Yield, Nutritive Value, and Profitability of Direct-Seeded Annual Forages following Spring-Terminated Alfalfa
Authors: R Noland, C Sheaffer, J Coulter, R Becker, MS Wells