As farmers look to reduce or even eliminate the practice of fallowing land across the High Plains, field peas are emerging as a promising substitute.
Lucas Haag, northwest area agronomist with Kansas State University, is intrigued by their potential.
"They only need a few inches of water and don't produce too much biomass," he said. "They are small plants and that's really what piqued my interest."
Haag is now working with other university researchers from Kansas, Nebraska and Colorado to learn more about how field peas can be integrated into rotations as a replacement for summer fallow. The grain-type spring-planted field pea is already grown on almost 100,000 acres in western Nebraska with a small amount of production in Northeastern Colorado and Western Kansas, but there are other types as well.
"We've been learning a lot about growing peas," Haag said at the High Plains No Till Conference in Burlington last month. "Interest has really picked up."
What makes the field pea attractive is that it will scavenge in-season precipitation without mining the soil moisture profile, a pattern demonstrated over multiple years in field trials at Garden City, Tribune, Colby and Akron, Colorado.
Still, it does take some moisture out of the system, usually to the detriment of the subsequent grain crop, Haag explained.
"If I look at everything we've done and seen in our research trials and with our on-farm cooperators, I would say we typically lose 7 to 10 bushels of grain yield on average compared to no-till chem-fallow, and there's about 2 inches less water in the soil profile at wheat planting time," he said.
From a cropping systems perspective, however, it might still make sense to growth them, he added.
As they grow, field peas stimulate soil microbial activity while optimizing the use of available water. In University of Nebraska studies, peas produced 36 bushels per acre yield on 11 inches of soil water, while fallow lost six inches of soil water to evaporation without producing anything, giving field peas an advantage of $110 an acre more in profitability.
"If we can't get a stand of wheat, that's a situation we don't want to be in," Haag conceded. "But in our research we've always been able to get a stand (following field peas.)"
Field peas do tend to thrive in a narrow temperature range, so early establishment is often critical, he said.
"Ultimately the challenge in our environment is that it is a cool season crop, and we are trying to get it in before the summer blast furnace gets turned on," he noted. Heavy residue can also prevent it from emerging in a timely fashion.
The longer the peas go before termination, the more nitrogen fixation activity will occur, but there's also a bigger hit to the subsequent cash crop, Haag said.
"Overall, you're probably looking at a relatively small amount of nitrogen becoming available over time," Haag said.
Currently, K-State and other universities are looking to find varieties and pea types that are better suited to the typical High Plains environment.
"We're looking for varieties that can maintain their growth rate under high temperatures and heat stress," he said. "There were 400 different genetic lines grown at Colby last year. We're just trying to find the ones that are adapted to our area."
Pulse crops in general, which are more commonly grown in the Northern Plains, are an excellent source of highly digestible protein, which makes them a valuable ingredient in livestock, pet, and human food products. They can also be used in sports nutrition bars and shakes, a fast-growing product segment. Most field peas get processed into split peas and exported for human consumption overseas or distributed through international food aid initiatives.
Haag now has a chickpea trial underway, since chickpeas can be marketed for pet kibble to several delivery locations in Southern Nebraska. Another option is to bin them on-farm and sell them through a broker, he said.
From 1984 to mid-2015, domestic pet food spending grew from $5.16 billion to $26.68 billion, an increase of 350 percent.
Haag is less optimistic about lentils.
"I'm about ready to give up on the lentils," he confessed. "I can see why guys like them as a companion crop. They do always come up, but they don't do much in terms of yield."
Field peas are not an entirely new crop; many farmers have grown them at one time or another over the years. But Haag said the combination of low commodity prices and interest in improving soil health have made them seem newly relevant again.
"We're just trying to open some doors for guys who want to intensify their rotations," he said. "What everybody's looking at is how to make it pay."