By Montana State University
Wheat growers who grow both pea and wheat in their fields are likely to lessen the economic risks of farming while maintaining the same level of profits as those who grow only wheat or leave a field fallow, according to a group of Montana State University (MSU) scientists.
The scientists recently published their findings in Agronomy Journal.
"Across the state, farmers for a long time have been touting the benefits of pulse crops, so it's nice to have detailed data pulled from an economic analysis that proves pulse crops are a safe bet, at least in (more) moist areas of the state," said Perry Miller, an MSU land resources and environmental sciences professor and the lead author of the study.
Miller, along with a team of researchers that included MSU soil fertility extension specialist Clain Jones and agricultural economics assistant professor Anton Bekkerman from the MSU College of Agriculture, compared six cropping systems over a four-year period, following a six-year soil transition period. Those cropping systems were: fallow followed by wheat (both tilled and no-till), continuous wheat, pea followed by wheat, pea that could be marketed for grain followed by wheat, pea that could be used for forage followed by wheat, and pea that was terminated and used as manure followed by wheat. The research team also performed an analysis of these systems when high and low rates of commercial nitrogen fertilizer were applied at seeding.
Their research showed pea is an agronomic and economic benefit to wheat cropping systems, for several reasons.
First, the organic nitrogen - a by-product of pea and a vital fertilizer that can be used by a successive planting of wheat - was utilized by the wheat as it grew and served as a reserve when there was excess moisture in 2010, Miller said.
Second, pea followed by wheat cropping systems consistently provided increased economic return stability and strong protein levels in wheat, despite the extra costs associated with these systems, such as additional seeding costs, according to Miller.
He added that buying and applying commercial nitrogen is often an immense cost for farmers. Ultimately, however, growing pea in a wheat system required less commercial nitrogen than in wheat systems that don't grow pea or other pulse crops.
The organic nitrogen from the pea also contributed to higher protein premiums, according to Bekkerman, who said consistently securing protein premium is important to maintain profitability.
During dry years, markets value higher protein wheat less, Bekkerman noted, because there is typically a surplus of high protein grain across most Montana markets. Conversely, protein price discounts are higher during wetter years when many farmers have higher yields but lower protein content.
The study suggested that in a wetter year, more organic nitrogen was released, and in a drier year, less nitrogen was released (to align with lower yields).
"We found that pea, even when used during the normal summer fallow period, took variability out of the system and changed the reliance on fertilizer because the nitrogen levels became adjusted to soil wetness," Miller said. "So, in a sense, the pea created a certain amount of resilience in the face of uncertain climate and protein markets."
The nitrogen levels in the soil from pea helped increase yield and protein of the wheat crop, according to Jones. At the same time, the nitrogen levels added benefits to the soil for future crops. These benefits were not found in continuous wheat and fallow followed by wheat cropping systems.
"Fallow is one of the most destructive agricultural soil management practices because of soil erosion, loss of soil organic matter and soil structure and nitrate leaching," Miller said.
He added that because fallow stores soil water, it generally reduces risk of crop failure and stabilizes yield and economic return, especially in drier regions of Montana.
Because moisture levels are not known in advance and can be different from year to year, a market's estimate of protein content, and a producer's economic return, must be evaluated for both high and low moisture scenarios, Bekkerman said.
To get a sense of historical difference in protein markets, Bekkerman analyzed data from 40 different Montana grain elevators over the last 12 years. Of those years, seven had low-protein discounts and five had high-protein discounts.
"Clearly, there are years when protein matters and when it doesn't matter much, though that's not something a producer knows ahead of time, so it's real uncertainty," Bekkerman said. "The idea here is if having peas in your rotation is going to increase your organic nitrogen, then you are likely going to benefit from higher protein levels, but the economic value of that benefit depends on the market and what kind of year it's going to be."
From his data set, Bekkerman found that in moist environments (that allowed for more intensive grain pea–wheat systems), average additional annual net revenue was $75 per acre higher than a no-till fallow–wheat system, regardless of the nitrogen rate or the differences in how much markets value protein across years. In less intensive systems, such as growing pea for forage or for manure systems followed by wheat (pea-based systems), economic outcomes depended on the applied nitrogen rate. When the full amount of recommended nitrogen rate was applied, both the pea-based and traditional fallow followed by wheat approaches had approximately the same net revenues and risk. However, when half of the recommended nitrogen rate was used, four-year economic returns for pea-based systems were, on average, $86 higher per acre and economic returns for the pea-based systems were 50 percent less risky, Bekkerman said.
"When nitrogen costs are a limiting factor in production, increases in the cost of nitrogen fertilizer can affect management strategies and economic returns," Bekkerman said. "A pea-grain system, however, reduces a producer's cost of nitrogen inputs without reducing average returns or the risk that those returns will be highly different across years."
Bekkerman said that the study found producers who reduce nitrogen input using fallow and wheat only are likely to have lower returns with more economic risk.
According the US Department of Agriculture 2014 Montana Agricultural Statistics, Montana is the leading producer of dry pea and lentils in the country, valued at more than $100 million annually. The National Agricultural Statistics Service reports the 2014 average price for pea was $10.60 per 100 pounds for Montana. In 2014, Montana produced 53 per cent of the nation's dry pea with more than 500,000 acres of pea grown.