The Prairie Star: Montana Ag Newspaper

MOCCASIN, Mont. - Studies have shown that a crop rotation of peas and wheat would allow low rainfall farmers to survive.

Researchers at the Central Agricultural Research Center in Moccasin, Mont. have been experimenting with this alternative form of farming, called the Ley farming system, which was featured at the center's annual field day in June.

The Ley system was developed in Australia where there has been a 10-year drought. The CARC researchers began working with Roy Latta, an Australia with a career in sustainable farming to develop a system suitable for central Montana.

The Ley system uses a low input annual legume to be only sown once then self-regenerate.

When they were first trying this, the Australians started with a three-year rotation. The crop was grazed by livestock; then it went into fallow to conserve moisture and control weeds.

But, Latta said all it did was control disease.

They added chemicals and disease-resistant materials. Fallow was not required, so it became a wheat-pea rotation.

“Ley farming is quite sustainable,” said Latta. “It allows low rainfall farmers to survive.”

When in the Ley system, the legumes fix the nitrogen from the air and manure which reduces nitrogen input for the following wheat, explained Chengci Chen of CARC. The benefit from nitrogen if this rotation is done year after year is that more nitrogen stays in the soil, added Clain Jones of CARC.

Jim Krall, of the University of Wyoming started working with Latta in Australia on 1993 on the Ley system. Now, he said the university has released a new winter annual type of medic that produces more biomass and is winter hardy.

The Laramie Medic has yellow flowers, produces a hard seed and self-pollinates unlike alfalfa. It can be sown one-half the depth of winter wheat.

With Ley farming, there is a long-term seed preserve, added Krall.

“You've got seed in the bank,” he said.

After realizing the seed in the bank, Dr. Dave Buschena investigated other potential savings with the Ley farming system.

Buschena, an economist at Montana State University, put together a budget using peas as a fallow replacement in the Ley system. Since the cost of fuel and fertilizer has doubled in the past two years, he said he wanted to know who to reduce costs using this sytem.

What Buschena learned is the nitrogen financial benefit is less than he thought.

“That's, I think, not where the savings is,” he said. “The savings is in the chemical cost if you can use it as a fallow replacement.”

Farmers can realize this savings by rotating peas in the fall, grazing in the spring and wheat in the fall, said Buschena. During the field tour, he presented a report on representative enterprise budgets for pea grazing, haying and harvest for seed when included in a wheat-based dryland rotation.

In his report, Buschena considered three uses of peas - grazing by livestock, harvesting for seed and haying.

Although peas are a potential replacement for fallowing because they fix some nitrogen, have other agronomic benefits and can be competitive with many weeds, they also may reduce soil moisture for subsequent crops.

Buschena's report showed that if soil moisture conditions support planting peas as a substitute for fallow, the net returns under all three uses were positive.

Since water loss may be quite significant when peas are harvested for seed, Buschena suggested evaluating the positive returns before foregoing fallowing costs.

He also noted winter peas may not be hardy enough to survive winter conditions in some parts of Montana, especially the east and north.