Drew Leitch of Nezperce, Idaho, uses cover crops and grazing animals to improve the health and productivity of the soil on his farm.
A report on Leitch’s operation is given in PNW 721, one of a group of case studies available from Pacific Northwest Extension Publishing, a cooperative venture of the University of Idaho, Oregon State University and Washington State University.
In 2012, Leitch began working with the University of Idaho by conducting a 23-acre test plot featuring both spring- and fall-planted cover crops and exploring their suitability for grazing as well as their effects on the growth of the subsequent cash crops.
Leitch’s 5,500-acre operation is on the Camas Prairie in Northern Idaho. It includes 2,500 acres of cropland and 3,000 acres of pasture. The elevation on the prairie ranges from 3,300 to 3,800 feet, which makes for a shorter and relatively cool growing season. Cash crops grown on the farm include wheat, Kentucky bluegrass, spring canola, garbanzo beans, peas and lentils.
Leitch runs a 125-pair cow-calf herd along with his dryland crop production. Previously, the limiting factor with his beef operation had been running low on pasture in the early summer. He began using cover crops to improve his soil and also to provide summer and fall pasture for his cattle.
Direct seeding of crops on his farm has been done for more than 20 years, which helped to make slow, steady progress to increase the soil organic matter. Cover cropping was added to help improve soil health and enhance feed availability for the cattle. The cattle manure adds minerals and the animal’s hoof action assists in incorporating organic matter into the soil and reduces soil compaction.
In addition to providing additional livestock feed, the cover crops extend the period of time that the soil surface is covered with a protective plant cover, which reduces soil erosion and helps to enhance the life of valuable soil organisms.
This operation uses a diverse mix of plant species as cover crops. Leitch usually uses at least one brassica, one legume and several annual grasses. The brassicas, like canola and turnips, have large taproots that penetrate the soil and reduce compaction. Legumes, such as peas and lentils, add nitrogen to the soil through their natural nitrogen fixation process. Grasses, like wheat and oats, retain soil nitrogen and reduce leaching, while providing large amounts of crop biomass.
Leitch’s spring-seeded cover crops are usually planted in April and May for summer grazing. He selects varieties that stay green longer into the summer, have good regrowth after grazing, winter kill in the fall and are not likely to become weeds.
Electric fences are used to control the grazing as the cattle move from one part of the field to the next. Management intensive grazing is practiced and livestock are moved every five to seven days. Leitch aims for one cow-calf pair or three 600-pound animals per acre.
The animals start by flash grazing over the green forage, then work their way back more slowly through the drier forage. The drier forage has good feed value, but is not as tasty as the greener material. The cattle are allowed to graze off about half of the plant material, so that the other half will be available to provide organic matter and minerals for soil improvement.
After harvesting a winter wheat crop, he will plant a fall cover crop that protects the soil until the following spring at which time he will terminate the fall cover crop and plant a spring cover crop.
Leitch has found that the use of cover crops has increased the profitability of his cattle herd, while continuing to improve the health of his cropland soil. The higher availability of summer feed has resulted in greater weight gains and he is able to run more cattle than before, increasing his income as he improves soil health.