Researchers established 20 percent bromegrass in the alfalfa stand, assuming utilization by dairy farmers. The research showed in well-managed alfalfa only 0.3 tons per acre per year of soil is lost, and in most years less. Farmers who can utilize pure bromegrass should use it on steep slopes for better erosion control than alfalfa. For farmers not able to utilize bromegrass, maintaining ground cover with alfalfa is important. The last project evaluated spray-killing alfalfa as a best management practice, instead of plowing under an old alfalfa stand.
Erosion occurs in the early spring.
One exception was a fall-killed stand that contained 40 percent grass. Ground cover of this stand was 30 to 40 percent in the spring, bringing erosion to within the allowable limit without affecting corn yields. On the other hand, spring-killed alfalfa minimized erosion but reduced corn yields. Studies now underway look at zone tillage in spring-killed alfalfa and profitable yields in corn. The researchers found that these best management practices can reduce soil erosion by 2 to 10 times the amount seen in traditional practices.