Integrating Livestock into Sugarbeet-Barley RotationsWritten by Jay Norton
By Jay Norton, UW Extension Soil Specialist
Driving around and talking to producers in the Big Horn Basin this fall, I noticed an increasing trend toward replanting barley for fall and winter grazing. Some producers are also lengthening rotations and including two to three years of alfalfa for seed or forage.
Sugarbeet-barley rotations are notoriously destructive to soil health because of intensive tillage, long periods of bare soil and the every-other-year frequency of heavily consumptive sugarbeets. Several research papers have shown that the less often sugarbeets are grown, the healthier the soil. One of the latest reports is from our on-farm study in the Powell area, in which both soil health and sugarbeet yield improved in the order sugarbeet-barley, sugarbeet-bean-barley, sugarbeet-barley-alfalfa-alfalfa (Hurisso et al., 2015).
Farmers are realizing that the early harvest of barley creates a window of opportunity. Barley can be replanted right behind the combine to grow a tall, green forage crop before freeze up. Some farmers irrigate and fertilize to maximize forage production. Others include a mix of other cover crop species to benefit both the soil and the livestock.
The system works especially well with sprinkler irrigation because of reduced requirements for tillage, leveling and bedding, but if those operations can wait until spring, it should benefit furrow systems as well.
We’re catching up with farmers to evaluate the benefits, but barley is known to be a great cover crop. It grows very rapidly, competes voraciously with weeds, is very salt tolerant and has prolific fine roots that improve soil tilth and organic matter content. Barley can produce more biomass in a shorter time than any other cereal crop. It can form a deep, fine root system that improves soil structure and scavenges valuable nutrients. Grown together with a legume like field pea, barley can stimulate more nitrogen fixation and capture it in easily-decomposed biomass. A USDA Sustainable Agriculture Research and Education (SARE) on-line publication provides an excellent description of barley and many other cover crops. Visit sare.org/Learning-Center/Books/Managing-Cover-Crops-Profitably-3rd-Edition for more information.
Several research studies have shown that grazing does not reduce soil health benefits of cover crops. To the contrary, a recent study in the southeastern U.S. found that grazing sped turnover rates of cover crop biomass, increasing biologically active carbon and soil microbial biomass without affecting the amount of potentially available nitrogen (Franzluebbers and Stuedemann, 2015). The benefits were greater under reduced tillage, which is another growing trend under sprinkler irrigated systems in Wyoming. We’re making plans to study interactions among cover crops, tillage and grazing in this part of the country, but we expect similar beneficial outcomes.
If grazing is not part of the picture, replanting barley could still be worth the effort, especially if other cover crops like nitrogen fixers and deep-rooted radishes are included. Planting just-harvested barley seed is a very cheap way to get a cover crop in the ground, and following the combine with the planter maximizes the time for growth before frost. Simply allowing volunteer barley to thrive and provide cover during winter could result in better soil health and productivity. The cover crops capture and cycle residual soil nitrogen and phosphorus from fertilizers to reduce losses from leaching, runoff or volatilization.
Overall, replanting barley after barley looks to be an excellent way to save soil, cycle nutrients and integrate livestock grazing into sugarbeet production systems. The benefits might be even greater if legumes and other cover crops are mixed with the barley seed. Expanding rotations to include perennial crops like alfalfa also has clear benefits for soil health and productivity.
The articles referenced above are cited as follows:
Franzluebbers and Stuedemann, 2015, Journal of Soil and Water Conservation 70(6):365-373.
Hurisso et al., 2015, Soil Science Society of America Journal: doi:10.2136/sssaj2015.02.0073.