Extending the Grazing Season and Integrating Crops and Livestock to Sustain Small Farms and Ranches in the Southern Rockies
1. To determine the ability of forage Brassicas and oats (Avena sativa L.) to provide late-season forage, and hairy vetch and winter rye (Secale cereale L.) to provide early-season forage, when overseeded into sweet corn stalks.
2. To determine the profitability of overseeding forage Brassicas, oats, hairy vetch, and winter rye into sweet corn stalks in terms of heifer average daily gain.
3. To determine the ability of forage Brassicas and spring oats overseeded into established pastures to provide increased late-season forage.
4. To disseminate to farmers and ranchers the results of the project.
The primary goal of our project is to develop forage production systems that extend the grazing season in the fall and provide more forage in the spring through overseeding of vegetable crops and irrigated pastures and increased integration of crops and livestock. Overseeded species tested have included forage Brassicas, hairy vetch, winter rye, spring and winter oats, and triticale. The project includes a grazing study to determine the profitability of overseeding several of these crops into sweet corn to increase the forage value of the stover after sweet corn harvest. Sweet corn was harvested in August. Corn stover and annual forages were sampled in early November and the fall grazing trial was conducted immediately thereafter. Paddocks were intensively grazed using stocker heifers for four to five weeks in the first two cycles of the trial, and about 9.5 weeks in the third cycle of the trial. In 1996 and 1997, total available forage was increased from 42 to 81 percent by overseeding oats or turnips, and overall nutritional quality was improved. Cattle average daily gain (ADG) and total gain per acre were not significantly improved by overseeding annual forages in either 1996 or 1997; however, the animals perhaps could have grazed longer in the oats and turnips treatments in 1996 and in the oats treatment in 1997 based on the amount of forage still left in the field in those treatments after cattle were removed. In 1998, however, average ADG and total gain per acre were improved substantially by overseeding forages.
Preliminary economic analysis results from fall grazing indicate that, in terms of net gain per animal from grazing after subtracting overseeding costs, grazing oats and turnips were about as good as the control in year one, but much better in year three. In year two, the control outperformed both the oats and turnips. Grazing turnips in year two would have resulted in the lowest returns and in year three the highest returns. Results from a second grazing study, spring grazing of rye and hairy vetch overseeded into sweet corn, indicate that stocker heifer gains were similar for both overseeded crops; ADG ranged from 1.6 to 1.9 pounds for rye and 1.3 to 1.9 pounds for hairy vetch. In the first and second year, hairy vetch forage was generally still available after the rye had been consumed, and so, for most of the replications, the animals were put back onto the hairy vetch after weighing for several more days of grazing. Trials were carried out at various farmer/rancher cooperator sites throughout the region and at the Alcalde Center in which pastures were overseeded with various summer- and/or winter-annual forages. We had limited success with summer annuals and found that winter-annual forages, especially in the higher elevations where growing seasons are shorter, may offer a better chance to extend the grazing season of pastures through increased productivity the following spring or summer; but, there needs to be a good stand established by fall of the overseeding year.
Although we do not have all of the field data analyzed to make conclusive statements regarding positive benefits or impacts, results to date from the grazing study indicate that significantly more forage is available for livestock grazing corn stover overseeded with turnips or oats compared with grazing the stover alone. It appears that, depending on type of cattle and cattle management, either overseeded crop has the potential to increase weight gains in the fall-winter. This would increase efficiency of land use by integrating sweet corn and livestock production. The on-farm studies at Canjilon and Zuni, New Mexico, indicate that there is potential to increase pasture yield by overseeding winter annual forages; however, stand establishment is critical and more research is needed to look at other species as well as other possible seeding or establishment methods. Continued research based on what is being learned at Canjilon and Zuni could lead to increased forage production on thousands of acres of cool season pasture in the Southern Rockies.
Farmer Adoption and Direct Impact
Because of our results to date, we believe it is premature to develop specific and/or final recommendations. However, preliminary results show increased crop production and increased cattle weights through overseeding annual forages; however, due to variable results from year to year, more research on some aspects of the project may be required to refine recommendations. Interested producers are encouraged to try overseeding oats, or low-cost turnip seed, into sweet corn on a small scale. If the producer feels yields are high and overseeding costs are low enough, a paddock could be seeded that is large enough to observe the grazing of two or more animals. The key is that the producer slowly integrate the practice into his or her system while paying close attention to costs vs. benefits.
Overseeding of cool-season pastures with annual forages is not generally recommended at this time. Benefits of any of the above practices will vary depending on environmental and management factors.
Reactions from Farmers and Ranchers
Producers have expressed interest in the project through questions, comments, and general discussion during field tours and field days.
To date, six producers have been involved in the project, primarily as farmer/rancher cooperators for the on-farm/ranch trials. They primarily assisted us in allowing us to use their land and in choosing the species to be used on their site.
Future Recommendations or New Hypotheses
On-farm results to date indicate that future research could focus more specifically on testing additional biennial or winter-annual forages for overseeding, particularly at the higher elevation sites. Preliminary results from the Zuni Pueblo site indicate that triticale may have more forage growth and/or quality in the spring and thus would also be a good candidate to test as an overseeded crop in sweet corn. Results from the Canjilon site indicate that hairy vetch, when established well, can be very productive in an established cool-season pasture. Thus, additional research is needed on simple, inexpensive, pasture-overseeding establishment methods.
The grazing study indicates that response to corn-stover plus overseeded crop can vary depending upon season and the group of cattle. Future research could address how and why cattle responses may vary. In addition, stands of overseeded crops, except perhaps rye, indicate that seeding rates could possibly be reduced without decreasing stands; this would decrease the costs of overseeding.
This summary was prepared by the project coordinator for the 2000 reporting cycle.