Using cover crops to extend winter grazing should significantly improve our cost per cow-day
I have always been interested in the use of strategic cover crops for enhancing soil health, boosting biodiversity and extending the grazing season. Influenced by the work of Gabe Brown and Keith Burns from Green Cover Seed, I’ve integrated cover crops into my farming practices to achieve multiple objectives, including extending winter grazing. Although I’m not a commodity farmer, I aim to replicate diverse farming scenarios on my farm, applying innovative techniques to enhance soil fertility, promote biological diversity and sustain the farm’s ecosystem.
Multifunctional Benefits of Cover Crops
One of the guiding principles in my farming approach is using cover crops not merely as a secondary crop but as a versatile tool that contributes to the farm’s overall health and productivity. These crops serve multiple purposes: they provide forage for deer in food plots, boost biological activity ahead of perennial pasture seeding and increase pasture diversity. This year we have seen two mom turkeys use these cover crop fields as a safe haven for their poults. Additionally, they play a crucial role in supporting pollinators and other beneficial insects, which have been a very rewarding study in itself.
Using Gabe Brown’s principles and Gary Zimmer’s year on / year off while balancing minerals, I’ve developed a rotational grazing system that uses cattle to enhance soil fertility and biological activity. The goal is not only to improve the land’s health but also to create a financially sustainable system.
Implementing Summer Cover Crops for Multiple Uses
We broadcast summer cover crops up to about July 15th, utilized in several ways to maximize their benefits. One of our practices involves preparing a field in the spring that has been heavily used for bale grazing. To rejuvenate this field, we use a shallow tiller in the spring, lightly incorporating year-old compost into the soil.
Another approach involves broadcasting half of the cover crop mix into hog paddocks the last day they are there. The remainder of the mix is broadcasted the day after the hogs have moved on. This allows the hogs to naturally incorporate the seeds into the soil, providing excellent germination conditions. These cover crops serve as a crucial safety net during the summer slump months, when pasture growth slows down. If necessary, we can graze these fields in August, providing high-quality forage during a typically challenging time. I’ve found great success in bringing our finishers into these summer cover crop mixes during their last week on the farm.
If rain is plentiful, we may skip grazing these fields in the summer, instead saving them for winter stockpile grazing. We consistently graze our perennial pastures into December, moving to the stockpiled summer annual mix paddocks after leaving the perennial pastures. The rain we have had this year has given us the best stand of summer annuals we have had, and I hope it translates to grazing well into January.
Extending Grazing into Winter
The cover crop mix we use includes warm-season soil builders from Green Cover Seed, sown up until July 15th. The components typically include:
- BMR sorghum sudan: a drought-resistant forage crop that provides substantial biomass
- Dwarf forage sorghum: known for high energy content and digestibility
- Black oats: a hardy cereal that contributes to soil cover and weed suppression
- Cowpeas: a legume that fixes nitrogen and provides protein-rich forage
- Non-GMO soybeans: another nitrogen-fixing legume that supports soil health
- Forage collards: a palatable brassica that thrives in cooler weather
This mix is broadcasted at 50 lbs/acre, ensuring a dense and productive stand for grazing well into winter. Additionally, I incorporate 3 lbs of hairy vetch and 10 lbs/acre of a perennial pasture mix, including clovers and a blend of grasses. This will kick in in year two with the other biannual forages to give us another grazing in the spring. If we decide to let that field go to perennial pasture, the initial base has a head start and we will broadcast an additional perennial pasture mix ahead of the spring grazing with the cattle.
Our cool-season mix that we broadcast post-July 15th is a base mix from Green Cover seed:
- Winter triticale: a hardy hybrid of wheat and rye, providing excellent forage and soil cover during cooler months
- Cosaque oats: a cool-season oat variety that offers nutritious forage and helps improve soil structure
- Winter peas: a nitrogen-fixing legume that thrives in cool temperatures, providing protein-rich forage
- Hairy vetch: a cold-tolerant legume known for fixing nitrogen and providing effective ground cover
- Collards: a hardy brassica offering nutritious leafy forage; ideal for cool-weather grazing
We again include our pasture mix and will top dress winter rye in September.
Stockpiling for Winter Grazing
The ability to stockpile forage for winter grazing is a key advantage of using cover crops. While the forage quality of the stockpiled cover crops may be lower than if grazed in August or September, it still surpasses that of most of our perennial pastures. If we can accumulate 3-5 tons per acre of dry matter in our cover crop fields, our goal is to achieve 100 cow grazing days per acre. This is significantly higher than the 50-60 cow days per acre we typically get from our perennial pastures, with 45-60 days of rest between grazings. Of course, we are skipping two rotations on these fields during the growing season.
By matching our stocking rate to the needs of our perennial pastures in a good year, we use cover crops as an insurance policy during bad years. In favorable years like this one, if we can gain an additional 100 cow days of grazing, we reduce the need for hay. At $60 per acre of seed, the cost comes to approximately $0.66 per cow day, compared to about $2 per cow day for hay at $120 per ton.
Monitoring and Safety Considerations
We’re closely monitoring our results and hope to provide more precise data on grazing days from these annual mixes this winter. However, it’s important to note the potential risks associated with certain cover crops. For example, sudangrass and sorghum sudan hybrids can produce prussic acid, which is toxic to cattle, especially after the first frost. To mitigate this risk, we avoid grazing these crops from the first frost until about a week after a full killing freeze, defined as temperatures below 28°F for three or more hours.
Can we create a system that gives us grazing days on the “soil building year” to prime and prepare the next growing season’s cash crop? Combining the lessons of Gary Zimmer, Gabe Brown and others, could this be the gateway for commodity farmers to start introducing some of these radical tactics that Acres U.S.A. has talked about for years? As corn prices plummet, could this be a real economic solution for conventional and ecological growers alike?
I hope so, I am eager to hear from our group of speakers in December to see what they think. Hope to see you all in December!
Taylor Henry is the owner and CEO of Acres U.S.A.
