Grazing Considerations in Late Summer / Fall
The following is from Grazing Bites and is used with permission.
by Victor Shelton, Retired NRCS Agronomist/Grazing Specialist
The weather certainly has changed. Some areas that were very wet for so long this spring are now dry. Ideally, a nice rain about every seven to 10 days would be what I would order if I could. Much more than 10 days and we are starting to be on the dry side. It is true that a drought is only about 14 days away at any point in time.
You can always reduce drought risk by making sure you are maintaining good soil cover, not over grazing and keeping the ground cool. This is easily done by maintaining at least 4 inches of live growth for cool season forages and 6 inches or more for warm season forages. That stop grazing height is the shortest forage left, not the tallest. If it is the tallest, you have already overgrazed it. If so, stop and let it rest as long as possible before grazing again.
Overgrazing when your area enters into droughty conditions or possible droughty conditions reduces the resilience of the plant. Most cool season forages have about as much active live roots below ground as they have growing forage above ground. Shortly grazed forage will therefore be less drought tolerate due to shorter roots lacking the ability to get to deeper moisture. Overgrazing also reduces livestock intake, yield potential, and the quality of the stand while stressing the forages.
If you do have any moisture, then it is an ideal time to plant some brassicas for late summer and fall use. Forage type brassicas are highly productive and digestible and usually can be grazed within 75 days after seeding, sometimes earlier. Brassicas need moisture to get started and for speedy growth and good yield. Summer seeded brassicas — seeded now to August — can help supplement forages and also help extend the grazing season. Turnips and rape can be planted almost the whole growing season as long as sufficient soil moisture is present. They mix well with Italian ryegrass for fall/winter grazing or with sorghum-sudangrass or millets for summer grazing. The common purple top turnip can yield over 10,000 pounds per acre of dry matter and provide an average 12-20% crude protein.
Brassicas do best when planted into a firm seedbed at a very shallow depth (1/4 inch or less), which means barely scratching the surface (if no-till drilling them) and good control of any growth is essential. Tilled ground should be cultipacked, broadcast seeded and then cultipacked again after seeding. Most brassicas are seeded at about 4-pounds per acre.
When possible, the ability to graze some dry forage and some brassicas at the same time is optimal. Brassicas contain a lot of water and crude protein but lack much fiber, and gains will be best when grazed with some dry material available to help maintain that rumen mat. Turnips will regrow if the growing point at the top of the bulb is not removed. Ideally, leave at least 4-6 inches of growth if you want to graze it again.
Kale can be seeded for fall/winter use with a light seeded cereal rye which can provide some good fall grazing and then more grazing the following spring. Oats are another option to mix with turnips for spring or fall use. I love the mix of oats, turnips and cereal rye for a later summer seeding. You can get a lot of really good grazing in the early fall out this mix and also into the late fall and still have the cereal rye for spring grazing, all while providing great cover, some allelopathic weed control and soil building benefits. Get seed now if you are thinking about doing this.
We still have a couple more weeks where warm season annuals such as sorghum-sudangrass, sudangrass and millets could be planted. The southern half of Indiana could extend this planting period to the end of the month as long as some moisture is available. I would strongly recommend a brown midrib variety of the sorghum-sudangrass for higher digestibility. Besides brassicas, cowpeas mix fairly well with these warm season annuals and add nutritional value. You only get one grazing or harvest from the cowpeas and they are best utilized by strip grazing in daily or small allocations.
More diverse mixes of annuals can also be utilized for grazing. Sometimes planting a forage crop after wheat is better than double crop soybeans and can certainly be a nutrient and soil builder for the next crop. The more diverse mixes could include soybeans, cowpeas, sorghum-sudangrass, pearl millet, foxtail millet, turnips, daikon radishes, kale, and sunflowers.
We are just a few weeks away from the start of the fall seeding period for cool-season grasses. With this in mind, it would be good to start thinking ahead about seed, fertility, lime and land preparation. I would strongly suggest that you assess the present stand before starting this endeavor this year due to inputs – if you can wait, wait.
If a new seeding is happening and the land is presently pasture or hay ground, then taking a late cutting or grazing it shorter than normal is a good place to start. If you are going to be establishing new grass, then it is best to completely kill out the existing stand completely. Trying to inter-seed grass into grass is normally a waste of time, money and of course seed purely because of competition of the existing vegetation. This is especially important if you want to move away from endophyte infected tall fescue.
Shop and choose a high-quality seed, named varieties and from reputable companies. Do the math and seed at pure live seed (PLS) rates. Take the amount of seed needed (4 lbs./Ac PLS) and divide it by (percent purity x percent germination); 4 lbs. divided by (.95x.80) = 5.26 pounds of seed needed per acre. A well established and managed forage crop should last for many years so take the time to do it right and it will pay you back in dividends for a long time.
I’m already seeing some white snakeroot. This is a poisonous plant that can be found on the edges of pasture, especially associated with some shade. It generally is avoided by livestock unless there is little else to eat. Also watch for drought-stressed forages that may be higher in prussic acid, especially sorghum Sudan's, Sudangrass, and Johnsongrass. If in doubt or concerned, test before grazing. If it is wilted, it is probably safer to wait.
Remember, it’s not about maximizing a grazing event, but maximizing a grazing season! Don’t get carried away with the hay, just manage advantageous grazing avenues — yep, keep on grazing!
Reminders & Opportunities
More pasture information and past issues of Grazing Bites are available at https://www.nrcs.usda.gov/wps/portal/nrcs/in/technical/landuse/pasture/
Purdue Forage Management Day will be September 1 at the Feldun-Purdue Agricultural Center, Bedford. https://ag.purdue.edu/agry/dtc/Pages/Calendar.aspx
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