Options for Improving Damaged Pastures

Rory Lewandowski, OSU Extension Educator, Wayne County and Stan Smith, OSU Extension PA, Fairfield County

Late spring through mid-summer of 2015 was one of the wettest years in recent years for many parts of Ohio causing pastures to suffer from excessive traffic and trampling. To add insult to injury or maybe just more injury on top of injury, in many parts of the state when the rains finally stopped, it turned drier than average until late fall. The result was that many pastures struggled to recover and a number of pastures were overgrazed going in to the winter. There is no doubt that some pasture and hayfield stands will be reduced as they come out of dormancy. This spring, one key decision facing managers will be whether or not to reseed the pasture or hay fields that have suffered from Mother Nature’s (and mismanagement) abuse over the past year or so.

Like most other input costs, the price of quality grass and legume seed is expensive. What are the most cost effective options to get these abused pasture paddocks back into a productive forage? Let’s look at several options and management strategies one might consider.

One low cost option, at least in terms of out-of-pocket expenses, is to do nothing. Nature abhors a vacuum; something will re-grow in these muddy, trampled paddocks if given enough time. The cost in this option is time. If you have the land base to set aside those torn up paddocks through the spring and early summer, they will renovate themselves. We generally have plenty of seed bank in the soil. Whether that seed bank contains desirable plants, or what percentage of desirable plants will make-up the re-growth are questions to be considered.

It is likely in those paddocks where the sod base was torn up, that summer annual species like pigweed, ragweed, barnyard grass and goose grass will show up in heavy numbers in addition to the grasses and clovers that had been present in the sod base. Clipping the summer annual weeds off before they go to seed will allow more light into the grasses and clovers that are coming back. By mid to late summer a light grazing pass could be made on these paddocks. If they are not torn up again in the next winter, the sod base will continue to thicken and good rotational grazing management can put them back into productive pasture paddocks the following year. The main question that must be answered in this option is; do you have the time and land resource base to be able to wait for the paddock to heal itself and lose a grazing season of productivity?

The next option to consider is seeding. Seeding offers the possibility to increase pasture productivity and to bring a new mix of forages into the pasture paddock. When Bob Hendershot, retired NRCS State Grasslands Specialist, has spoken to graziers one of the points he’s made is related to pasture genetics. Bob pointed out that row crop producers use new and improved genetics to increase crop yields and as livestock producers we seek to improve our livestock genetic base, but we don’t give that same attention to pasture genetics. Bob frequently asked, “How old are the genetics in your pasture forages?” There have been advances in forages; grasses and legumes bred to better tolerate grazing, genetics that allow plants to be more palatable and productive. A sacrifice paddock that has suffered from trampling and reduced stands may be an opportunity to bring some new and improved forage genetics into the pasture mix.

Talk with your seed representative or County Extension Agriculture Educator about a pasture mix of specific species that might work best for your situation. A legume species should be part of most pasture seed mixes. Graziers should aim for a 30% to 35% evenly distributed legume stand throughout the pasture paddock. At this level, supplemental nitrogen should not be needed in future years, reducing one pasture management expense, and providing a boost in the energy content of the pasture sward. If the area to be planted needs to get a quick cover due to erosion concerns and/or some quicker production is needed for grazing, then include some annual ryegrass seed in the seeding mixture. Adding 5-6 pounds of annual ryegrass/acre should provide some early cover and an early grazing pass because it is quick to germinate and grow. Another option that could be considered is including some winter wheat in the mix, again to get some quick germinating cover on the area. Winter wheat planted in the spring will stay vegetative and can provide some good quality forage.

Once you decide to add some new forage seed to your pasture paddock, how you answer the next question may determine when you plant that seed. What is the soil pH and what are the soil fertility levels in the paddock you intend to seed? Seed is not cheap and buying the new and improved grass and legume genetics will cost you more than older genetics. Make sure that seed, once planted, has a chance to become a productive plant and maximize its genetic potential. That begins with soil pH and soil fertility.

Soil pH should be above 6.0, with a goal of 6.5. Soil phosphorus (P) level should be at 25 ppm when using the Bray P1 soil test extraction, or 40 ppm with the Mehlich III test. Given an average Ohio cation exchange capacity (C.E.C.) of 10, soil potassium (K) level should be 100 to 120 ppm. If your soil tests are reported in pounds per acre instead of ppm, then these numbers should be doubled, respectively, to 50 (or 80 with M III) for P and 200 to 240 for K. If your soil is not close to these numbers it may be worthwhile to put off a spring seeding, apply the needed lime and fertilizer this spring and aim for an August seeding. In those paddocks that are severely torn up, it offers the rare opportunity in a pasture situation to spread lime and/or fertilizer and then use tillage to incorporate it into the root zone while smoothing out the soil surface and preparing a seed bed.

According to the Ohio Agronomy Guide, a spring seeding should be completed by April 20 to 25. Earlier is better. As we move past mid-March frost seeding is no longer a seeding method option, and in any case is not a good seeding method for grasses. That leaves us with conventional drilling, use of a no-till drill or a broadcast seeding followed by some type of cultipacking. The key concepts to keep in mind any time a forage seeding is made are:

* Reduce weed or sod competition for the new seedling. This relates to soil preparation. If the pasture paddock has been excessively trampled and torn up, it may only be necessary to do some leveling off of the ruts before running a drill over the paddock. Broadcasting the seed and then running a cultipacker over the surface can also work well. If broadcasting seed, consider applying half the seeding rate length-wise over the paddock and then the other half cross-wise over the paddock. Seeding in two different directions will give better seed distribution. On a sod base, make sure the forage has been grazed down tight into the soil surface. A no-till drill works well in this situation. If the sod is thin, but has not been able to be grazed down tight before seeding, then application of a herbicide to kill the sod back should be considered. Application of glyphosate 7 to 10 days before seeding can be used.

* Do not seed too deep! Many stand failures can be traced back to planting the forage seed too deep. Seed should be planted about one-quarter of an inch deep. It is better to err on the side of planting shallower rather than deeper, especially in a spring seeding.

* Pay attention to seeding rates. For example, according to the Ohio Agronomy Guide an orchardgrass, red clover, and white clover mixture would be seeded at a per acre rate of 7 pounds of orchardgrass, 4 pounds of red clover and 2 pounds of white clover on a pure live seed basis. Check the label to determine the percentage of pure live seed and adjust seeding rates accordingly. In our example, if orchardgrass had a pure live seed percentage of 85, and red clover and white clover had a pure live seed percentage of 70, then our actual seeding rate per acre of these seeds are: 8.25 lbs. of orchardgrass, 5.75 lbs. of red clover and 2.85 lbs. of white clover. Calibrate the seeder!

* If the specific legume species you are planting has not been in the pasture paddock for a few years be sure the seed is inoculated with the correct rhizobia bacteria to insure the plants will be effective in fixing nitrogen. Sometimes, legume seed will come with a coating that contains the rhizobia bacteria. Be aware that this coating changes the seeding rate. Generally you will have to seed more pounds per acre of this coated seed to get the targeted non-coated seed rate. Read the label and calibrate the seeder!

It typically takes about 6 to 8 weeks for a new seeding to become established. Ideally the new seedlings can develop a good root system while soil moisture is plentiful and before summer temperatures arrive. This is the reason behind setting the spring seeding date target around April 20th or before. After the seeding has emerged and started growth and once the grass plants get about 6 inches tall, it is beneficial to either do a clipping or a light grazing pass that takes off the top couple of inches. This will allow light to get down to the young clover seedlings to promote growth and the clipping/grazing will also stimulate tiller formation in the grass seedlings. Do not graze or clip off the young clover seedlings. After about 8 weeks of growth, or towards the end of June, begin to manage the stand using good rotational grazing principles.

In some cases it may be advantageous to delay the planting until late summer. Depending on where in Ohio you are located, the target date for a late summer seeding is August, ranging from early in the month in northern parts of the state, and before the end of the month in the south. Some reasons for waiting until late summer include adding lime or fertilizer to improve the soil pH and soil fertility levels before the perennial seeding, or taking time to reduce competition pressure from weeds or an aggressive fescue sod base. This does not mean the paddock must remain unproductive during this time. A short term crop can be planted that will provide some summer grazing while helping to reduce weed pressure and/or kill back a fescue sod. This might be the place to use annual ryegrass. As mentioned earlier, it germinates fast and provides the quickest grazing of our grass options. It needs to be managed to prevent it from going to seed, so frequent, short duration grazing passes work. Another option in this scenario is to seed a forage turnip during April, possibly along with a cereal grain like winter wheat. In about 6 weeks there should be high quality forage to graze. Under rotational grazing principles, you might get several grazing passes before the August summer seeding of your perennial grass/legume mixture. A third option would be to seed a sorghum x sudangrass hybrid or brown mid-rib variety of sudangrass in the later part of May. The tall, vigorous growth out competes a fescue sod base while providing a high tonnage, good quality forage that will be ready to graze before mid-July. Under good rotational grazing principles, multiple grazing passes can be made before it is time to make the late summer seeding.

There are options available that allow beaten up pasture paddocks to recover and become productive grazing paddocks again. The specific option chosen depends upon the resource base of the producer, farm forage goals, and timing. Regardless of the option used, planning, management and some cooperation from Mother Nature are necessary to achieve success.