Editors Note: We got a lot of interest in Troy’s article “Pragmatic Pasture Clipping.” Stuart Gardner wrote this in-depth response about his experience with pasture mowing.
Mowing, bush-hogging, cutting, and clipping are all terms used to describe the mechanical process of harvesting or cutting of pasture vegetation. Strategic mowing (followed by an adequate rest period) is a great management tool, if timed properly! It is an important tool for a sustainable grazing pasture based operation. It can, somewhat, replace use of intensive (35,000 lbs./acre stock density) or mob grazing(80,000 lbs./acre) to uniformly harvest plant material. Of course, without the benefits of pulling (grazing) action, hoof (trampling) action, and uniform distribution of manure and urine from the livestock. Many grazers don’t have the enthusiasm, desire, time and skills to implement effective intensive and mob grazing methods. Mowing on rangeland is entirely, another topic!
STRATEGIC is the key descriptive word in use of this management tool. The timing is key! Typically the ideal time is during the peak period of the growing season, which is June 15 to September 15, for my area. Most typically, mow the grazed pasture after every other grazing period, then let it rest! The key is to do it immediately after grazing. I always want to see fresh manure on the tractor tires! Mow before regrowth if fully initiated (another key point). Mow when there is not much to mow (the livestock have had opportunity to remove what they wanted), except for manure and urine spots, weeds, and over-mature plants that the animals did not graze. The timing also saves fuel, wear and tear on equipment, and valuable time.
STRATEGICALLY MOW to the grazed height of the desirable forage(s), usually 3 – 4 inches. Allow 3 -4 weeks of rest before grazing and the height of the forage to reach about 10 inches, so that when the livestock graze they can take a full bite. Maturity is the key to forage quality, here in the deep south. Strategically mowing a pasture every 2 months during the peak growing season is hardly intensive use of the practice. These time periods and days of rest should be adjusted to your fit your operation, resources, and location. Here it looks like this:
Graze 1-3 days, rest for 3-4 weeks, STRATEGICALLY MOW. [typical synopsis: mow day 1, rest 28 days, graze 3 days, rest 28 days (that is about 60 days between strategic mowing implementation)].
Both methods have a positive impact on the natural resources. Learning to realize those impacts, both long and short term, is the key. What response to the management did you get from the action or in-action?
The strategic mowing use in the grazing system provides a larger volume and higher quality pasture, over the growing season. I think that there is about a 25% increase in pounds per acre of beef production using this strategic mowing management in a well managed rotational grazing system. Growing more and better forage usually comes with a cost. That is great, if you are prepared to utilize that forage to convert it into a product like meat or milk. If not, the practice may not have an immediate payback. If strategic mowing is implemented properly and persistently, it will have a long term positive effect on your pasture trend and soil health. A 3-6 inch high dense sod base is the product of this system. Growth above that point is grazed off by the livestock.
The rest period is the key. Dense deep root systems are developed and maintained by the desirable forages. Problems with infestations of undesirable plants is drastically reduced due to the dense closed sod. Water infiltration and holding capacity will increase. Organic matter content and soil tilth will improve. Strive to keep 75% or more of your ranch in great condition with this type of system. The other acreage can be used for a sacrifice area during the winter or drought periods, with the nutrients and the disturbance from the livestock used to improve fertility and improve soil quality.
Strategic mowing with rest, allows the desirable plants to have a chance to compete with undesirables! When the strategic mowing is implemented the plants are all put “in the starting gate” together. The desirable forage plants, which have evolved under grazing pressure, will normally grow back much faster than those undesirable that are not accustomed to being harvested. Under this management method the desirable plants can and will out compete most undesirable plants for sunlight, moisture, and nutrients. Prescribed Grazing is achieved when the grazing is managed to a level that allows for the desirable forages to be sustained, maintained, or increased in a grazed pasture system without the consistent inputs of agronomic practices. Many say that 60 – 80% desirable composition is the goal. I think that 60% should be the minimum goal. The grazing management is driving the trend! Grazing management is an art and science. The dynamic ecosystem of a pasture must be understood and the grazing management implemented to achieve sustainability and success.
In a typical continuous grazing management scheme or in a grazing system with long grazing periods, the undesirable plants are usually not grazed and are allowed to develop substantial leaf area and a deep expansive root system. The desirable plants are grazed over and over again while the undesirables are left alone. Which type of plant has the advantage? The undesirables! The re-grazed, and most often over grazed, desirable plants have a diminished amount of leaf area and root systems. They simply cannot compete! The pasture trend is negative or declining! Most often, use of agronomic tools such as herbicides and fertilization is implemented, using conventional ideology, to combat the negative or declining pasture trend or loss of desirable plants! These agronomic based inputs are only a Band-Aid, and will not sustain the stand in an economical and ecological manner. The negative trend can be halted or even reversed, temporarily, as long as the input dollars continue.
My grazing operation and my work area is in the deep south where we get about 50 to 70 inches of rain, in most years. The weather anchor always tells us that we have had an average year, at the end of each year. Their perspective is different from a grazier’s! This year was typical of the roller coaster weather cycle that we have been experiencing over the last 10 years. Monthly rainfalls normally average 4-8 inches, throughout the year. In 2015, January – March the weather was cloudy, cool, and dry (6.9 inches over 90 days). Slow cool season forage growth was the trend. Between April 1st and July 1st we received 45 inches of rain (in 90 days). The trend was very fast regrowth, high forage production, and muddy conditions. July 1 – September 8, we have sporadically, received 3 inches. Dry conditions over the last few months have set the trend. Regrowth is slow and production is low. I always tell my novice clients, “Welcome to Agriculture! Never expect the average year!”
I have managed pastures for several years without mowing or clipping. I have managed the same pastures with strategic mowing after every other grazing period. Both management schemes were implemented with and without spot spraying of herbicides for invasive plant control.
The grazing system I’ve implemented is a 2 herd 30 pasture rest based rotational grazing system. The yearlings get the best forage and the brood cow herd gets the rest. Grazing periods are 1 – 3 days and rest periods are 3 to 5 weeks. The yearling herd consists of ~ 150 head and the cow calf herd consists of ~ 40 cows. 100 acres of the 300 acres is planted to cool season forages (ryegrass, oats, berseem clover, and vetch) in October. That 100 acres is limed and moderately fertilized to soil test recommendations and strip or paddock grazed. During the warm season period the 100 acres is in volunteer crabgrass, broadleaf signal grass, and common bermudagrass. The remaining acreage is grazed under natural conditions and consist of volunteer bermudagrass, bahiagrass, crabgrass, dallisgrass, and carpetgrass.
Certain weeds, like blackberry, dewberry, Chinese tallow trees, and Prickly Sida, persist with both management schemes. These undesirables are more of a problem in the non-mowed system. Spot spraying is usually implemented when these weeds are 20% or more of the canopy in each pasture. Success with control of the blackberry and dewberries requires no mowing for a period of one year prior to treatment. Herbicides that have a residual component are not used on the pastures.
Hopefully, this information will be helpful to you!
G’day Stuart,Your reply held the most important detail in that it explained the need to leave the “right ” height of stubble for good recovery of the pasture.
Down here we are in what is the Temperate zone (on the eastern side just inland from the coastal zone) with 4 distinct seasons and winters down to -8 c with the occasional snow fall,summers are up to 40 c and can be quite dry for 2 months or so.We have one Native sp (Poa labillaedieri)which creates quite dense thickets with a lot of thatch(good cover ,but can restrict other grasses).Two years ago I “cool burnt”about 10 acs of dense thickets and this spring after good late winter rain the volume of other sp is producing good sheep feed. The Poa’s have recovered over the last 2 springs to be quite healthy ,the stock only graze the freshest of young tips after burning and the flower/seed heads.But its the cover it provides for lambing ewes that I value it for.Frank.
G’day,Down here in Aussie our system is based on perennial pasture species and the idea of slashing/clipping growth exposes the dormant crowns to heat for cool sp and frost to warm sp.When you clip to a lower height you expose the stock to the ideal conditions for re- infection of internal parasites. Leaving the pasture to its own devices means that annual sp have the chance to grow ,flower and seed and thereby add to the pasture diversity . Frank.
Our pasture system here is based on perennial warm season forages and annual cool season forages. The article was focused on the summer grazing period and on pastures with perennial warm season forages. Clipping is never implemented with the cool season annuals. The period stated in the article is during the peak of our growing season, June 15 – September 15, in the deep southern USA. Our first hard freeze here, historically occurs in mid or late December and the last freeze usually occurs in early March. Ninety percent of our nights reach dewpoint, there is a heavy dew just about ever morning here. It’s a great environment for parasites and plant diseases. Our climate is considered to be humid subtropical.
Most parasites in the larval stage do not climb up more than 2 inches on a blade of grass or other forage plant. They must be ingested by the host animal to perpetuate the life cycle of the parasite. The focus is to maintain a 3-6 inch sod and graze the regrowth above that height. Properly implemented grazing systems severely reduce parasite issues. Some of the native perennial grasses like Eastern Gama Grass and Switchgrass, require that we leave a stubble of 8-10 inches and allow for rest periods of 30-45 days. The native perennial grasses are much more sensitive to exposure and damage to the growing points or crowns, by overgrazing or mowing. When hay is made using these species it is cut at an 8-10 inch height and usually during the peak growing season.
Clipping or slashing is only one of the many tools that can be used to manage pastures. It has to be used strategically. It does not necessarily have a negative effect on diversity. Most weeds or forbs are readily grazed by the livestock, especially when in the vegetative stage of growth, prior to flowering and before setting seed. Clipping can be used to manage the stage of maturity and quality of the plants in the pasture. That includes the weeds or forbs. The timing of grazing is critical to achieve success. There must be adequate quality and quantity for the type of livestock being grazed or browsed. Clipping can be part of a dynamic rest based rotational grazing system that requires lots of thought and the appropriate actions.
Excellent article! I’m wondering if implementing a variation of this would work in our drought prone area – TEXAS.
The principles remain the same in a drought situation for pastureland. The grazing and/browsing by livestock will have to be stopped. The grazing can resume when the desirable forages reach an adequate height. They should then be grazed down only to an acceptable height. Then allowed to recover, whatever time it takes. Livestock should be removed from the majority of pastures, desirable forages cannot recover or react to moisture, whenever it is eventually received, if the desirable plants are overgrazed. Clipping without the rest from grazing is much less effective. Just clipping with livestock present will knock back the remaining undesirable plants, because it will have been harvested, and the clipping can put some cover or litter down on the ground to provide some protection to the soil. Soil that is covered with litter or dead vegetation will be protected from direct sunlight. The protected soil will have a much cooler temperature in the heat and warmer temperature in the cold. Infiltration of the rain is also drastically increased when litter is present on the soil surface.
Can strategic mowing be a good addition to your pastor management?
Mowing may help, but–in my experience–“clipping a pastor’s wings” too severely may discourage his/efforts in tending the sheep.
Nice one, Stuart!
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