Professional weed control is a task almost all property owners or land managers must continually do each year. From homeowners dealing with the annoying weeds in a lawn to range managers who are in constant battle with invasive and noxious weeds, the control of weeds may be as simple as a ‘do it yourself’ procedure or may require a specialized approach.
But first, let’s begin by highlighting how land is used in the United States and then shed more light on weed control for land management.
How is land used in the United States?
The United States is comprised of 1.9 billion acres that is divided up as follows:
- Pasture/range – 34.6%
- Land used for forage production or grazing livestock.
- Forest – 28.6%
- Primary use for a variety of forestry-related products and services.
- Cropland – 20.7%
- Land used for food production and forage for livestock.
- Special use – 8.9%
- Includes national parks, wildlife areas, highways, railroads, and military bases.
- Urban – 3.9%
- Includes areas designated for human settlement, e.g., cities, towns, etc.
- Miscellaneous – 3.9%
- Includes cemeteries, golf courses, deserts, marshes, and other areas designated a having ‘low economic value’.
Now that we know how land is used in the United States, let’s focus our attention on pasture and range. That is the dark blue section, partially separated from the pie chart above.
Are range and pasture similar?
The primary vegetation produced on range and pasture is herbaceous plants and shrubs.
- Range consists of native vegetation that is predominantly grasses, grass-like plants, forbs, or shrubs suitable for grazing or browsing.
- Pasture, on the other hand, is primarily used to produce adapted, domesticated forage plants for livestock.
Both range and pasture provide forage for beef and dairy cattle, sheep, goats, horses, and other domestic livestock. In addition, many species of wildlife depend on range and pasture for food and cover.
Together, range and pasture are critical for the survival of about three-quarters of all domestic livestock. Protecting these vital resources in the face of some land management challenges is crucial to sustaining our livelihoods.
What are the major land management weed control challenges?
Anything that affects the quality and quantity of available forage will impact the amount of food available to the livestock we depend upon or our livelihoods. For most range and pasture, the major challenge is an infestation of specific weeds, some of which may be classified as noxious.
- Whereas a grassy weed is basically a plant that is objectionable and interferes with the activities or welfare of man, a noxious weed is a plant regulated or identified by law as being undesirable, troublesome, and difficult to control.
Unlike cropland where weed management is intensive and results are more predictable, weed control in range and pasture is more difficult. Grazing by livestock and wildlife can put a lot of pressure on forage resources often leading to overgrazing.
In western United States, overgrazing has converted some range previously dominated by perennial bunchgrasses to range dominated by annual grasses. Range that is dominated by annual grasses is susceptible to invasion by weedy species.
- Presently, over 300 weed species have been identified as weeds of range and pasture. These weeds are estimated to cause losses of $2 billion annually to the United States economy.
- Among the weed species that invade range and pasture are some of the most problematic, and often noxious plant species such as cheatgrass (Bromus tectorum), leafy spurge (Euphorbia esula), and yellow star-thistle (Centaurea solstitialis).
What happens when weeds invade rangeland and pastureland?
Uncontrolled weeds impact the livestock industry by:
- Lowering yield and quality of forage.
- Interfering with grazing.
- Poisoning animals.
- Increasing costs of managing and producing livestock.
- Reducing land value.
- Negatively impacting wildlife habitat and forage.
- Depleting soil and water resources.
- Reducing plant and animal diversity.
So, how does a land manager address the weed infestation challenge?
Effective weed management begins with good pasture and range management. If the health of the pasture or range declines, weeds & weed seeds will invade the land and become established. Additionally, many of the invasive species will incorporate root systems & produce annual weeks. Once they become established, weeds must be controlled to ensure the production of forage on the pasture and range.
Weed management options for long term pasture and range include:
- Cultural methods which generally increase the competitiveness of the forage.
- Mechanical methods such as mowing which improve the appearance of the forage and temporarily halt weed growth and reproduction.
- Biological methods where a biotic agent such as a pathogen is used to suppress weeds.
- Chemical methods which involve the use of fast acting herbicides to control weeds.
Chemical methods usually are the preferred method for professional weed control in pasture and range.
How can you control pasture and range weeds with weed control products & herbicides?
Use the following steps:
- Scout infested fields – this involves routinely walking or driving through the pasture of range to identify a weed issue. Scouting helps define the scope of the problem which then informs control decision-making.
- While scouting, properly identifying the problematic weed species is a crucial first step.
- Weed species identification guides are easily available and should be used to ensure you make the correct identification.
- Misidentification can be extremely costly from the standpoint of the herbicide being ineffective and the forage yield and quality being compromised.
- Select a herbicide to apply – base your selection upon:
- The forage species being grown.
- The weed species present.
- Application method.
- Environmental impact.
Remember to read the product label to ensure that the herbicide you select is safe to use in pasture/ range.
- Herbicide application technique – herbicides can be applied either as preemergence or postemergence treatments.
- Preemergence treatments – application of herbicides made before weeds germinate and emerge. An understanding of the biology and ecology of the weed species is important when using pre-emergence herbicides.
- Postemergence treatments – application of herbicides made after weeds have emerged. Knowledge of weed life cycle characteristics is essential for maximum efficacy. Furthermore, postemergence herbicide may be applied as either broadcast or spot treatments.
- Broadcast treatments – where herbicide is applied over the entire pastureland or rangeland that has the weed infestation.
- Spot treatments – if the problem weed is localized and not wide-spread, spot treatments as opposed to a broadcast application may be the best technique to use that will also be less-costly.
- Use of an adjuvant – when applying herbicides as postemergence treatments, adding an adjuvant to your spray mixture can enhance the activity of the herbicide and/or modify its physical properties. For example:
- Nonionic surfactant – reduces the surface tension of spray droplets which improves the wetting of plant foliage and increases herbicide uptake. In addition, nonionic surfactants help breakdown waxy cuticles of leaf surfaces which enables more effective herbicide uptake for improved control.
- Water conditioning agent – to be used if you think your water source might compromise herbicide activity. A water conditioning agent can buffer the pH of the water, chelate iron, sequester hard minerals like calcium and magnesium salts, and promote wetting of foliage and uptake of herbicide.
- Drift control agent – to be used if environmental conditions may cause spray to go off-target and cause unintended damage elsewhere.
- Defoaming agent – to be used if you anticipate the development of foam in the spray tank that might compromise herbicide efficacy.
For more information on adjuvants visit https://brewerint.com/products/.
- Evaluate control efficacy – evaluate how effective your control measure two to four few weeks following application and repeat applications if needed, and if possible.
Brewer International has been a leader in land and water chemistry since the 1980’s and for over 40 years has proudly served it’s national and regional distributors.
Our products are used widely across the United States in agriculture, aquatics, forestry, rights of way, and land management.
Our customers trust our dedication to quality ingredients, tried and true formulas, and positive outcomes.