Chapter 14: Best Management Practices for Lawns and Pastures

As an owner or resident of property adjacent to a stream or river, you are responsible for preventing livestock manure, pesticides, sediment and other pollutants from reaching waterways. A variety of established practices (known as Best Management Practices, or BMPs) are available to manage riparian areas to promote stream health and maintain water quality.

Managing Runoff from Homesites and Fields

One of the most effective ways of maintaining water quality in the Gallatin’s waterways is putting space between human activities and surface water in streams and wetlands. Maintaining healthy riparian vegetation is the most effective way to trap sediment and pollution before it enters surface waters. Vegetative cover also provides erosion control and flood management benefits, as well as affording habitat for fish and wildlife. Depending on where you live and the size of the waterway, you should consider providing a buffer of one or more of the following types:

Riparian forest buffers - NRCS recommends forest buffers (trees and/or shrubs) adjacent to streams, lakes, ponds, and wetlands. Riparian buffers are tailored to the type of channel and size of the active floodplain.
Filter strips - These are grass strips or other permanent vegetation at the edge of a cropped field or animal confinement area that are intended to catch sediment and runoff before it enters the stream.

If your property has lost its streamside vegetation due to historical uses, consider reestablishing riparian vegetation. NRCS has technical information on how large buffers ought to be and what plants will be most cost-effective to reestablish.

Overwatering can lead to erosion and sedimentation, a leading cause of impairment in the Gallatin Watershed.

Irrigation

Knowing when and how long to irrigate your lawn or pasture can save both time and water and prevent erosion. Careful attention to plant species, soil moisture and soil type is necessary to ensure that you are irrigating properly. Pastures in the Gallatin Valley are often planted to introduced plant species to increase production. These pastures may need additional water and fertilizer to keep them productive. In general, you should irrigate when soil moisture drops to about 50 percent of its water-holding capacity in the top 3 feet of soil. You can tell it is time to irrigate if soil from the top 18 inches crumbles when you try to form it into a ball, does not stain your fingers when you squeeze it, and feels only slightly moist. Irrigate sandy soils for short periods (2-3 hours) at short intervals for a total of 1.4 inches every 6 days, and clay and loam soils for longer periods (9-12 hours) at longer intervals, about 3.1 inches every 12 days.

Lawns in our area normally need about 1 inch of water a week in a single watering. More frequent watering may actually harm your lawn, because it will not develop a deep root system and will be more susceptible to fungus growth. Watering in the heat of the day or during windy periods should be avoided. Gardens and landscaping can often benefit from installation of water-conserving systems like drip irrigation.

Livestock Management

Livestock management or the lack of it can have a tremendous impact on the vitality of any riparian or wetland area on your property. It can have impacts on your neighbors downstream as well. You can use many practices to reduce livestock impacts on these areas by:

Developing non-riparian sources of water for livestock

Livestock damage riparian areas by browsing down plants holding the bank together and by breaking down the banks. Livestock confined in a stream corridor leaves manure in the stream, which can affect water quality downstream.

• Developing fountains and other sources of water away from streams will reduce the amount of time livestock spend in and near the stream.

Limiting duration of livestock use

Healthy pastures have more surfaces covered with grass, which not only prevents surface erosion into surface waters but also provides your animals with more forage. To maintain healthy pastures:

• Don’t put animals out in the spring until your pasture grasses are 6 to 8 inches high.
• Rest a part of your property during the grazing season by subdividing your property into smaller distinct pastures that can be grazed intensively.
• Horses do not need to graze 24 hours a day; 4-6 hours a day will meet all of their nutritional needs. Horses can be held off pasture the rest of the day, and should be moved to new pasture when grasses are grazed down to 3 to 4 inches.
• Don’t overstock. A 1,100-pound horse needs about 875 pounds of forage per month, and grasses need a regrowth period of a month or more during mid-summer. Too many animals can quickly deplete your pasture.

The amount of water required to support an animal unit (AU - a mother and young is 1 animal unit) of livestock can be estimated by the following:

Allowing streambank vegetation to thrive

Keep streambank vegetation healthy by:

• Considering exclusion of livestock from riparian areas. You can prevent livestock from degrading willows, trees and other riparian vegetation by excluding them with fencing.
• Maintaining water gaps and gravel pad crossings. Where livestock need to cross the stream to access other pastures or where no other water is available, create water gaps. Ranch managers in the Gallatin have used construction fabric and a gravel pad to create crossing areas between gently sloping streambanks. Cattle use these crossings preferentially, which greatly reduces streambank trampling. Fencing of adjacent riparian areas can enhance use of water gaps.
• Planting willow cuttings. Planting willows and other shrubs to control erosion and reestablish fish and wildlife habitat can restore degraded riparian areas. Willows sprout from fresh cuttings with little difficulty and are a cost effective and efficient way to restore riparian vegetation to streams where it has been lost. Willow cuttings need to be planted in bare, disturbed banks without grass competition.

Water gaps provide opportunities for riparian vegetation to recover.

Pest Management

Improperly applied and stored pesticides can easily enter both surface and ground water. Insecticides are primarily organophosphates and carbamates that kill insects by damaging the central nervous system. They can kill fish and wildlife in the same way. Pyrethroids are synthetic versions of naturally occurring insecticides. While they have low toxic effects to mammals, they are highly toxic to fish. Herbicides generally work to interfere with photosynthesis or alter plant growth, but may also have unintended effects on fish and invertebrates. While many herbicides have short toxic lives, some are easily transported by runoff or groundwater, which could have devastating effects on nontarget plants in wet areas.

• Avoid spraying in wetlands and riparian areas.
• Avoid pesticide applications between 10 a.m. and 4 p.m. and/or when wind speeds are greater than 5 mph.
• Use buffer zones of unsprayed crops or vegetation to protect adjacent wetlands or riparian areas.
• Don’t use pesticides near stream edges. Use appropriate pesticides near streams. For example, use pyrethroids in upland areas but avoid their use near streams.
• Use biological and mechanical control where possible in areas near wetlands and streams.
• Follow label guidance explicitly.

How to Reduce Your Use of Pesticides

Cultural practices

• Choose plants with known resistance to common problems.
• Consider common sense methods of dealing with pests: rotating crops like potatoes, cleaning up garden debris, hand-picking pests, using row covers or traps, or tolerating some level of damage.

Biological controls

• Include plants near your garden that favor natural enemies of garden pests. Marigolds will repel nematodes, for instance, and ladybugs are available locally commercially for control of aphids.
• Many predators, parasites and pathogens of garden pests are available commercially. Bacillus thuringiensis, a naturally occurring pathogen, is available for the control of caterpillars.

Low-toxicity pesticides

• Insecticidal soap is potassium salt-based and controls aphids, red spider mites and mealy bugs.
• Pyrethrum is derived from the chrysanthemum plant and is effective against most insects­but do not use near streams.

Xeriscaping: The Water-Efficient Landscape

Picking Appropriate Species

Xeriscaping means using plants adapted to the semiarid conditions found in south central Montana and caring for them in ways that require less water. Many gardeners and landscapers have found that using adapted plants not only results in healthier lawns and gardens that use less water but requires less management as well. Talk to your local nursery about plants that will not only complement your home but will also thrive without heavy doses of water.

Practical lawns

While turf grasses are important in reducing runoff and controlling erosion, lawns should not be larger than necessary to meet some special function. Maximum water conservation is achieved when lawns are irrigated separately from trees and shrubs. When water restrictions are in place, lawns may go dormant, but will recover.

Mulches

Mulches of bark, compost, sawdust and plant waste (straw, leaves and grass clippings) help reduce evaporation from the soil. Use mulches on gardens and

Mowing

Cutting grasses too low increases water demand and causes roots to die or deteriorate. Bluegrasses and ryegrasses should be cut no lower than 2 to 2.5 inches, and fescues 2.5 to 3 inches. Removing more than one third of the blade in one cutting injures the root system.

Some Plants Adapted for Our Climate

Grasses for dryland lawns

• Sheep fescue “Covar” (bunchgrass)
• Tall fescue “Alta” (bunchgrass)
• Streambank wheatgrass “Sodar” (sod forming; playing fields)
• Western wheatgrass “Rosana” (sod forming; erosion control)
• Thickspike wheatgrass “Critana” (sod forming; playing fields)

Perennials

• Blanketflower
• Plains coreopsis
• Prairie smoke

Shrubs

• Mountain mahogany
• Red twig dogwood
• Lewis mock orange

Trees

• Water birch
• Green ash
• Ponderosa pine

Fertilizing

Over-fertilizing does not improve plant growth and can damage the roots of turf grasses and pasture grasses, as well as harm water quality.  Nitrogen and phosphorus, components of fertilizer, are easily washed into ground and surface waters.  Fertilizer washed into a wetland can literally choke it to death, because the increased nutrients will cause algae to flourish, depleting the oxygen needed by other organisms.  Follow label instructions and request a soil test from NRCS to better ascertain your specific fertilizer needs.

Composting

You can extend the life of your septic system by limiting the amount of solid material that goes into your tank by composting organic waste.

Information

Montana Native Plant Society - Source Guide for Native Plants of Montana, MNPS, Linda Iverson, Box 3733, Big Timber, MT 59011

DNRC - Tips on Land & Water Management for Small Farms & Ranches in Montana, and Riparian Grazing Successes on Montana Ranches
(406) 444-6667

NRCS - technical information on Riparian Buffers: Riparian Forest Buffers, Montana Technical Guide Code 391; recommendations for low maintenance turf grasses for Montana
(406) 587-6929

Alternative Energy Resources Organization - Groundwater Protection for Farmers and Ranchers
(406) 443-7272

Montana BLM, Montana Forest and Conservation Experiment Station - Successful Strategies for Grazing Cattle in Riparian Zones, Riparian Technical Bulletin No. 4, Jan. 1988
(406) 243-2050

MSU Extension Service - Circular 1280, Landscape Trees and Shrubs

Resources

NRCS - assistance in designing an appropriate irrigation system for your property
(406) 587-6929

NRCS - classes in pasture management for horse owners
(406) 587-6929

The Gallatin County Weed Control District
(406) 582-3265

< Back to The Gallatin Watershed Sourcebook Table of Contents