Best Management Practices
Best Management Practices (BMPs) are land management practices that lessen the environmental impact of an activity. There are hundreds of different BMPs that address different impacts of agriculture, and adopting even a few can often make an enormous difference. In many cases, these BMPs can have economic benefits as well, improving the efficiency of operations and/or increasing production.
The NRCS has an exhaustive list of BMPs for managing crop and forest lands and raising livestock, with over 170 different BMPs eligible for federal funding or cost-share through numerous USDA programs.
Some of the most important BMPs for water quality are discussed briefly here but for more detailed information, contact your local USDA service center.
ATTRA, the National Sustainable Agriculture Information Service, is another good source for information on sustainable agriculture practices, and provides hundreds of free, in-depth publications on virtually any agricultural topic you could imagine, from conservation easements to organic tobacco and even ostrich farming! For more information or to order one of their publications, visit attra.ncat.org or call 1-800-346-9140.
Keeping nutrients and soil on your land and out of the stream
Two major sources of water pollution are nutrients and sediment, which move from farm fields and lawns to nearby waterways. This is a lose-lose situation – no one wants to lose precious soil and nutrients that could support a more productive crop. Luckily, there are lots of ways to manage this problem, many of which qualify for federal cost-share programs.
No-till farming decreases erosion, enhances moisture retention, and helps compacted soil recover to healthy conditions. No-till is on the rise nationwide, and an increasing number of crops can be planted using no-till methods. Where no-till is not an option, strip-tilling can be a good compromise between the benefits of conventional tillage and no-till.
In between growing seasons, cover crops prevent erosion of fallow land, reduce runoff, and can help reduce weed pressure. In a conventional tillage system, leguminous crops can be grown and tilled into the soil to provide additional nitrogen. In a no-till or strip-till system, crop residue from cover crops can reduce weed pressure, retain moisture, and prevent erosion during the growing season. Many cover crops can also be harvested.
Conservation crop rotation
Plan crop rotations in a way that conserves soil and minimizes fertilizer/ pesticide/herbicide.
Pesticides and nutrients are major pollution sources in rural waterways, and proper management is essential. Correct calculation of nutrient/pesticide needs can minimize pollution and lower costs.
Integrated pest management (IPM)
When managing pests, combine biological and physical pest control strategies and targeted pesticide use to minimize the quantities of pesticides applied.
GPS technology allows producers to map in-field variables such as crop yield, nutrient levels, and moisture content, so fertilizer and water can be applied precisely, reducing excess nutrient runoff and saving money.
Avoid tile drains whenever possible. If you must use one, consider using a denitrifying bioreactor or artificial wetland (see edge of field BMPs) at the outlet to help absorb excess nutrients in the drain water and limit flash flooding.
If using manure as a fertilizer source, use a manure injector for liquid manures to reduce odors, limit impacts on air quality due to volatile gases, and reduce nutrients and pathogens in stormwater runoff. New technology has recently developed to apply this injection concept to dry manures such as poultry litter as well.
Install grassed waterways to balance field drainage with infiltration/erosion reduction.
Plant shrubs/trees between fields to trap runoff and reduce water and wind erosion.
Healthy streams, healthy livestock
Whether you raise a few animals or a large herd, these best management practices can improve the health of both your water and your livestock.
Moving stock between multiple fields limits grazing pressure in any one area, reducing erosion and nutrient and pathogen pollution in runoff. It can be done using permanent fencing or temporary electric fencing.
Fencing livestock away from natural water sources prevents contamination by pathogens and nutrients and helps preserve stream banks. Cattleexclusion fencing, when combined with an alternative water source, can improve livestock health by keeping stock off of unstable, possibly dangerous stream banks.
Alternative water sources
providing pump-fed drinking troughs or tanks allows livestock to drink without needing a natural water source such as a pond or stream. Avoiding direct watering can also benefit livestock by preventing access to potentially contaminated water.
Prevent livestock from damaging the soil or causing erosion when congregating at water sources or hay rings by hardening heavy-use areas or using mobile hay wagons and water troughs.
Using a bridge or culvert is preferable, but if a stream crossing for livestock is necessary, it should be hardened to reduce erosion.
Edge of Field BMPs
Keeping our streams healthy
Whether you own a farm or just live in the country, “edge of field” practices help keep our waters healthy. See the reverse of this brochure for funding sources to cover implementation costs.
Leave forested buffers of 50-100 feet between cropland or pasture and a stream or waterway (including sinkholes!) whenever possible. Riparian buffers trap sediment and filter nutrients, pathogens, and other pollutants out of edge of field runoff.
Preserve existing wetlands between the field and stream – these ecosystems help control flooding, trap sediment, and filter pollutants from edge-of-field runoff. Artificial wetlands can also be built at the field edge to provide similar benefits.
Streambank and shoreline protection
Protecting the streambank from erosion helps limit sediment pollution and preserve your land. When possible, try to use natural methods rather than riprap or hard-armoring.
Denitrifying bioreactor or wall tile drains
Wall tile drainscan deliver damaging quantities of nutrients to nearby streams. Denitrifying bioreactors provide carbon-based material (usually wood chips or sawdust) in an underground chamber to provide food for bacteria that break down nitrates from the tile-drain system.
These structures can limit erosion at gully heads, reducing soil loss and preventing further gullying damage on agricultural land.
Edge of field basins trap sediment, reducing sediment pollution in nearby streams
Keeping our forest streams healthy
Forestry involves dozens of sustainable management practices, of which a few are mentioned here. Recent surveys have shown wide adoption of these practices (nearly 90% adoption for some BMPs) in Tennessee – so don’t be left behind! If you are a logger or a landowner who is selling timber rights on your land, learn how to make sure the harvest protects your waterways.
After harvesting, use cover crops or other sediment control measures to reduce post-harvest erosion, especially if clear-cutting.
Includes numerous co-growth activities such as using the space between tree rows in an orchard or nursery for crops or pasture, growing shade crops in forests, or including species at the outer edge of a riparian buffer that generate additional income through non-timber production.
Retaining the riparian zone (forested areas along streams) helps prevent erosion, maintains the canopy cover to keep streams shaded and cool (high stream temperatures can be dangerous for many aquatic species), and limits excess organic matter and nutrients from reaching the stream.
Proper road/stream crossing design
Logging roads and stream crossings should be designed to minimize erosion and allow fish passage in streams.
Uneven-aged selection forestry
Clear-cutting can be damaging to forest wildlife and can increase erosion. Consider ongoing individual-tree or group selection as an alternative. These methods are more complex than clear-cutting but can create a healthier forest
Resources for Best Practices
Making positive changes isn’t always cheap but many best management practices can save you money in the long term, and there are organizations and agencies that offer grants or loans to help.