Best Management Practices
Best Management Practices, BMPs, are managerial practices and structural or nonstructural methods, that are effective and practical, in preventing or reducing the movement of sediment, nutrients, pesticides and other pollutants from the land to surface or ground water, or which otherwise protect water quality from potential adverse effects of agricultural activities. These practices are developed to achieve a balance between water quality protection and the production of crops within natural and economic limitations.
The Environmental Protection Agency (EPA) recognizes the use of BMPs as an acceptable method of reducing nonpoint source pollution.
Nonpoint source is diffuse pollution that comes from almost everywhere; it even occurs naturally to a certain extent. The amount of pollutants from any particular spot is small and insignificant, but when combined over a large area, can create water quality problems.
Although it is unrealistic to expect that all nonpoint source pollution can be eliminated, BMPs can be used to minimize the impact of agricultural practices on water quality. These practices must be reasonable, achievable and cost effective.
Selecting BMPs that are practical, economical and site specific is an important step in controlling nonpoint source pollution. There may be more than one correct BMP for reducing or controlling potential nonpoint source pollution.
Members of the El Dorado County Agricultural Water Quality Management Corporation are required to use the BMPs for their particular agricultural operation. From large farmer to backyard gardener BMPs help ensure current and future water quality.
Pesticide Management Practices
- Manage pesticides and pesticide use so that applications are targeted to an identified pest and applied so as to minimize the potential for offsite movement. This will eliminate, reduce, or slow the direct discharge of pesticide(s) to adjacent watercourses.
- Use a Pest Control Operator to identify pests and determine appropriate action. Specific pests and areas can be targeted to minimize the use of broad-spectrum pesticides.
- Base application decisions on environmental conditions (wind, rain, temperature, etc.), scouting data, pest thresholds and/or risk assessment models. Growers may use pest traps or County Agriculture Department monitored traps to determine if there is a need to apply pesticide(s). This will eliminate unnecessary pesticide applications that are based on calendar scheduling.
- Select pesticides with lower risk of runoff or leaching based on pesticide chemistry and site conditions, i.e. soil type and slope conditions. This will help to prevent any materials from entering adjacent watercourses via runoff and/or soil movement.
- Manage overall seasonal use to minimize the amount of pesticide(s) needed to be effective. Regularly scheduled applications of pesticides will be reduced or eliminated, thereby eliminating the possibility of pesticide(s) entering waterways.
- Regularly, at least once annually, check and calibrate application equipment and/or injectors. This will eliminate the possibility of excessive chemical application, over spray, and/or drift that could adversely affect adjacent waterways.
- Incorporate a backflow prevention system or air gap so that pesticides cannot enter the water source when filling sprayers.
- Use biological controls where possible to reduce or eliminate the need for applying pesticide(s).
- Introduce populations of beneficial insects when appropriate to eliminate the need for applying pesticide(s).
- Store, handle and apply pesticides according to labels as required by law. The safe handling will eliminate the possibility of materials leaking to unwanted areas.
- Comply with Department of Pesticide Regulation Pesticide Application Permit requirements. Read labels and follow all directions.
- Use a Pest Control Operator PCO for pesticide applications. PCOs are trained to apply pesticides in the most environmentally friendly methods in accordance with current DPR rules.
- Use organic materials when and where conditions allow. An example would be to mulch around crops to reduce water and herbicide needs.
- Cultural practices are applied when and where appropriate to reduce pesticide use. An example would be to mow instead of applying herbicides.
- Consult with a UCCE Farm Advisor to identify any unknown causes of crop damage in order to determine the correct pesticide(s) to be applied.
Nutrient Management Practices
- Mix and load fertilizer on low runoff hazard sites away from surface water and wellheads to minimize any chance of soil movement into the well or surface water.
- Use plant tissue analysis to assist in fertilizer application decisions so as to apply correct amount(s) of the specific nutrient(s) needed.
- Incorporate a backflow prevention system if applying fertilizers via your irrigation system so that fertilizers will not be allowed to enter your source water system.
- Planting cover crops that fix nitrogen in the soil will help reduce the need for commercial nitrogen fertilizers.
Irrigation Water Management
- Manage irrigation systems and events so as to eliminate, reduce, or slow the direct discharge of runoff to adjacent watercourses.
- Participate in an IMS program provided by a local water purveyor or the EDCWA to schedule irrigation events to accurately provide water based on the plants’ needs and soil moisture status.
- Use ETO data to schedule irrigation events to accurately provide water based on environmental conditions.
- Maintain and monitor irrigation system(s) on a regular basis to ensure designed performance and uniformity of coverage. Timing will depend on the frequency of irrigation application and the system being used.
- Use drip or micro-sprinkler irrigation systems to maximize water application efficiency when economical and practical.
- Know the water holding capacity of the agricultural operation soil so as not too over irrigate, which might result in irrigation water runoff.
- Know the soil infiltration rate so that irrigation systems are designed and operated so as not to exceed the water absorption rate of the soil.
Erosion and Sediment Control Management
- Manage erosion so as to eliminate, reduce, or slow the direct discharge of sediment to adjacent watercourses.
- Use cover crops between rows to stabilize soil in the area.
- Use vegetative buffers down slope of the irrigated lands to stabilize soil in the area and help filter sediment out of storm water.
- Use water bars and diversion ditches on service roads within and adjacent to the irrigated agricultural operation to prevent erosion in these traffic areas.
- Apply gravel, vegetative material and/or establish a cover crop on service roads within and adjacent to the irrigated agricultural operation to prevent erosion in these traffic areas.
- If terracing is necessary comply with county grading requirements to ensure that a proper grade is maintained on terraced sites so that soil cannot leave the area.
- Use grassed waterways, lined channels and/or diversions in ditches and channel banks to stabilize and hold soil in place.
- Use sediment control basins where practical and necessary to allow sediment to settle from irrigation and/or storm water runoff.
- Visually monitor runoff during excessive storm events to identify previously unknown problem areas to allow repairs to take place before additional soil movement can occur.
- Apply and/or manage plant residues or other materials on the field soil surface to ensure there is successful reseeding and continued viability. Plant residue can be mulched on top to prevent erosion and reduce soil moisture evaporation.