Notes from NRCS online site on BMPs http://www.nrcs.usda.gov/technical/standards/nhcp.html Focus on key BMPs Function, benefits, and drawbacks listed
Definition Novotny & Olem: BMPs are methods and practices or combination of practices for preventing or reducing nonpoint source pollution to a level compatible with water quality goals. SWCS: a practice or a combination of practices that are determined by a state or a designated area wide planning agency to be most effective and practicable means of controlling point and nonpoint source pollutants at a level compatible with environmental quality goals
Various types of BMPs Source reduction or transport interception/reduction Structural and managerial
Conservation Tillage Leaves at least 30% of the soil covered with crop residue Examples no tillage, mulch tillage.
Source reduction, managerial practice Benefits Reduced erosion Increased infiltration Reduction in evaporation Increased organic matter Improved soil health/quality Reduced sediment/nutrient loss Concern Increased leaching and loss of dissolved nutrients & pesticides
Contour farming Farming along the contours Source reduction, managerial
Benefits Reduces sheet and rill erosion Water and Moisture conservation Reduces sediment bound pollutants Drawbacks Large storms can cause overtopping of furrows
Strip Cropping Strips alternate between close grown crops Source reduction, managerial
Benefits - 1. Reduced sheet and rill erosion. 2. Reduced wind erosion 3. Increased infiltration and available soil water. 4. Reduced dust emissions into the air. 5. Improved water quality. 6. Improved visual quality of the landscape. 7. Improved wildlife habitat
Buffer Zones Vegetated buffers Transport interruption/reduction Structural BMP
Benefits Reduce erosion Increase infiltration, decrease runoff Reduce nutrients, metals, bacteria, pesticides Provide habitat Biomass
Cover Crops Crops between harvest and planting of primary crop Source reduction, Managerial practice
Benefits Provide soil cover and reduce erosion Sequester nutrients Reduce evaporation losses Increase organic matter and soil quality Possible negative impact Herbicides used to kill cover crop
Nutrient Management Optimize the input of nutrients amount, form, placement, and timing of nutrients Source reduction, managerial practice
Benefits Reduce the losses of nutrients in runoff Increase/optimize yields Decrease inputs of nutrients to the farm Reduce farm operational costs Involves - Soil testing Manure testing Crop Tissue testing Target crop yields
Manure Storage Facility Store manure or ag waste before application Source reduction, structural BMP
Benefits Reduce nutrients, pathogens, and other contaminants in runoff Use manure more effectively and efficiently over the year Generate farm income through sale of manure Cost creation of the storage structure.
Integrated Pest Management Use of management practices for pest control that result in efficient production of food and fiber using the minimum amount of pesticides Source Reduction, Managerial BMP
Important components Maximum use of biological and cultural control Regulatory procedures Adherence to pesticide labels Crop rotation Pest resistant and pest tolerant crops Scouting by IPM specialists and skilled farmers
Precision Farming Precise application of nutrients and other inputs based on specific soil and crop needs Technology intensive managerial practice Source reduction
Take into account the spatial variability of farm topography, soils, water/moisture and crop requirements
Vegetated waterways, terraces, diversions Transport reduction, structural BMP
Benefits: 1. Safe disposal of runoff water 2. Erosion control is concentrated flow areas of a field 3. Improved water quality 4. Improved wildlife habitat 5. Reduced sediment damage 6. Improved landscape aesthetics
Sediment Basin / Check Dam Transport reduction, structural BMP
Benefits Sediment retention Reduction in nutrient exports Drawbacks Soil is exported from the farm High maintenance
Stream Fencing Source reduction, structural BMP
Prevent input of nutrients and bacteria in waterways Prevent stream bank erosion Enhance stream habitat Installation and maintenance costs are very high
Rotational Grazing Source reduction, managerial BMPs
Benefits Prevent soil erosion and runoff generation Reduce soil compaction
Constructed Wetlands Transport reduction, structural BMP
Benefits Buffer runoff Reduce sediment and nutrient exports from farm Provide habitat Drawback Large land area, initial costs.