How soil improves/protect environment Important environmental laws BMP’s Calculating manure application rates Use of buffer strips Remediated degraded & contaminated

soils

Soil is nature’s waste treatment plant› Physically filters› Chemically filters› Organic filters

Groundwater pollution is among highest priorities

Focus on animal wastes

Clean Water Act› Control discharge of pollutants into

navigable waters› Focus on point-source pollution

What is this? Anyone wanting to operate facility that may

discharge into freshwater mush have permit

› EPA regulates Must control effluent quantity & quality

Safe Drinking Water Act› Federal gov’t control of treatment facilities,

wellheads, etc.› Maximum contaminants set› State enforces EPA standards

Comprehensive Environmental Response, Compensation, & Liability Act› Makes owners/operators of hazardous

waste disposal sites liable for cleanup costs & property damage Each and every party responsible regardless

of level of guilt

Resource Conservation & Recovery Act› Authorizes EPA to control waste generation,

treatment, storage, transport, disposal

› Extends only to active & future sites Clean Air Act

› Establishes air quality standards› Cleaned up industrial & auto emissions

Federal Insecticide, Fungicide, Rodenticide Act› All pesticides must be EPA registered› Ensures pesticide benefit > environmental

harm

› Producers must provide documentation of risks & strict labeling

Pollution Prevention Act› Prevent/reduce pollution at source› Waste-management hierarchy

Prevention Recycling Treatment Disposal

Point Source vs. Nonpoint Source Pollution› Point source – pollution from identifiable

source Tightly regulated Large ag units can be considered under this

› Nonpoint source – many places contributing to pollution, can’t track to any one person/place

BMP Implementation› Voluntary› Some states enforcing BMP’s

May have grants/incentives if yields are less May deny operation if found in

noncompliance

BMP’s for Reducing Nutrient Pollution› Some examples follow

Animal-feeding Operations (AZ)› Minimize leaching/runoff of N by harvest,

stockpiling, disposing of manures› Sufficient water-control facilities for N

contaminated water in case of huge rain N Fertilizer Applications to Crops (MN)

› Realistic yield goals› Record keeping› Adjust N rates according to soils

› Prudent manure management› Don’t apply N above recommended rates› Increase N use efficiency by plants

Sewage Sludge & Wastewaters› Compost outside for >21d› Store at specific time/temp to decrease

pathogen load› Treat w/ lime (reduces heavy metal uptake)› Pasteurize› Ocean-dumping banned in 1981› Class A Biosolids

Treated sludge w/ no detectable pathogens Meets vector standards Low levels of heavy metals

› Class B Biosolids May contain pathogens Permits issued only after careful inspection

of application site & risk of pollution Residences Waterways Crops, etc.

Animal Manures› Low value product reduces shipping

feasibility

› Tendency to overapply› Guidelines:

All runoff, outdoor retention facilities sufficiently sized to control excessive rains

Watertight lagoons, ponds, etc. Incorporation of wastes into soil ASAP after

application Apply only to max safe rates

Use IPM Apply at lowest rates possible for

control Predatory organisms Use disease resistant varieties Vary pesticides used Acknowledge environmental risks at

application time Incorporate, if possible

BMP’s› Decrease N losses through runoff, leaching› Decrease pesticide usage› Decrease salinity by improving irrigation &

cropping systems› Improve erosion control

Controls P, N, pesticide pollution Decreases sedimentation

› Use buffer strips

Buffer Strips› Permanent vegetation meant to intercept

& filter materials that may pollute water› Benefits:

Traps: >50% fertilizers, pesticides >60% pathogens Heavy metals >75% sediments Snow

Reduce noise/odor

Turn rows for farm equipment Food, cover, shelter for wildlife Improve aesthetic appeal

Decreasing CO2 Emissions› Decrease fuel use› Alternative energy sources

Wind power Geothermal

› Grow combustible/renewable fuels Ethanol Biodiesel Cellulolytic ethanol (Biomass)

Decreasing Greenhouse Gas Emissions› Reduce livestock emissions by altering

diets› Reduce methane emissions from sources

like rice› Decrease denitrification of N› Use cleaner burning fuels

Remedies for Soil Quality Problems› Increase organic matter› Decrease soil erosion› Decrease soil compaction› Decrease risk of soil crusting

Leaching› Let nature wash away & filter contaminants› Will only work in permeable soils

Phytoremediation› Planting of specific plants to treat polluted

sites› Two options:

Plant doesn’t digest, but provides environment suitable for microbes than can digest the pollutants

Plant does absorb pollutants Can harvest & remove

› Slow process Vapor Extraction

› Pulls contaminants out w/ sealed environment treating w/ air/incineration, carbon filter

Bioremediation› Microbes decay contaminants› Can be combined w/ other methods

› May also be expensive› Public tends to like (thinks its more

natural) Soil Disposal

› Excavation & disposal in landfill› Very expensive & drastic