Managing crops and animals near shorelands

Crops and animals affect water quality

Rainfall and snowmelt running off farmland or seeping into the ground can carry pollution into lakes and streams. Pollution carried by runoff is called nonpoint source pollution.

The main cause of today's water quality problems is the large number of nonpoint pollution sources.

Raising crops and animals can contribute to nonpoint pollution if runoff is not properly treated.

Sources of nonpoint pollution in Minnesota

Many different types of crop and animal operations contribute to nonpoint source pollution, from dairy and beef farms to sled dog kennels and hobby farms. These operations send nutrients and organic matter into surface water that can create pollution:

• Pasturing animals along stream banks can cause erosion that adds sediment to lakes and streams.
• Farming steep fields in continuous row crops can create sheet and rill erosion that strips away topsoil. The topsoil that ends up in lakes and streams often carries nutrients and pesticides.

Major agricultural pollutants

The major nonpoint source pollutants are sediment, nutrients, pesticides, bacteria and oxygen-demanding substances.

• Sediment. Eroded soil particles from fields, ditches and streambanks make water turbid, damaging fish and plant habitat and reducing water's aesthetic appeal. This sediment may carry nutrients and heavy metals with it.
• Nutrients. Fertilizer or animal waste in runoff water delivers nutrients such as phosphorus and nitrogen to lakes and streams, causing excessive algae and weed growth. High nitrate concentrations in drinking water can present a health threat for infants.
• Pesticides. Agricultural chemicals such as insecticides or herbicides can wash off crops and fields into lakes and streams where they can be toxic to fish and other aquatic life. Some pesticides threaten human health if they reach drinking water supplies.
• Bacteria. Runoff or seepage from feedlots and failing septic systems can carry coliform bacteria into surface and groundwater, presenting health risks for drinking or body contact.
• Oxygen-demanding substances. Manure, sewage, crop residue and other decaying organic matter use up oxygen needed by fish.

Best management practices to prevent nonpoint source pollution

Minimize the impact of agriculture on nearby lakes and streams by using these best management practices (BMPs).

Control erosion on cropped land

Careful management of tillage practices can make farm operations more profitable, reduce erosion, and improve water quality. Some tillage options to consider are:

• Mulch tillage.
• No-till and ridge-till systems.
• Contouring and grass field borders.
• Strip cropping.

Many farms still use the moldboard plow in a conventional tillage system. Consider these options to reduce erosion:

• Fall plowing heavy soils is the best option, but the ground should be left rough and cloddy. Winter conditions can help improve your soil structure by reducing the clump size. Leaving a rough surface also helps cut down surface erosion.
• Never disc a fall plowing unless it is early enough to establish a fall cover crop. Discing or making seedbeds in the fall will create the opportunity for significant soil and nutrient loss.
• Spring plowing is your best option in lighter soils and can reduce overall soil erosion.

Use basic best management practices to lessen your negative impact on water quality:

• Soil management.
• Crop rotation.
• Nutrient management.
• Seeding fragile and drainage areas with grass for sediment control.

Use diversions and roof gutters to control runoff

A diversion is a permanently vegetated ridge constructed at the base of a slope to safely divert the runoff. Gutters simply redirect significant amounts of water away from building foundations or, in this case, an animal barnyard.

Manage manure properly

Use a manure catchment

This structure allows for the buildup of manure and channels liquid manure to a single outlet. Liquid manure can be either stored and used to fertilize fields or "treated" by a grass filter strip. Solid manure within the catchment can be removed during the growing season and applied to the field, adding organic matter and nutrients. There are many designs and methods of storage for managing both solids and liquids.

Install a grass filter strip to filter nutrients

This is permanent grass sod that filters potentially harmful nutrients from the manure catchment area. In the growing months, excess nutrients can be utilized by the grasses. This method is enhanced by the addition of a buffer strip between the grass filter strip and the stream.

Maintain buffer strips along lakes and streams

Buffer strips consisting of natural or planted woody vegetation can enhance the removal of excess nutrients along lakes and streams. The buffer strip acts to:

• Stabilize soil.
• Trap nutrients by filtering runoff.
• Shade and cool the water to improve aquatic habitat.

The wider the buffer strip, the greater its effectiveness. Planting high-value tree species could increase your farm's future value.

Install stream crossings and fencing to keep livestock away from streams

Low-flow gravel crossing. The least expensive method is to make a low-flow gravel crossing, allowing livestock access to pasture on the other side of the stream.

Culverts and bridges. These are more costly but might be necessary in sensitive areas. These also can be built to allow machinery to cross.

Fencing. Fencing can be installed on either side of the crossing as gates to prevent them from walking along the stream. Fencing animals out of lakes or streams will prevent water pollution. Water your animals with electric pumps, solar-powered pumps, mechanical nose-pumps, and stock watering ponds.

You may need permits for work done along streams or lakes.

Use intensive rotational grazing for pasturing livestock

Intensive rotational grazing provides better forage for your animals while improving sod and soil coverage between grazing cycles and can reduce overall erosion. Fencing animals from sensitive areas is also important.

Convert marginal fields to other uses

Highly erodible and marginal fields can be converted to various uses and provide long-term financial and environmental benefits. Some conversion possibilities are:

• Intercropping trees and pasture.
• Planting nut trees or high-quality timber.
• Planting Christmas trees.
• Using native and imported species for wildlife habitat.

Store fuel, fertilizer and pesticides safely

A small amount of fuel oil, gasoline, diesel, fertilizer or other chemicals can contaminate a large volume of water.

Fuel oil, gasoline and diesel:

• Locate tanks away from other buildings and water.
• Dike the area around above-ground tanks to contain spills.
• Follow maintenance, safety and disposal precautions.

Fertilizer and other chemicals:

• Store only small amounts for short periods.
• Clearly mark containers and check their condition.
• Cover and store on a sealed surface to contain any spills.
• Properly dispose of outdated unused chemicals. Contact your county solid waste officer who may accept unused chemicals free of charge.

Contain silage and haylage properly

Improperly contained silage can contaminate ground and surface water. Use these basic best practices to minimize risk from these operations:

• Store silage away from any water source.
• Provide impermeable surface soil around the storage.
• Install a seepage collection system.
• Divert clean water away from the area.
• Adequately cover silage.

Regulations that apply

Owners of feedlots with more than ten animal units must have a feedlot permit from the Minnesota Pollution Control Agency (PCA). Check with local zoning authorities for assistance.

Program assistance for agricultural BMPs

These agencies all offer programs to help people plan and adopt BMPs:

• Soil and Water Conservation District (SWCD).
• MN Board of Water and Soil Resources (BWSR).
• Natural Resources Conservation Service (NRCS).
• Farm Services Agency (FSA).

SWCD, state, and federal cost-share programs are available to help people apply these practices. Planning and design assistance is offered at no cost, and up to 75% of the installation cost can be covered by cost-share dollars.