Beneficial practices which improve water quality

Beneficial (or best) management practice (BMPs) is the term used to describe a practice, or system of practices, designed to minimize the impact of agricultural activities on natural resources while at the same time maintain economic viability of the agricultural industry.

To ensure a supply of good quality water for agricultural purposes (domestic use, livestock watering, crop spraying, etc), it is necessary to consider BMPs at three levels:

• watershed management, to protect both surface and ground water sources;
• management of the water source (such as a dugout, river or ground water aquifer) and
• appropriate treatment for a specific use.

Watershed Management

For Prairie agricultural land, watershed management techniques offer the first water treatment strategy for maintaining good water quality. Watershed management includes beneficial management practices (BMPs) which protect surface water supplies (dugouts, small reservoir, rivers or lakes) and ground water aquifers (shallow or deep water supplies below ground) by reducing the potential for contaminants to enter the water source. Some examples of substances which could contaminate a water source include sediment, fertilizer, pesticides, animal waste, animal pharmaceuticals, fuel, oil and hazardous products used in farming, or by-products used in agricultural processing.

There are three general types of beneficial practices which help reduce the risks of water quality degradation.

1. Managing agricultural Inputs

Managing agricultural inputs is an important element of pollution prevention. Proper handling and use of fertilizers, manures and pesticides will prevent or limit the impact on the environment.

• Nutrient management is the practice of applying fertilizers and manures only in the amounts that can be taken up by the crop. Over-applications increases the risk of contaminating surface and groundwater supplies. Read more about this practice in Nutrient management planning.
• The use of pesticides can be minimized through "Integrated Pest Management". This refers to a management strategy that includes an understanding of the target pest and use of a combination of physical, chemical, biological and cultural controls. Proper storage, mixing and handling are also essential in minimizing risk to the environment. Read more about this practices in Pest management and water quality
  
• Another practice includes livestock watering at sites well away from natural water courses (including wells or sensitive aquifers)in order to keep manure out of the water and building fences to prevent cattle access to water courses. Read more about this practice in Alternatives to direct access livestock watering

2. Controlling erosion and runoff

Controlling erosion and runoff is an important beneficial management strategy. Runoff from fields to which pesticides, fertilizer and manure are applied, as well as runoff from livestock operations can contaminate water. Practices such as strip-cropping, shelterbelts and use of cover crops prevent erosion and reduce the movement of nutrients and pesticides from agricultural land. Read more about how shelterbelts can affect the water quality of dugouts.

Residue management through conservation tillage and continuous cropping is also effective at controlling erosion, but requires higher inputs of fertilizer and herbicides. Read more about soil practices which affect water quality.

3. Barriers and buffers

Barriers and buffers can be planted to intercept potential contaminants from agricultural lands. In most cases, these are strips of vegatation that slow the velocity of runoff water enough for sediment to settle out, water to infiltrate into the ground and nutrients to be taken up by plants in the vegetated buffer zone.

Grassed waterways, vegetative strips and field borders are examples of buffers that can be used in annually cropped fields.

Where buffer zones surround a stream or lake, they are usually referred to as riparian buffers. These strips capture sediment and nutrients from water that is moving into the waterway from surrounding agricultural lands. The vegetation also stablizes the banks and shores from the erosive action of the waterway itself. Read more about Riparian management practices.

Management of Water Sources

Management of the water source includes best management practices (BMPs) to sustain the best possible water quality at the source (Table 2).

Table 2: Best Management Practices to Protect Water Sources

BMPs for Surface Water Sources

• proper siting and design of river or dugout intakes
• selective and limited use of algicides in farm ponds
• control of surface water inflow to the reservoir or dugout
• use of biological, chemical or physical techniques such as aeration, coagulation or reservoir covering

BMPs for Groundwater Sources

• diverting surface water runoff away from well pits
• protecting sensitive aquifers,
• preventive maintenance such as shock chlorination of wells when necessary.

Visit our water quality page for more information about specific dugout management practices and the Sustainable Water Well Initiative (SWWI) page for information about shock chlorination.

Treatment

For Prairie agricultural land, watershed management techniques offer the first barrier for maintaining good water quality. Management of the water source is the second barrier, aimed at maintaining and improving water quality. Although both strategies will improve the quality of the source water, they can not drastically improve water quality when a pure water is necessary, such as for boilers used in agricultural industry. Of concern for human health, the first two barriers are not are not capable of providing safe and aesthetically-pleasing household water. Watershed management and water source protection strategies must be combined with other treatment processes, such as in-house treatment and disinfection, to ensure that the water is safe for drinking and aesthetically-pleasing for general household use. In-house treatment methods are described in more detail in the Water Quality Matters publication titled In-house Treatment Systems. A variety of treatment methods are also possible for other agricultural uses.

These beneficial practices are the first step in reducing the impact of agricultural practices on water quality. For more information about beneficial management practices, browse the following publications:

How and why do producers decide to adopt a particular BMP?

The answer to this question is not well understood. A survey of producers was undertaken in a study by the Department of Sociology at the University of Saskatchewan. The exploratory social survey was designed to gain a better understanding of how producers select risk-mitigating BMPs to protect water supplies in Saskatchewan. The data established that a variety of factors affect farmers' decisions to adopt BMPs. These include economic, institutional, organizational and social factors (Kehrig 2002). The University of Saskatchewan web site provides the electronic version of the complete thesis titled Agricultural Practices and Water Quality in Saskatachewan: The Social Ecology of Resource Management, as well as the annotated bibliography.

For more information about rural Prairie water quality and treatment technology:

• visit our water quality page;
• contact our water quality unit staff or your local AAFC-PFRA office;
• read Prairie Water News, available from PFRA, or on the Internet at www.quantumlynx.com/water