Land Application of Manure

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Revised December 2005

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Introduction

Odours, dust from road traffic and potential soil and water contamination are often associated with land application of manure. These issues can be addressed effectively through proper management techniques and through an awareness of cropping principles and environmental regulations.

What's in Manure?

Manure contains a variety of plant nutrients, such as carbon (organic matter), nitrogen, phosphorus, potassium and sulfur. All of these nutrients are important for crop growth. If managed properly, these nutrients in manure can be used as fertilizer. For more information, refer to the Farm Practices Guidelines for Hog/Poultry/Dairy/Beef Producers in Manitoba.

Other components in manure include:

Water – liquid manures contain over 90% water; solid manures are 50-80% water.

Pathogens – as discussed in a separate publication ("Health Issues and Livestock Production"), livestock manure contains a broad spectrum of microorganisms. Good personal hygiene (hand washing, clean clothing, etc) minimizes health risks after contact with livestock manure.

Salts – excessive salt levels in soil can result in reduced crop growth. The amount of salts in manure applied to soil can be monitored and addressed by a detailed soil test. To prevent the buildup of salts in the soil, salt levels in manure should be monitored through soil testing. alt levels can be minimized through changes to the feed.
Metals (micronutrients) – copper, zinc, iron and other minerals are found naturally in soil as well as in manure and in some commercial fertilizers. Many of these metals are micronutrients – required in small amounts for optimum crop performance. Metals in manure are generally at such low concentrations that they will not build up to toxic levels in the soil if manure is applied at rates that meet nitrogen or phosphorus requirements of crops. Regular testing of the soil and plant tissues by the producer can be used to monitor micronutrient levels.

Manure as a Fertilizer

Manure has often been viewed as a waste product that needs to be disposed of as easily as possible. In the past this has resulted in over-applications in some areas and stockpiling of solid manure in others.

Today, it is recognized that manure should be treated as a fertilizer that has value to crop production. It must be applied at rates based on the amounts of nutrients in the manure and specific crop needs. This avoids excess application of manure to land.

Minimizing Odours

Unpleasant odour from land application of manure may be the greatest concern the public has with livestock production. Although this operation usually does not last for more than a few days and only happens once or twice a year, the odours emitted during land application can be objectionable.

Producers can limit the impact of odours on neighbours by consulting with them. When spreading occurs during times neighbours are less likely to be outdoors, odours may be less noticeable.

Working manure into the soil or injecting manure below the soil surface limits the amount of odour produced. Odours can be further minimized when manure applications take place early in the day in cool weather with appropriate consideration for wind speed and direction. Producers should follow recommended setbacks from neighbouring residences. Manure spillage on public roads must be avoided, and if a spill occurs, Manitoba Conservation must be notified. For more details on minimizing odours, refer to the fact sheet, "Livestock Odours: Sources, Concerns and Solutions."

Road Traffic Issues

Frequent trips back and forth from manure storage to manure application areas with large equipment can produce additional inconveniences to neighbours. If conditions are dry, heavy equipment traffic can produce dusty road conditions, which may affect neighboring residences. Dust problems are best addressed by minimizing equipment traffic. Wind speed and direction should be considered and alternate routes, if available, should be planned in advance. In extreme cases, the producer should implement dust control measures, such as calcium chloride applications.

If conditions are wet, frequent trips with large equipment can damage roads. Producers should take steps to minimize damage to public roads and, if necessary, wait until drier conditions prevail.

Soil and Water Contamination

Heavy applications of manure that exceed the nutrient requirements of crops can result in a buildup of nutrients in the soil. Some nutrients may be carried downward through the soil by precipitation and enter the groundwater. Manure that is applied and not worked into the soil can be washed off the land by heavy rains, particularly on sloping land. It can then enter ditches, streams and other surface watercourses.

If significant amounts of nutrients build up in the soil and water over time, these resources may be affected.

Manitoba Conservation requires that manure be applied in such a way that specified maximum nitrate levels in the soil, based on soil type and crop grown, are not exceeded. Manitoba Agriculture and Food provides information on how best to meet the nutrient requirements of various crops while protecting soil and water resources.

Manitoba Agriculture, Food and Rural Initiatives' Farm Practices Guidelines for Hog/Poultry/Dairy/Beef Producers in Manitoba recommends buffer zones between areas in which manure is applied and ditches, streams, etc. to protect surface water from manure runoff.

Winter Application – A Concern?

Applying manure to frozen ground is a concern because manure cannot be injected or worked into frozen soil. Manure does not readily infiltrate frozen soil and the likelihood increases for manure to run off and enter surface watercourses. Regulations are in place to control winter application of manure. All new livestock operations and existing operations with 400 or more animal units are prohibited from spreading manure in the winter. Existing operations with 300-394 animal units may continue to spray manure in the winter until Nov. 10, 2010. They must observe setback distances from property lines and watercourses based on the slope of the land to be used for manure application. For details, refer to the Farm Practices Guidelines for Hog/Poultry/Dairy/Beef Producers in Manitoba.

Soil and Water Contamination

If significant amounts of nutrients build up in the soil and water over time, these resources may be affected.

Winter Application – A Concern?

Manure Management Plans

Manitoba Conservation requires that manure management plans be completed annually by all large livestock operations. These plans must be submitted to Manitoba Conservation by July 10 for fall applications and by February 10 for spring applications. Plane filed alter these deadline are subject to a $100 administration fee. Manure management plans indicate the parcel(s) of the land that will receive manure, the crop(s) to be grown, the amount of nutrients required to grow the crop(s) and the amounts of nutrients available in the manure.

This information allows the operator to calculate the amount of manure that will be applied to the land. The two major components of a sound manure management plan are the manure analysis and the mandatory soil test for nitrogen. The soil test indicates the current fertility status of a selected area of land and provides recommendations on the amount of fertilizer to add. Annual soil testing of other nutrients is also useful to indicate whether there is a buildup of nutrients or salts in the soil.

A manure analysis provides information on the quantity of nutrients present in the manure sample. For more information on manure testing, refer to the fact sheet, "Manure Management Facts: Manure as a Resource," available at local Manitoba Agriculture, Food and Rural Initiatives' offices.

Summary

When spreading manure, weather conditions and the timing and method of application should be considered in order to minimize odours and the impact on neighbours.
Injection into the soil or rapid incorporation of manure by cultivation effectively reduces odours.
Odours and road dust from manure applications should be minimized out of consideration for neighbours.
Winter application of manure is prohibited for new, large operations. Because of the risk of runoff, this practice should be avoided by other operators.
Developing and following proper manure management plans ensures that the components in manure are applied to agricultural land to meet crop nutrient requirements.

For further information about public issues refer to other titles in the series: "Living with Livestock Production" available from Manitoba Agriculture, Food and Rural Initiatives offices. More detailed information can be found on the Internet at www.gov.mb.ca/agriculture/livestock. Copies of the Farm Practices Guidelines for Hog Producers in Manitoba are available from Manitoba Agriculture, Food and Rural Initiatives offices in rural Manitoba and from Agriculture Publications at 8^th floor, 401 York Avenue, Winnipeg MB R3C 0P8 (FAX: 204-948-2498) .

Prepared By: Manitoba Agriculture, Food and Rural Initiatives, Manitoba Conservation and Manitoba Health