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A well-designed and properly constructed on-farm nutrient storage is an important component of all livestock operations. Manure or other prescribed material is a valuable source of nutrients for crop production. When properly stored, it can retain much of its nutrient content allowing for maximum benefit to growing crops. In addition, proper storage and handling of manure could lead to better relationships with other rural residents.

Solid manure storages may be temporary or permanent. The different types of permanent solid manure storages are outlined in this Factsheet. For more information on temporary solid nutrient storage, see OMAFRA Factsheet, Temporary Field Storage of Solid Manure or Prescribed Nutrients, Order No. 05-009.

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What is a Solid Nutrient?

One of the biggest challenges for farm operators when it comes to storing their manure is determining what options are available.

The first step is determining if the operation is producing a solid or liquid form of manure. The dry matter (DM) content of the manure is the simplest method of determining the form of manure. The Ontario Ministry of Agriculture and Food (OMAFRA) has defined solid nutrients as a prescribed material with a DM greater than 18%. The DM content of the manure can be determined by sending a representative sample of the manure to an accredited lab for analysis.

For operations that would like to determine their DM content using a lab analysis it is recommended that the manure be tested each time the storage is emptied. Repeat this procedure annually and record the lab analysis results. For operations that do not have readily available lab results may use the NMAN Software to determine an average DM content for their operation.

For a quick reference, listed below are examples of typical livestock operations and the respective DM ranges the operations would fall into.

Greater than 50% dry matter

Greater than 30%, but less than 50% dry matter

Greater than 18% but less than 30% dry matter

*These operations can move to a higher DM range with additional bedding or allowing the liquid portion to be stored in a liquid tank. On average, it takes 1.5 kg of additional bedding per 100 kg of manure to increase the dry matter content by 1%. (MWPS - 18 Livestock Waste Facilities Handbook). On average, the removal of 1 L of liquid will decrease the moisture content of 5 kg of manure by about 2%. (MWPS - 18 Livestock Waste Facilities Handbook)

The drier the manure, the less likelihood there are problems associated with runoff, odours and 'stack-ability'.

Deep-bedded operations are management systems that use a greater amount of bedding than normal.

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How Much Solid Nutrients Do I Need To Store?

The next challenge for farm operators is to determine the amount of manure being produced and how long it needs to be stored. Record keeping can provide a good indication of the amount of manure produced. The challenge comes for operations that do not have accurate records or those planning to expand their operation. OMAFRA has developed a computer program that specializes in manure production and storage sizing requirements (MSTOR). MSTOR enables the user to calculate manure production from different types of livestock, both annually and for a specified time period. MSTOR factors items such as bedding into its manure production calculation. MSTOR is also an excellent source to find the average amount of bedding used for specific livestock types.

 

How Many Days of Storage Do I Need?

The next step is to determine the amount of days needed to store the manure generated. For all livestock operations, OMAFRA recommends, as a best management practice, that the operation have a minimum of 240 days of storage on the Farm Unit. For operations requiring a Nutrient Management Strategy under the Nutrient Management Act, 2002, they must have a minimum of 240 days of storage on the Farm Unit. There are some instances where 240 days of storage may not be necessary. Ontario Regulation 267/03, as amended, provides some flexibility for those operations. The exceptions to the requirement to have 240 days of storage are:

Permanent vs. Temporary Storage

You now know how much you are producing and for how long you can store it. The next question is - what storage type to use? This Factsheet focuses only on permanent solid storage facilities. However it important to distinguish between permanent and temporary storage types. See Table 1.

Table 1. Differences Between Permanent and Temporary Storage

	Permanent Storage	Temporary Field Storage
Storage period	Long-term, usually 240-400 days or more	Short-term, 24 hours to 300 days maximum
Proximity to barn	Usually beside the barn where manure is produced	Usually far from the barn, in or near fields where material land applied
Walls	Usually walls, but not always	Usually no walls, but bales can work temporarily
Floor	Concrete floor or earthen base	Earthen base
Location	Always in same place beside barn/road access	Changes from field to field depending on the crop rotation

How big do I have to build my permanent solid storage?

Once you've decided to build a permanent solid storage facility, the next question is how big it has to be. You can now determine how much solid manure you are producing based on the number and type of livestock. You have also determined the required days of storage based on the manure management of the operation (e.g. period of use, manure transfer frequency and manure application frequency). The required days of storage can be achieved by adding up the actual days of all means of storage available to the farmer. Farms can use the days of storage available through temporary storage and permanent storage (including in-barn storage).

Sizing the Solid Manure Storage

The OMAFRA computer program, MSTOR, is the best way to determine the size of solid manure storage required to provide the planned number of days of storage capacity. The following scenarios were based on operations trying to achieve best management practices.

Example 1:

A farmer plans to build a new 50 beef cow barn that is 50 ft by 50 ft. The farmer's NMP indicates manure will be applied twice a year. The farmer estimates 2 ft of bedded pack will accumulate in the barn before having to clean it out. Using MSTOR, the farmer determines the barn can hold up to 80 days of storage. Therefore, the farmer would only have to design a new permanent solid storage facility for 160 days.

Example 2:

A farmer plans to build a new 2 storey broiler barn, 300 ft by 60 ft to house 40,000 chickens. The farmer's NMP indicates manure will be applied twice a year. The farmer determines up to 150 days of storage can be obtained by using the temporary infield storage criteria. Therefore, the farmer would only have to design a new permanent solid storage for 90 days.

Example 3:

A farmer plans to build a new 50 cow dairy barn 100 ft by 50 ft. The farmer's NMP indicates manure will be applied twice a year. The farmer decides there will be no bedded pack and has no plans to temporary store the manure in field. Therefore, the farmer would have to design a new permanent solid storage for 240 days.

Example 4:

A farmer plans to build a new 50 cow dairy barn 100 ft by 50 ft. The NMP indicates manure will be applied only once a year. The farmer decides there will be no bedded pack and has no plans to temporary store the manure in field. The farmer would therefore have to design a new permanent solid storage for 365 days.

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Types of Permanent Solid Nutrient Storage

Permanent solid storage can occur in-barn or outside. Typically, an in-barn solid manure pack or deep-bedded scenario requires more bedding to maintain the DM content. However, an in-barn solid manure pack or deep-bedded scenario can be limited by height or other structural factors. Typically, an outside permanent solid storage consists of a floor with or without walls surrounding it. Farm operators have several options for both the floors and walls.

Floors

The flooring may be concrete or other material that a professional engineer determines will provide equivalent protection to a concrete floor. Another option is an earthen floor; however the applicability of an earthen floor is limited to the soil properties of the floor. Operations with 300 NU or more that want to use an earthen floor for a new or expanding permanent solid storage must perform a geotechnical investigation to ensure the soil properties meet the criteria set out in Ont. Reg. 267/03, s. 66 as amended. Furthermore, earthen uncovered floors tend to be difficult to clean if excess liquid is not drained away.

Walls

The walls can vary in height and type of material. The following are different types of walled storages that are considered to be a permanent solid storage:

Concrete Walled Storage

Concrete is the material of choice for manure storage. It is durable, resistant to corrosion and moderately priced. Plus, because of the durability and strength of concrete walls it becomes much easier to handle manure especially if you are using heavy equipment to load and unload the storage. Concrete walls must be reinforced with steel (see Figure 1).

Figure 1. Example of a concrete walled structure that can be used for manure storage.

Steel Bin Storage

Prefabricated, bolt-together glass-lined steel manure tanks are most commonly used for liquid manure storage but can be adapted to store solid manure. The glass coating on the steel is a must to prolong the life of the steel panels.

Wood Walled Storage

Wood beams and planks can also be used as walls surrounding solid manure storages. Wood should be pressure treated to prolong useful life. Sealing the walls against seepage may be a problem. Care is also needed around this type of storage to prevent mechanical damage during loading and unloading.

With the exception of the concrete walled and steel bin storage, all the others may have either a concrete or earthen based floor.

Each one of these solid storages may be roofed. The advantage to roofing a permanent solid storage is to eliminate potential runoff from rainfall and therefore eliminates the need for runoff management measures, which could include additional storage to contain the runoff.

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Runoff

Runoff is defined as any liquid that has come in contact with manure, may contain components of manure in solution or suspension and is allowed to escape from the storage area.

The volume of runoff generated depends such factors as the DM of the manure, surface area of the solid storage, precipitation, etc.

Improperly stored, solid manure can cause as much environmental damage as liquid manure due to the release of liquid runoff from the storage (see Figure 2).

Figure 2. Runoff being generated from a solid manure storage.

Consequently, some type of walled system is desirable around at least 3 sides of the solid manure storage. Walls are critical because they:

Figure 3. Example of covered solid storage.

 

Figure 4. Example of runoff containment from a yard.

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Runoff Management System

OMAFRA recommends all operations that store solid nutrients have a runoff management system. Con-ventionally, the only management options available to farm operators were to:

The options above are still highly recommended by OMAFRA as runoff management systems. However, many of these options may be economically or physically challenging for farmers. That's why O. Reg 267/03 has added another runoff management option along with the original 3 to provide some flexibility to farm operators.

The fourth runoff management option should not be used by all operations. It is limited by the size of the storage facility (floor size no greater than 300 m²) and the DM content of the manure (greater than 30%). The storage facility must also have at minimum 3 walls that are at 1 m in height. Significant amounts of runoff are not expected from operations that have smaller, 3-walled storage facilities and that handle drier manure. The fourth runoff management system involves an increased physical barrier from surface water. The increased physical barrier must consist of a permanently vegetated area that has a flow path distance that is:

 

What is a flow path?

Flow path refers to the distance it takes for water to travel from the manure storage to a surface water source. A flow path does not necessarily have to be a direct measurement from the manure storage to the surface water source it can be manually diverted away. Figure 5 illustrates how the flow path distance may be constructed.

Figure 5. What a flow path could look like.

How long does the flow path distance need to be?

The distance of a flow path is directly influenced by the DM of the manure before it is placed in the storage facility. The drier the manure the less potential for runoff and therefore the shorter the distance from the surface water. For operations that produce solid manure with a DM content greater than 30% the flow path distance in the physical barrier must be at least 150 m. For operations that produce solid manure with a DM content greater than 50% the flow path distance in the physical barrier must be at least 50 m.

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Storage Design

Traditionally solid storage facilities were usually constructed on the farm without acquiring the services of an engineer. Farm operations that are phased-in under the NMA and are constructing a new permanent solid nutrient storage facility must hire an engineer. The only exception are new permanent solid nutrient facilities less than 600 m³, with walls less than 1 m high. Whether your operation is phased in or not it is recommended that all new permanent solid nutrient storage facilities be designed by a professional engineer and a professional engineer supervise construction.

Risk Associated with Different Types of Solid Storages

Combustion

Fires can occur in poultry manure storages due to spontaneous combustion. These fires are a result of self-heating due to microbial activity within the manure pile. During the heating process, combustible gases are formed and released into the voids within the pile. If in sufficient quantity and a high enough temperature, upon contact with oxygen these gases will ignite. Incomplete combustion will result in charring of the manure within the pile. These charred or blackened sections can ignite if suddenly exposed to air when being moved or land applied.

The risk of spontaneous combustion is elevated when litter of various ages is placed together in one pile. The interface between wet (30%-50% moisture) and dry liter from different flocks is the predominate source of combustion 2-3 ft. below the surface. This process occurs frequently 2-6 weeks following the gathering together of the pile. If your operation handles such material fire fighting equipment on hand or immediate standby as ignition often occurs as soon as the interior of the pile is exposed to the air.

Prevention involves proper placement of the manure during piling.

Monitor temperature daily with a 4 ft. long stem ther-mometer. If temperatures are above 160°F, prepare for action; if the temperature reaches 190°F then a fire is eminent. Soaking the pile with water and not removing it only results in the fire reoccurring a few hours later. The heat within the pile dries out the water and the pile starts burning again. The only way to insure that the pile does not reignite is to completely remove the pile and land apply. If a fire does occur you should only use water to extinguish the open flame.

Surface Water Movement

The storage should be bermed to divert clean surface water away from the storage to prevent unnecessary storage and handling of additional liquids.

Structural Failure

Pay carefuly attention to the structural integrity of the storage floors, walls and roof structures (if present). Ensure construction joints are water tight to prevent the drainage of liquids in or out of the storage - except where it is properly transferred to a liquid storage unit.

Ventilation of Roof Structures

Manure gases are corrosive to metals. It is important for the durability of storage structures to take precautions taken to prevent structural deterioration of the storage components.

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For Further Information

Contact your local or regional agricultural office for lists of experienced design engineers and construction contractors. Standard storage designs are available from the Canada Plan Service. Other related Factsheets can be found on the OMAFRA web site.

 

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