Chapter 18 - When Storage is Necessary

When litter is to be stored, there are several acceptable methods to consider. An easy, but unacceptable, method is simply just to pile it outside the house. These exposed piles can result in runoff, which causes nutrient loss and environmental problems. These problems can be prevented with just a little thought and effort, considering the following points.

Stacking

Proper stacking of poultry litter will minimize problems with nutrient loss and potential environmental contamination. Choose a well-drained site that will be convenient to get to, but will not drain directly into streams or other areas such as sinkholes where it might cause problems. Position the length of the stack up and down the slope to prevent water from collecting behind it. Stacks should be uniformly shaped with steep sides and a well-rounded top. Stacks formed in this manner will shed water and be less likely to lose nutrients and will provide sufficient heating to reduce potential disease-causing organisms.

Plastic Covers

Stacked litter can be further protected by covering it with plastic. It is not as important to compact the litter; however, the rounded top and steep sides of the stack are important. A windbreak of some sort near the stack could help prevent damage to the plastic. Use heavy-gauge (6 mil) plastic sheeting, anchor it to prevent wind damage and take care not to tear holes during application. Anchor the plastic at the edge of the stack by placing it in a small trench and backfilling with soil. Old tires and rope placed over the plastic can be used to reduce wind damage.

Concrete Slab Stack Pad

Some producers may already have or wish to construct a concrete slab for use in stacking poultry litter. This an further reduce the chances of nutrient loss and water contamination. However, its greatest advantage may be in convenience to the producer. In constructing a concrete slab, plan on using six inches of concrete on top of a compacted layer of gravel or crushed rock that is at least six inches deep. Footers should be formed along the edges that are at least 12 inches deep to add strength. Wire mesh reinforcement will also add strength to the pad. A good gravel or crushed rock roadway leading to the pad will allow access when the ground is wet and soft.

The litter should be stacked as discussed previously. More litter can be stacked on the pad if it is well-compacted as the stack is built. If a plastic cover is to be used, heavy wooden boards or concrete blocks can be used to hold down the edges.

Concrete Bunkers

Above- or below-ground concrete bunkers such as those used for making silage can be used for storage of poultry litter. The walls will allow a higher and more compact stack than can be achieved on a concrete slab. This results in a smaller surface of the litter being exposed to the air and weather, thus reducing the chance of nutrient losses. As with the other types of stacks, a plastic cover can be used to keep water out.

Roofed Structures

Structures with permanent roofs can be used for storing poultry litter and are very effective in protecting it from the elements. However, they have several disadvantages. First, they are more expensive to build and maintain as compared to the other alternatives. Any metal parts, such as roofs, are subject to rapid corrosion. The roof may limit access by equipment and limit compaction of the litter as it is stacked. A covered structure will likely be used by wild birds that may transmit avian diseases.

In building a roofed structure, the floor and walls that will be in contact with poultry litter should be constructed of concrete. When litter comes in contact with wood or other combustible material, a fire is possible as the litter heats soon after stacking. Be sure the roof is high enough to allow access by equipment for stacking and loading. If the roof is 12 feet or higher, walls may be needed to prevent rain from blowing in

Caution

Poultry litter heats through microbial activity during the first few weeks after it is stacked. Temperatures of 150° to 200°F are not unusual. When manure or litter from different sources and/or moisture contents are stored together, or if the moisture content is over 25 to 30%, temperatures can go higher, and spontaneous combustion may occur. Do not stack wet litter in contact with dry litter. Monitor temperatures of stacked litter daily for a week or two after stacking to detect overheating. Stacked litter should not be applied to growing crops until the internal stack temperature is 100°F or less.

Nutrient content of stacked litter is usually quite different from fresh litter. Stacked litter should be sampled and tested at least two weeks after stacking and as close to the time of application as possible.

Summary

With prior planning and good management, the nutrient value of litter can be preserved and contamination of surface and ground water can be prevented with a minimum of added expense. More elaborate systems are available that are effective and convenient as well as more expensive. Producers should choose what fits best in their situation and protects the environment.