by Sally Colby
It doesn’t take long for manure to accumulate on a farm, even with small numbers of livestock. It also doesn’t take long for water to become contaminated if manure isn’t properly stored, hauled and applied.
Jeff Porter of the NRCS National Animal Manure and Nutrient Management Team said the practices used on the farm are more important than the size of the operation. “Think about state laws, local regulations and aesthetics,” he said. “Material stored outside without a cover is prone to slow leaching and more severe runoff following rainfall.”
Some of the major considerations when planning manure management on a small farm include animal type and numbers, waste stream (liquid, solid, slurry), how much land is available for application and whether additional land will be necessary for land application.
Farm owners should also consider state and local regulations and requirements, what kind of technology is available, what’s required for that technology, operational type and size, possible added-value products, labor requirements and equipment.
“It all comes down to the dollar sign,” said Porter. “What are these practices going to cost, and what kind of an impact will they have on the overall operation?”
Porter focuses on three manure management aspects on small farms: production, storage and treatment. Production is based on animal numbers and types, which determines the type of manure, then determines how manure can be stored and/or treated. Another important consideration is potential runoff areas and how runoff will be handled to protect water.
Manure type is an important factor in regard to cleaning, collection and storage. Most animals excrete manure in an area where that manure will be cleaned, collected and stored, and most manure is in slurry form – neither liquid nor solid.
Time of year is an important consideration for manure handling. In winter, when animals are often confined in a lot for feeding and to preserve pastures, there will be more manure tonnage. Cattle maintained on pasture for the winter will continue to spread manure on their own depending on the space they have, whether it’s a sacrifice lot or a true pasture. While sheep and goats produce drier manure, indoor housing of these species through winter will result in a thick pack that will require removal in spring. Heifers in confinement produce significant quantities of manure that need to be scraped, stored and spread – again, according to state and local regulations.
Porter said one of the factors farm owners can influence is keeping clean water clean. “That’s extremely important,” he said. “If we can divert any of the clean water away from contaminated areas where there’s manure or runoff, it reduces the volume of materials that need to be dealt with. Roof runoff also has a tremendous impact.”
Properly installed and maintained gutters and downspouts on animal housing buildings help reduce the amount of runoff entering holding areas. Gutters and downspouts also help keep solid manure solid so it can be transported to the field without extra water. Porter added that on farms, a French drain can help keep clean water clean. Other farms use a series of simple settling basins that allow solids to sink to the bottom. In such systems, the liquid portion is diverted to a grassy area where the nutrients are taken up by plant roots. Such systems should be installed with guidance from the NRCS or other private companies that design manure handling systems in accordance with state and local regulations.
For many beef or small-scale dairy farms, a bedded pack or composted pack is used for housing, and that area also becomes manure storage. The pack is started with minimal bedding, with fresh bedding added as necessary. Other farms use a composted bedded pack, which involves more bedding material but results in a more useful product. Depending on how many animals are housed on the composted bedded pack, they are moved away from the pack area while the pack is tilled, which provides aeration and encourages continued composting action.
Some farms compost manure outside the animal housing area. For these operations, options include covered structures to help manage moisture levels and minimize leaching and runoff. Manure in windrows can be turned regularly with simple equipment such as a bucket on a tractor. Composting bins are another option, and should be set up so materials can be moved from one bin to another with a front-end loader. A manure composting system is also useful for handling mortalities if it’s designed and used within recommended guidelines for that purpose.
Liquid manure can be stored in a holding pond, which requires permitting, professional design and professional installation. Considerations for holding ponds include the water table and the proximity of streams and other bodies of water. Some farms have to create diversions for water with guidance from NRCS.
In some situations, it’s worthwhile to invest in a screw press to separate liquids from solids, then compost the solids. The composted solids can be used as animal bedding on the farm, or sold as an added-value product.
Manure that is somewhat dry and mixed with a significant amount of dry material such as bedding or waste hay can be cleaned regularly and stored in a stack. The stack should be established on a concrete pad and surrounded by concrete or wood sides. Some small farms use bins made from old straw or hay bales. Many states are working with farm owners to add covers to dry manure storage facilities.
The most essential piece of equipment, no matter the size of the operation or the kind of animals raised, is a tractor with a bucket. The tractor and bucket should be sized to fit every aspect of the facility, or vice versa. For example, if composting bins will be used, they should be sized to fit the width of the tractor bucket.
Farm owners should always be aware of state-to-state variations regarding siting, coverage of stored manure and composting. It’s also important to be aware of state and local regulations on permitting, zoning and the level of exposure to storm water.
No single option will address all manure management issues. It’s important to evaluate the operation, make sure it fits your needs and if necessary, use a combination of practices to address manure management.