Evaluating the Environmental Benefits and Economic Opportunities of In-Vessel Composting Solid Dairy Manure

View the project final report

Commodities

• Animal Products: dairy

Practices

• Animal Production: manure management
• Natural Resources/Environment: windrow composting
• Soil Management: composting

The grant operation encompassed three host farms: Endres Berryridge Farms, Maier Farms, and Hoffman Farms.  Jeff Endres, partner at Berryridge Farms, led the grant project and assisted the other two host farms by educating their owners on compost development.  All three farms are located in northcentral Dane County, Wisconsin and within the Yahara River watershed.

Berryridge Farms is a dairy operation owned by three brothers: Jeff, Randy and Steve Endres. The diary operation includes 500 Holstein milk cows, 400 heifers and 1,100 acres.  The cropland is made up of 550 acres of corn, 300 acres of alfalfa and grass, and the balance made up of soybeans and wheat.

Maier Farms is a dairy operation composed of 650 cows and 1,400 acres of tillable ground. The cropland is in a corn and alfalfa rotation.

Hoffman Farms is a dairy and steer operation that milks 300 dairy cows and has 300 steers on feed at all times. They operate 1,200 acres of cropland on which they grow corn, alfalfa and wheat.

The grant allowed the three farms to create and manage windrows of their own materials to be composted. In addition, the three farms utilized bedded-pack manures as their composting base and then added other feedstocks, (feed residuals, grass, waste baleage, etc.) if they were available, at the time of windrow creation.  The grant project had one windrow per farm for a total of three windrows.

Introduction:

Endres Berryridge Farms has utilized or been a part of many types of sustainable practices throughout its operation:

• Cover crops on tillable lands, excluding alfalfa fields for the last six years
• Various tillage practices: conservation tillage for the first 30 years, no-till for the following 20 years and strip tillage for the last three years
• Wetland revitalization project with County, started five years ago, to convert farmland back into a wetland
• Native grass buffers were created in collaboration with Dane County that could be harvested for livestock feed and bedding. This was part of the wetland restoration plan started five years ago.
• A United States Geological Survey (USGS) monitoring station was hosted to evaluate water quality and quantity from tiles and surface water runoff. This project was started four years ago and finished last spring.

The farm owners and operators are members of Yahara Pride Farm and the Clean Lakes Alliance. Scott Maier and Jeff Endres are current board members. Yahara Pride Farms is a farmer-led organization that evaluates and promotes management techniques and technologies to reduce nutrient transport to the Madison, WI chain of lakes. Yahara Pride Farms has evaluated new manure application technologies, cost-shared the planting of cover crops, and developed and implemented a sustainable farm certification program to identify high-risk practices for farmers. Many of these practices have been completed over the last 5 years and continue to be researched.

There are two ultimate questions for this grant project:

1. Could composting be incorporated into the farming system in an economic and workable way?
2. Is composting a best management practice for moving nutrients out of a watershed?

In order to answer these questions, farm operations have to look at several aspects:

1. Where are they going to compost?
2. How much time can be allocated to composting?
3. What needs to change operationally?

Does the composting system fit within current ordinances and regulations? Berryridge Farms began planning and developing the project by answering the above questions. The farm owned a reclaimed commercial pit. When the pit was acquired, area contractors had wasted soils there and those soils were leveled and graded to make a uniform, flat surface with perimeter ditches to handle stormwater. This reclaimed site made nearly a perfect working surface and was well vegetated to section off buffers for runoff control. The farm currently stacks their dry, solid manures and feed residuals when it cannot be applied to working fields or pastures. The farm felt they could easily integrate the windrow creation and management. The only difference was where they were transporting their feedstocks for composting. The transportation of the feedstocks to the reclaimed pit was a time saver because it was closer to the production area, was large enough to handle the volume of material they estimated, and could be easily organized to save stacking time.

As with many farming systems, there are unanticipated changes that occur. In this project’s case, the application for the grant was written to operate and maintain a proprietary, predeveloped in-vessel system. Due to equipment availability, the system had to be changed to a windrow system. This change increased cost because a turner had to be rented or leased and additional labor hired. The farm was able to locate a custom compost turner from a company which could be operated by one of the farm’s tractors as the alternate.

The other host farms went through a similar process to site their windrows. One was within the production area of the farm and the second was along a field access road. Both locations allowed for good access and were maintainable.Windrows at all facilities were made mid-July. Delay in start-up was due to weather, scheduling and completing other farm activities, such as planting. All windrows were created from bedded-pack manures with some minor differences. Those differences included feed refusal in one windrow and shredded drywall as bedding in another.Windrows were monitored on a 10 day cycle by visual inspection and temperature. Each windrow was turned three times during its breakdown cycle of 4 months or approximately 13 weeks. These results can be evaluated in Table 1.

The composting project had the goal of answering nine questions:

1. Do we have alternatives to spreading bedding pack manure on fields in the winter by utilizing composting?
2. Does composting bedding pack manure give the farmers options to be able to sell their excess nutrients from their farms in the form of compost?
3. Could we develop a product that is marketable and profitable for operations?
4. What are the economic benefits of using composted bedding pack manure?
5. What are the environmental benefits?
6. Does composting help our watershed manage manure more effectively as a whole?
7. Are there disadvantages of using composted bedding pack on the herd?
8. Could we double the benefit of using corn stalk and straw by being able to re-enter it in free stall barns after the compost process?
9. Does spreading of bedded pack manure on cropland in the winter slow down the warming up of soils in the spring and could it delay planting?