Background

Rosenholm-Wolfe Dairy is a farming business located in Buffalo County, WI in an area that is characteristic of the non-glaciated topography along the Mississippi River corridor in western Wisconsin. The farming operation consists of four owner-operators and fifteen full-time and part-time employees. The main enterprise is five hundred milking cows along with five hundred head of replacement youngstock. Forage is the emphasis that is grown on the seven hundred thirty-five acres that is in crop production. Also included in the business is the Cowsmo Compost enterprise. Cowsmo Compost markets three thousand cubic yards of finished superior grade compost to a variety of customers.

Introduction

In 1997 after six years of passive composting with one half of the number of livestock using separation and flushing technology, Rosenholm –Wolfe Dairy doubled in size. With that growth came the increased amount of manure that needed to be used to it’s best potential. With cropland that ranges in 0% slope to 25% slope it was necessary to be able to apply manure timely without over applying nutrients contained within. Along with the varied slopes of the cropland five navigable fresh water streams dissect the cropland. These factors were the cause to consider various options for matching nutrient application to nutrient use in the cropping system. By researching soil sample results it was found that the soils were very high in nutrients even with intensive cropping and high yield results.

The need to export part of the manure generated in some shape or form to meet the 590 Nutrient Requirements of the business was identified. Since the attempt to broker manure to neighboring farms was not met with enthusiasm, (because of high levels of nutrients in those soils also) we continued to pursue the composting avenue to help export some nutrients. It was believed that the potential for a return on investment was possible by composting and marketing the end product to customers that were looking for the attributes that high quality compost can provide.

Discussion

The definition for compost according to the U.S. Composting Council is; a product resulting from the controlled biological decomposition of organic wastes, that have been sanitized and stabilized to a degree which is potentially beneficial to plant

growth when used as a soil amendment. This is the end product that we have defined. But before the “product” becomes reality we must engage in the process of composting. And the definition for composting is; a managed process that controls biological decomposition and transformation of biodegradable material into a humus-like substance.

In 1997, Rosenholm-Wolfe Dairy took a proactive approach to composting versus the passive approach taken the previous six years. The proactive approach included an emphasis on quality and decreasing the time needed to complete the composting process to obtain a market ready product.

Facilities

To achieve this goal it was necessary to upgrade the composting “facility”. This upgrade was completed in the fall of 1997 and was put into use the following spring. The components of this upgrade include;

1. A new separation area for separating manure solids. What leaches out of the pile below the inclined screen separators drains back to the reception pit and to the first stage holding pond. This area was constructed of watertight concrete.

2. A new staging area for the separated manure solids adjacent to the separators to build homogenous piles in preparing the material for delivery to the compost site. During this process the piles are still on water tight concrete with some additional drainage that drains to another sump that pumps the effluents to the holding ponds. Also the first heat cycle is beginning with temperatures reaching 110 degrees Fahrenheit.

3. A new two-acre asphalt concrete composting site was constructed for access to the active processing facility independent of weather conditions. This is the place that separated manure solids are built into windrows to optimize the biological process.

4. A new loading ramp to facilitate loading of market ready product into large trucks was built and incorporated into the composting site.

5. A tractor and windrow turning equipment was purchased to turn the windrows on a regular basis.

Processing

Once the separated manure solids are in their respective windrows and the carbon to nitrogen ratios are in balance, the biological process of turning organic material into a humus like substance becomes more intense. Taking the temperature of the windrows becomes a daily routine to monitor the progress of the oxygen loving “bugs” (aerobes) that go to work in breaking down the carbon segment of the material. Along with temperature, the need to monitor moisture content and porosity is also essential because of the biological intertwined complexity of the process.

At predetermined thresholds for temperature, moisture, and porosity the windrows are inverted with the specialized turning equipment to maintain the proper parameters for optimal composting. Depending on the prevailing weather conditions windrows may need to be turned to “dry out” excess moisture and at other times water may need to be added to bring the windrows back to the proper moisture level.

During this time period the volume of the material is significantly reduced with up to 60% of the volume disappearing in the material makeup. This is either positive or negative depending on the prospective. If you are looking for less material to ultimately land spread it is a positive. If you are marketing the end product to consumers it is a negative because of the large shrink that is experienced.

When the biological process begins to slow down in the windrows the windrows are relocated with an endloader into larger “curing” piles where the biological process continues but at slower rate. This is where the compost will become a stable marketable product that will be advantageous to almost any growing medium that is chosen, that uses mineral and organic matter for the root zone.

The question asking “Is composting manure an option for you”, can have an elusive answer. You need to identify the best use of a waste product from livestock that has inherent value as a plant food or soil builder. A number of questions need to be asked before one delves into the composting world.

Some of these questions may be included in the following list;

· How much manure is generated annually?

· What types of manure are generated?

· How does weather affect manure handling?

· What is the land base and needs of the soil at the chosen location?

· How much economic resources will be committed to make appropriate use of the manure generated?

· How much human resources will be committed along with the quality of human resources?

· If composting is utilized, to what extent? All of the manure that is generated or certain types?

· If composting, are carbon to nitrogen ratios achievable for a successful biological process to take place?

· If composting, can the processing site pass current regulatory rules?

· If composting, is there a solid commitment of follow through with the extra work of an additional enterprise? Can it produce an economic return?

· If compost is produced, will it be for on farm use or for export off the farm?

· If exporting off the farm, do you have a market for your particular product?

As you can tell by the above list, many answers are needed to be able to come to a viable conclusion that works for your business when you are considering, “making the most of manure”.

Summary

For Rosenholm-Wolfe Dairy, the decision to compost was not an easy one to arrive at because of all the complex factors that had to be considered. The decision included incorporating existing types of equipment and facilities for manure handling with new types of equipment and facilities. Some of the manure generated is hauled daily and/or weekly. Whereas, other manure is stored for months in holding structures then applied to the land. And of course, some manure generated is composted and exported off the farm.

In this particular case, the business is making the most of manure by using a combination of different methods. First, to ensure that nutrient requirements are being met on the cropland that is used to grow forage. Second, meeting the requirements of the 590 Nutrient Management Plan. And third, making the best effort to conserve our natural resources. Composting becomes an integral part of the puzzle in this situation because of the difficult topography, amount of manure generated, acres of cropland in relation to the number of livestock raised, and high soil nutrient levels.

With the need to export some nutrients off the farm and to ship those nutrients a greater distance away from the business, volume reduction was needed. By producing a quality product such as Cowsmo compost it could be marketed to consumers that may not be farm related and located greater distances away.

References

The U.S. Composting Council-Compost Operating Facility Guide