Manure composting

Managing manure

Agriculture is an important part of Dane County’s economy and culture. Clean Lakes Alliance is working with partners to promote agricultural actions that balance conservation practices with farm sustainability and profitability.

Conservation practices like buffer strips, seeding of cover crops, low-disturbance manure injection, and manure composting are all actions farmers can take. These actions can help our local farms and protect water quality too!

Manure composting - spreading of organic materials into windrows to dry out and become a soil-like material
Manure is spread into windrows as it converts from organic materials into a soil-like material.

What is manure composting?

Composting converts organic materials into a soil-like material. Manure composting is a treatment process that converts raw manure into a product that is easier to handle and safer to apply.

Farm equipment is first used to pile solid manure into rows. The rows of manure are turned periodically. Through the turning process, the solid manure reduces in size and becomes compost. The process also reduces pathogens in the material, such as Salmonella, E. coli, and Listeria. Some farmers have also noticed a decrease in fly larvae through the composting process, which helps control fly populations in nearby barns.

More positive impacts of manure composting

  • Eliminates the need to spread manure in the winter when runoff impacts are high
  • Use of composted manure helps decrease runoff and erosion by improving soil structure
  • Requires more handling than spreading raw manure, but decreases the manure volume by one-third and bulk weight by 20-50%, allowing for easier transport
  • Increases flexibility in the timing of manure spreading by providing an alternative temporary storage option
  • May increase alfalfa regrowth and yield, and finished compost can be applied over mature hay crop
  • Reduces odors and converts manure into a more uniform, fine-textured consistency that facilitates land spreading
As the manure drys out and warms, it reduces in size and becomes compost
As the manure dries out and warms, it reduces in size and becomes compost

Why is manure composting needed in our watershed?

Manure is often used as a fertilizer on agricultural lands. It allows farmers to recycle the nutrients that are already in place.

Manure can easily wash into nearby waterways during times of precipitation or snow melt. Composting, on the other hand, can improve the timing of field applications. As a result, harmful runoff into our waterways can be reduced. When manure washes into nearby waterways, it brings harmful nutrients like phosphorus into our lakes. Phosphorus is the main culprit of algae blooms. Just one pound of phosphorus can generate up to 500 pounds of algae in our lakes!

Compost can act like a sponge on a field, and it doesn’t hurt growing crops. University of Wisconsin researchers have found that the controlled composting process produces nutrients in a more bioavailable form ready for plant uptake.

The rows of composted manure undergoes a process which helps speed up the drying time of the organic material
The rows of composted manure undergoes a process which helps speed up the drying time of the organic material

Clean Lakes Alliance’s role

In 2016, Clean Lakes Alliance secured a $60,000 grant from the Fund for Lake Michigan to finance a two-year research project with the University of Wisconsin-Madison Department of Soil Science and Yahara Pride Farms to study the water quality impacts of manure composting.

The 2016-2017 pilot project involved three dairy farms within the Yahara River Watershed. It built upon previous work funded through a North Central Sustainable Agriculture Research & Education Farmer Rancher Grant.

From 2018-2019, Clean Lakes Alliance, Yahara WINS, and Dane County funded an expansion of the composting project in partnership with Yahara Pride Farms. The project involved 12 total farms, including at least two confined animal feeding operations (CAFOs). Clean Lakes Alliance invested an additional $50,000 with the goal of further assessing the operational, economic, and environmental aspects of manure composting.

Composted manure spreader
Composted manure spreader

The status of manure composting

Dane County has invested in a composted manure turner and is looking into investing in a community composting facility. The County has budgeted for a composted manure spreader in 2020. Yahara Pride Farms will use the equipment to assist livestock farmers in the watershed with manure composting.

Additional resources