Manure Management in California CAFOs: Five Areas to Evaluate

By Innovative Ag Services – Nathan Heeringa

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CAFO operations in California need to regularly evaluate their management of manure, especially given the rapidly changing dynamics over the past few years.  Risk management is often the driving force behind manure management; however, it should also be evaluated as part of the operating cost of the CAFO and an opportunity to maximize the nutrient value of dairy waste.  Below are five focus areas to consider in optimizing your manure management program.

Export of Solid Manure

• Record all exports of solid manure using manure manifest.

• Compost solid manure to increase its value and market demand.

• Educate growers about the nutrient and regenerative value of manure compared to common commercial fertilizers.

Export wastewater

• Understand the cost of hauling water, which can be expensive, but recognize there are situations where exporting wastewater is feasible.

• Concentrate on the nutrients before exporting, as the solid and nutrient content of slurry can vary five-fold.

• Highlight the value of manure to growers by emphasizing its nutrient and regenerative benefits.

Improve the Agronomic Use of Wastewater

• Increase crop yields, which can be evaluated on a per acre, per acre-foot of water, or per unit of wastewater applied.

• Acquire more land through purchase or lease or set up wastewater agreements to allow for export and application elsewhere.

  • Irrigation water supply may be the limiting factor, so the investment in water is as important or more important than land.

• Upgrade plumbing to expand or improve wastewater distribution.

• Decrease commercial fertilizer use and expand wastewater use.

Enhance Wastewater Treatment Options

• Increase holding time of wastewater to promote nitrogen volatilization, the most common liability in wastewater management.

  • Reduce water use in milking parlor.

  • Reduce water use in cooling systems.

  • Reduce water use in flush and cow cooling systems.

  • Increase water holding capacity by regularly removing the solids from wastewater storage.

• Explore Vermiculture, technology recognized and supported by CDFA that uses earthworms and carbon-rich media to remove nitrogen from wastewater.

• Consider fertilizer generation technologies, which are quickly developing, as dairy waste is a prime source for organic or regenerative based fertilizers.  These systems are often patented and require significant capital investment, typically making them feasible only for operations with enough animals to produce the volume of fertilizer needed for financial return.

Final Thoughts

New technologies and management strategies should be carefully evaluated. While now may not be the right time for you to implement every change, it is always a good time to learn.  Take the time to assess your current system and observe the variety of manure management approaches being used across the industry.  Manure management has always been a critical component of CAFO operations, and it is expected to play a larger role in years to come.