Home News Ag Economics North Coast Dairies Reduce Methane, Produce Compost & Improve Soil Health

North Coast Dairies Reduce Methane, Produce Compost & Improve Soil Health

Earlier this month, the California Climate & Agriculture Network (CalCAN) organized a tour of two organic dairies and a farm in Sonoma County. We invited several local experts and state Assemblymember Damon Connelly to learn from each other and discuss how to support family dairy farms and sustainable dairy management. The tour was incredibly inspiring and generated productive dialogue among dairy producers, technical assistance providers and sustainable agriculture advocates. Assemblymember Connelly was actively engaged throughout the afternoon, asking important questions and demonstrating his commitment to his agricultural constituents and community.

Focus on AMMP: Reducing Methane Emissions

The central focus of the conversation was on California’s Alternative Manure Management Program (AMMP). California dairies produce a significant amount of agricultural methane, much of which comes from the anaerobic decomposition of liquid manure.  AMMP was designed to fund equipment which separates manure solids from liquids and produces valuable compost, thereby reducing potent methane emissions caused by anaerobic decomposition in manure ponds.

The Calfiornia Department of Food and Agriculture (CDFA), which  administers AMMP, reports that as of January 2024, AMMP-funded projects throughout California have reduced greenhouse gas emissions by 1.5 million metric tons of CO2 equivalents (MTCO2e) over five years, an amount equivalent to removing more than 300,000 cars from the road for one year. However, Governor Newsom’s proposed 2024-25 budget would stall this progress by dramatically cutting funding for the AMMP program and several other climate smart agriculture programs.s.

Touring Sustainable Dairies in Sonoma County

Renati Dairy: Innovative Manure Management

At Renati Dairy, the first stop on the tour, we heard from Denny Renati and his nephew Ty about their third-generation farm which produces organic milk from cows pastured on beautiful rolling hills outside of Petaluma. Ty successfully applied for an AMMP grant a few years ago in order to upgrade their manure management system and reduce methane emissions.

Rather than using water to flush their stalls, they now scrape the manure into collection pits where two aerators oxygenate the slurry and minimize methane off-gassing. They use a simple auger solid separator to remove manure from the liquid waste stream and reuse the water. The solids are dried and composted and usedas healthy bedding for their cows, reducing costs and greatly decreasing the truckloads of rice hulls coming from the Sacramento Valley that they used to import for bedding. The Renati’s plan to pursue a grant from the Healthy Soils Program to help pay for applying the compost to their grazing land.

Auger solid separator used to remove manure from the liquid waste stream which allows the water to be reused.

“We took advantage of the AMMP funding to become more economically efficient and sustainable. Without it, we never could have afforded the improvements.”  – Ty Renati

Triple C Dairy: Year-Round Composting

At Triple C Dairy, just off Highway 101 north of Petaluma, we were joined by a few other dairy producers and had a tour from Bob Camozzi and his nephew Blake. They have a similar solid separator as the Renati’s. Bob Camozzi used AMMP funding to build a covered barn to help compost the manure solids year round, something they couldn’t previously do during the rainy season because the compost would have been too wet. They are applying compost to their pastures where they’ve seen improvement in soil health and pasture fertility as well as the ability of the soil to absorb water during the winter rains. Composted manure also minimizes the leaching of nitrates into groundwater.

Year-round compost barn.

Throughout the tour, it was emphasized that dairy producers need the support of technical assistance providers to help them design the methane-reducing projects and apply for the grants. We were lucky to have with us several important partners who do just that: Randi Black from the UC Cooperative Extension in Sonoma, Patricia Hickey from Gold Ridge Resource Conservation District and Anya Starovoytov from Sonoma Resource Conservation District.

Jeff Creque from the Carbon Cycle Institute, a CalCAN coalition member, also reinforced the importance of technical assistance and taking a carbon farm approach to optimize greenhouse gas emissions reductions and carbon sequestration in soils. Representatives from Clover Sonoma and Organic Valley also participated and talked about how important government funding is to keep the dairies that produce milk for their brands in business and thriving while also providing climate solutions.

Camozzi Farm: Research and Innovation in Composting

Our third stop on the tour was in the middle of a field of hay on the Camozzi farm where we gathered to hear from UC Berkeley researchers Dr. Whendee Silver and Dr. Tibisay Pérez. They are conducting studies on the effect of incorporating basalt rock dust and biochar into manure compost. Biochar is produced through a process called pyrolysis (burning organic waste at high temperatures in an oxygen-free vacuum) and can be a way to convert agricultural waste such as almond shells and hull waste, removed trees, and other woody plant material into a valuable product.

Assemblymember Connelly and Dr. Tibisay Pérez walking through the waist-high hay.

With sophisticated state-of-the-art equipment that is nearly invisible amid the tall hay, the researchers are measuring which combinations of compost, basalt and biochar have the greatest benefit on a number of outcomes including soil nitrogen retention, soil structure and health, plant productivity and greenhouse gas emissions. Their findings will build upon a 2022 studythat found that adding biochar to composted manure can reduce methane emissions by 60 to 84 percent compared to composting alone.  The Camozzi’s see their collaboration as another way to contribute to dairy sustainability and the health of their communities.

The Need for Consistent Funding

California’s projected budget deficit of $44.9 billion has resulted in a mix of funding delays, clawbacks, and no new proposed funding for CDFA’s suite of climate smart agriculture programs. This interruption in funding will set back efforts to reduce greenhouse gas emissions, sequester carbon on agricultural land, and slow efforts to reach the state’s climate goals.

As we heard loud and clear during these tours, farmers want to be part of the solutions to climate change and they understand how doing so can also lead to greater financial stability.

CalCAN is part of a coalition of food and farming organizations calling for the legislature to include funding for climate smart agriculture in a climate bond measure., We see a climate bond that includes funding for these programs as one answer to ensuring continued progress toward curbing climate change. — By Renata Brillinger, California Climate & Agriculture Network

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