carbon sequestration through compost
Farm compost

Practicum Project | 2020

Carbon sequestration through compost

The San Joaquin Valley of Central California is an agricultural powerhouse, producing almost half of the nation’s fruits and vegetables. However, this production is not without trade-offs. Agricultural operations often result in unhealthy air quality, increased greenhouse gas emissions, and excessive water usage – the Central Valley is home to five of the ten cities with the worst air quality in the United States, and agriculture uses approximately 80 percent of all developed water in drought-prone California despite representing only 2-3 percent of the state’s GDP.

Air pollution associated with agriculture in particular causes major health problems, including respiratory diseases, cancer, and even premature death. This is especially a problem for low income migrant workers who are exposed to the pollutants on a daily basis. With some of the nation’s highest asthma rates for children, the families living in these areas also bear the burden of agriculture.

To help combat these issues, composting holds promise in increasing water capacity, building soil health, and improving air quality. Increased water capacity in soil due to compost could mean less need for irrigation flow, cutting costs for farmers, and freeing more water going for other uses. Improved soil health has the potential to increase yields and provide more food to growing populations at reasonable prices. These soil benefits from compost may even help lessen the Valley’s current reliance on inorganic, highly polluting fertilizers. Using agricultural byproducts, predominantly manure, as compost may be an effective way to sequester carbon, storing it in the soil instead of releasing it to the air. This practice has the potential to help offset the carbon footprint of one of the largest sources of greenhouse gases in the state.

If composting proves to be an effective method of sequestering carbon on a large scale, it could have major implications for combating climate change, improving the lives of migrant farm workers and families, and improving soil nutrient and water capacity. There has been little definitive research into the ability of soil to take in carbon from the atmosphere. Our team aims to quantify the potential benefits compost could have for carbon sequestration in the San Joaquin Valley, while still taking into consideration the needs and costs of farmers.

Team: Charlotte Bloemsma, Ashley Hailer, Venezia Ramirez, Caroline Schreck, Shruthi Selvan

Advisor: Peter Kareiva

Client: Sustainable Conservation