Current Research

Composting is a scalable strategy to divert organic waste from landfills, reduce trace gas emissions, and provide a valuable soil amendment for healthy food production. There is growing interest in decentralized community led composting operation to engage community members in waste diversion and increase local food production. However, there is little composting research or organic waste generation data at small community level scales. This collaboration with Central California Environmental Justice Network, FoodLink, and Wukchumni Tribe set ups the resources for monitoring community organic waste generation and implementing their own on site composting prococess. 

Dairy manure management is the largest source of methane in California due to storage of liquid dairy manure in anaerobic lagoons. Installation of anaerobic digesters that serve as a cover over anaerobic lagoon storages are the primary methane mitigation strategy to capture manure methane for utilization as biogas. However, field measurements on the effectiveness of digesters has not been conducted at scale in California. Using a mobile laboratory with laser based methane concentration analyzers over nine field campaigns before and after after digester installation, we aim to shown strong methane emissions reduction and the important of temporal variability in climate, farm management, and operational parameters on emissions. 

Liquid dairy manure anaerobic digestate application to soils as a fertilizer can lead to high GHG and ammonia emissions. Emissions are also variable considering the vast variability in on-farm soil properties and digestate composition that can exist throughout California's large dairy industry. In lab incubation experiments we aim to show how soil properties such as texture and organic matter content, soil moisture treatments, and the digestate N dynamics drive variability in nitrous oxide, ammonia, and carbon dioxide emissions from soils sampled from dairies across California.