What happens above ground in agroecosystem management impacts what transpires below ground. UC Santa Cruz ARCS Scholar Suzanne Lipton is focusing her PhD research on agroecology, which she explains is “how you could make agricultural systems more sustainable by relying on ecological processes rather than industrializing them.” “The biodiversity in an agricultural system or around an agricultural system can affect what's known as “ecosystem function” in the soil. I'm interested in specifically nutrient cycling in the soil,” she explains.
Enter the dung beetle.
“They have different nesting behaviors and provide ecosystem services through these behaviors. Dung beetles live in the dung, nest in the dung, or they tunnel underneath it. They bring dung balls with them that they lay their eggs in, or they take a ball of dung and roll it away from the dung pile,” Lipton explains. “And then they bury that dung ball, a dense nitrogen and carbon source, in the ground.”
The beetles help by bringing nutrients into the soil for plants and aerating the soil. Lipton studies how dung beetle activity changes the soil microbial community, which can impact nutrient cycling. “Other studies have shown that they decrease the greenhouse gas emissions in manure because dung can emit nitrous oxide and methane, and it decreases those emissions. They also help with seed dispersal by planting seeds found in the dung, and control fly populations by destroying fly eggs deposited in the dung,” Lipton continues.
To look closely at the soil microbial community in samples, Lipton uses a technique called meta-barcoding. She extracts DNA from the soil, sequences the DNA, and compares these sequences to a database to see which fungal and bacterial species are present. Her research is “paying attention to how the landscape is affecting the agricultural system and how the agricultural system is affecting the landscape.”
Lipton studies three pasture grazing sites in Central California, each with distinct climates. She examines how dung beetle abundance and diversity shift grazing management practices. Based on her findings, Lipton shares her information with the ranchers, who may want to adapt cow density, rotation, or location.
Lipton’s interest and knowledge of agriculture and agrifood systems is deep. As a pastry chef at a farm-to-table restaurant, she talked to farmers bringing their produce and learned about the challenges of composting in New York City.
She earned a master’s in Public Administration in Environmental Sciences and Policy from Columbia University. She worked for non-profits focused on food and agriculture and co-authored the book “Sustainable Food Production: A Primer for the 21st Century.”
Lipton considers her ARCS Scholar Award “the best thing that you can get during your PhD, which is time to focus on your research without having to work as a teacher’s assistant or work on somebody else's research. With the ARCS Scholar Award, I'm going to take this summer to work on my own research, and that will really help me move along.”
