Previous speakers & Topics



If you would like to be put on the distribution list to receive a Center 'update' announcement 1-2 times per month regarding events and activities in sustainable agriculture happening at Cal Poly and on the Central Coast, click here or email the Center For Sustainability with the word "subscribe" in the subject. Please use the same address to notify the Center of any pertinent announcements!

For detailed listings of other events, opportunities and resources for sustainable agriculture at Cal Poly and on the Central Coast, please visit recent postings on our Announcements page!
Soil Workshop

Sustainable Ag Lecture Series - Spring 2013

Each term, the Center for Sustainability hosts a public lecture and/or event highlighting topics in sustainable agriculture, food or resource management.

Friday, May 17
9:00 a.m. - 3:00 p.m.
San Luis Obispo Grange Hall


May 17 Workshop Highlights New Methods for Assessing Agricultural Nutrient Levels

The Cal Poly College of Agriculture, Food and Environmental Sciences’ Center for Sustainability and the Cal Poly Compost Project hosted a special public workshop titled “Understanding & Testing Agricultural Nutrients” Friday, May 17. The event was part of the center’s ongoing training in nutrient cycling in soils and was presented in collaboration with the Coastal San Luis and Upper Salinas – Las Tablas RCDs (resource conservation districts) and with the support of center donor, Deb Robinson.


Andrew Sparda
Robert Miller

Joe Mullinax
Emmy Williams

The workshop educated farmers, composters, certified crop advisors, extension specialists, land managers, consultants and anyone else interested about how nutrient cycles work in soils and how key agricultural nutrients (nitrogen, phosphorus and potassium) can be measured quickly, effectively and economically to establish best management practices. In particular, training on new technologies such as biological carbon dioxide-burst potential to assess nitrogen availability in soils were of special value to those needing to manage soil fertility. Measuring the respiration of soil organisms provides valuable information on how nutrients are being used, which is critically important in systematic soil function and in nutrient management planning.

The training comes at a critical time for the California agricultural industry, which is being called upon increasingly to monitor and budget nutrients. The accurate quantification of agricultural inputs to soils will play a fundamental role in safeguarding soil, water and air quality into the future.

The training featured leading experts in soil testing and management including Bob Miller, soil scientist, professor and coordinator of laboratory proficiency programs. Currently the technical director of the Agricultural Laboratory Proficiency program with Collaborative Testing Services Inc., Miller has more than 25 years of experience coordinating soil analysis proficiency testing programs. He received his bachelor’s and master’s degrees from the University of Nebraska. Before earning his doctorates in soil fertility and soil chemistry at Montana State University, he managed a plant nutrition laboratory at Texas A&M University. He served as director of the Division of Agriculture and Natural Resources Diagnostic Laboratory at UC Davis and as extension soil specialist from 1988 to 1997. In 1992, he co-founded the Western States Proficiency Testing Program, which pioneered agricultural inter-laboratory collaboration in the Western U.S. In 1997, Miller joined Colorado State University as an affiliate professor in Soils and Crop Sciences, where he was a leader in the development of the North American Proficiency Testing program (NAPT).

Also speaking were Joe Mullinax, certified plant pathologist and owner of Denele Laboratories in Tulare, Calif., and Emmy Williams, soil scientist and laboratory manager of 20 years at Betteravia Farms in Santa Maria, Calif.

This unique combination of expertise provided workshop participants with a deep understanding of the state of the art in testing soil and agricultural amendments; how national laboratory proficiency programs (including NAPT and ALP) are seeking to standardize such testing; what industrywide data collection is revealing about nutrient use; and how progressive laboratory recommendations are best interpreted for maximum efficiency in agricultural nutrient utilization. Industry trends and forecasts were discussed. Local experts gave guest presentations highlighting regional efforts and testing concerns related to water quality security.

For more information, e-mail or call 805-756-5086.