CalCORE: Connecting California Farmers and Scientists to Improve Rotational Strawberry and Vegetable Systems

Watch this video at

CalCORE: Connecting California Farmers and Scientists to Improve Rotational Strawberry and Vegetable Systems

Joji Muramoto: When I started to do research and soil testing for farmers, when I saw they appreciated the data I provided, I realized, "Oh, I can do something for them. Doing something useful for farming...that has been my passion."

Diego Nieto: In this region there is a very broad organic industry thatincludes both the large corporate growers and also the small-scale diversified growers. There are 49,000 acres of certified organic ground in two counties [Santa Cruz and Monterey] that is valued at close to $367 million. Seventy-five percent of the organic strawberries that are grown in California are grown in these two counties. So it is really a nice hot spot to do organic sustainable research in strawberry.

Goal 1: Building the CalCORE Network

Carol Shennan: The acronym CalCORE stands for California Collaborative Organic Research and Extension network. We have now, I think, more than 15 growers involved in one way or another with the network, plus many extension agents, and local organizations and industry people, as well as researchers from half a dozen different places.

Tim Campion: It has been a great collaboration. We pick up new information from them and they are always well organized and informative.

Steve Pedersen: I think the community elements of the CalCORE trial has been one of the major benefits for me. Some really good nuggets of information you'll pick up just standing on the sidelines and talking to people. And also being introduced to all the different researchers has been really valuable.

Carol Shennan: We have made a special effort to try and involve the Spanish-speaking farming community in the project by working with the organization ALBA, The Agricultural Land Based Association, who work to help farmworkers become organic farmers.

Nathan Harkleroad: It has been really important to do outreach to the Latino communities because so many Latinos are owners and operators of farms in our region, and particularly strawberries.

Goal 2: Researching Integrated Systems to Manage Fertility, Disease and Pests

Carol Shennan: The main research goal is to look at developing rotation systems that are both economic but also have a smaller environmental footprint as possible.Where we try to address issues of pests, and diseases and nutrients all in the same rotations, and that is really what the core of calCORE is.

There are a number of specific questions we are trying to ask. The first one is about length of rotation: How often can you grow strawberries? And, how do the particular crops you grow in rotation affect the health of the strawberries? Particularly in terms of disease management, because that is the main limitation for organic strawberries in many cases, is soilborne diseases.

Steve Pedersen: Our strawberries are by far our largest earning crop per acre, so most of our crop planning is centered around setting things up for a good strawberry crop. We have to be really careful in our rotations choosing where to grow things; a lot of the vegetables that we grow turn out to be hosts for verticillium in particular.

Carol Shennan: The secondary goal is to look at the use of anaerobic soil disinfestation or the addition of mustard seed meals as strategies for controlling disease. Each of those affects fertility, so we are also doing a lot of measurements of soil fertility. We are also interested in the biological control of important pests.

We ended up with quite a complicated study. One of the ways we've tried to cope with that and still get realistic information from the farms is that we are using something that is called a mother-baby design, where we have a big mother experiment where we do all the replications. And then the growers in the group decided on a subset of those treatments to test on their own farms, and those are the baby trials which we now have on 6 different farms.

Jaime Lopez: CalCORE has really helped us with learning more about new processes or better practices for organics. It has helped us in grounds where we do have high amounts of soil diseases, and it has helped us to suppress those soil diseases to have a better production.

Rigoberto Bucio: Now with this project for which I was fortunate enough to be invited, I have learned it is necessary to do soil analysis, and to carry things out in an orderly way. I learned that sometimes if we don't do soil analysis, we unknowingly apply too much fertilizer.

Steve Pedersen: There are some pretty major benefits. And one of those, and it has been reinforced by the CalCORE experiments, is the importance of using broccoli as a rotational crop for strawberries, which is something we do pretty much across the board now. And getting introduced to the concept of ASD, anaerobic soil disinfestation, is another one and I think that shows great promise.

Carol Shennan: You really have to have the perspective of the farmers because they know their systems in ways that as a researcher I can never know. I can get really excited about some basic science questions, don’t get me wrong, but my real passion is how can we use scientific knowledge to help improve the productivity, ecology; and the human dimensions of our agricultural systems.

Published March 28, 2016

This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.