Past Research

Pathogens can often attack multiple species. This could affect how pathogens spread and the impact of the diseases they cause. Two host species are more likely to share a pathogen when they are closely related to each other. This multi-year research project explored three important predictions that follow from this simple idea. The first is that in nature, the complex networks of plants and their pathogens will be structured in predictable ways that reflect the evolutionary relationships among the species. Second, when a new plant species (such as a crop) is introduced into an area, pathogens will “spill over” from close relatives already growing there. Third, because pathogens are less likely to spread between species that are not closely related, mixtures of crop species could be designed to suppress disease pressure in agriculture. In the process of testing these predictions, researchers developed new analytical tools for the study of plant disease and for the protection of agriculture and other plant resources.

Researchers characterized the plant-pathogen networks of three plant communities and tested predictions against the empirical networks. Novel hosts were used in a transplant experiment in the field and an inoculation experiment in the laboratory to measure which local fungi colonize novel hosts, and how the phylogenetic structure of local plant-fungus networks affects fungal spillover to novel hosts. On the UCSC Farm researchers tested whether the “Dilution Effect” lowers disease pressure in cover crop mixtures, and whether greater phylogenetic distance among intercropped species suppresses disease.

Center for Agroecology/UCSC participants: Ingrid Parker, Greg Gilbert, Darryl Wong. 
Funding: National Science Foundation (NSF DEB-1655896) 2017-2020

Selected related publication:
Diverse campus landscapes are ideal outdoor laboratories—and classrooms, UCSC News

In agroecosystems, including urban gardens, insects provide important services, such as pollination and pest control. However, few studies have examined the drivers of insect biodiversity in urban gardens, and the implications of this diversity for pollination and pest control services.

This project examined insect biodiversity in 19 urban gardens in the Central Coast region, including the handworked gardens at the UCSC Farm and UCSC’s Alan Chadwick Garden. Garden study sites capture a range of landscape diversity (e.g. forest, farmland, pasture, or urban sprawl), a range of economic status, and a large degree of cultural diversity. Insect sampling focused on 5 groups including one group of pollinators (bees), and four groups of organisms that provide pest control services (ants, spiders, wasps, and ground beetles). UCSC undergraduates are assisting with sampling insects and plants, and students with interest in Geographic Information Systems (GIS) are examining the landscapes surrounding each study site.

Center for Agroecology/UCSC participants: Stacy Philpott, UCSC Research Specialist Peter Bichier, UCSC undergraduate students Simone Albuquerque, Stephanie Coronado, Michelle Otoshi, Robyn Quistberg, and Casey Wing. 
Cooperators: City of San Jose Community Gardens, City of Santa Cruz City Gardens, Salinas Chinatown Garden, ME Earth, Our Green Thumb at Monterey Institute of International Studies, Seaside Giving Garden, Mi Jardin Verde, Homeless Garden Project, Live Oak Grange, Aptos Community Garden, Salinas Community Garden, The Forge at Santa Clara University. 
Funding: UCSC New Faculty Research Grant.

Anaerobic soil disinfestation (ASD) controls soilborne disease by acid fermentation process through anaerobic decomposition of incorporated carbon sources. Rice bran is the most typical carbon source for ASD in California. However, the cost of rice bran is increasing and the use of cover crop as a carbon source may be able to reduce the cost and the carbon footprint of the practice.

This 3-year grant supported an ongoing pilot study iat the Center for Agroecology/UCSC Farm comparing Sudan grass or wheat as cover crop, each cover crop plus reduced rate of rice bran, rice bran only, and untreated check. Soil N dynamics and strawberry yield are being monitored.

Center for Agroecology/UCSC participants: Carol Shennan, Joji Muramoto
Funding: US Department of Agriculture Methyl Bromide Transition Program

Producing quality organic seedlings for vegetable, flower, and herb production is challenging for seasoned growers, and more so for beginning farmers and nursery operators. This project aimed to increase the viability of vegetable, herb, and flower growers and nursery operators by improving the success and sustainability of their seedling production.

The project included a soil mix trial comparing a standard commercial organic soil mix, soil mix amended with sifted compost, and soil mix amended with compost and bone meal, using broccoli, peppers, and sunflowers as test crops. Data on germination, seedling size, "holding" success, and other factors were collected.

Center for Agroecology/UCSC participants: Christof Bernau, Kellee Matsushita-Teng, Skye McIntire, Jan Perez, Martha Brown, Erin Foley. 
Funding: California Department of Food & Agriculture Specialty Crop Block Grant.

Selected related publications:
See the Grower Guide developed as part of this grant.
CDFA grant supports organic greenhouse production and training, UCSC News

In urban agroecosystems, ecological functions such as pest predation by insect natural enemies result in ecosystem services that increase crop life and production. This study examined drivers of pest predation services in urban gardens and correlate services with garden features. Observational and manipulative research on the relationship between aphid pests and ladybeetle predators were used to ask: 1) what local or landscape characteristics of gardens correlate with abundance and taxonomic and functional diversity of predators in urban gardens? 2) What features of gardens or predator communities enhance predation services? 3) What local pest management strategies do practitioners employ in each respective urban garden?

This research aims to contribute to understanding impacts of community biodiversity and composition on ecosystem services, and of potential ecological mechanisms and social practices enhancing services in urban agroecosystems.

Center for Agroecology/UCSC Participants: Monika Egerer, Stacy Philpott  
Funding: Heller Agroecology Graduate Student Research Grant

This project builds on over 40 years of organic specialty crop production and training of beginning farmers at the 30 acre farm and three acre market garden of the Center for Agroecology at the University of California, Santa Cruz (UCSC). It also builds on a Center for Agroecology-led regional collaboration for beginning farmer training and the Center for Agroecology online curriculum for agriculture educators. This project produced 10 specialty crop Grower Guides in English and Spanish on specific crops grown using organic and sustainable production practices. These crops were demonstrated at the Center for Agroecology Farm, with distinct blocks of mixed vegetables and cut flowers providing data for publications covering varietal choices, production practices, and economic analysis.

See the Grower Guides series developed as part of this specialty crops grant.

Center for Agroecology/UCSC participants: Christof Bernau, Martha Brown, Kirstin Comerchero, Sky DeMuro, Orin Martin, Eliza Milio, Jan Perez, Darryl Wong 
Funding: California Department of Food and Agriculture Specialty Crops Block Grant Program

Initiated in 2014, this project developed effective tools and models for advancing a healthy school environment by directly addressing candy and junk food competition in and around schools. The project aimed to help add policies and procedures to enhance the school environment by targeting mobile vendors and other sources of unhealthy foods outside of the cafeteria that compete with the efforts to improve healthy on-campus options.

Additional information:
"Change Up for the Good" Business Pledge for Healthier Choices
Healthy School Food, Healthy Celebrations, Healthy Fundraising, and Healthy Incentives information

Center for Agroecology participants: Tim Galarneau, Jan Perez  
Community Partners: Central Coast School Food Alliance, "Food, What?!", FoodSmith, Jovenes SANOS 
Funding: Monterey Peninsula Foundation, United Way

In this project, funded by the California Department of Agriculture’s Specialty Crops program, Center for Agroecology staff members worked with Food Service Directors from Monterey, San Benito, and Santa Cruz County school districts to identify and implement collective buying strategies of California fresh fruits and vegetables. Cost savings from the project were used to purchase additional locally produced specialty crops.

The Center for Agroecology supplied partner districts with technical assistance for multi-district collective buying of specialty crops, along with menu planning and marketing support. By documenting this and other similar efforts, UCSC provides “best practices” information statewide to allow the project to scale-up. This project aimed to increase the purchase and consumption of California fresh fruits and vegetables in operations that serve over 125,000 meals per day (including breakfast, lunch, and supper programs) and support nutrition for vulnerable populations and children.. 

The project builds on existing efforts and momentum to increase local and regional produce sourcing in the Central Coast of California. The Center for Agroecology has helped facilitate ongoing conversations since winter 2010 with Central Coast school districts to increase consumption of fruits, vegetables, and healthy options in school meal programs. This project establishes institutional purchasing and lifelong consumption patterns for California specialty crops.

Center for Agroecology Participants: Tim Galarneau, Jan Perez, Food System Working Group Interns. 
Cooperators: Food Service Directors from 9 Central Coast school districts. 
Funding: California Department of Food and Agriculture (CDFA) Specialty Crop Block Grant Program.

Few issues are more important to parents than the health of their children, beginning with the food they eat. The Center for Agroecology has been a leader in serving the Central Coast School Food Alliance, an action research project that brings together leaders and practitioners from food service, food banks and K-12 education, to collaborate on improving school food programs.

WhyHunger, a nonprofit organization based in New York City, funded the Center to disseminate and amplify successful community-based program models and activities that reduce health disparities by increasing the availability of and access to healthy food within low-income and rural communities. With this support, the Center for Agroecology assists the Central Coast School Food Alliance to access information resources from WhyHunger’s Grassroots Action Network database, access information and analyses on food deserts through WhyHunger’s Food Security Learning Center, and access WhyHunger’s financial resources to address the problem of food deserts in the Central Coast Region of California.

Center for Agroecology participants: Patricia Allen, Tim Galarneau, Jan Perez  Funding: U.S. Department of Agriculture, WHYHunger

Related publication: Galarneau, T., S. Millward, and M. Laird. 2013. Farm to school efforts: Innovations and insights. Furthering Healthy Food Systems in California. Santa Cruz, CA: Center for Agroecology.

A 2013 grant from the U.S. Department of Agriculture aimed to expand opportunities for UCSC students studying sustainable agriculture, and for Central Coast junior college and high school students who might not otherwise have considered a career in agriculture. The three-year, $730,000 grant was part of the USDA’s Higher Education Challenge program, which funds efforts to improve agricultural education in the U.S. and attract students to the agricultural sciences. UCSC teamed with Cabrillo and Hartnell colleges, along with the “Food, What?” and Greenaction programs that serve high school students, to bring more students into four-year degree programs focused on sustainable agriculture.

Center for Agroecology Participants: Damian Parr, Stacy Philpott, Daniel Press. 
Cooperators: Deborah Letourneau, Carol Shennan, UCSC Environmental Studies Department. 
Funding: USDA/CSREES/NIFA

Related publication: USDA grant boosts opportunities for sustainable agriculture education. UCSC News.

This project aimed to prepare well-trained new farmers for sustainable production and small farm viability, to support these farmers in their early years of operation, and to build a mentorship and peer farmer network that will help ensure their long-term viability and success. A special focus of this project was providing top-quality training and support resources to new and future farmers from socially disadvantaged and limited resource communities. Read more about this project.

Center for Agroecology Participants: Christof Bernau, Martha Brown, Jim Leap, Orin Martin, Liz Milazzo, Diane Nichols, Jan Perez, Daniel Press, Darryl Wong 
Collaborators: California Certified Organic Farmers, Community Alliance with Family Farmers, Ecological Farming Association  
Funding: USDA's Beginning Farmer and Rancher Development Program 

Cabbage aphid and diamondback moth (DBM) are two important pests of organic Brassica crops in central coastal CA. Predacious syrphid larvae and the DBM parasitoid Diadegma insulare are the most economically important biological control agents of cabbage aphid and DBM, respectively, in this region. However, pest suppression can be inconsistent or occur too late in a growing season for a successful harvest. Syrphid species-specific analyses are needed to determine which syrphid species are most reliably associated with a successful harvest. Regarding DBM in this growing region, there no studies to document D. insulare parasitism in commercial Brassica crops and the vast majority of growers are unaware of this parasitoid’s presence. Collections of larval and pupal DBM from Santa Cruz and Monterey Counties suggest that D. insulare is in fact widespread and very often prevents DBM from exceeding economic thresholds, particularly in the absence of insecticides.  

Center for Agroecology/UCSC participants: Diego Nieto, Janet Bryer, Sean Swezey, Carol Shennan 
Cooperators: Jacobs Farm 
Funding: USDA OREI

Related publication:
Nieto, D. J., Shennan, C., Settle, W. H., O'Malley, R., Bros, S. and J. Y. Honda. 2006. How natural enemies and cabbage aphid (Brevicoryne brassica L.) population dynamics affect organic broccoli harvest. Environmental Entomology 35: 94-101.

A variety trial examined the performance of 15 varieties of blueberries grown under organic conditions at the Center for Agroecology Farm on the UCSC campus. Planted in January 2004, the trial was designed to provide organic growers with information on appropriate varieties for Central Coast growing conditions.

Center for Agroecology participants: Jim Leap, Liz Milazzo
Cooperators: Aziz Baaumeur and Mark Bolda, UC Cooperative Extension 
Related publication: Brown, M. 2007. Blueberry variety trial at UCSC Farm bears promising fruit. The Cultivar 25 (1,2): 5–6.

Lygus bugs (Lygus hesperus) are a key pest of strawberries on the California central coast. Two European parasitoids, Peristenus relictus and Peristenus digoneutis, were released in Santa Cruz and Monterey Counties as part of a California Strawberry Commission-funded project to reduce lygus bug populations. P. relictus has since become established in California and has contributed to lygus bug reductions in strawberries. P. digoneutis did not become established; this was likely attributable to a poor climatic match between where it was collected and released.

This project aimed to improve lygus bug control through the collection, release and establishment of a new P. digoneutis population that is best-suited to the strawberry-growing regions of central California. Based on this parasitoid’s performance in Europe and the northeastern United States, we anticipate that its establishment will benefit California strawberry growers by further diminishing lygus bug populations.    

Center for Agroecology/UCSC participants: Janet Bryer, Diego Nieto, Carol Shennan.
Cooperators: Kim Hoelmer, USDA; Charles Pickett, CDFA; Michael Seagraves, Driscoll's Berries; Tom Dorsey, New Jersey Dept. of Agriculture.

This project examined the effect of three treatments (zero, medium, and high) of organic nitrogen fertilizer on aphid density in broccoli and cauliflower crops. Cabbage aphid and DBM numbers and harvest rates (floret size, % contamination) will be compared between treatments 1a, 2a and 4a (Table 1) representing a range of N input levels. 

On half of the treatment replicates Entrust, a spinosad-based organically-compliant insecticide, will be applied to eliminate syrphid larvae (Smith et al. 2008), in order to clarify the effect of fertility on aphid densities.  This method of syrphid exclusion will also allow us to distinguish the efficacy of syrphid predation relative to aphid abundance and harvest rates.  

Center for Agroecology/UCSC participants: Carol Shennan, Sean Swezey
Funding: USDA OREI 

Hedgerows began to appear on Central Coast farm edges in 2000, due largely to the efforts of the non-profit Community Alliance with Family Farmers (CAFF). On the Central Coast, hedgerows consist of linear assemblages of trees, shrubs, herbs and grasses, many of them native species, which provide multiple services to farms.

The objectives of this study, conducted from 2005 to 2007, were (1) to assess the habitat quality of different hedgerow plants for insect natural enemies and pests, (2) to track the movement of insects from hedgerows into adjacent crop fields and (3) to test the effect of hedgerows on parasitism rates of an economically important pest, the cabbage looper (Trichoplusia ni).

The question of whether or not hedgerows can enhance biological control services in Central Coast farm systems is best addressed with on-farm studies. Thus we assessed the hedgerows that growers planted in their fields, rather than manipulate hedgerow and crop field plantings. While this approach can add more variability or “noise” to results, detected patterns also better reflect the ecological reality of hedgerows planted in Central Coast farms.

Center for Agroecology/UCSC participants: Tara Pisani Gareau, Carol Shennan
Funding: US Department of Agriculture, Earthbound Farm, UCSC Environmental Studies Department, the Center for Agroecology

Related publications: 
Pisani Gareau, T., Farmscaping with hedgerows in the central coast of California: Examining the potential for biological control. Poster session 24: Agro-ecology, Wednesday, August 10. 2005 Annual Ecological Society of America Annual Meeting, Montreal, Canada.

Pisani Gareau, T. and C. Shennan. 2010. Can hedgerows attract beneficial insects and improve pest control? Center Research Brief #13, Center for Agroecology.

This project integrated an imported biological control agent into managed alfalfa trap crops in order to improve control of a key pest, the lygus bug (Lygus hesperus) in organic strawberries. By incorporating the selective endoparasitoid Peristenus relictus, which is a nymphal parasitoid of the lygus bug, into a managed alfalfa trap crop system, a more balanced systems-management approach to control of a key pest is being achieved.

This study examined the effectiveness of P. relictus at parasitizing L. hesperus. Parasitism distribution patterns were examined, with an emphasis on alfalfa’s effects on parasitism in associated strawberries. Also of interest was describing the ability of this parasitoid to persist within a managed trap-cropping system, where alfalfa is routinely treated with a tractor-mounted vaccum. These efforts helped establish a management approach to lygus bug control in organic strawberries that integrates both physical suppression (trap crop vacuuming) and biological control.  

Center for Agroecology/UCSC participants: Janet Bryer, Diego Nieto, Sean Swezey 
Cooperators: Charles Picket, CDFA Biological Control Program; Pacific Gold Farm 
Funding: USDA Organic Agriculture Research and Extension Initiative (OREI)

Related publications and presentations:
Brown, M. 2006. Center researchers find pest control help for Central Coast organic strawberries. The Cultivar 24 (1): 5–6.

Pickett, C. H., S. L. Swezey, D. J. Nieto, J. A. Bryer, M. Erlandson, H. Goulet, and M. D. Schwartz. 2009. Colonization and establishment of Peristenus relictus (Hymenoptera: Braconidae) for control of Lygus spp. (Hemiptera: Miridae) in strawberries on the Central California Coast. Biological Control 49: 27-37.

Pickett, C. H., Nieto, D. J., Bryer, J. A., Swezey, S. L., Stadtherr, M., Wisheropp, D., Erlandson, M. & M. Pitcairn. 2013. Post-release dispersal of the introduced lygus bug parasitoid Peristenus relictus in California. Biocontrol Science and Technology 23: 861-871.

Nieto, D. 2013. Trap cropping in organic strawberries to manage lygus bugs in California. eOrganic Webinar

The lygus bug, Lygus hesperus, is a key pest of strawberries on California’s Central Coast. Center researchers have spent a number of years developing an effective “trap crop” system for this pest. Rows of alfalfa are inter-planted in strawberry fields to attract lygus bugs away from the strawberry crop. A tractor-mounted vacuum is then used weekly to remove this pest from alfalfa. Lygus bug-induced strawberry damage is monitored to document yield improvements associated with trap cropping.

One important component of pest management relates to movement into and within this system. By utilizing protein-marking techniques, preferential springtime lygus bug adult immigration into alfalfa trap crops (relative to adjacent strawberry rows) can be verified. Alfalfa’s mid-summer retention of lygus bugs, also verified through these marking techniques, is useful in describing pest behavior in the context of plant host preference.   

Center for Agroecology/UCSC participants: Sean Swezey, Janet Bryer, Diego Nieto, Carol Shennan
Cooperators: James Hagler and Scott Machtley, USDA-ARS, Pacific Gold Farms 
Funding: USDA Organic Agriculture Research and Extension Initiative (OREI)

Related publications and presentations:
Brown, M. 2002. USDA grant funds Lygus study. The Cultivar 20 (1): 11.

Brown, M. 2007. Strawberry pest control research garners federal funding. The Cultivar 25 (1,2): 17. 

Brown, M. 2009. New tracking method helps researchers design pest control strategies. The Cultivar 27 (1): 1-2, 22.

Brown, M. 2009. New "crops at risk" grant funds lygus control efforts. The Cultivar 27 (1): 14.

Nieto, D. 2013. Trap cropping in organic strawberries to manage lygus bugs in California. eOrganic Webinar.

Swezey, S. L., D. Nieto, and J. Bryer. 2007. Control of western tarnished plant bug, Lygus hesperus, Knight (Hemiptera: Miridae) in California organic strawberries using alfalfa trap crops and tractor-mounted vacuums. Environmental Entomology 36(6): 1457–1465. 

Swezey, S. L., Nieto, D. J., Hagler, J. R., Pickett, C. H., Bryer, J. A. and S. A. Machtley. 2013. Dispersion, distribution and movement of Lygus spp.(Hemiptera: Miridae) in trap-cropped organic strawberries. Environmental Entomology 42: 770-778.

Organic strawberry and vegetable growers on California’s Central Coast face two major production challenges: managing soil-borne diseases without the use of chemical fumigants, and providing crops with optimum fertility while protecting water quality in sensitive habitats. UCSC researcher Joji Muramoto, Center faculty affiliate Steve Gliessman, and Steve Koike of UC Cooperative Extension, worked with landowner Robert Stephens and strawberry grower Daniel Schmida to study a five-year organic strawberry/vegetable rotation at Stephens’ Elkhorn Ranch. This work followed three years during which the research team characterized the soil and monitored soil health indicators (levels of V. dahliae, nitrogen, and phosphorus) while the land was undergoing conversion to organic management.

Goals of the strawberry/vegetable crop rotation study included finding ways to shorten the period between strawberry crops while maintaining disease-free soil, and optimizing the use of fertility inputs to ensure that crops receive enough nutrients to produce well while minimizing leaching and nutrient runoff.

Center for Agroecology participants: Joji Muramoto, Steve Gliessman (faculty affiliate), Carol Shennan.
Cooperators: Steve Koike, Daniel Schmida, Robert Stephens.
Funding: U.S. Department of Agriculture

Related publications:
Brown, M. 2003. Organic strawberry/vegetable rotation study monitors agroecosystem health. The Cultivar, 21:2, 5-6. 

Muramoto, J. et al. 2005. Maintaining agroecosystem health in an organic strawberry/vegetable rotation system: the first 4 years. Poster presented at the Annual Meeting of the ASA-CSSA-SSSA, Salt Lake City, Utah, Nov. 6-10, 2005. 

Muramoto et al. 2006. Maintaining agroecosystem health in an organic strawberry/vegetable rotation system (part 5): Final results. Poster presented at the Annual Meetings of the ASA-CSSA-SSSA, Indianapolis, Indiana, Nov 13-16, 2006. 

Brown, M. 2009. Organic research network members present findings at central coast workshops. The Cultivar 27 (1): 10-12.

Broccoli plants infested with the cabbage aphid (Brevicoryne brassicae) may be damaged to the point that they are unharvestable. In a study initiated in the spring of 2001, Center researchers examined factors that affect the degree of aphid infestation, including the plant’s location in the field, the impact of wind direction, the growth stage of the broccoli when the aphids arrive (arrival time), and the location of the aphid colony on the plant itself. They also examined the effect of planting a “good bug blend” of over a dozen species, mostly clovers, cornflowers, and poppies, adjacent to the broccoli crop to see whether the blend can attract sufficient beneficial insects to help control aphid infestations. The project was located at the former Ft. Ord military base, where UC Santa Cruz leases land to Pure Pacific Farms for organic vegetable production, and at the Center’s on-campus farm; it continued through the 2004 cropping season.

Center for Agroecology participants: Diego Nieto, Bill Settle.
Cooperators: John Savage, Pure Pacific Farms. Jeff Honda, San Jose State University.
Funding: US Department of Agriculture

Related publication: Nieto, D. J., C. Shennan, W. H. Settle, R. O'Malley, S. Bros, and J. Y. Honda. 2006. How natural enemies and cabbage aphid (Brevicoryne brassicae L.) population dynamics affect organic broccoli harvest. Environ. Entomol. 35(1): 94-101.

Maintaining water quality is an ongoing challenge in the Monterey Bay watershed, where industry, urban development, and farming all affect sensitive waterways. Center researchers collaborated with researchers and growers in the Pajaro River and Elkhorn Slough watersheds to monitor and identify the impacts of various land uses on water quality, and advise growers on ways to minimize soil erosion and runoff from their farms. Both watersheds drain into the Monterey Bay National Marine Sanctuary, the largest such sanctuary in the U.S. Initiated in fall of 2000, the Center’s water quality monitoring efforts focused on nitrate and phosphorous levels in rivers, creeks, and agricultural drainages, as well as algae "blooms" and their effects on aquatic systems. Results of this monitoring work were used to help landowners and resource managers understand the relationship between land use activities and local water quality, and to help growers reduce nutrient runoff from their fields.

Center for Agroecology Participants: Marc Los Huertos, Gerhard Epke, Kristy Morris, Carol Shennan.
Cooperators: Community Alliance with Family Farmers, Monterey Bay National Marine Sanctuary, Natural Resources Conservation Service, Santa Cruz County Farm Bureau, UC Cooperative Extension, USDA-Agricultural Research Service, Watershed Institute at CSU Monterey Bay.
Funding: US Department of Agriculture, State Water Quality Control Board

Related publications: 
Brown, M. Study examines agriculture’s impact on central coast water quality. The Cultivar 19:2, Fall/Winter 2001. Los Huertos, M., L. Gentry, and C. Shennan. 2003. Land use and water quality on California’s central coast: Nutrient Levels in Coastal Waterways. Center Research Brief #2, Center for Agroecology

Los Huertos, M., C. Phillips, and C. Shennan. 2006. Land use and phosphorus levels in the Pajaro River and Elkhorn Slough watersheds. 

Center Research Brief #8. Santa Cruz, CA: Center for Agroecology and Sustainable Food Systems. 
Los Huertos, M., C. Phillips, A. Fields, and C. Shennan. 2004. Pajaro River nutrient loading assessment. Central Coast Water Quality Control Board. SWRCB No. 02-056-130-0. 

Los Huertos, M., L. E. Gentry, and C. Shennan. 2001. Land use and instream nitrogen concentration in coastal agricultural watersheds. In Optimizing Nitrogen Management in Food and Energy Production and Environmental Protection: Proceedings of the 2nd International Nitrogen Conference on Science and Policy. 

Ruehl, C. R., A. T. Fisher, M. Los Huertos, S. D. Wankel, C. G. Wheat, C. Kendall, C. E. Hatch, and C. Shennan. 2007. Nitrate dynamics within the Pajaro River, a nutrient-rich, losing stream. Journal of the North American Benthological Society, 26(2):191–206. 

For the past 44 years, people from across the U.S. and around the world have been coming to UC Santa Cruz to learn organic farming and ecological horticulture skills and concepts. What began in 1967 as the UCSC Student Garden Project, an informal student apprenticeship with English gardener Alan Chadwick, has since grown into the internationally known Apprenticeship in Ecological Horticulture, offered each year through the Center for Agroecology.

In 2009 the Center for Agroecology undertook a comprehensive survey of alumni both to document the impacts of the program and to get suggestions for ways to improve the Apprenticeship. The survey was designed to address two basic questions: Is the Apprenticeship accomplishing its goal of contributing to a more sustainable food system? To what extent did the program contribute to alumni’s activities? Results of the survey are summarized in Center Research Brief #14.

Center for Agroecology participant: Jan Perez.
Cooperators: Damian Parr, UC Davis; Linnea Beckett, UC Santa Cruz.
Funding: Foundation for Global Community.

Related publications: Perez, J., D. Parr, and L. Beckett. 2010. Achieving program outcomes? An evaluation of two decades of Apprenticeship in Ecological Horticulture at the University of California, Santa Cruz Farm and Garden. Journal of Agriculture, Food Systems and Community Development.

Brown, M. and J. Perez. 2010. Impacts of the apprenticeship program: An overview and summary of the alumni survey. Center Research Brief #14. Santa Cruz, CA: Center for Agroecology and Sustainable Food Systems.

In 2008, Center farm manager Jim Leap and UC Cooperative Extension farm advisor Aziz Baameur established a study of water use in organic tomato plantings to test the effects of various irrigation treatments, with the goal of finding an optimum water-use strategy that would result in improved flavor while minimizing potential yield losses.

Baameur and Leap established four replicates each of five irrigation treatments: 100%, 75%, 50%, 25% and 0% of water requirements based on California Irrigation Management Information (CIMIS) recommendations. Each replicate consisted of a 40-foot row of ‘Early Girl’ variety tomatoes irrigated with drip tape; the water stress treatments began after the plants were established. Soil water moisture sensors (a type of tensiometer) were used to quantify water depletion at the root level.

Results of the 2008 study showed no significant yield differences across the water treatments. According to Baameur, the ‘Early Girl’ variety showed remarkable plasticity to water stress. All treatments produced respectable yields of between 19,000 and 21,000 pounds per acre. Three tasting panels of 44 participants preferred the taste of tomatoes from water-stressed plots compared to those grown with ample water. Similarly, the panels found more appealing fruit aroma in tomatoes receiving the low water treatment.

Related publications: 
Brown, M. 2008. Study of reduced water inputs on tomatoes underway. The Cultivar 26 (1): 13.

Brown, M. 2009. Less irrigation makes for similar yields, tastier tomatoes. The Cultivar 27 (1): 15.

This project examined some of the reasons behind the statistics that show significant inequalities in the U.S. food labor sector that are patterned along lines of gender, race, and class.The research included individual interviews and group conversations with men and women employed in the food industry, such as farmers, farm workers, and restaurant workers, to address questions of how patterns of inequality are reproduced, how social disparities are experienced, and how the social categories of class, race, and gender interact to produce inequity.

Center for Agroecology participant: Patricia Allen
Cooperator: Carolyn Sachs, Penn State University
Funding: National Science Foundation's Sociology Program

Related publication: Brown, M. 2009. Labor inequalities in the U.S. food system examined. The Cultivar 27 (1): 13.

This research involved an extensive, interview-based study on the motivations, assumptions, and practices of “buy-local” campaigns in the U.S.

Center for Agroecology participant: Patricia Allen 
Cooperator: Clare Hinrichs, Penn State University

Related publications:
Allen, P. 2010. Realizing justice in local food systems. Cambridge Journal of Regions, Economy and Society, 1-14. Advance Access published online May 14, 2010.

Allen, P., and C. Hinrichs. 2007. Buying into “buy local”: agendas and assumptions of U.S. local food initiative. In L. Holloway, D. Maye and M. Kneafsy, editors. Constructing alternative food geographies?: representation and practice. Elsevier Press.

Allen, P. and A. B. Wilson. 2008. Agrifood inequalities: Globalization and localization. Development 51 (4). Special issue: The future of agriculture Hinrichs, C. and P. Allen. 2008. Selective patronage and social justice: local food consumer campaigns in historical context. Journal of Agricultural and Environmental Ethics. 21:329-352.

Brown, M. 2009. Role of social justice in "buy local" campaigns examined. The Cultivar 27 (1): 14.

Sustainable farming practices include improving soil conditions by planting cover crops. In 2002, Center researchers and affiliated faculty established trials at the Center’s Farm to compare two cover cropping strategies: a one-year fallow treatment cover crop of perennial rye grass, overseeded after a few months’ growth with crimson clover, versus an annual winter cover crop treatment (bell bean, vetch, oat grass mix). The researchers were particularly interested in the levels of organic matter generated by each treatment and the nitrogen available to crops following the cover crops’ incorporation.

Researchers found that available nitrogen in the perennial cover crop treatments was consistently lower through most of the experiment, suggesting that less nitrogen was available for loss from the system, but also less available to the developing crop. Yields of broccoli (a nitrogen-sensitive crop) planted after the cover crops were incorporated were significantly lower in the perennial cover crop treatment. However, yields of a potato crop planted following the cover crops were not affected by the treatments. In addition, soil respiration remained higher in the perennial cover crop treatment, even following the cover crop’s incorporation, suggesting higher levels of microbial populations in the soil.

One reason for the relatively lower available nitrogen from the perennial cover crop was the poor establishment of the overseeded clover due to gopher and slug damage. Nitrogen limitation for subsequent crops would be reduced with a good clover stand or with an addition of compost at the time of the perennial cover crop's incorporation.

Despite the impact on yields, the goals of organic production (e.g., soil building, decreased nitrogen loss) may justify the use of perennial covers and fallow periods to improve soil quality, especially in systems undergoing the transition from conventional to organic management where soil organic matter and microbial activity levels tend to be low.

Center for Agroecology participants: Jim Leap, Marc Los Huertos, Carol Shennan.
Cooperators: Weixin Cheng, Michael Loik, UCSC Environmental Studies Department. 
Funding: US Department of Agriculture.

This study examined the extent of food deserts (areas with limited access to affordable, nutritious food) on California’s Central Coast. The purpose of this study was to identify areas where affordable, nutritious food is not abundant and to identify potential markets for small-scale growers. This study pioneered new approaches in the use of GiS for mapping regional food systems and food security.

Center for Agroecology participant: Phil Howard 
Cooperators: Brian Fulfrost, Environmental Studies Department, UCSC; Agricultural Land-Based Training Association; Second Harvest Food Bank

Related publication: Fulfrost, B., and P. Howard. 2006. Mapping the markets: the relative density of retail food stores in densely populated census blocks in the Central Coast region of California. Report to the Second Harvest Food Bank of Santa Cruz and San Benito Counties and the Agriculture and Land-Based Training Association.

Contemporary efforts to create change in the food and agriculture system increasingly focus on the potential power of consumer demand and choices. However, we know very little about consumers outside of opinions about price and convenience.

To learn more about consumer perspectives on sustainable food systems, Center staff conducted focus groups with consumers recruited from grocery stores and farmers markets. This work was part of a larger study on Central Coast food systems. The goal was to learn more about what consumers know about the food system, what they would like to know, and their views on social and ecological issues. Based on focus group results, we developed larger-scale survey to supplement the qualitative data with quantitative information. This written survey was sent to 1,000 households in April 2004 using names and addresses randomly sampled from the study area, which were provided by a marketing firm. The instructions indicated that the primary food purchaser for the household was to complete the questionnaire. The final response rate was 48.3%.

Our survey results indicate that growers, processors, and retailers could do a better job of providing their customers with information on the way that food is produced, processed, transported, and sold. They should recognize safety and nutrition as consumers’ top concerns, but they should also devote attention to ethical issues, particularly the humane treatment of animals, environmental impacts, and social justice issues. Because respondents identified labels as their preferred source of information about their food, eco-labels may be an appropriate way to address these matters.

A majority of respondents indicated a willingness to pay more for strawberries that embodied a living wage and safe working conditions, even at price premiums up to 71% higher. The rapid growth of organic food sales, as well as sales of fair trade products from other countries, suggests that promoting the ethical values (such as a living wage) represented in food will continue to be a promising marketing strategy.

Our ultimate goal was to identify potential directions for educational efforts on the social and ecological impacts of the current food system, particularly the issues that consumers will find most relevant to their concerns.

Center for Agroecology participants: Patricia Allen, Phil Howard, Jan Perez 

Funding: US Department of Agriculture

Related publications:
Howard, P. 2006. Central Coast consumers want more food-related information, from safety to ethics. California Agriculture 60:1, 14-19. Howard, P. 2005. Central Coast consumers' interest in food systems issues: demographic and behavioral associations. Center Research Brief #7. Santa Cruz, CA: Center for Agroecology. 

Howard, P. 2005. What do people want to know about their food? Measuring Central Coast consumers' interest in food systems issues. Center Research Brief #5. Santa Cruz, CA: Center for Agroecology.

Howard, P. and P. Allen. 2008. Consumer willingness to pay for domestic ‘Fair Trade:’ Evidence from the United States. Renewable Agriculture and Food Systems 23(3), 235–242. Cambridge University Press.

Gender is a key social justice category for sustainable agrifood systems. This research explores the ways in which women’s material, cultural, and personal lives are shaped through their interactions with the contemporary agrifood system, and how they, in turn, are reshaping the agrifood system in the U.S.

Center for Agroecology participant: Patricia Allen
Cooperator: Carolyn Sachs, Penn State University

Related publications:
Allen, P. 2004. Together at the table: sustainability and sustenance in the American food system. University Park, PA: Pennsylvania State University Press.

Allen, P., and C. Sachs. 2007. Women and food chains: the gendered politics of food. International Journal of Sociology of Food and Agriculture 15 (1): 1-23.

In 2008 the Center for Agroecology initiated a research and education project to explore how business can be a catalyst and an agent for positive change within the food system. We pursued key research questions, assessed innovative business practices and models, and collaborated with farmers, workers, consumers, NGOs, and other food system stakeholders in order to study and build capacity for economic models that advance the triple bottom lines of economic integrity, environmental soundness, and social equity.

What is a “Triple-Bottom-Line”?
The triple bottom-line combines the equal concerns of “people, planet, profit” when making business decisions. This refers to addressing issues of economic integrity alongside efforts to both alleviate strain on the environment (or repair it) as well as providing social benefits to stakeholders such as employees, customers, and the community. There is no one-size-fits-all measurement for the triple-bottom-line and indeed each business creates their own unique definition of it. This work includes:

• Stakeholder Engagement: Center research Rebecca Thistlethwaite developed an Advisory Committee made up of diverse individuals with expertise in various aspects of business, the food chain, research, and policy. The Advisory Committee met to discuss the research questions, methodology, potential collaborators, and outreach planning. The goal was to have a real world “sounding board” to ground the research and to connect it to other work going on throughout the country.
• Case Study Research: Center researcher Rebecca Thistlethwaite developed case studies (now available online) of businesses around the country with diverse ownership structures at different levels of the food system “from seed to table.” Businesses studied include nonprofits, investor-owned corporations, co-ops, sole proprietorships, and other business models, and she is making a special effort to include those that are owned by women and minorities. The goal was to highlight the successful elements within each model and across all of these models so that others may learn from and potentially replicate aspects of their businesses in order to scale up these models and practices to become the mainstream.
• Community of Practice: Via conferences (such as The Business of Sustainability conference held on January 20, 2010 at Asilomar, California), workshops, webinars, and publications, we collaborated with like-minded organizations to share best practices, honestly discuss challenges, understand the role of policy, and inspire new ideas and leaders to create a transformative movement to change the paradigm of business in the food system.

Center for Agroecology participants: Rebecca Thistlethwaite, Bill Leland, Hilary Melcarek  
Funding: Appleton Foundation, Eucalyptus Foundation, US Department of Agriculture

Related publications: Brown, M. 2009. New project evalutes businesses as catalysts for food systems change. The Cultivar 27 (1): 13. 

Find links to the case studies at Innovative Business Models Case Study Series

Annual crops receive a substantial proportion of the insecticide used in California agricultural fields. Biological control of agricultural pests, a powerful alternative to insecticides, is difficult to achieve in short-term crops such as vegetables because frequent tillage and harvest of crops as well as the reduction of non-crop vegetation near to crop fields in recent decades, disrupts the natural enemies of crop pests. Improved biological control of pests could reduce reliance on pesticides along with concomitant environmental and public health problems. Although innovative California growers have implemented the use of hedgerows and farmscaping tactics—such as patches of perennial vegetation in lands surrounding vegetable crops—to conserve and enhance natural enemy populations for biological control by providing stable resources and refuges, these practices have not been evaluated.

In research conducted on 34 central coast organic farms, from 2004-2007, we measured natural enemy use of both common hedgerow plant species (farm-scale) and association with vegetation and other landuse factors in the land surrounding each farm (landscape-scale). Additionally, we measured movement distance of both pest and natural enemy species from hedgerows into crop fields and whether presence of hedgerows on farms or vegetation at the landscape-scale was associated with rates of attack on “sentinel” pest species within crop fields.

Center for Agroecology/UCSC Participants: Deborah Letourneau, Carol Shennan, Sara Bothwell, Tara Pisani Gareau. Cooperators: 25 central coast organic farmers/producers.
Funding: U.S. Department of Agriculture NRI, UCSC STEPS Institute, UCSC Department of Environmental Studies, Center for Agroecology.

Related publication: Pisani Gareau, T. and C. Shennan. 2010. Can hedgerows attract beneficial insects and improve pest control? Center Research Brief #13, Center for Agroecology.

With the efforts to develop a more sustainable campus food system at UCSC, researchers in the Center’s social issues group were interested in assessing student, staff, and faculty attitudes, concerns and support for a variety of food system issues. Center researcher Jan Perez worked with members of the campus’s Food Systems Working Group, including UCSC Dining Services, Community Agroecology Network, and Students for Organic Solutions to develop a web-based survey designed to find out what the UCSC community thinks about food system issues. Survey results helped the groups find potential support for their work, tailor education efforts, and determine campus attitudes toward the future of sustainably produced food at UCSC. The UCSC Office of Budget and Planning implemented the survey.

Asked to identify food issues and other current issues that were important to them, survey respondents ranked protecting the environment, food access for low-income people, improving food safety, improving job conditions of workers in the food system, and reducing the use of pesticides in the food system highest. The food issues that were the least important to people were limiting genetic and developing local food systems. In fact, 8% of the respondents were “unsure” about the importance of local food systems—the most people to pick that category.

Respondents were also asked to rate their level of interest on a number of topics. Food safety and nutrition were the primary interests people have in their food, followed by topics that encompass the impact of food production on others (wages, working conditions and treatment of animals) and the environment. The topics garnering the least interest are the distance food travels, and the influence of large corporations.

Other questions addressed interest in various “eco-labels” such as organic, humane treatment of animals, water quality, locally produced, and Fair Trade; whether respondents were willing to pay more for food produced with social justice criteria (fair wages and working conditions); and how often people purchased Fair Trade, organic, or locally produced food.

Center for Agroecology participant: Jan Perez
Cooperators: UCSC Dining Services, Community Agroecology Network, and Students for Organic Solutions Funding: US Department of Agriculture, Central Coast Grant

Related publication: Perez, J., and P. Allen. 2007. Farming the college market: results of a consumer study at UC Santa Cruz. Center Research Brief #11. Santa Cruz, CA: Center for Agroecology and Sustainable Food Systems.

The Center's social issues researchers headed up a collaborative, 2-year study to analyze the viability of institutional markets such as universities and colleges, hospitals and correctional facilities, for small- and medium-scale growers, particularly those farming organically or using other environmentally sustainable farming methods. The research group examined both the potential market for these growers, and the extent to which alternative distribution models help return profit to the farmers.

Center for Agroecology participants: Patricia Allen, Gwendoly Keith, Jan Perez
Cooperators: Shermain Hardesty, Cooperative Extension specialist, Department of Agricultural and Resource Economics at UC Davis; Gail Feenstra, Jeri Ohmart, and Tracy Perkins, UC Sustainable Agriculture Research and Education Program (SAREP). Anya Fernald, Kristen Schroer, and Marisol Asselta, Community Alliance with Family Farmers (CAFF)
Funding: US Department of Agriculture’s Cooperative State Research, Education and Extension Service (CSREES)

Related publications: 
Allen, P. 2008. Farm to institution programs. Family Farm Forum, USDA CSREES. Nov. 2008. See page 8.

Brown, M. 2006. Center researchers lead USDA-funded study of farm-to-institution programs. The Cultivar 24(2): 1–3.

Brown, M. 2007. First year of farm-to-institution study offers insights into potential, challenges. The Cultivar 25(1,2): 7–8.

Brown, M. 2009. Study examines food system priorities, perspectives of college students. The Cultivar 27 (1): 5.

Community Alliance with Family Farmers, Building Local Food Programs on College Campuses. 

Nationwide, schools serve 6.5 billion meals each year, affecting children, parents, teachers, and food producers and processors. Since their inception in 1946, school food programs have undergone little change until recently. But in the past several years, fiscal crises of school districts along with concerns about child nutrition and economic concentration in the food system have led to various innovations in school food programs and policies. These include banning on-campus sales of fast foods, soft drinks and other foods high in fat and sugar. In addition, some school districts have joined with the sustainable agriculture movement to develop farm-to-school food requisitioning programs, bringing together two seemingly unrelated issues—child health problems and the viability of small farms. Farm-to-school programs aim to increase the nutritional value of children’s school meals while simultaneously providing a secure market option for small-scale growers.

A study initiated in 2003 examined some of California’s innovative school food projects to determine how school food programs are determined and developed. The project addresses a variety of questions, including: How and why are different school food projects and programs developed? What roles are played by community demographics and locality? How are school policies negotiated among various constituents? Who gets included and why? How do some districts become innovators while others do not? How do budgetary considerations and/or entitlement availability affect what takes place? How do federal and state policies and programs shape what can be done?

In addressing these questions, the researchers hoped to identify some of the most effective school food programs and pinpoint what has made them successful. This preliminary work will form the basis of a broader research effort to assess the potential of school programs in furthering the development of sustainable food systems.

Center for Agroecology participant: Patricia Allen.
Cooperator: Julie Guthman, Community Studies Department, UC Santa Cruz  
Funding: The Center for Agroecology

Related publication: Allen, P., and J. Guthman. 2006. From "old school" to "farm-to-school": neoliberalization from the ground up. Agriculture and Human Values 23 (3): 401-415

As part of a USDA-funded study of California’s central coast farming practices and food systems, the Center’s social issues staff examined the effect of alternative production, marketing, and research efforts on both ecological sustainability and social conditions for growers and consumers.

Community Supported Agriculture (CSA) is a marketing alternative that’s shown promise for keeping small-scale farmers in business and creating a connection between farmers and consumers. Center researchers used a written questionnaire, focus group interviews with CSA members, and interviews with CSA farmers to better understand whether central coast CSAs are fulfilling some of their promise, and identify constraints and opportunities of this system.

Results from the study show that CSAs have had positive results. CSA members are eating better and are showing evidence of being more connected to the source of their food. Farmers generally find CSAs to provide more security than most other marketing arrangements. Additionally, they are growing high quality produce and are incorporating ecologically sound farming methods into their production practices.

Although central coast CSAs offer an important alternative for both growers and consumers, they still face challenges for long-term viability. Issues such as member attrition (most frequently due to lack of choice for quantity or product mix), availability of organic food from other sources, and a culture based on cheap food, convenience and choice could hinder the growth of CSAs.

In the spring of 2003, Center researchers received funding to expand their study of CSAs to the state of California, focusing in particular on the relationship between food security and small-farm security.

Center for Agroecology participants: Patricia Allen, James Murrell, Jan Perez.
Cooperator: Julie Guthman, UCSC Community Studies Department.
Funding: US Department of Agriculture, UC Sustainable Agriculture Research and Education Program.

Related publications: 
Perez, J. 2002. Community supported agriculture on the central coast. The Cultivar 20:2, pp.1-3, 18. 

Perez, J. 2004. Communitiy supported agriculture on the central coast: The CSA grower experience. Center Research Brief #4, Center for Agroecology. 

Perez, J., P. Allen, M. Brown. 2003. Community supported agriculture on the central coast: The CSA member experience. Center Research Brief #1, Center for Agroecology.

People are working to construct new initiatives and civic organizations that challenge the existing food system and seek to build alternatives. Consumers, activists, and farmers have organized a growing number of alternative food initiatives (AFIs) that seek to incorporate values such as regionalism, seasonality, community, environmentalism, and food security into the food system.

In 2001, the Center’s social issues researchers received a grant from the UC Sustainable Agriculture Research and Education Program (UC SAREP) to continue their study of groups and programs spearheading AFI efforts in California. The study’s central question was: How are alternative food initiatives conceptualizing and creating change in the agrifood system? In order to answer this question the researchers conducted 37 interviews with organization leaders of nine different types of AFIs and nine focus groups with AFI participants.

Their findings show that there are many Californians concerned about the food system, and that they share a perception that food system problems have systemic and structural, rather than individual, causes. Despite this analysis, California AFIs are much more focused on local issues and activities than on broad issues and large-scale actions, with participants deeply engaged where they feel they can make a significant difference on a local level. While AFIs share general beliefs about problems and solutions in the agrifood system, they tend to work in isolation from each other.

Center for Agroecology participant: Patricia Allen.
Cooperators: Margaret FitzSimmons, Mike Goodman, Keith Warner, UCSC Environmental Studies Department.  
Funding: UC Sustainable Agriculture Research and Education Program

Related publications: 
Allen, P., M. FitzSimmons, M. Goodman, and K. Warner. 2002. Shifting plates in the agrifood landscape: The tectonics of alternative agrifood initiatives in California. Journal of Rural Studies 19: 61-75.

Allen, P. M. FitzSimmons, M. Goodman, and K. Warner. 2003. Alternative food initiatives in California: Local efforts address systemic issues. Center Research Brief #3, Center for Agroecology.