Fighting in the Dirt

For eons farmers have battled two things – pests and the weather. While we still can’t control the weather, we can fight pests that target our crops, whether in agricultural fields or our own back yards.

For the past decades, farmers have primarily relied on pesticides, but we now know that many of these chemicals are toxic and pests develop resistance to them. There is a high demand to find effective and safe options to traditional pesticides, especially for organic farming.

Enter WCAHS new investigator, Dr. Chris Simmons, who is working on such an alternative. It’s called biosolarization. Think of it this way, biosolarization simply means harvesting the power of biology (bio) plus the sun (sol) to kill pests. Add plastic and compost, and you are ready to roll.img5902p87

Well, it’s not quite that easy. Simmons is specifically studying how to use biosolarization to replace fumigants, toxic gases that are pumped into the ground under the cover of heavy plastic tarps, to kill soil pests before planting. You many have seen this done in fields with rows of plastic. While fumigants work quickly against pests, they are essentially nerve gases that can cause serious injury and even death when inhaled by farmworkers or nearby communities if not used correctly.

In place of adding fumigants to the soil, Simmons adds compost and leftover skins and seeds from grape or tomato processing, wets the soil, and then covers it with plastic tarps to let biosolarization do its work. Heat from the sun becomes trapped under the tarp, encouraging heat-loving bacteria to grow, making the soil more acidic, which along with the high soil temperature helps eliminate pests like weed seeds, insects, worms, and many fungal and bacterial pests. Simmons is optimizing this process (timing, compost to use) for specific California crops grown in the Central and Imperial Valleys.

While the science of biosolarization is still evolving, there is no reason why we can’t use its cousin, solarization in our own garden. Solarization is just biosolarization minus the “bio” part – you don’t need to add specific compost to the soil. Instead you just tightly cover the heavily wetted soil with plastic during a hot, sunny time of the year. This will trap the heat of the sun to kill garden soil pests. In addition, your soil may become more nutrient rich as the heat breaks down organic matter.

You can do this easy, inexpensive project in a day and be rewarded in 4-6 weeks with a healthier garden.

Solarize Your Garden in 5 Simple Steps



Step 1. Get rid of any dead plants and other debris in your soil by hand picking or raking them away.

Step 2. Smooth the soil surface so that it is level.

Step 3. Water the soil so that it is wet up at least 1 foot deep.

Step 4. Place a clear plastic tarp on top of the soil. Plastic sheeting or plastic “drop cloths” for painting are readily available at hardware stores. Secure the edges of the tarp with soil.

Step 5. Remove the tarp after 4 to 6 weeks­ and begin gardening.

To see a more detailed demonstration of garden bed solarization, check out Alabama Cooperative Extension System Regional Agents James Miles and Mike McQueen in this video.


Protect Yourself with Integrated Pest Management

If there is one thing that hasn’t changed through the centuries, it’s the battle between pests and farmers. Stories of whole crops being decimated in the blink of eye are recorded in every culture.

Today, there are incredible resources to help with this age-old problem, including one housed right here in Davis – the University of California Integrated Pest Management (UC IPM) program. IPM provides scientifically based information on how to effectively deal with pests whether they are natural or exotic or in urban, agricultural, wildland or natural areas.

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Dr. Jim Farrar, director of UC IPM, recently visited WCAHS and gave a seminar talk on “IPM and Agricultural Worker Safety.” Pesticides are extensively used in farming. In 2014 alone, California registered 2.5 million pesticide applications. Agricultural workers are especially vulnerable to getting exposed to pesticides when directly handling them, such as during mixing or spraying, and when walking through fields and encountering pesticide drift in the air and residue on plants.

UC IPM provides both online and instructor led courses on the newest advances in pest management as well as basic safety skills with pesticides. Farrar stressed that continuing pesticide safety education is key to protecting agricultural workers and their families from harm. For example, workers can learn how to correctly use personal protective equipment when applying pesticides to avoid exposure and why it is important to wash work clothes separately from household clothes.

IPM also provides online information on how to deal with common pests found in the home, on our pets and even on us! For example, IPM has advice on managing ants, rats, lice and fleas. Farrar emphasized that while it is often difficult to eliminate pests 100%, they can be actively managed and controlled with the PAMS approach:

             Prevent pests from infesting.

             Avoid conditions that are conducive to pest damage.

             Monitor for pests and properly identify them.

             Suppress pests with appropriate tactics.

The PAMS approach works because it takes the long-term view of controlling pests. You can find detailed tips on how to manage all types of pests at the UC-IPM website.

How healthy is your California neighborhood?

You can easily find out using CalEnviroScreen, an online environmental health screening tool that scores each of the state’s 8000 census tracks for pollution burden and population characteristics.

Sacramento Business Portraits

Gina Solomon, Deputy Secretary for Science and Health, Cal EPA

Gina Solomon, Deputy Secretary for Science and Health at the California EPA, was a recent WCAHS seminar speaker and  explained that each California census tract has been scored for pollution burden and population indicators of environmental health. Pollution indicators include ozone, particulate matter, diesel, drinking water, pesticides, toxic releases, traffic, cleanups, and groundwater. Population characteristics include age, asthma, low birth weight, low education, linguistic isolation, poverty, and unemployment.

To see how your census track is doing,  click on the pollution burden or population characteristic map, find the particular census track you are interested in, and then click on an individual pollution indicator or population characteristic tab. Each census track is color coded. Darker colors indicate a greater score and relatively higher pollution burden / population vulnerability than areas with lighter colors and lower scores. For example, the pesticide burden for the City of Monterey is much less (light color) than the area surrounding the City of Salinas (dark color), which is heavily farmed and famous for fruits and vegetables.


CalEnviroScreen was created to help implement a state law (SB 535) requiring 25% of  proceeds from the state’s cap-and-trade auctions be invested in projects that benefit disadvantaged communities, including 10% for projects located within these areas. Thus, CalEnviroScreen allows the state to identify California communities with the greatest cumulative exposure to pollution and send state resources to those who need it most.

Lucky for us, CalEnviroScreen is also a great resource for public health researchers interested in a specific problem or location or how multiple environmental stressors affect a community. Dr. Solomon pointed out that many of California’s most disadvantaged communities are in rural, agricultural areas, and CalEnviroScreen can provide WCAHS researchers with a wealth of information.

WCAHS Celebrates California Ag Day 2016

How long does it take to adapt to high temperatures? That was one question on the trivia wheel that WCAHS brought to California Ag Day 2016 at the State Capitol on March 16th. The answer, by the way, is 2 – 14 days for the average person to acclimate to high heat.

2A. Leslie at CA Ag Day

Leslie Olivares with the heat illness trivia wheel.

California Ag Day is annual event that celebrates the abundance of California agriculture and its work force – the farmers, ranchers, laborers – and all that agriculture provides to our communities. Over forty exhibitors involved with all facets of state agriculture, including WCAHS Education and Outreach Specialist Teresa Andrews and Junior Specialist Leslie Olivares, step up tables on the west steps of the Capitol for the public to visit.

The popular WCAHS prize wheel focused on heat illness prevention, which is an especially relevant concern for farm workers, or anyone, spending long periods of time working outside during heat events in California. Children as well as adults were eager to spin the wheel to test their knowledge and win a prize.  The relaxed, family friendly event was a great way to promote our educational work and future training on heat illness.

WCAHS thanks California AgrAbility not only for the incredible work that they do for farm worker health, but also for graciously sharing their table with us. We were pleased to be part of California Ag Day and will attend similar outreach events in the coming months. For more information on these events, contact WCAHS at or (530) 752-5253.

Check out this California Department of Food and Agriculture YouTube video to learn more about the day.

Coming soon! National Farm Safety and Health Week 2014

PrintSeptember 21-27 is National Farm Safety Week. This year’s theme is “Safety Counts: Protecting What Matters.” The theme underscores the importance of working together to build a safer and healthier agricultural work place. California produces nearly half of US-grown fruits, nuts and vegetables. At the heart of this industry are the farmers and agricultural workers, whose labor provides us with an abundant food supply. However, they, and often their families, are exposed to a unique, sometimes hazardous workplace that can affect health at all age levels.

During National Farm Safety Week, the 10 Agricultural Centers funded by the National Institute for Occupational Safety and Healt2014 Farm Safety Ad-Spanishh salute those working in agriculture. You can watch online safety videos through a special YouTube channel. These safety videos are designed for producers, extension agents, and farm families. Safety Counts: Protect What Matters, go to or visit the Western Center for Agricultural Health and Safety website at, which is housed at the University of California, Davis.


Bilingual Video Made to Help Hmong American Farmers with USDA Funding

Independent Hmong farmers can learn about USDA financial assistance available to them through a bilingual video produced by the National Hmong American Farmers (NHAF). The  10 minute video, called “Working with the USDA,” describes loans and grants available to farmers.

The video, which is available in Hmong with English subtitles, follows Mary Vu, a Hmong farmer near Fresno, California. Mary owns 11 acres and grows strawberries, flowers, and vegetables. Mary has lost crops due to bad weather, so she goes to her local USDA Farm Service Agency (FSA) office in Fresno. Mary has been a farmer for many years, in her native country as well as in France, but she is not very aware of how the USDA could help her during these hard times. The video is an educational tool to help Hmong farmers learn about the financial support they can get and help other groups better understand some of the common struggles small farmers face.

Mary is directed to Tou Thao, an FSA loan officer, who explains that there are 2 types of loan programs available to help farmers like her: direct loans or guaranteed loans. Tou describes how much money Mary could borrow, for what purpose, and for how long with the different types of loans. Mary also learns that there are grants available to help here improve her farm, for example, by installing drip irrigation or protective crop covers. Information on all the FSA loans described in the video is available in the web booklet, “Your Guide to FSA Farm Loans.”

The NHAF is a non-profit 501c3 organization whose mission is to preserve Hmong-American farm culture by promoting economic self-sufficiency for Hmong-American and other immigrant and ethnically underrepresented farmers. They provide services to independent farmers  throughout the country, with special focus on California’s Central Valley farmers, who may have limited access to government programs. Contact NHAF at Email: or (559) 225-1081.


Welcome to the WCAHS Blog

THE WESTERN CENTER FOR AGRICULTURAL HEALTH AND SAFETY (WCAHS) at UC DAVIS has made strides in areas of research, prevention/intervention and education/outreach. It is uniquely situated to address and affect the health and safety of farmers, farm family members, hired farm workers and their families because of its co-location with the UC Davis Schools of Medicine and Veterinary Medicine, its Colleges of Agriculture and Engineering, and the California’s Central Valley, one of Western agriculture’s most intensive and productive regions. WCAHS has taken a leadership role in addressing western agricultural health and safety issues, including health among migrant and seasonal (hired) farm workers, ergonomics of labor-intensive crop work, respiratory hazards in dry-climate farming, health of women and children in agriculture and pesticide safety. The public (general and agricultural) have been recipients of educational programs. WCAHS’ electronic communications (newsletter, list server) have expanded educational efforts of the center internationally.