California Megafires and the Effects on Agriculture

By Hayley Philip January 3, 2019 | 7 MIN READ

The Dirt:

Wildfires are devastating, not only to the families whose homes are demolished but also to the land and farmers supplying our fruits, vegetables, wine grapes and cattle for dairy and meat production.

Sustainable Agriculture

California Megafires and the Effects on Agriculture

Animal Welfare

Soil and Crop Management

By Hayley Philip January 3, 2019 | 7 MIN READ

The Dirt:

Wildfires are devastating, not only to the families whose homes are demolished but also to the land and farmers supplying our fruits, vegetables, wine grapes and cattle for dairy and meat production.

California leads the nation in producing 90% of all fruits, nuts, and vegetables.

Grapes, almonds, tomatoes, broccoli and much more are grown in the fertile valleys between mountain and sea. Unmatched by any other state in terms of output per acre, the yield in California is 60 percent higher than the national average.

In addition to being a major produce player, California holds the #1 spot in dairy production in all of the U.S., grossing upwards of $6.5 billion in 2017. Cattle for meat production in California is valued at roughly $2.5 billion.

To round out this workhorse state, California produces over 90% of all U.S. wine.

However, California’s recent drought and long dry season make it more susceptible to fire. In the past two years, uncontained wildfires have devastated over 7.3 million acres of land in the golden state. That is about the size of Connecticut and New Jersey combined!

, California Megafires and the Effects on Agriculture

Infographic by Sara Chodosh, capturing the intensity of the fires in California in the last five years.

The majority of the 2017-2018 fires were contained within the forests and non-agricultural land, but a number of rangelands, cannabis farms, dairy farms, citrus groves, avocado orchards, and vineyards were affected, making an impact on growers and California’s $50 billion agricultural industry.


, California Megafires and the Effects on Agriculture

The rate of burn for the 2018 Camp fire is incomprehensible; increasing in speed from 20,000 acres to over 100,000 acres burned in two days. That rate of scorch is equivalent to one football field burning every second. (Source)

Wine: Unintended Ashy Undertones

Unlike the 2017 fires where most of the wine crop had already been harvested, 2018’s bore witness to California’s most severe fires, which spread just before or at the onset of ripening, when grapes soften and change color.

Grapes are vulnerable to smoke damage because of their permeable skin. Depending on fire intensity, length of smoke exposure and stage of vine growth, unharvested grapes can take on smoky, ashy, or bitter characteristics. Consumers find this “smoke taint” unappealing.

While only a small percentage of wines may have been affected by fires and smoke, and these undesirable characteristics of smoke taint can be managed, winemakers do have to take on added costs in eradicating these flavors to avoid disappointing wine drinkers!

, California Megafires and the Effects on Agriculture

Scorched ground and shriveled grapes at the Michael Mondavi Atlas Peak Vineyard (Source:

Livestock Rangeland Scorched

The wildfires had an impact on the region’s farms and ranches, burning buildings, and the grazing land for dairy cows, cattle, horses, and other livestock. Butte County, where the 2018 Camp Fire raged, suffered rangeland losses of 30,000 to 40,000 acres, displaced animals, and destroyed pens, corrals, barns and more.

The Thomas Fire impacted all 7000 acres of rangeland stewarded by the
RA Atmore & Sons and Rancho Ventura Conservation Trust.

“Many of the oak woodlands were lost to the fire, as well as cattle, miles of fences, and other ranch infrastructure. The grasses and other vegetation are coming back. We will be battling invasive and noxious weeds now more than ever. We will need to adaptably manage woody species within the rangeland to achieve realistic goals that serve to improve forage, enhance wildlife habitat and protect our urban neighbors from the devastating effects of wildfire. One thing we learned from the Thomas Fire was “it’s not a matter of if the next Thomas Fire will come; but when.”  Richard Atmore, Ventura County Annual Crop and Livestock  Report, 2017

, California Megafires and the Effects on Agriculture

A cow walks by the flaming hillside in Groveland, California, August 2013. Source: Noah Berger, for National Geographic

Fruits & Veggies Fried

Ventura County, home to 118,000 acres of prime farmland and more than ½ of the total harvested acreage in the country for avocado, lemon, celery, and strawberries, was hit particularly hard during the 2017 Thomas Fire. The fire inflicted severe damage on hillside ranches, consuming forage needed for livestock, destroying barns, irrigation systems, equipment and machinery, and scorching or incinerating several thousand acres of avocado and citrus trees.

“We estimate that we lost 80% of our avocado crop for this year and next. At this point, four months after the fire, we project that over 40% of our avocado trees are dead or unlikely to recover fully. That is over 60 acres. Avocados take several years to come into full production. Even if we could replant right away, we are looking at about 6 years to full recovery.,Realistically, if we replant everything to avocados, it will be many years before we can get back to 2016 production levels.”  –Deborah Brokaw Jackson Brokaw Ranch Company  (SourceVentura County Annual Crop and Livestock  Report, 2017)

As the fires in the hillsides raged, the smoke traveled for miles. This complicated the lives of the farmers and farmworkers and the harvesting of perishable vegetables. The thick smoke haze delayed ripening and harvest, and workers couldn’t work in the fields due to unhealthy air conditions. An already stressed labor situation now experienced shortages of manpower.

Soiled Soil

Wildfires have a direct effect on soil. Contrary to a prescribed burn— which is a healthy burn often utilized by farmers to eradicate weeds or unneeded brush, or by forest rangers to manage forests from forest fires— an uncontrolled wild burn can yield heat levels above 400 degrees. These temperatures can cause irreversible harm to the land.

When the soil is burned at such high temperatures, the organic matter is incinerated. Depending on the intensity and duration of the fire, the recuperation time can be upwards of three years for soil to fully restore nutrients back to its original state. The hard, ashy residues that are left on the topsoil decrease the ability of the soil to absorb water, which increases the likelihood of runoff.

, California Megafires and the Effects on Agriculture

The graphic depicts the inability of water to penetrate the ashy soil, which causes dangerous runoff. (Source)

Because the soil can no longer take in water, there is an increased risk for landslides and flooding. In addition, the silt from the landslides can overrun the reservoirs, contaminate drinking water and create blockages in irrigation systems that supply water to farmlands. Flood risk remains significantly higher until vegetation is restored—up to five years after a wildfire. Mudslides and flooding are the current challenges California is facing in the wake of the recent fires.

How are farmers and ranchers protected from these disasters?

The U.S. Federal government plays a significant role in assisting farmers and ranchers with financial losses caused by natural disasters through the USDA’s Farm Service Agency.

The Disaster Recovery Reform Act of 2018 acknowledges the shared responsibility of disaster response and recovery and aims to build the nation’s capacity for the next catastrophic event.

The Bottom Line:

The images and stories of loss of life, land, animals, farming and business operations and homes due to these destructive wildfires are devastating. But the families, farmers, and ranchers are resilient, and our nation’s framework allows for recovery and rebuilding. As put by Deborah Brokaw Jackson, farmers are “action-oriented optimists who don’t give up. We are accustomed to risk. We like challenges. These strengths will help us recover from (these fires).”