(CN) — Often touted as the breadbasket of the world, California's San Joaquin Valley is the most agriculturally productive region on Earth with over 250 different crops grown. But the area is also a well-irrigated desert, and years of below-average rain and snowfall have dried up its relatively few water sources.
So far, farmers in the region have fallowed approximately 100,000 acres of farmland. Experts believe that by 2040, drought may force up to 500,000 acres to be fallowed. Extreme drought has already led to a combination of less water being shipped through the Central Valley Water Project, curtailments of surface water pumping and requirements of sustainable management of groundwater pumping to combat subsidence.
But fallowed land also becomes a dust hazard for people living in nearby communities already affected by some of the worst air quality in the nation. The Public Policy Institute of California (PPIC) released two reports and held a webinar Tuesday to discuss both fallowing of land and the resulting dust pollution as well as a solution: dryland farming.
Caitlin Peterson, associate center director and research fellow at PPIC, touted the potential for dryland and water-limited agriculture in the San Joaquin Valley. In the past, farmers raised dryland crops as part of a normal crop rotation though the practice is less common today. The unpredictability of precipitation in the region can lead to dryland crop failures, however, unless limited irrigation is provided to establish the crop.
“Models shows that even with a little bit of water to get settled the success rate increases and the yields themselves increased beyond the threshold of five tons,” said Peterson.
She said winter wheat is best for forage — hay or silage for livestock and dairy cattle — as it requires less overhead and effort to grow then other crops. But the price point for winter wheat lags well behind almonds or other cash crops, which could deter farmers from making the transition.
And there are other concerns as well, Peterson said.
“One is that salts will accumulate because they will no longer be flushed from the soil and invasive weeds will pressure native plants," she said. She also highlighted the importance that irrigated farmland provides in limiting dust and providing habitat for birds and other aquatic species. This would be lost if farmers fallowed their fields without some sort of cover crop.
“One of the highlights of the report is that fields that incorporated dryland farming practices are able to retain water at or higher than fields that are just fallow,” said Peterson.
Much of the San Joaquin Valley is beset with natural features that trap particulate matter — mountain ranges on all sides and high-pressure ridges that trap air through the summer months. This can cause a number of health issues for the young and those with pre-existing conditions — and agricultural dust makes it worse.
Andrew Ayres, research fellow at PPIC, noted proactive management of dust and farmland can help support air quality improvements in the San Joaquin Valley. He presented a map of communities throughout the San Joaquin Valley — especially in the northern part of the valley and in Madera and Kings counties — and how they could be affected by dust if additional fields are totally fallowed.
“Many of those areas which will be impacted by the increase in dust will be low-income and rural communities,” said Ayres. “This will lead to more chronic and respiratory illness along with developmental issues among children.”
He said it will take innovative thinking from local, state and federal agencies to implement solutions.
One of the main issues for farmers is funding. This can include whether it is worth the cost of ripping out an orchard for a dryland type of crop — a discussion that was prevalent during the panelists portion of the webinar.
Mark Hutchson, walnut and almond farmer from Chowchilla, said ripping out an orchard is not cheap. He noted grant funding would be a factor in convincing farmers to move to dryland farming and other cover crops.
Reyn Akiona, executive director of Valley Eco, said one way for farmers to fund cover crops is through private companies looking to offset carbon emissions. Cover crops and winter wheat naturally store carbon.
All the panelists agreed that solutions to the problem will need to be innovative, especially as drought conditions are expected to continue, and funding will need to be consistent. Some of the ideas batted about include water banking, storage and other types of dryland crops outside of winter wheat.
PPIC expects to release additional reports on the topic through 2022.
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