Fresh, clean water is of vital importance to every organic farmer, but extended droughts, unpredictable weather patterns, and toxic runoff threaten food producers’ access to an adequate supply. Many scientists and farmers see climate change as a key causative factor. They’re also finding that organic methods can help. We asked experts in California, Vermont, and Illinois to share their insights for dealing with these conditions.
PROBLEM: DROUGHT DANGER
Even when California experiences a deluge of rain and snow, as was the case in the winter of 2016–17, the possibility of drought always looms there. In the Central Valley, where many vegetables sold in the United States are grown, the damage to groundwater supplies from pumping and overdrafting (taking out more than is replenished) might never be repaired. Following years of drought (2011 to 2016), the recent abundance of water is forcing scientists and engineers to reexamine reservoir management and water storage. Luckily, the years of scarcity have encouraged innovative and efficient irrigation techniques that are continuously studied and tweaked to create useful strategies for farmers.
With most reservoirs in California now at or near capacity, it’s hard to argue that the state is still in a long-term drought, says Doug Parker, Ph.D., an agricultural economist and the director of the California Institute for Water Resources. “We got some good rain out of the recent storms,” he says, “but does that mean we can all start turning on taps and wasting water? Of course not.”
Efficient use is crucial to the recovery of stored groundwater and aquifers, which provided more than 65 percent of irrigation water during the drought. Underground resources can be recharged (or “rewatered”) if managed like a “savings account,” Parker explains. When they are drawn down during a drought, they need to be filled up during
One method farmers have used for years to do this is surge flooding, but the value of this strategy hasn’t been researched and well understood until recently, Parker says. It’s highly effective for certain crops, like dormant grapes (which are not damaged by flooding), but now scientists are studying how the strategy could work for almond trees or vegetable crops. And they’re exploring which soil types work best, and how nutrient loss and pesticide contamination can be avoided, when growers employ the technique.
Emma Torbert and Katie Fyhrie take a different approach to drought management at Cloverleaf Farm near Davis, California, where they raise fruit trees and vegetables on 4 acres. With master’s degrees in horticulture and agronomy, the farm partners rely on their science backgrounds to conduct small experiments that test how much stress (through reduced water and fertilizers) their trees can handle. With microsprinklers fed only from a 200-foot well, they have been able to reduce water usage by almost 50 percent over the past five years. They apply water at night, when evaporation is at its lowest, and use new irrigation technology, such as soil moisture probes and gray-water washing systems.
The partners are also trying out different native drought-tolerant crops, such as elderberries and an overstory of oak trees from which they will harvest acorns to produce and market acorn flour. Additionally, they have experimented with dry-farming a variety of cantaloupe that thrived on leached water from a nearby corn crop.
“I don’t think that one year of water is going to make many farmers relax,” Torbert says.
SOLUTION: NIGHTTIME IRRIGATION
|Farmers:||Why they use it:||Scientist says:|
|Emma Torbert and Katie Fyhrie (not pictured), Davis, CA||Microsprinklers target crops directly. Irrigating after dark lets water soak in before sun and heat evaporate it.||Underground resources can be recharged if managed like a “savings account.” When they are drawn down during a drought, they need to be filled up during wetter years. —Doug Parker, Ph.D., agricultural economist|
PROBLEM: CLIMATE VARIABILITY
In Vermont, opposite weather extremes—heavy downpours in summer followed by short droughts—are causing the most concern among farmers. Such extremes in a system that has been accustomed to slow, consistent rain can lead to soil erosion, which in turn can cause nutrient and sediment runoff into lakes and other aquatic habitats. A separate challenge is that slowly rising average temperatures in the state are making winters less severe and welcoming new pests and diseases. For organic farmers, these impacts mean more money spent on labor, drainage and irrigation systems, and new growing techniques, like the use of high tunnels in the summer to keep moisture off tomatoes.
One of the most important ways farmers can protect their land and businesses from climate variability is to manage their soils to allow for better water infiltration and drainage, says Joshua Faulkner, Ph.D., an adjunct professor of plant and soil science at the University of Vermont and the coordinator of the Farming and Climate Change Program at the university’s Center for Sustainable Agriculture. The main methods he suggests? Planting more cover crops and tilling less.
Increasing organic matter in the soil through legume cover crops, manures, and compost—instead of synthetic nitrogen—can help soak up rainwater and build the soil’s capacity to retain moisture. Plus, producing more nitrogen on the farm, as opposed to bringing it in, can help farmers improve their profits, he adds.
If there is a silver lining to climate change, Faulkner says, it’s that the growing season is getting longer, allowing for the production of different crops and varieties—peaches, for example, or the okra, eggplant, sweet potatoes, and other warm-season produce that seventh-generation farmer Alan LePage is now growing on his 40 acres of certified-organic land in Barre, Vermont.
Like his great-grandmother who introduced farmed strawberries to Vermont, LePage experiments with new crops. “Crop diversity on a small farm really helps,” he says. “If you lose onions and wheat, at least you’ve got okra and eggplant.”
To prepare for storms that can bring 4 inches of flood-producing rainfall at once, LePage uses a customized bed-raiser to build up rows to 18 inches above the soil level. In times of drought, he employs plastic mulch to conserve moisture in the soil for crops like melons that are extremely sensitive to water deficits.
SOLUTION: RAISED ROWS
|Farmer:||Why he uses it:||Scientist says:|
|Alan LePage, Barre, VT||Building up planting rows allows excess water to drain away from crops during heavy rains.||Manage soil by reducing tillage to allow for better water infiltration and enhance the soil’s capacity to retain moisture. —Joshua Faulkner, Ph.D., soil scientist|
PROBLEM: NUTRIENT LOSS
Nitrogen runoff from farms in the Midwest has been much in the news in recent years. In 2015, Des Moines Water Works, a public utility, filed a pioneering lawsuit against three rural counties in Iowa over nitrate pollution in waterways, claiming that underground drainage tiles in the counties funneled high levels of nitrates from farm fields into the Raccoon River, a source of water for 500,000 central Iowa residents. The Iowa Supreme Court ruled in January 2017 that Des Moines Water Works could not receive damages for the high levels of nitrates in the water, but the suit may prove successful in forcing drainage districts to seek permits under the federal Clean Water Act, increasing regulation for about 3,000 districts statewide, which would impact farmers too.
Organic farming is part of the solution to the pollution problem, says Michelle Wander, Ph.D., a soil scientist at the University of Illinois at Urbana-Champaign. Although many organic farmers in the region are already using best management practices, awareness of how cover crops and the “4 Rs” of fertilizing (right source, right rate, right timing, and right placement) can effectively reduce pollution and save money is increasing. But, she says, the challenge is how to determine these variables for individual farms and help farmers improve their methods.
Two farmers in Central Illinois are examples of seasoned growers who have endeavored to learn about proper nitrogen-
and water-management practices to keep improving theirs. Allen Williams runs a 2,000-acre operation 15 miles east of Decatur, where he grows corn, soybeans, cereal grains, and pumpkins. He’s been using cover crops to try to improve the health of his soil and decrease nutrient runoff since 1972 and more recently has worked with the University of Illinois on a study of 16 different types. He is, according to Wander, also a master of the 4 Rs.
Dave Bishop, owner and operator of PrairiErth Farm in Atlanta, Illinois, since 1979, is another huge proponent of planting cover crops to sequester nutrients and improve soil biology, and he is planning to try no-till practices in the near future. But perhaps the most important way Bishop maximizes the nutrient content of his soil and bolsters his economic outlook is through biodiversity. He produces corn, soybeans, wheat, oats, vegetables, beef, pork, eggs, and honey.
“Diversity on the farm is just like diversity in your investment portfolio,” he says. “Why would you put all your money in one crop?” Farmers who are really concerned about sustainability must shift away from nonreplaceable resources, he adds. Fertilizers you add are much more prone to runoff than soil-based nutrients are.
SOLUTION: COVER CROPS
|Farmer:||Why he uses it:||Scientist says:|
|Dave Bishop, Atlanta, IL||Cover crops sequester nutrients in the soil, reducing the need to add fertilizers that are prone to runoff.||Do a “fertilizer budget” to figure out the “4 Rs” (right source, rate, timing, placement) so you reduce pollution and increase your bottom line. —Michelle Wander, Ph.D., soil scientist|
Ariana Reguzzoni is an organic farmer and journalist based in Sonoma County, California. Her work has appeared on PBS and in publications including Time, Grist, and Civil Eats.