Cover Cropping’s Many Benefits
Winter cover crops just look good.
“To me, it’s nice just driving through the valley and seeing green fields,” said Jason Vander Kooy, co-owner of Harmony Dairy. A field with a cover crop “just looks so much better.”
But cover crops are far more valuable to Skagit farms than the pleasant view they provide to the valley. They are an essential tool that improves soil and water quality and boosts plant productivity and farm operations.
“It’s hugely beneficial to the ground, the environment around it, and the farmer,” said Vander Kooy. It is not time- or cost-free, though. Nevertheless, Vander Kooy thinks “you’re probably tripling, quadrupling your money doing this.”
Benefits may seem clear, yet cover cropping includes many components and is complicated.
“Before” photo from Peter Contrastano of Fredonia Farms
Benefits of Winter Cover Crops
Statistics about soil erosion are staggering. The national average of soil loss, on a conventionally tilled field left bare through the winter, is 20.5 tons of soil per acre, according to Ryan Gelwicks, a farm planner with the Skagit Conservation District.
Winter cover cropping, along with different tilling methods, can reduce soil loss drastically, making erosion reduction a top priority for the district.
Cover cropping provides more benefits than erosion control alone. When the plants are turned back into the soil, benefits multiply.
“The farmers here really understand the value of soil organic matter and adding it back in,” said Deirdre Griffin LaHue, an assistant professor of soil health at Washington State University’s Northwestern Washington Research and Extension Center.
Besides helping to manage nutrients, a good cover crop enhances the soil’s structure, allowing water to flow through the soil better and improve drainage in Skagit’s often-wet soils.
These improvements to the soil can boost crop yields in the future, but that’s not all. “The hope is that over time, if you’re treating the soil well, you’ll start to see that benefit in increased yield,” said Griffin LaHue, “but maybe also in reduced fertilizer or reduced irrigation inputs, or maybe you don’t need to do as many tillage passes to work the soil up.” This is some of the research LaHue and her collaborating scientists study.
Cover crops help with weed control, too, as Peter Contrastano is finding out.
Contrastano is new to the valley, the owner and farm manager of Fredonia Farms, which he describes as a community farming project. When he purchased the 25-acre tract, he inherited a neglected and weedy patch of ground. After consulting with agronomists, farm planners, and local farmers, Contrastano put down a ton and a half of organic spring rye seed, purchased locally. Weed control is Contrastano’s top priority with the cover crop, but he is eager to see the other benefits.
“After” photo from Peter Contrastano of Fredonia Farms
Defraying Costs
Finding these multiple benefits is important, because cover cropping is not cost-free.
The Skagit Conservation District assists through its ongoing cover cropping program, which both Vander Kooy and Contrastano used. At the current rate, the district can pay up to $6,000 for seed expenses per landowner. The program has no minimum or maximum acreage requirements, having supported as little as a quarter of an acre to as many as 600 acres, according to Gelwicks. This year the program included 14 participants and helped get cover crops on almost 500 acres.
The process is fairly simple. A farmer fills out an application online and a farm planner, like Gelwicks, makes a site visit to discuss options and create the plan. The list of potential cover crops is long, allowing farmers choices depending on their soil and crop needs. Depending on where the grant originates, the district might pay seed companies up front or reimburse the producer for the seed. The district inspects the field to ensure the plan was followed.
“It’s about getting conservation on the ground and finding willing relationships,” said Gelwicks.
Since the conservation district is non-regulatory, it can develop easier relationships and provide information and resources farmers can use. Sometimes, producers are apprehensive about working with a government agency and some of the potential paperwork, but Gelwicks said, “We try to take on that paperwork load as much as we can.”
Even with assistance, cover cropping is not cost-free.
For the most part, farmers cannot harvest a cover crop. A grass cover crop might furnish some feed, and some growers save fava beans for seeds. But each pass with equipment takes fuel and time. Generally, farmers earn nothing for their effort. Instead, it requires a different kind of accounting that includes those potential yield boosts and reduced costs in fertilizer or irrigation.
Timing, Long and Short
The timing is crucial.
“To have a successful cover crop, you need to get it in early enough that it’s going to be able to grow enough in the fall to establish well,” said Griffin LaHue. Since some of Skagit’s main crops are harvested late in the year, this can make it hard to get a cover crop into the ground fast enough.
This year, for instance, Vander Kooy planted about 150 acres in cover crops, but the weather got too wet too soon to plant all the fields he wanted. The unpredictability of the weather means that “every year is different,” Vander Kooy said. Some years, he pointed out, it is too dry to get the winter crop in.
Cover cropping looks and sounds simple, but it is a complex practice with both immediate and long term benefits and challenges.
“It’s easier said than done,” said Griffin LaHue. “It’s more complicated than people think it is.”
“It’s very important for us as a district to continue to have funding coming in the door for landowners to allow them to do these practices, because the longer that we can keep these fields covered with some kind of vegetal cover during the wintertime, that’s when you’re going to see those soil changes,” said Gelwicks. “A big takeaway from winter cover cropping is that it’s not just a one-year fix; it’s a system that you’re going to adopt.”
Much of the research and practices are just for a year of cover cropping, but the benefits might accrue over longer terms, such as leaving the cover crop in for three or four years.
Reducing Uncertainty while Strengthening Soil
Already, Skagit farmers overwhelmingly see the benefits of cover cropping, but defining those more precisely is an ongoing project.
The research of LaRue and others at NWREC provide more information to allow farmers to make informed decisions. Farmers always balance many competing needs. Figuring out how many years of consistent cover cropping might reduce irrigation or fertilizer inputs, for example, will improve an operation’s holistic accounting.
Farming is filled with inevitable uncertainty. The practical and research programs around cover cropping are helping to support farmers and the land and water that sustain them.
Story by Adam Sowards