Members of a local environmental group are launching an effort to enrich the soil in the food bank’s newest garden and grow food there this summer while working to reduce Vashon’s waste stream.

Called Waste to Garden, this three-year project is part of Zero Waste Vashon’s mission to recycle the island’s organic waste and transform it into useful products. Part of the initiative will include an informal test of several soil amendments, ranging from worm castings to wood chip mulch. The heart of the project, however, will adhere to strict scientific protocols and determine the effectiveness of biochar (charcoal made from plants) and a microbiotic solution designed to restore the soil’s healthy flora. During and after the growing season, Zero Waste Vashon members involved with the project — and islanders they hope will volunteer to join them — will study the plants thoroughly, determining their overall quality and weighing what they produce. This year’s results, along with further soil testing, will help inform what actions the group will take next year as it continues the study.

“We will explore what does best for the island’s glacial till soil and get it up to high fertility,” said project leader Will Lockwood, a board member of Zero Waste Vashon and a co-director of its science team. “We will let our land tell us what is best.”

Much of Vashon’s soil is depleted because of multiple clear cuttings, Lockwood said, but the soil at the food bank’s garden site, located behind the IGA plaza, is particularly poor. There, the sandy loam that once nourished strawberry fields has been covered with several inches of fill from construction sites, and while restoring the soil’s vitality is essential to growing food in the garden, it will also provide valuable information to gardeners and growers on Vashon and beyond.

When Zero Waste Vashon formed two years ago, its members hoped to recycle many types of the island’s waste, including food scraps, yard debris, meat and manure, with an anaerobic digesting system. Such systems create both compost and methane — energy that could be used locally.

Julia Lakey, one of the group’s founders, said the members came to understand creating such a system was too narrow a focus and that they needed a better understanding of the size and content of Vashon’s waste stream to know what could be developed from it. The new green waste program at the transfer station, which enables islanders to drop off both yard and food waste, is part of that effort. Lockwood said it has far exceeded projections since it began last fall, and it continues to grow each month. While early signs  point to success, the waste is still taken off the island for composting, and large quantities of compost are shipped back to the island — a system that Zero Waste Vashon members say is not as environmentally or economically sound as it should be.

“Sooner or later we have to realize there are smarter ways to master our processes,” Lockwood said.

He and Lakey say one smarter process would be to turn Vashon’s yard and food waste into usable products on the island for island use. Biochar, which has been used to nourish the soil for thousands of years, has gained attention more recently because it sequesters carbon along with improving the soil, and could be part of such a process. The green waste program cannot take anything larger than 4 inches in diameter, Lockwood noted, but materials bigger than that could be turned into biochar and used to nourish Vashon’s soil and create a closed loop on the island, from garden to waste to garden: coming from Vashon’s soil, restoring Vashon’s soil and creating jobs along the way.

The study at the food bank garden is part of that vision and is intended to show just how effective biochar is — and is a necessary step in determining if there might be a market for biochar produced on the island. Such a market, Lakey said, could include not just gardens, but farms and land purchased by the Land Trust — any land with soil that needs replenishing.

But first, Lockwood, a team of scientists he is working with, other Zero Waste Vashon members and volunteers have work to do in a 2,400-square foot plot in the middle of the food bank garden.

The garden study, set up in a checkerboard fashion in the garden, will include four test areas arranged in a grid: baseline soil that has been modestly amended, soil with biochar added, the soil treated with the microbiotic solution, and the soil amended with both the microbiotic solution and biochar.

Lockwood theorizes that the most prolific growth will come from that final section, amended with both biochar and the solution.

A study he conducted last summer with bean plants in pots of soil amended with a wide range of products found that biochar mixed with a fertilizer with microbial components was particularly successful in growing healthy plants with robust yields.

When looking for a site to replicate that test on a larger scale, Lockwood said the food bank site, close to town and easily accessible, seemed like a good fit.

“We wanted to do something in collaboration with the community for the benefit of the community,” he said. “And we wanted to take on a challenge.”

Norm Mathews, the owner of Thriftway, owns that plot of land and has leased it to the food bank since 2014 for free. Since then, the food bank has established infrastructure there, including fencing and a greenhouse, and has grown cover crops to help restore the soil’s health. This summer, staff and volunteers will plant food crops there for the first time.

Robbie Rohr, the food bank’s executive director, said they are pleased to be part of the Waste to Garden project.

“We really think what Zero Waste Vashon is doing is a great project to offer Vashon and beyond,” she said. “It seems like the kind of project that could have a large impact on a wide scale, and we want to support that.”

The food bank farm manager, Rachel Fesler-Schnitzer, is also enthusiastic.

“I am looking forward to learning more about compost and using the amendments they are experimenting with. I think their research will be beneficial overall to manage the soil and to make it the best and most productive it can be.”

She noted that a cover crop planted in the area Zero Waste Vashon plans to use did not come up well.

“That patch is a particularly non-fertile and rocky piece,” she added, supporting the notion that the group has met its goal of taking on a challenge.

Work for the Waste to Garden project is getting underway this month at the garden, and Lockwood said he would like to see volunteers at work parties every Sunday afternoon during March and April and again during the harvest season. Beginning work will include clearing rocks, adding soil amendments, tilling the soil, setting up an irrigation system and creating signage.

He noted that he is not going into the project with a lot of assumptions.

“There will be some things that I hope will be surprises,” he said. “It is a grand experiment. It should be a fun project.”

To volunteer for the Waste to Garden project, contact Will Lockwood at will.lockwood@zerowastevashon.org. The first work party is set for 1 to 3 p.m. Sunday, March 13. For more information about Zero Waste Vashon, see zerowastevashon.org.

Later in the season, there will also be opportunities to volunteer in the larger food bank garden not included in the study. For information on those opportunities, call the Vashon Maury Community Food Bank at 463-6332.