A mason jar sits on the counter of the lab of ECHO’s Florida campus, (now known as the North America Regional Impact Center (RIC)) black pea-sized beads at the bottom with cloth-wrapped bell pepper seeds sitting on top. Yesterday, Educational Research Associate Dr. Guin Perry put wet and slimy seeds into the jar. Today, those seeds are dry. In one more day, they’ll be dry enough for long-term storage – ensuring bell pepper seeds can be planted in the future. 

The black beads at the bottom of the jar are the secret behind the quick drying. They’re also the result of seven months of research, testing, and tweaking between Perry and Appropriate Technology (AT) Manager Elliott Toevs, who seek to create a reliable and cheap two-ingredient desiccant for ECHO community members. 

“Having a desiccant that is easy to make and accessible is critical for the project,” Toevs said. “Anything focused on smallholder farmers’ success and profitability is a worthwhile endeavor for us to be pursuing.”

A desiccant is a substance designed to induce and sustain a state of dryness. Cat owners buy kitty litter – a desiccant – in order to keep the litter box dry. New products have silica gel packets in the box to prevent moisture damage. Farmers and gardeners use zeolite beads, a commercial desiccant, to dry seeds before and between planting. 

Drying seeds with a desiccant allows for more effective long-term storage. There’s a minimized risk of fungus and disease damage and premature sprouting due to moisture, and the seeds don’t get damaged as they might when dried in the sun. With more certainty, growers can be self-sufficient, use less seed, save money, and save seeds for longer.

“Let’s say a farmer has an awesome crop this year. Being able to keep seeds from that awesome crop means that next year’s crop has the potential to be great too,” Perry said. “It improves the chances of having healthier crops every year because now they’re able to save seeds faster and better for longer.”

Seed Bank Manager Holly Sobetski encounters the importance of seed drying in her own work on ECHO’s Florida campus. Outside, the summer weather is often surpassing 90 degrees, and the humidity can easily be described as sticky. The dampness in the air prevents the seeds from reaching the ideal moisture content, opening the door for seed spoilage. 

Sobetski avoids this by drying seeds in heated dryers before storing them in sealed containers in a 45 degree, 40% relative humidity environment. She’ll often add a silica bead packet in bulk bags of seed as a safeguard. 

In short, Sobetski stores seeds in ideal conditions.

“But most farmers and communities cannot afford equipment to keep their seeds in these conditions,” Sobetski said. “It’s expensive.”

Without education about or access to seed drying techniques such as desiccants, farmers can face devastating seed loss. Sobetski remembers one Tanzanian farmer who stored a large bag of valuable cowpea seeds.

After storing, the hope was to plant the seeds half-an-inch deep into warm soil. The results would be quick, with the legume producing after about two months. Once harvested, the cowpeas would be cooked like a green bean and enjoyed, and more seeds would be saved. 

With this in mind, the farmer properly sealed the seeds into an airtight, multi-layered crop storage bag, protecting the cowpeas from weevils. 

The seeds, however, were moldy and unusable when taken out for planting. The cowpeas had too much moisture when they were put into storage, largely due to the humid conditions. Had the farmer dried the seeds with a desiccant before sealing them in the bag, spoilage could’ve been avoided. 

“Farmers and community seed banks need low-cost options for drying down seed before storage as well as keeping seeds dry in storage, especially if the storage conditions are not optimal,” Sobetski said.

While Zeolite works for some, Perry realizes it is not an affordable or readily available desiccant option for many of the farmers ECHO equips.

“I thought ‘maybe we can come up with something that’s free, that people can make themselves, that’s a version of Zeolite,’” Perry said.

In January, Perry and Toevs began developing a desiccant made up of wood ash and clay. ECHO community members can feasibly gather these resources by collecting wood and clay-rich soil. However, making a desiccant takes more care and attention from that point on.

After gathering the soil, Perry separates clay from the mix. This is accomplished by stirring together the soil with water and then allowing everything that isn’t clay to sink to the bottom. The clay binds to the water and stays on top. This top layer can be poured off and strained into a separate container, leaving the sand and silt behind. After sitting for as long as 24 hours, the clay regathers and settles to the bottom of the mixture. The final step is pouring the mostly-separated water and clay through a cloth, allowing the water to run through while the clay stays in the fabric. The cloth can be tied up and left to dry for about 12 hours, and what’s left behind should be soft and smooth clay.

Wood ash is created from the combustion of wood — it’s the white, powdery residue remaining after a bonfire. This can be gathered and used for the desiccants. 

Once the clay and wood ash are ready, they can be mixed together with water. As Perry has progressed in her work, the desiccant balls have improved. They are now rolled with a more consistent and smaller size, maximizing the efficiency of the absorption. 

After a batch is rolled, the desiccant balls must be fired in heat of almost 1000 degrees Fahrenheit — a job fit for a forge, which Toevs fires at the Appropriate Technology Shop.  

Beyond the forge or a kiln, Perry and Toevs are researching whether or not this firing could be accomplished by a rocket stove. 

The heat of the firing process creates calcium oxide, the chemical compound that pulls moisture in to the bead. The beads can be dried out in an oven and reused up to five times before losing significant absorption abilities. Perry is most proud of this reusability that she has discovered in her research. 

“It does take energy to make them, but if I can use them five times and dry out seeds for my crop for five seasons, then I make them once every five years, and I get to use them over and over again,” Perry said.

Reusability is crucial for the future adoption of the desiccants among ECHO community members. Perry and Toevs are now investigating whether refiring the beads in the 1000-degree Fahrenheit heat used in the original firing would reactivate the calcination process, creating more calcium oxide. In other words, they are looking to dry the beads out, revive the absorbent qualities, and boost reusability for seed drying. 

As Perry and Toevs continue to tweak the desiccant-making process, small-scale farmers like the man in Tanzania are at the forefront of every decision made by ECHO. The most sustainable, accessible, and labor and resource efficient methods are prioritized to minimize economic and productivity risks to the smallholder farmer.

“The people that we’re seeking to serve, smallholder or subsistence-level farmers, the marginalized in the whole scheme of things, have fewer resources at their disposal to make a change,” Toevs said. “A small change like this can provide better and longer seed saving which in turn can lead to better harvests and nutrition.”

Your support of ECHO makes this research, and so much more possible to benefit small-scale farmers around the world. 

From clay and wood ash, to healthier and drier seeds, we are grateful for the abundant growth in lives all around the world!