2015 Biochar Expo

This year’s Biochar Expo attracted some fifty people interested in learning more about biochar. It was held at the Discovery Garden Pavilion.

A Japanese-type, sloping, steel kiln fabricated locally by the UCC Welding Department is used to burn a rick of dry fir and other wood materials. Eventually the rick is pushed down to burn all pieces equally.

Water extinguishes the fire and stops the process.

The char can be broken up into small pieces or added to the soil “as is".  We added the 5 to 7 gallons of char to the Demonstration Bed without breaking it up into smaller pieces or pulverizing it.

A couple days later, the biochar bed was turned and the char forked into the top 6" of soil. The other bed was turned over and smoothed out, too. We will plant cover crop(s) before the end of November.

Ending the Season

The last of the peppers and tomatoes were harvested and we began clearing out the plants. We noticed a varmint had already harvested most of the carrots.

Something's been digging in the garden!

Last of the tomatoes!

In this first year crop, few differences between the two sides were noticed. Next year we’ll have to adjust the overhead sprinklers so both sides get adequate and equal water. We will re-test the soil, add amendments as necessary, and plant different crops.

Aside from the onions, carrots and beans, we saw little difference in plant growth between the two beds. Our yields of squashes, cucumbers, peppers and tomatoes were good from both beds. In mid-September, the squash and cucumber plants were removed because of powdery mildew. They had quite overgrown the small space of the gardens.

Harvesting the Crop

Here are some of the vegetables harvested from the garden over the summer.

The squash plants were “volunteers” transplanted from the worm beds where they were found sprouting. Unfortunately, they were evidently from hybridized squash and yielded gourd-like produce.

Watering the Beds

From June through September, the two biochar beds were sprinkled with water every Monday, Wednesday and Friday along with the other plants in the Discovery Garden; however, because of the very hot weather this summer, both were sprinkled by hand most other days, too. Even with the extra water, the carrots and beans on the non-biochar side did not germinate because the overhead sprinkler often missed that tiny section of the garden. During July, small and curly tomato leaves was evidence of heat distress, but the foliage returned to normal in August as it cooled. Our onions failed to thrive as well, most likely because of crowding and shading.

Installing the Signs

New signage was installed in the Compost, Hummingbird and Biochar areas.

Planting the Beds

Each bed was planted with equal numbers of carrots, beans, tomatoes (Sweet Millions), zucchinis, hard squash, Tanja cucumbers, red and white onions, and Anaheim peppers.

Adding the Compost

The finished compost was mixed in with the top 6” of both beds, the biochar-charged compost in the bed on the left, and we started planting.

Amending the Soil

The soil in the beds was tested by the Douglas County Master Gardeners’ Soil Test Lab and amended according to recommendations: 0.1 lbs Potassium, 0.8 lbs Nitrogen, 0.5 lbs Magnesium.

Preparing and Constructing the Beds

4/28/15
We obtained approval to put the beds in back of the Hummingbird Garden in the Compost Area. During the winter, the tall grasses occupying the space were dug up and moved to other areas and the compost started. In April we began screening soil from the Master Gardener topsoil pile and bringing it over to the site.

5/26/15
Three 2” x 12” redwood boards were purchased, cut and assembled into two identical 4’ x 6’ raised beds. The beds were filled with topsoil from the Discovery Garden’s pile.

Checking on the Compost

When we checked the composters, we found a number of worms in the biochar composter were congregated around its rim and lid, while the ones in the other composter had not. We speculated that the worms were attempting to escape contact, at least temporarily, with the biochar. Perhaps the biochar created an unfriendly environment for them. We decided to leave them alone and see what happened. Within a month, they had apparently returned to the composting materials and we noticed no more unusual worm behavior. We turned the compost in the containers one time during the next four months.

Making the Compost

The Compost Team filled two Earth Machine composters (also known as “Darth Vader” composters) with composting materials. Some 100-200 earthworms were also added to each composter. Five gallons of biochar was mixed into one of the composters.

Approving the Budget

The Douglas County Master Gardeners’ Executive Board Committee approved the Biochar Demonstration Project materials budget.

Obtaining the Biochar

A five-gallon bucket of biochar (approximately .67 cu. ft.) with a known chemical profile was obtained from a local source.