The First Year’s Data from the 2012 CenUSA Biochar Demonstration Garden Report

The past few months, we’ve been covering the story of the 2012 CenUSA biochar test or demonstration gardens at three Minnesota sites.

Lynne Hagen has been providing us with the inside scoop on what they are learning about biochar, how they chose the biochar, how they prepared the three MN test garden sites, and most recently, she shared the 2012 challenges of these biochar test gardens.

2012 CenUSA Biochar Demonstration Gardens Report

Biochar as a soil amendment for gardens?
Does biochar make a good soil amendment for gardens?

Wait no more to get the detailed scoop on how the gardens performed with biochar as a soil amendment in 2012, the first year of this research project.

The first year’s data has been gathered and summarized in this 2012 CenUSA Biochar Demonstration Garden Report (PDF).

The report covers project research design details and data collection as it relates to specific annual, vegetables, and shrub roses used in all of the CenUSA biochar demonstration gardens. Overall, the summary emphasizes the need for continual research to best understand how biochar affects these garden soils and crops:

The more we learn about biochar, the more we need to learn. From an overall standpoint, there appeared to be some benefit of using biochar in the nutrient-depleted sandy soils at the Andover site for some crops. Yet, there was a decrease in growth in some plants and higher yield in others. In the Arboretum and St. Paul campus sites, we noted similar results, but more crops seemed to decline with biochar than without it.

In 2013, continual improvements will be made to streamline data collection, making sure volunteers are asked to collect the data most important to research results. Projects leaders will also focus on developing a clearer and easier method for documenting the data to help guarantee more consistency in data reporting.

Data will continue to be collected and analyzed across 4 out of the 5 years of the CenUSA Bioenergy project. One result is clear from the first year’s research: Extension Master Gardener volunteers have been instrumental and valued in their support on this research project.

Biochar Test Gardens in St. Paul
Biochar Test Gardens in St. Paul, MN

Stay Tuned for Biochar Demonstration Garden Updates in 2013!

Stay tuned, in the next couple months, we’ll take you through the events of 2013 as we watch the story of the CenUSA Bioenergy demonstration gardens unfold in the second year of research!

-Karen Jeannette

“The CenUSA Bioenergy project is supported by Agriculture and Food Research Initiative Competitive Grant No. 2011-68005-30411 from the National Institute of Food and Agriculture.”





2012 The University of Minnesota Biochar Test Gardens and Challenges (Part 4)


In my last few posts, I’ve described how University of Minnesota Extension Master Gardeners have been involved with the 2012 biochar test gardens with the CenUSA Bioenergy project.  As you’ll see throughout this post, from planting to data collection, we met some challenges with germination, weeds, insects and plant diseases in 2012.

2012- Plans and Design for CenUSA Bioenergy Biochar Test Gardens

What did we decide to grow?

Plants for Biochar Test Gardens
Plants for Biochar Test Gardens

Each site was designed to include basic plants that typical homeowners would grow such as annuals, perennials, vegetables and herbs. The design was laid out with short annual plants in the front and perennials near the back.

Edible crops that were grown included: green beans, tomatoes, green and hot peppers, Swiss chard, leafy kale, cucumbers, lettuce, asparagus, potatoes, and basil.

Ornamental crops included zinnias, petunias, marigolds, MN hardy mums and Ole, Lena and Sven hardy shrub roses.

First Year Test Garden Challenges

Seed and Shade Challenge

Early on we had some germination issues with the beans. Two of the three teams opted to replant, but by the time the second planting germinated, the Swiss chard was so large it shadowed the bean row too much…so no beans.

The potatoes were also spotty. The potato sets were mailed too early from the company we purchased from and even though they were kept under refrigeration, they got moldy and their germination was poor as well.

Pest Challenges: Aster Yellows, Japanese Beetles, and Weeds

Other challenges in the gardens included weeds, Japanese Beetles in two of the tree sites, more weeds, aster yellows disease on marigolds and petunias…and did I mention weeds?

The captioned photograph to the left shows a marigold infected with Aster yellows next to a healthy marigold (however it didn’t stay healthy very long) and embraced by purslane.

Marigold infected by Aster Yellows (yellow arrow), taken over by purlane (orange arrow)
Marigold infected by Aster Yellows (yellow arrow), taken over by purslane (orange arrow)


What to do with Poison Ivy in Andover?

The Andover site as I mentioned, was filled with small trees and underbrush including poison ivy – that also became a challenge to deal with.  However, the Master Gardeners did a great job of keeping it under control by using herbicides only around the exterior perimeter of the garden and hand pulling any sprouts that came up in the garden.

A couple of volunteers were nervous about eating produce that may have poison ivy roots coming into contact with the vegetable roots. Upon researching this concern with the Minnesota Department of Health, they felt the risk was low, but if the poison ivy roots came into contact with root vegetables like the potatoes, it was cautioned to peel the vegetables first.

Poison Ivy
Poison Ivy - A very undesirable weed to have at the Andover test garden


I then went a little further in my research and learned that the famous naturalist, Euell Gibbons, used to recommend eating poison ivy leaves – just a little a day, to build up a tolerance to the urushiol (the toxins in the poison ivy). I then noticed someone had blogged that they tried that and the only side effect they experienced was a little itchiness in their behind after the poison ivy passed through. YIKES!

End of Season Differences in the 2010 Biochar Test Garden

Comparing Lettuce Between Sites – Difficult Since Japanese Beetles Got Dibb

The lettuce, the earliest season crop, was harvested first. However, the Japanese beetles had such voracious appetites in the St. Paul Campus garden that less than 50% of the plants were left to weigh. The Japanese beetles hit the Arboretum site too, but not as badly. Japanese beetles haven’t found Andover yet (which is farther north than the other two sites), but they have been spotted less than six miles from that test site.  I have a feeling we may see them in 2013.

The gardens did get a little over crowded especially in the nutrient rich St. Paul Campus and Arboretum sites. To ease some of that, the Swiss chard was harvested early which allowed for more room for the kale and other vegetables. I will talk a little more about the harvest under “Collecting Data”.

Differences in Garden Vigor?

Overall the gardens at the St. Paul Campus and the Arboretum have the most vigor. It would be safe to guess that is because the soil was so much better, plus the added nitrogen resulted in heavy plant growth. In Andover, there appeared to be a lot of nutrient deficiency, not surprising considering it is very sandy soil and the 10-10-10 fertilizer,applied only once in the spring and had leeched through the soil early in the season.

Interestingly though, there was a noticeable difference on kale size between the control plots and the biochar treated plots. I believe that may be because of the moisture and/or nutrient holding capabilities of biochar in the poorer soils. However, it will be tough to gain analysis between treatment one and treatment two, because treatment two also has morning shade, which also contributes to the moisture not evaporating as quickly, and it also didn’t suffer from heat stress as much as the other two plots.

Collecting Data Will Lead to a More Comprehensive Report Soon!

Zinnias and Swiss Chard growing in Biochar Test Gardens
Zinnias and Swiss Chard Growing in Biochar Test Gardens

Most of the data that we wanted to collect had to do with growth and yields. Weights and counts were collected on produce such as potatoes, cucumbers and tomatoes, plus plant heights, widths, stem strength, bloom production, etc. were also monitored on all of the plants. A comprehensive report with all of the results will be coming soon.

As we prepare for 2013, we are now putting together what we learned from the 2012 growing season so we can improve data collection and improve our research with the  CenUSA Bioenergy project for 2013.

From here on forward, stay tuned, as we begin to blog about our 2013 season as it happens this year!


–Lynne Davenport-Hagen
University of Minnesota Extension
Master Gardener Program Coordinator-Anoka County
CenUSA Biochar Research & Display Garden Project Coordinator-USDA NIFA Grant


“The CenUSA Bioenergy project is supported by Agriculture and Food Research Initiative Competitive Grant No. 2011-68005-30411 from the National Institute of Food and Agriculture.”

Planning, Preparing, and Planting Minnesota Biochar Test Gardens (Part 3)

In two previous blog posts, I gave an overview of what we are seeking to learn through this biochar research project, and how we chose and added biochar to the test gardens.  Early in the planning, we first needed to find three locations to implement the gardens.  Next Extension Master Gardener volunteers needed to be recruited and trained about the project.

As part of this CenUSA Bioenergy project, Master Gardener volunteers completed a specialized training to learn about biochar and the CenUSA grant that supports it.  Each of the three sites in Minnesota has one or two team leaders and approximately 10 other volunteers per site.  Master Gardeners were involved in many facets of the research including planting and maintaining gardens, collecting data measurements and harvesting crops as needed.  They were asked to share their observations at the State or County fairs, horticulture field days or other community events.

How We Selected the Minnesota Biochar Test Garden Sites

All of the sites in Minnesota and Iowa needed to be identical in size because the same number of crops needed to be grown at each site. All of the gardens are 1000 sq ft and each site is divided into three plots of 300 sq ft.  Each site has a control plot with no biochar added, treatment 1 has 150 pounds of biochar and treatment 2 has 300 pounds of biochar.

It was also important to have locations with different types of soil to see how the biochar would react with the crops.  All three sites in Minnesota had to be developed from its original condition, meaning two of them had turf that needed to be removed and one was actually in an area filled with underbrush, small trees and weeds.  Soil tests were also conducted at each site and the gardens were amended with fertilizer based on the recommendations of the soil tests.

Biochar Test Gardens and MN Landscape Arboretum
Biochar Test Gardens at the MN Landscape Arboretum

Each site had its own unique issues with watering.  While we tried to replicate what a typical homeowner would do,the Arboretum site became the most labor intensive.  There was a sprinkler head close by, but the Master Gardener volunteers needed to run hoses and water by hand. The other two sites had irrigation that was scheduled by timers.

1) The Minnesota Landscape Arboretum Test Garden

Selecting the Arboretum as a site for this project was a no-brainer.  The Arboretum gets well over a quarter million visitors per year.  It was a great location to showcase this research project.  A couple of site locations at the Arboretum were considered.  Ultimately, the final decision was made and the biochar test garden is located on the 3-mile drive next to the Dahlia Trial Gardens.

Thankfully, the Arboretum staff removed the sod and tilled the soil to loosen it before we began.  One of our fabulous Master Gardener volunteers also offered to install deer proof fencing…a must have.  My colleague Julie, and I, amended the soil with fertilizer and biochar on May 18th.  It also happened to be a 97 degree day with high humidity to-boot. Ugh! Our soil test recommended that we use a nitrogen-only fertilizer with a ratio of 23-0-0.  The soil at the Arboretum site is loamy clay – not too terrible to work in.  The biochar arrived in 50 pound bags, so we just opened the end of the bags and slowly dragged the biochar over the areas of the garden where we needed it, and then my colleague tilled the biochar and the nitrogen fertilizer into the soil at the same time.

2) The St. Paul Campus Test Garden

The garden at the St. Paul Campus located at the intersections of Gortner and Folwell Avenues, was another great location. It is in close proximity to the Display and Trial Gardens and is visited regularly by students, staff, faculty and visitors.   The actual site was a former low-mow turf trial plot.  The sod was not removed but instead was tilled into the soil, which in hindsight we should have asked that it be removed.  The soil also has a fair amount of clay in it.  Because this site was irrigated regularly and wet when we started, it was challenging to work in.

The soil test in this garden also recommended a nitrogen only fertilizer of 23-0-0, the same as the Arboretum site.  The tiller got its workout that morning when trying to mix in the biochar and the fertilizer in the lumpy wet clay mess.  Deer isn’t a problem at this site, but rabbits are so a short fence was installed.

Biochar Test Gardens in St. Paul, MN

3) Bunker Hills Park in Andover Test Garden

The Andover site was a last minute surprise and a very exciting prospect. We originally had a site selected at UMore Park in Dakota County which is on the south end of the Twin Cities.  A new mining operation expanded in that area and there was uncertainty about whether the biochar research garden could remain in the same location for four years.

All along I had my eyes on the Regional and County Extension office location in the Anoka County Bunker Hills Park in Andover as a potential site for the biochar project.  The reason I was hoping for this site is because it is on the north end of the Twin Cities and in the middle of the Anoka sand plain.  Since biochar is known to have positive benefits in nutrient depleted soils, this sandy site was a good option. When I explained the issues about the Dakota County site to the Anoka County Parks Department staff, they were more than willing to accommodate the needs of the project.  Not only did they bring in a Bobcat and clear out an existing area of small trees and underbrush, they also enhanced their irrigation system to allow us to set a sprinkler that was set-up on a timer.  In addition, they brought in a couple of loads of mulch to help beautify and complete the project.  Since this garden is in a large suburban park, a deer fence needed to be constructed there as well.

Biochar Test Gardens at Andover
Biochar Test Gardens at Andover

The soil test recommended a well-rounded fertilizer with a 10-10-10 ratio. One variable in this garden, that presumably will affect the research, and that isn’t present in the other sites, is that one end of the garden gets shade in the morning hours, but full sun the rest of the day. Because of this, it was anticipated that crops would not get as much heat stress as the rest of the garden and the water would not evaporate as quickly, so there was a good chance those plants would be healthier overall from the other two treatments.

What’s next?

We learned a lot the first year (2012) about the sites themselves, how the biochar interacted with the soils, and how data is best collected.  Next week, we’ll share what we learned from our 2012 data collection and research with the CenUSA Bioenergy project.

by Lynne Davenport-Hagen
University of Minnesota Extension
Master Gardener Program Coordinator-Anoka County
CenUSA Biochar Research & Display Garden Project Coordinator-USDA NIFA Grant

“The CenUSA Bioenergy project is supported by Agriculture and Food Research Initiative Competitive Grant No. 2011-68005-30411 from the National Institute of Food and Agriculture.”