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Footnotes from the Field

Footnotes from the Field: Biochar

in 2016/Current Issue/Footnotes from the Field/Grow Organic/Standards Updates/Tools & Techniques/Winter 2016
Making Biochar

Marjorie Harris BSc, IOIA VO, P.Ag. with many thanks to Zbigniew Wierzbicki of Elderberry Lane Farm for sharing his knowledge and experience

Turning Wood into Long Term Soil Fertility

Hooray! Biochar has arrived in the new PSL Nov. 25th 2015 edition!

Biochar is considered an excellent way to increase long term soil fertility. As an early pioneer in the farm production and use of biochar, Zbigniew Wierzbicki of Elderberry Lane Farm has always been eager to share the dos and don’ts of his biochar experience. Zbigniew is a strong advocate for the appropriate on-farm use of biochar and its correct production techniques.

The first question is; what is ‘Biochar’?

It seems to have appeared out of nowhere onto the COR PSL. The term Bio-char (biomass derived black carbon) was only coined in 2006 by Dr. Johannes Lehmann at Cornell University’s Crop and Soil Sciences department. Interest in biochar stems from the relatively obscure history and puzzling existence of the Terra Preta (literally ‘black soil’) or ‘dark earths’ scattered throughout the Amazon Basin which have caused much recent scholarly discussion, research and theorizing.

The current consensus is that Pre-Colombian peoples between 2500 to 500 B.P. created the Terra Preta by adding burnt agricultural wastes and pottery kiln ashes to their gardening soils. The Terra Preta soils were first reported in 1542, by the Spanish explorer Francisco de Orellana, to the Spanish court about his discovery of fertile lands supporting a large civilization living in the Amazon rain forest. However, by the time further expeditions arrived, the indigenous Amazonian populations had succumbed to European diseases and the existence of their civilization along with the fertile soils drifted into myth and legend.

In 1885, Cornell University professor, Dr. Charles Hartt described the Amazonian ‘dark earths’. Finally in the
20th century research and interest in the Terra Preta took off after Dutch soil scientist Wim Sombroek reported pockets of rich soils in his 1966 book, Amazon Soils.

Amazingly, these soils created more than a thousand years ago still demonstrate sustainably fertility that support astounding growth potentials compared to their neighbouring poor quality soils. They are rich in mineral nutrients and contain high concentrations of organic matter, on average three times higher than in the surrounding

The Pyrolytic Process

The pyrolytic process involves heating the biomass materials in the absence of oxygen. This causes a chemical reaction process whereby carbon transforms into highly interlinked aromatic chains forming a very porous and absorbent product. Pyrolytic heating causes 75% loss of the original biomass while retaining 50% of the plant carbon. The highest temperature reached during pyrolysis influences the molecular structure and the nal pore size and pore distribution, factors that govern its absorptive behaviour in the environment.

The resulting biochar is highly stable and resistant against microbial decay for thousands of years. Biochar increases overall surface area in the soil that can provide niches for increased microbial populations, which aid in reducing plant diseases, such as damping off, by mechanisms that are still unclear. Studies have demonstrated that biochar treated soils mitigate greenhouse gas emissions by reducing nitrous oxide release by up to 90% and by sequestering carbon compound residence time for thousands of years. Biochar also holds nitrogen, phosphorus, and many other minerals for slow release, while increasing the cation exchange capacity (CEC) and water retention ability of the soil.

Making Biochar

Activating the Biochar

As Zbigniew notes, the fresh biochar must first be “activated” by absorbing nutrients. Scattering a light layer of biochar on the barn oor will let the biochar absorb the nutrients from the straw-manure litter while keeping the barn oor sweet and protecting livestock feet from diseases. Biochar can also be charged by soaking it for two to four weeks in any liquid nutrient (urine, plant tea, etc.). If the biochar is not properly activated before being applied to the soil it will absorb the available soil nutrients to fill its absorptive capacity, depleting the soil. Once properly activated by adsorbing the ammonia (NH3) from barn urine and manure, biochar becomes an excellent slow release fertilizer full of bioavailable nitrogen compounds lodged in the carbon pores waiting for release by microbial action. There is evidence that biochar is beneficial to arbuscular mycorrhizal fungi that develop symbiotic relationship with plant roots for greater nutrient uptake.

How to Make Your Own Biochar

1. How to stack wood: Zbigniew emphasizes that biochar burning must be a top down process. The wood stacking method is opposite from what is learned in Boy Scouts, where small kindling is placed on the bottom, Zbigniew explains. When making biochar you place the large wood pieces on the bottom in a pit or trench and pile the small wood on the top, causing the pile to burn downward. Using this stacking method causes the volatile gases that form as the biomass heats up to be consumed by the high temperatures at the top of the pile instead of being released into the air, as is the case in a normally constructed fire.

2. Dig a trench or pit: and bury all of the roots, slash, and large logs. Compact the pile, and put lighter material on top. The intensity of the fire is so incredible that there is no smoke, it creates a very clean burn, and a large amount of biochar is produced. Cover the red hot coals with dirt or if you have a burning pit, cover it to finish the process in a reduced oxygen environment. This prevents the formation of polycyclic aromatic hydrocarbons (PAH) in the kiln. Regular burning creates lots of PAH’s, which contaminate the soil and air.

3. Drenching is optional: Zbigniew drenches his biochar at the very end. The caution here is that the liquid from the biochar is very alkaline and the area the liquid goes cannot be used for gardening. Zbigniew has a permanent ditch for catching the liquid.

4. Activating the biochar: After the material is cold, crush into a fine gravel size for use on the bottom of the barn to catch urine and other nutrient goodies. Poultry barns and large livestock barns can all use biochar on the oor. Biochar is like a magnet absorbing minerals. As it absorbs minerals and urine from the animal waste it becomes activated.

5. Neutralizing the biochar: Remove from the barns when saturated and put into the compost with other crop and farm waste. The composting process helps neutralize it before spreading into the garden soil. The microbes of the garden soils will release the minerals from the biochar as they are needed. Because of this microbial release action the biochar will release mineral nutrients for a very long time.

6. Cautionary note: Zbigniew emphasizes that because biochar is so alkaline and so very long acting, it is very important to test your soils pH first. Although composting does move the biochar pH toward neutral you need to check your soil pH to manage it properly for long term changes.

All photos: Marjorie Harris

Clough, T.J., Condron, L.M., Kamman, C., Müller, C. (2013). A Review of Biochar and Soil Nitrogen Dynamics. Agronomy, 3, 275-293; doi:10.3390/agronomy3020275.
Lehmann, J. (2012). Integrated biochar systems for soil fertility management. Cornell University, Mar 26.

The Two Faces of the Vegetated Buffer

in Current Issue/Footnotes from the Field/Land Stewardship/Organic Standards/Spring 2016/Tools & Techniques

By Marjorie Harris BSc, IOIA VO, P.Ag.

CAN/CGSB 32.310-2015
5.2.1 Measures shall be taken to minimize the phsyical movement of prohibited substances onto organic land and crops from:
a) adjacent areas
If unintended contact with prohibited substances is possible, distinct buffer zones or other features suf cient to prevent contamination are required:
Clause 5.2 Environmental Factors
Clause 5.2.2
Buffer zones shall be at least 8 m (26 ft 3 in) wide;
Permanent hedgerows or windbreaks, articial windbreaks, permanent roads or other physical barriers may be used instead of buffer zones;


Recent studies by the BC Ministry of Agriculture show that pesticide air blaster applicators create a pesticide residue burden of 10% concentration in the spray drift 30 feet from the application site! A vegetated buffer can be a multi-functional operational bonus for the organic enterprise, in addition to meeting the COR standard requirements for preventing unintended contamination by prohibited substances via air flows.The primary function of the vegetated buffer is to stop dust particulates and spray drift. Seven key features are considered in the design plan: height, density, orientation, length, width, continuity/uniformity, and cross-sectional shape. As such, trees and shrubs are layered to either trap and capture air flow by dense foliage porosity or to modify air flow into a chimney to cause dispersion and dilution.

The outer vegetated buffer face can work to shield and reduce pollution from incoming spray drift, dust, and odours, while the inner vegetated buffer face can provide habitat for sacrificial crops and beneficial organisms. Windbreaks, shelterbelts, and vine covered trellis/fencing can all be designed as effective vegetative buffers to address environmental interface pollution issues.

Conifer trees, especially the wild-type Excelsa Cedar, have been found to have the best type of density for providing air flow porosity, and year round protection from interface pollution of all kinds. In dry areas like the Southern Okanagan these moisture dependent hedges will require some drip irrigation and that cost needs to be balanced with the overall value to the organic operation.

The inner facing surface of the vegetated buffer can be companion planted with flowering plants and shrubs to increase overall biodiversity, and to provide food sources and habitats for beneficial, birds, insects, amphibians and native pollinators. A healthy population of beneficial organisms can go a long way to increasing crop yields and controlling garden pests.

A flower packed habitat will attract nectar-feeding insects such as bumbles bees, butterflies and hoverflies, which lay their eggs where there is an abundant supply of aphids for their larvae to feed on. Studies have demonstrated that alfalfa, mustard, yarrow, coriander, cosmos, French marigold, and nasturtium all attract an increase in a wide variety of predatory ladybugs.

Also, consider planting native flowers, plants, and herbs to boost the habitat biodiversity for native pollinators. Often, hybrid plants with large, showy flowers have little or no pollen.

One of the best plants for attracting native pollinators is hyssop. Hyssop’s strong aerosol aroma also helps to protect brassicas by masking their scent from white cabbage butterflies. Members of the mint family are favorites of Tachinid flies, hoverflies, and parasitic wasps; try planting mint, lemon balm, catnip, and pennyroyal.

Todd Carnahan, author of Gardening with Native Plants, recommends the drought tolerant ocean spray brush, nodding onions, and kinnikinnick, which doubles as a great ground cover and produces red berries in the fall.

The vegetated buffer will provide nesting areas for solitary bees and many other beneficial organisms. Remember to construct some rocky areas, puddles and muddy patches too catch fresh water to meet their daily water needs.

Buffer Benefits:

  • Enhances crop yields
  • Provides habitat for biodiverse beneficials (birds, insects, amphibians)
  • Reduces wind erosion
  • Shelters livestock, crops and structures 
(homes outbuildings, roads)
  • Captures water runoff, nutrients, increase moisture resilience
  • Filters and reduces spray drift, dust and help control odors
  • Provides wildlife travel corridors and habitat
  • Increases moisture capture
  • Reduces light and noise pollution

The good news for those who would like to explore the value in establishing vegetated buffers is that funding is available through the Environmental Farm Plan Program to offset some of the major costs associated with risk assessment, design, and planting, making the application process all the more worthwhile.

The Environmental Farm Plan (EFP) Program BMP funding is managed through ARDCORP as follows:

Whole farm initial risk assessment is free and completed with the help of an EFP Planning Advisor. The vegetative buffer design and plan is required to implement a vegetative buffer and is covered up to $2000. This can be completed by an EFP Planning Advisor or qualified professional.

Once the plan is approved, under the EFP BMP program, producers can apply for a cost share incentive of 60% up to $15,000 for installing a vegetative buffer. A guidebook entitled Vegetative Buffers for Intensive Agricultural Operations in British Columbia will be published later in 2016.

For further information about the funding program and the soon to be released guidebook please contact: David Trotter, M.Sc., P.Ag. | Agroforestry | Sector Development Branch, BC Ministry of Agriculture | p: 604-556-3148| cell: 778-549-6641 | david.trotter@

“Create a Bee Friendly Garden”. David Suzuki Foundation.
Todd Carnahan, Gardening with Native Plants. Diagram Credit Ministry of Agriculture.
[] Accessed 18-03-2016
Boisclair, J., Lefrançois, E.. Leblanc, M., Stewart, K., Cloutier, D., et al. (2012). Preliminary observations on the potential of owering strips to attract bene cial insects. Canadian Organic Science Conference.
Todd Carnahan, Gardening with Native Plants.

Species at Risk

in Footnotes from the Field

Marjorie Harris

Species at Risk Partnerships on Agricultural Lands and Critical Habitat Protection

Good News! Environment Canada has rolled out a new initiative aimed at protecting critical habitat for endangered species on commercially farmed agricultural lands. This is great for those species that took eons to adaptively evolve for just those particular critical habitats that are being threatened. The Species at Risk Partnerships on Agricultural Lands (or SARPAL, since that’s a bit of a mouthful) initiative may also help to support organic farmers who are conscientiously implementing the Environmental Guidelines in British Columbia Certified Organic Production Operation Policies and Management Standards Section 7, Book 2 Version 10: Environmental Protection Guidance:

Organic operators should adhere to the strictest possible management program in order to protect and enhance soil and water quality in the environment. Organic farmers, and others in the trade, have a commitment to environmental protection.

This is a basic principle of the organic movement and must be respected before all other considerations.

The theory of evolution developed by the 19th century English naturalist Charles Darwin was based on the premise of natural selection. Organisms are naturally selected for survival, competition, and reproduction by acquiring small, inherited adaptations over many gen- erations spanning millenia.

In today’s world, organisms are faced with a succession of environmental challenges from habitat loss to fatal and mutagenic toxins as they grow and develop.

With the rapid pace of current imposed environmental challenges, the adaptive plasticity of most organisms becomes overwhelmed and they are placed on a path to extinction. SARPAL may help to restore breeding habitat by assisting with costs associated with developing and implementing species at risk protection on agricultural lands.

The new initiative to protect critical habitat is funded by the federal government through the National Conservation Plan under the SARPAL umbrella program. The species being targeted have to be listed on the federal Species at Risk Act (SARA). SARPAL will include two phases:

  • A 5 year pilot/‘proof-of-concept’
  • An on-going implementation phase

The on-going implementation phase will focus on achieving protection of the species at risk on agricultural lands in ways that will ideally benefit both species and producers.

Currently, demonstration projects have been set out with the assistance of the BC Cattleman’s Association. The demonstration projects are focusing on two ranch land habitat species: the Yellow-breasted Chat and Lewis’s Woodpecker. The recovery strategy includes identifying critical habitat geographically and assessing the environmental features such as plants, water, and needs of the species to live and reproduce.

Funding is available to pay for the infrastructure to establish Best Management Practices (BMP) that protect the endangered species’ critical habitat and a Stewardship Agreement may be entered into that benefits the landowner and the species at risk.

The Yellow-breasted Chat
Scientific Name: Icteria virens auricollis

Only 40 breeding pairs are currently known of in the Okanagan/Similkameen region. The Yellow-breasted Chat prefers woodland riparian zones composed of dense tickets of wild rose and ooded oxbows.

Recovery Plan Best Management Practices:

  • Protect nesting area by improving fencing and adding cross fencing to exclude livestock from accessing the riparian zone
  • On-going maintenance for fencing
  • Restore some water ow to marsh lands and re-flood oxbows
  • Control invasive plants
  • Install alternative watering facilities for livestock (troughs)
  • Develop public education material.
  • Reduce livestock grazing in riparian zones known to have Yellow-breasted Chat

If you are interested in this program or want more information on SARPAL, contact Danielle Prevost, Environment Canada:

Marjorie Harris, BSc, IOIA V.O., P. Ag. Email: mar-

“Let food be thy medicine and medicine be thy food.” – attributed to Hippocrates

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