Activated Biochar

Exploring Manure‑Charged Biochar for Soils and Nutrient Management

The SoilRes3 Lab at UBC, in collaboration with BC Dairy, is leading a project exploring activated (or “charged”) biochar produced from dairy manure.

The goal is to better understand whether manure‑charged biochar can serve as a practical soil amendment and manure management tool in dairy and mixed farming systems in British Columbia.

This project builds on several years of research testing how biochar behaves in agricultural soils and how its performance changes when combined with nutrient‑rich materials such as manure. The current phase of work focuses on translating this research into farm‑relevant settings, using realistic application rate

1: WHY does this research matter for BC farms?

In BC regions with a high concentration of livestock agriculture, managing manure nutrients remains a real challenge. Limited land base, narrow application windows, and the risk of nutrient losses can reduce the value of manure while increasing costs and environmental risk. Many farms are also working with soils that are moisture-stressed or have declining structure, which can limit nutrient use efficiency and crop performance.

This project is grounded in those realities. It explores whether combining dairy manure and biochar could help retain nutrients, improve soil function, and better use materials already present within local farming and forestry systems.

2: WHAT is this research exploring?

Biochar does not perform the same way in all soils or systems, and how it is managed matters. Applying biochar without first “charging” it can temporarily tie up nutrients already in the soil. Charging biochar with manure before application may turn it into a slow‑release nutrient carrier, but this depends on how it is done and at what rate.

This project is testing how manure‑charged biochar behaves under realistic farm conditions in BC, focusing on feasible application rates, nutrient behaviour, and soil and crop response. The goal is to understand where this approach may add value, and where it may not.

For an overview of what biochar is, how it is produced, and general use considerations, see the Biochar Factsheet.

‘Charging’ bioochar with dairy manure

3: WHAT does previous research tell us?

Previous field and greenhouse research at UBC has shown promising results when biochar is first charged with dairy manure. These studies suggest manure‑charged biochar can help hold nutrients in the soil, support plant uptake, and reduce reliance on additional fertilizer in some systems.

Biochar is also very stable in soil, meaning it stays in place for a long time rather than breaking down quickly. However, results vary depending on soil type, application rate, and the method of biochar production and management. This variability highlights the need for more testing under real farm conditions.

4: Current research goals

The current phase of research focuses on testing manure‑charged biochar under conditions that reflect how farms actually operate in BC. This includes using application rates that are more realistic and looking at how biochar fits within existing manure management and soil practices. The project is also considering practical questions around feasibility, fit, and potential costs and benefits at a farm and regional scale.

Research and demonstration work is underway at several sites:

Controlled experiments at UBC are comparing standard biochar, manure‑charged biochar, and similar combinations to better understand nutrient behaviour, plant growth, and soil response.
Field trials on the Sunshine Coast are testing these approaches under farm‑like conditions, with a focus on soil nutrients and crop biomass.
In Abbotsford, a demonstration project is exploring whether adding biochar during manure processing can help reduce odour and retain nutrients.

FAQ on Biochar Application

Does it make economic sense to produce and sell biochar, or is it better to use it on‑farm?

Biochar has a high market value, especially when sold into retail or specialty markets, so there can be a strong incentive to sell it. However, biochar is just one part of a larger value chain. When biochar is produced and used on‑farm—charged with manure and applied to fields—it can generate value through multiple benefits, including nutrient retention, reduced fertilizer needs, and improved soil performance. In many cases, the combined value across the whole system can be greater than selling the biochar as a standalone product.

Since dairy manure is liquid, would farms need solid–liquid separation before using biochar?

Not necessarily. How biochar is produced and used depends on each farm’s system. Farms without solid–liquid separation can still charge purchased or produced biochar using liquid manure and apply it to fields. Alternatively, farms can combine liquid manure with other organic materials (such as crop residues or by‑products) to charge biochar. The approach is flexible and can be adapted to different farm setups without requiring major infrastructure changes.

How often would biochar be applied at rates of 3–5 tonnes per hectare?

Based on available biomass and current research, applying biochar at 3–5 tonnes per hectare every four to five years appears feasible in BC. Application frequency ultimately depends on feedstock availability, production capacity, and farm goals. More research is underway to better understand long‑term effects and optimal timing.

Would uncharged biochar remove nutrients from soil, and when would those nutrients be released?

Yes. Uncharged, low‑nutrient biochar can temporarily absorb nutrients from the soil, making them less available to crops. Over time—ranging from a few months to a couple of years—those nutrients may be released as soil microbes break down other organic inputs. If biochar is not charged first, it should be applied several months before planting to reduce the risk of nutrient tie‑up.

Does annual tillage reduce biochar stability or residence time in soil?

It can. Biochar often becomes physically protected within soil aggregates. Tillage can break down those aggregates, potentially reducing biochar’s residence time in soil. That said, the most chemically stable fractions of biochar are still likely to persist for a long time, even under tilled conditions.

Can biochar help reduce soil contamination, such as heavy metals or microplastics?

Yes, biochar has been widely studied as a soil remediation tool, particularly for heavy metals. Its porous structure can bind contaminants and reduce their mobility in soil. There is less research on microplastics, but the same principles may apply. This strong binding ability is also why applying uncharged biochar to soil is discouraged—it can absorb nutrients as well as contaminants, temporarily making them unavailable to plants.

Were transportation emissions and costs considered when moving biochar or feedstock?

Transportation costs are an important consideration. In one case study, trucking feedstock to a pyrolysis facility cost about $20 per tonne. Transport using diesel trucks does generate emissions. Mobile pyrolysis units may reduce emissions by bringing the equipment to the feedstock source, reducing the number of trips required. More work is needed to fully compare fossil‑fuel and electric transport options.

Is syngas or heat from biochar production ever reused?

Yes. Some biochar production systems are designed to capture syngas and heat generated during pyrolysis. This energy can be reused to dry feedstocks or support the process itself, making production more energy‑efficient and closer to self‑sustaining. There is significant room for innovation in designing more efficient and circular biochar production systems.

What feedstock was used to produce the biochar in the study?

The biochar used in the study was produced from forest residues.

How was biochar quality (porosity, pH, etc.) controlled in the research trials?

The biochar used in the trials was sourced from a commercial supplier. Its characteristics depend largely on the feedstock and how it is produced. Rather than trying to control every property, researchers test biochar samples through certified laboratories to confirm pH, nutrient content, and heavy metal levels before use. This type of testing is recommended for both researchers and farmers to ensure biochar quality and safety.