Chicken Manure Biochar as a Sustainable Peat Substitute for Growing Media

Peat has long been a staple in horticultural growing media due to its excellent water retention, high structural stability, and low levels of pathogens and heavy metals. However, peat extraction has caused significant damage to peatlands—vital carbon sinks—and triggered the release of greenhouse gas emissions. As a result, there is growing pressure to find more sustainable alternatives to peat.

One promising substitute gaining attention is biochar made from chicken manure. Biochar is a carbon-rich material produced through the pyrolysis process, in which organic materials such as agricultural waste or animal manure are heated under low-oxygen conditions. Chicken manure biochar offers several unique advantages in terms of both nutrition and physical properties.

Benefits of Chicken Manure Biochar

Recent studies have shown that chicken manure biochar contains high levels of phosphorus (P) and potassium (K), approximately 2–5%, which are essential nutrients for plant growth. Although it does not store nitrogen, the biochar exhibits a high pH level (between 9.2 and 12.3), making it a natural liming agent capable of neutralizing acidic soils.

Its physical characteristics are also noteworthy. With a high water absorption capacity—reaching 158–232% of its dry weight—it helps retain moisture in the soil for longer periods. This is particularly valuable for potted plants or intensive farming systems like greenhouses.

Biochar processed at temperatures between 525–725°C also demonstrates high stability, meaning it decomposes very slowly. This makes it ideal for long-term use in soils, where it can improve structure and serve as a carbon sink for extended periods.

Is It Safe for Plants?

One concern about using organic waste like chicken manure is the potential presence of heavy metals or harmful compounds. However, analysis shows that chicken manure biochar does not contain toxic substances at hazardous levels, with the exception of chromium (Cr), which may require further attention.

Additionally, the biochar has been found to be free from harmful compounds such as dioxins, furans, polycyclic aromatic hydrocarbons (PAHs), and PCBs—common byproducts of the pyrolysis process. This makes it relatively safe for use in growing media.

Why Biochar Can Replace Peat

Various materials—such as coconut coir, wood fiber, and green waste compost—have been explored as peat alternatives. However, biochar offers unique advantages, including customizability in terms of particle size, moisture content, and nutrient levels. Furthermore, it has the ability to bind heavy metals and reduce soil salinity, making it suitable for contaminated or marginal agricultural lands.

Importantly, biochar is more resistant to microbial decomposition compared to typical organic matter, meaning it remains effective in the soil for longer periods without quickly losing its benefits.

Towards More Sustainable Agriculture

With rising awareness of the environmental impacts of agriculture and the urgent need to reduce climate change contributions, chicken manure biochar stands out as a smart, eco-friendly solution. It not only reduces reliance on peat but also promotes the productive use of livestock waste—a resource often overlooked.

By integrating chicken manure biochar into growing systems, we can take a meaningful step toward regenerative agriculture and a healthier, more sustainable planet.

Discover more about SAWA’s innovative biochar production and its impact on sustainable farming.

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