In the past ten years or so everyone from industrial farmers to your average gardening-enthusiast would have heard the term “biochar” at least once. It’s been touted as “black gold” by environmental scientists, claims that its benefits range from increasing the overall yield on farms, to preventing climate change.
Studies have revealed that the origins and use of biochar in agriculture stretches back thousands of years. While similar to charcoal, biochar is used as a soil amendment rather than as a fuel source. Societies within the Amazon have used biochar by mixing it into their soil in order to help improve the overall yield of farms and agricultural production.
Let’s stop for a moment and separate the sound bites from the science and ask ourselves: How useful is biochar? In the past decade or so, dozens of studies have put biochar to the test in order to better understand why it is so effective in promoting plant growth.
Here are the top two scientific reasons why you should be using biochar on your farm or in your garden:
Nitrogen loves biochar
Farmers understand how important nitrogen is to plant growth. All plants require nitrogen in order to grow healthily and produce food, as it is an essential ingredient in the photosynthesis process and the growth of all plant-life.
The problem at hand for many farmers and growers is that even with nitrogen-based fertiliser, even less than 50% of the nitrogen is taken by the crop, with much of it leached with rain and irrigation run-off, or lost as ammonia gas. While there are short-term solutions such as using chemical additives, in the long-term this is not a sustainable option as run-off and wastage from these chemicals can degrade organic soil content and the health of the crop itself.
The good news is that numerous studies have proven that biochar, especially that made from plant material, can drastically reduce the amount of nitrogen run-off within the soil. Basically, biochar keeps nitrogen in your soil for longer. Allowing growers to become less dependent on chemical solutions, and ensure that crops are getting the nutrients essential to their growth.
Biochar keeps your soil wet
Ever since the dawn of the agricultural age farmers have been looking for ways to become more efficient with their water usage, from developing sophisticated irrigation systems to creating new types of fertilisers. This is especially important in drought-prone countries like Australia.
One of the great benefits of biochar when mixed with soil is that it significantly increases soil moisture retention. This is generally attributable to the porous nature of biochar. While the microscopic holes, or micropores dotted throughout biochar might not seem like much, they can actually make a huge impact on a crop’s growth. Not only do these pores help trap water in the soil for longer, they retain nutrients to make them more accessible to plants and they also act as a habitat for beneficial microbes.
Studies have consistently shown that adding biochar to soil increases a plant’s drought tolerance and leads to greater resistance of leaf and root diseases.