An article in a magazine caught my eye the other day, scientists were looking for gardeners to take part in an experiment, the Big Biochar Experiment to be precise. I’d heard a bit about biochar but didn’t know much so out of curiosity I took a look at the website. Several days later I now have a bag of biochar soil conditioner in my kitchen waiting to be used on my allotment.
So what is biochar? Well it’s the result of heating plant material, known as biomass, in a closed container with little or no air allowed in. As the plant material is broken down half of the CO2 that the plant absorbed during it’s life is released but crucially the other half is trapped within the remains of the burning process. The potential importance of this is huge. Currently a large amount of waste from agriculture, forestry, saw mills and paper making facilities is burnt or sent to landfill. When this waste decomposes all of the CO2 trapped in the material is released into the atmosphere contributing to the rising levels of CO2 in the atmosphere. To be able to reduce this figure by half would make an enormous difference to the global need to reduce CO2 levels. Unlike other plant material, say that put in compost heaps, the carbon stored in biochar breaks down incredibly slowly, over the course of hundreds and even thousands of years.
However, this is not the only advantage of biochar and this is probably the bit that is of most interest to food producers, whether that’s on an allotment or on a farm. So far, trials have shown that biochar improves the structure of soils, aids the breakdown of pesticides, increases yields and improves root development. Biochar does this because it’s particles have a high surface area. This creates areas in the soil where beneficial fungi and other organisms thrive, it improves the water and nutrient holding capacities of the soil and raises the soil’s pH which is important as most soils gradually become more acid over time.
The use of biochar is not new though. Humans have been creating biochar for millions of years. We know how the ash and charcoal left after forest fires improves the fertility of the soil and in the Amazon early settlers created the highly fertile Terra Preta soils with a slash and burn technique. Despite this knowledge studies into the benefits on European soils are only in their early stages and this is where the Big Biochar Experiment comes in. The team of scientists behind Oxford Biochar Ltd, a not for profit organisation, want to see if biochar can be used effectively in a sustainable way. It is the first major experiment on the use of biochar in gardens and on allotments. As yet the scientists don’t have enough data to assess fully the potential benefits of biochar. And this is where us gardeners can help. To take part all you have to do is register and you will receive your own bag of biochar soil enhancer. You then create a bed 1 metre by 1 metre as a control and then 1 or more 1 metre by 1 metre beds where you incorporate the biochar. The seeds you sow in all the beds must be the same, sown at the same time and the same density. Then as the summer goes on you need to record the germination rates, health of the plants and yields. You then send this data to the scientists where they will collate and study the information. The scientists are still looking for more volunteers for the experiment so if you’re interested go to the Big Biochar Experiment where you’ll find more information about the potential benefits, how to register and what is involved in the experiment.
So now all I have to do is work out where I’m going to put the biochar and then the experiment can begin.