Soil at Meadow Orchard is very shallow as the majority of the site was previously used as tennis courts, the ground has previously been made up with a thick drainage layer of clinker under the tennis court surfacing, leaving very little topsoil.
The clinker itself can be broken up into the subsoil but that leaves us very little actual topsoil or organic matter to help prevent compaction, aid drainage and water retention in the heavy clay soil. One method of helping with these soil conditions is to add Biochar.
Our new cook stoves
As well as our Hookway Retort and Two Drum retort we now have a couple of Top-lit updraught cook stoves. A Top-lit updraught (TLUD) is a small retort for producing charcoal. In a TLUD the biomass is loaded into a drum (a 60l or 25l oil drum) and a small fire lit on top. Primary air is drawn in from small holes below the biomass, the limited supply of air or oxygen creates dense smoke, this is then mixed with secondary air pulled in from holes near the top of the vessel. The draft of secondary air ensures the complete combustion of the wood gases, creating a very efficient stove.
The benefits of a Biochar Stove
A biochar retort effectively cooks the biomass, driving out volatile organic compounds in the wood smoke, this prevents these potentially damaging greenhouse gasses from being released into the atmosphere. As well as providing a valuable soil amendment a biochar stove also provides an efficient hotplate to cook on, a small oven for baking, consuming the fraction of the wood than cooking on an open fire.