What is Biochar
Biochar is used as a soil ammendment, it is rich in carbon and can endure for centuries in the soil. It is a type of charcoal, made from biomass, biological material / plant or animal material via thermal decomposition [burn baby burn]. You'll want to avoid meats, although it is useable the best results are obtained from plant material and manure. The International Biochar Initiative defines biochar as "The solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment" in other words burnt organic mass ....
Researchers studied biochar made from manure and gave it tow thumbs up validtaing that it can improve soil properties and increase yields. They suggested a solution of chicken and cattle manure, but if you have aceess to horse manure that'll work fine . It's not advisable to use waste from carnivores such as cats and dogs.
In nature biochar is at times created by natural forces, forest fires and so forth. Pre-Columbian Amazonians made biochar by smoldering agricultural waste in pits. Early settlers called it terra preta de Indio, which is still a local name for areas of rich dark soils in the Amazonian region. They are believed to have been created by pre-Columbian Natives and abandoned after the Spanish and Portugese invasions.
Biochar will increase soil fertility in low pH acidic soils and in effect enhance agricultural productivity. It aids in retaining nutrients and water, and protects against erosion. It also provides protection against some plant diseases.
DIY Biochar - Make your own Biochar
To make biochar you do NOT want to burn organic material till it turns to ash, that being the case all you've created is ashes, ash is good for soil in most cases but is not the same as, or as good as biochar [See: Wood Ash as Fertilizer]. Bio char as previously stated is charcoal not full ash. When making biochar I like to break out the marshmallows and turn it into a family event.
One basic and simple mode of creatinging biochar is to thinly stack woody debris combined with other organic material in a shallow pit you've dug out in a garden bed. Burn it till the smoke begins to thin out, and while still burning lightly smother the fire with a thin layer of soil, letting the embers continue to burn. Allowing the embers to burn allows the gasses produced to create heat, feeding a reaction that eliminates impurities. When the gasses have been consumed, the fire is quenched leaving behind only pure Carbon. When it's ready to dowse it with water they'll still be some smoke emenating from it - like I said you aren't making ashes, but charcoal.
The charcoal you've just created will improve the soil and enhance nutrient availability for plants. Before planting come spring you'll want to work this char into the soil. Homemade biochar is sometimes laced with nutrients. You can mix it with compost or nutrient-rich organic solutions such as bone meal or fish emulsion while working it in. Over time the biochar rich soil will harbor more nutrients, but for the first season after your burn, adding some nutrients is advisable.
Biochar, in addition to being useful to gardeners is being researched for carbon sequestration, it is believed to have the potential to reduce greenhouse gases.
A more efficient method for large scale biochar production [but also more labor intensive ] is using a kiln. Large metal drums will suffice as your kiln. As my biochar production is done using the pit method, at this point I'll pass you onto another website which covers the barrel method very well ... Back to Backyard Biochar - Living Web Farms
1. Science Daily - Biochar from manure waste enhances soils
Permaculture is a philosophy of utilizing nature for the mutual benefit of both humans and the ecosystem. It involves observing natural functions and interactions of plants, birds, bees, bugs, toads, snakes, soil, rain, and all the elements and factors present in a natural setting and designing or actually redesigning them to suit our needs without destroying micro-ecosystems around us and ultimately the macro ecosystem. Permaculture Basics