The main argument against the use of biochar as a carbon sequestration agent takes two forms: 1) opposition to large industrial applications that profit from char production, and 2) Wardel's test of carbon loss within bagged samples. The control of the former issue is likely to be productively dealt with by society rather than by worrying - if small scale systems are feasible for farmers to use as part of their normal soil management activity and the benefits to them outweigh the use of additional fertilizer and they can accumulate the energy needed to run their local operations from materials that would be respired into CO2 in a few years, all will benefit. There are a number of other factors of biochar activity in soils that have been glossed over that opponents miss in their rush to maintain the status quo. This is unfortunate because there are many other damage points produced by current systems that widespread application of effective small scale systems could correct. Even advocates as prominent as Lester Brown decry the loss of soil carbon as the cause of failed states, but he has not begun to understand the potential for biochar to ameliorate that condition. I would worry more about human population levels than industrial perfidy. The US is now facing the effects of large scale agribusiness excesses and these will be reined in by people choosing against these greed based systems. Local farms need support with effective systems. As to the second item, Danny Day suggested that placing carbon in an isolated environment where a biological population can still operate but without the normal conditions where there are many different kinds of materials for fuel is not a fair measure of what actually will happen in a soil environment. It is akin to placing a human and a mouse in a confined space for an extended period and asking whether people eat mice. Writers could do more homework before writing!

I hope this it will help you
“The Biochar Revolution” with “The Biochar Solution”
http://biochar-books.com/
It is a truly biochar Bible.
I believe this is the most beautiful holiday gift for your loved ones.