Dear Richard Haard,
> Thank you very much for your reply, Dr Reddy. Your protocol for preparing biochar has been an inspiration to myself and I am sure others. My own tests begun in 2007 did not pretreat the char but showed a synergism with compost additive through 2009 crop year, even though the project had several problems.
> You mentioned both biochar compost, and biochar only applications.
Yes there are two methods of application of Biochar, which can be discussed under four categories.
Biochar compost Application
Point - eg. Horticulture
Spread - eg. Paddy
Biochar compost preparation practice
1. Biochar + compost + green mulch + soil microbes + (pottery shards / fish bones / brick pieces / etc.)
2. Addition of biochar to Farm Yard Manure pits in small quantities every day from traditional stoves - a traditional practice most common in India. The composition is (Cattle dung, cattle urine, straw, biochar, ash, pottery shards, pottery tile pieces, etc.)
Biochar only application
Point - Biochar mulching - eg. Horticulture
Spread - Biochar broadcasting - eg. paddy
Biochar Prepartion methods - Many.
> How much biochar are you using in relation to biochar compost ?
3% to 5% biochar by weight is suitable for red soils, more biochar application is bad for soil worms and the results are not so explicit. I prefer application of biochar in small pieces rather than powder form. Yes, there is need to do lots of experiments to arrive the figures for various types of soils.
> Do you have recommendation for using VA mycorrhizae?
> Are growers in India using trap crops to avoid need to purchase VA inoculum?
I have not done any experiments yet. Yes, we do have trap crops.
> We are temperate climate here and now entering winter season. I have a small growth chamber and am attempting to study microbial succession on charcoal. This paper describes a study using wood baits resulting in a well defined, 3 seral stages in colonization of wood by fungi.
> Kodsueb, R., McKenzie, E.H.C., Lumyong, S. and Hyde, K.D. (2008). Fungal succession on woody litter of Magnolia liliifera (Magnoliaceae). Fungal Diversity 30: 55-72.
> I am wondering about sequential habitat preparation of biochar for beneficial microbes before the aggressive heterotrophs come in with soil/compost additives.
I am just a learner in this area, you are doing great experiments, I look forward for your successful experiments and results.
In Asian countries, rice husk charcoal which can be carbonized by simple methods in field soon after harvesting has been one of the most common materials for soil amendment. It seems that rice husk charcoal has been used for several thousand years since the beginning of rice cultivation in Asia, because rice husk with high content of silica is decomposed a little in soil and useless as a compost material.