|Sandy tropical soil has almost no CEC.|
|Black soil in the tropics with biochar.|
Charcoal in the soil can act as a retention agent, stopping nutrients, micro-fauna and fertilizers from being leached from tropical soils during heavy rainfalls. It allows organic material in the soil to build up, thereby providing plants and trees with a much better and more productive natural environment in which to grow.
|Charcoal can be made of any organic matter.|
|Note dark soil near surface - nutrients.|
|Worldwide interest in biochar is huge.|
|Clay in soil can prevent drainage too.|