I have been making char and using IBC totes for irrigation. They work well as the volume fills any swale or small canal on my 3 acres.

The Char mixed with silt and clay (basically the sifted desert soil) gets put in the IBC tote with water. Sometimes I aerate them sometimes not. Algae grows in them adding to the organic matter along with the small biochar slurry.

Pretty low tech, but still effective at getting some carbon and life in the soil where none is.