This is the simplest and convenient method for farmers to convert the crop residue / biomass in the farm lands into Biochar http://biocharplus.blogspot.com/. 'Biochar Trench Earth Mound' / 'Staggered Biochar Trench Earth Mound' of 2 to 3 feet depth and 1.5 to 2 feet width could be made using simple tools in a agriculture fields. (deeper trenches can also be made) It is more convenient to make such trenches after ploughing the field. Trenches perpendicular to the slopes also benefit the steep sloppy areas as water harvesting means. All the crop residue otherwise burnt openly can be collected and dumped into these trenches lengthwise. More biomass can be added by pushing it with a stick. Once the trench is filled with biomass and compact, should be covered by grass / weeds / broad leaves / etc. After covering it up, soil should be spread on the trench, a lengthy mound is created. Some water could be used to make the soil compact and for sealing the mound of biomass. A small hole is left open for lighting the biomass at one end and at the other end a very small opening is left open. Once it is lit, white smoke starts emitting at the other end. Small holes to be made in a biochar lenghty trench at every 10 to 15 feet in a biochar trench and light it. Or one could create staggered trenches of 10 to 15 feet in length instead of lengthy single trenches. After 24 hours the biomass is converted into biochar, also one could see that the mound height also reduces. Any little smoke or embers should be quenched with water or covered with soil while removing the biochar from the trench.