A Proposal for Technology That Farmers in Sub-Sahara African Countries Who Have Few Capital Acquire Soil Hardening Material

Import of rice is increasing and production increase of rice is required from a viewpoint of food security in sub-Sahara Africa. Although an irrigation paddy field is effective in production increase of rice, many canals are unlined, a sudden heavy rain etc. erode them, and a water supply function deteriorates. For this reason, the structure of suppressing erosion is required. But firm reinforcement by cement etc. cannot be performed, since farmers do not have sufficient capital. Then, how to generate a soil hardening material (calcium oxide) easily from the shell (calcium carbonate) was examined as a low cost canal reinforcement measure which farmers can implement. As a result, 800 degree C required for calcium oxide generation was obtained using kiln with covering the upper part which can be easily constructed on site. Moreover, it turned out that a calcium oxide can be efficiently obtained by performing two-step burning. Furthermore, it found that the production cost of a kiln is equivalent to five bags (50 kg per bag) of cement.