METHOD FOR PRODUCING HERBICIDE AND FERTILIZER FOR PADDY- RICE PLANT CULTIVATION

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a herbicide and a fertilizer for paddy-rice plant cultivation with which an aquatic plant to be a herbicide and a fertilizer in a paddy-rice plant cultivation can be always in a luxuriant state in a paddy field during a paddy-rice plant cultivation and microalgae and duckweed being aquatic plants can be mass produced at a low cost while maintaining a high productivity. SOLUTION: A paddy field is divided by walls 14 and partition materials 15 to form a water reflux. Water is forcedly refluxed along the reflux route by a water wheel 16 and a carbon dioxide gas is supplied from a carbon dioxide gas feed opening 17 to water to simultaneously culture Anabaena of blue-green algae and Azolla. The cultured Anabaena of blue-green algae and Azolla are supplied as a herbicide to a paddy field 11 for paddy-rice plant cultivation during two or three months before or after rice planting in the paddy field 11 for paddy-rice plant cultivation and as a fertilizer after that. After harvesting of paddy-rice plant, the Anabaena of blue-green algae and Azolla are harvested, mixed with a compost raw material and made into a feed for fish and shellfish and used.