PROBLEM TO BE SOLVED: To improve plant growth by enhancing saccharification with photosynthesis by which carbon dioxide is extracted from water for cultivation of fish and shellfish, and the carbon dioxide is supplied to a plant cultivation chamber and absorbed to plants.SOLUTION: A plant cultivation method comprises the steps of: extracting carbon dioxide from water for cultivation of fish and shellfish； mixing the carbon dioxide with air so as to set a concentration of carbon dioxide to a constant concentration of 3 vol.% or less； and supplying air having carbon dioxide higher than that in atmosphere to a plant cultivation chamber and circulating the air. The concentration of carbon dioxide is measured, and the carbon dioxide extracted from the water for cultivation of fish and shellfish is automatically supplied when the concentration of carbon dioxide is equal to or less than the constant concentration.SELECTED DRAWING: Figure 1【課題】 本発明は、魚介類の養殖水から二酸化炭素を抽出し、植物栽培室に供給して、植物に吸収させ、光合成により糖化を高め、植物の生育を向上させることを目的としている。【解決手段】 魚介類の養殖水から二酸化炭素を抽出する工程と、該二酸化炭素を空気中に混合して３容積％以下の定濃度とする工程と、二酸化炭素を自然値より多く含む空気を、植物栽培室に供給循環させる工程と、二酸化炭素の濃度を計測し、定濃度以下を検知した時には、魚介類養殖水由来の二酸化炭素を自動的に補填供給することからなる植物栽培方法。【選択図】 図１
