The present invention provides a highly versatile farmland improvement method that can improve the soil environment of farmland on a large scale at low cost. [Solution] Agricultural land improvement method is to mix soil improvement material containing woody crude fiber produced by adding fulvic acid or humic acid in the process of blasting woody material into the farmland where nitrous oxide is generated, It is characterized by reducing dinitrogen monoxide. [Selection] Figure 3【課題】低コストで、大規模に農地の土壌環境を改善することができる、汎用性の高い農地改善手法をもたらす。【解決手段】農地改善手法は、フルボ酸又はフミン酸を木質資材の爆砕処理の過程で加えることで製造される木質粗繊維を含む土壌改善資材を一酸化二窒素が発生する農地に混合し、一酸化二窒素を減少させることを特徴とする。【選択図】図３
