PROBLEM TO BE SOLVED: To provide a weed control material and its usage in which a cure time is short, initial strength development is high, a labor of mowing can be reduced, and persistence of weed control and environmental protection can be secured.SOLUTION: (1) A weed control material is formed by containing Portland cement, a magnesium oxide, a calcium aluminate and soil. (2) Further, the weed control material of (1) is formed by containing gypsum. (3) The weed control material of (1) or (2) is formed such that the calcium aluminate is CaO/Al2O3, a molar ratio is 1.0-3.0, and impurities are 15 mass% or less. (4) Further, any weed control material of (1) to (3) is formed by containing a magnesium chloride and/or a magnesium sulfate. (5) The usage of the weed control material is provided in which any weed control material of (1) to (4) is spread on the ground, and is watered and covered thereupon. (6) The usage of the weed control material is provided in which any weed control material of (1) to (4) is kneaded and mixed with water, and is spread or blown on the ground for covering.SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】硬化時間が短く、初期強度発現性が高く、草刈の労力を軽減でき、防草の持続性と環境保全が確保できる防草材及びその使用方法を提供する。【解決手段】（１）ポルトランドセメント、酸化マグネシウム、カルシウムアルミネート及び土壌を含有してなる防草材、（２）さらに、石膏を含有してなる（１）の防草材、（３）カルシウムアルミネートが、ＣａＯ／Ａｌ２Ｏ３モル比１．０～３．０、不純物が１５質量％以下である（１）又は（２）の防草材、（４）さらに、塩化マグネシウム及び／又は硫酸マグネシウムを含有してなる（１）～（３）ののいずれか防草材、（５）（１）～（４）のいずれかの防草材を地面に敷き詰めてその上に散水して被覆する防草材の使用方法、（６）（１）～（４）のいずれかの防草材を水で練混ぜて地面に敷詰または吹き付けて被覆する防草材の使用方法、である。【選択図】なし
