The Properties of Ground Limestone

General Chemical Properties

• Ground limestone is basically natural calcium carbonate, which is mined as whole limestone and then ground for lawn and agricultural use. Calcium carbonate (CaCO3) is a rich source of elemental calcium that is used in antacid medications and dietary calcium supplements.The calcium furnished by the limestone used in lawns is also an important plant nutrient that stimulates proper grass growth. Ground dolomitic limestone, which is less commonly available as a lawn product, also contains magnesium carbonate, which releases magnesium, another important plant nutrient.

Alkaline Properties

• Ground limestone is a mild alkali, with a pH of about 8. When applied to soil with a pH of 6 or lower, it serves to regulate the pH by bringing it to 6.5 which is ideal for growing grass. The amount of limestone needed is determined by the type of soil and the present pH, with moister soils needing more limestone to raise the pH.

Toxicity and Other Dangers

• Ground limestone is non-toxic and non-caustic. Like all fine dusts, it can cause irritation if inhaled. It reacts with acids to release gases, so that it should be stored away from liquid acids such as muriatic (hydrochloric) acid or acid drain openers.

Appearance

• Ground limestone is a fine grayish-white dust which is light in texture. It is applied using a spreader on the setting for fine powders such as insecticide dusts.