Which amendment raises soil pH other than lime?

Which amendment raises soil pH other than lime?

• A. Lime
• B. Sulfur
• C. Limestone
• D. Calcium carbonate

Answer: (C)

Soil pH rises when you add materials that neutralize acidity and supply basic cations. Liming materials do this by increasing calcium (and sometimes magnesium) and by reacting with hydrogen and aluminum ions in the soil, reducing acidity. Limestone is calcium carbonate, a classic liming material. When added to acidic soil, it slowly dissolves and releases calcium and carbonate, which neutralize acidity and raise pH. Although lime is the general term many gardeners use, limestone is another form of lime, just a natural one, that achieves the same pH-raising effect. Sulfur, by contrast, acidifies soil as it oxidizes to sulfuric acid, so it lowers pH rather than raises it. Calcium carbonate is also a lime source, so it fits the same category as limestone. Therefore, limestone is the amendment among the options that raises soil pH, aside from the generic lime.

Soil pH rises when you add materials that neutralize acidity and supply basic cations. Liming materials do this by increasing calcium (and sometimes magnesium) and by reacting with hydrogen and aluminum ions in the soil, reducing acidity.

Limestone is calcium carbonate, a classic liming material. When added to acidic soil, it slowly dissolves and releases calcium and carbonate, which neutralize acidity and raise pH. Although lime is the general term many gardeners use, limestone is another form of lime, just a natural one, that achieves the same pH-raising effect.

Sulfur, by contrast, acidifies soil as it oxidizes to sulfuric acid, so it lowers pH rather than raises it. Calcium carbonate is also a lime source, so it fits the same category as limestone. Therefore, limestone is the amendment among the options that raises soil pH, aside from the generic lime.