Question

Colloids are important to soil formation because:____. group of answer choices

a. of their positive charge, which allows them to attract acidic compounds
b. they attract cations, which act as nutrients for plants
c. they allow water to move easily through the soil.
d. they allow for breaks in the soil so that water and gases can travel through.

Answer 1

Colloids in soil help attract and hold onto cations, providing essential nutrients for plants and contributing to soil’s cation exchange capacity, which buffers changes in nutrient supply.

Step-by-step explanation:

Colloids are important to soil formation because they attract cations, which act as nutrients for plants. These colloidal particles often carry a negative charge, which is essential in delivering nutrient cations to plants, such as Ca2+, K+, Na+, NH4+, and Mg2+. Colloidal particles in the soil serve as an 'ion exchange surface' and demonstrate a high cation exchange capacity, meaning that they can buffer changes in nutrient supply and are key to maintaining soil fertility and promoting healthy plant growth. These cation exchange sites can replenish minerals like potassium when plant roots absorb them, ensuring a continuous supply of nutrients in the soil solution. As a result, soils with higher cation exchange capacity are generally better for agriculture.