Soil colloids are extremely small particles found in soil that have a high surface area relative to their mass. They are composed of clay minerals, organic matter, and iron and aluminum oxides, and play a crucial role in soil fertility and nutrient availability. Colloids have a negative charge on their surface, which allows them to attract and hold onto positively charged ions like calcium, magnesium, and potassium. This helps to prevent these nutrients from leaching out of the soil, making them available for plant uptake. Colloids also play a role in soil structure and water retention, making them essential components of healthy soil.
