What term describes the amount of water present in the soil that is accessible for plants to absorb through their roots?

What term describes the amount of water present in the soil that is accessible for plants to absorb through their roots?

• A. Field capacity
• B. Moisture availability
• C. Wilting point
• D. Soil moisture deficit

Answer: (B)

The water that plants can actually use comes from the soil water held between field capacity and the wilting point. Field capacity is what remains after gravity drainage, while the wilting point is the moisture level where plants can no longer extract water. The portion between these two limits is the water available to plant roots, often called plant-available water; in the terms of the options, this is described as moisture availability. That’s why it’s the best fit: it directly refers to the portion of soil moisture that plants can access. Field capacity alone isn’t the accessible part (it marks the upper bound), and the wilting point marks the lower bound beyond which water isn’t available. Soil moisture deficit refers to how much water is lacking relative to a reference, not the accessible amount.

The water that plants can actually use comes from the soil water held between field capacity and the wilting point. Field capacity is what remains after gravity drainage, while the wilting point is the moisture level where plants can no longer extract water. The portion between these two limits is the water available to plant roots, often called plant-available water; in the terms of the options, this is described as moisture availability. That’s why it’s the best fit: it directly refers to the portion of soil moisture that plants can access. Field capacity alone isn’t the accessible part (it marks the upper bound), and the wilting point marks the lower bound beyond which water isn’t available. Soil moisture deficit refers to how much water is lacking relative to a reference, not the accessible amount.