Which term describes the moisture threshold below which wilting occurs?

Which term describes the moisture threshold below which wilting occurs?

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

Answer: (C)

The moisture threshold below which wilting occurs is the wilting point. This is the soil moisture level (or the corresponding soil water potential) at which plants can no longer pull enough water from the soil to meet their transpiration needs, so their cells lose turgor and wilting starts. As soil dries, the matric potential becomes more negative, making it harder for roots to extract water; once you reach the wilting point, the plant cannot maintain turgor even if some water is present, and wilting results. The range between this point and field capacity—the moisture level after gravity drainage—represents the plant-available water: water that plants can use. Field capacity marks the upper end of this usable range, where excess water has drained away, while the wilting point marks the lower limit. The other terms describe different concepts: soil moisture deficit is how much water is lacking relative to field capacity, and soil moisture recharge is the process of soil rewetting after drying.

The moisture threshold below which wilting occurs is the wilting point. This is the soil moisture level (or the corresponding soil water potential) at which plants can no longer pull enough water from the soil to meet their transpiration needs, so their cells lose turgor and wilting starts. As soil dries, the matric potential becomes more negative, making it harder for roots to extract water; once you reach the wilting point, the plant cannot maintain turgor even if some water is present, and wilting results. The range between this point and field capacity—the moisture level after gravity drainage—represents the plant-available water: water that plants can use. Field capacity marks the upper end of this usable range, where excess water has drained away, while the wilting point marks the lower limit. The other terms describe different concepts: soil moisture deficit is how much water is lacking relative to field capacity, and soil moisture recharge is the process of soil rewetting after drying.