The pF value of soil moisture, defined as $\text{pF} = \log_{10}(h)$ where $h$ is soil water tension head in cm of water, at Permanent Wilting Point ($15\text{ bar} = 15,300\text{ cm of water}$) is approximately:
Options:
(A) 4.18
(B) 2.54
(C) 7.00
(D) 0.00
Answer Key:
A
Step-by-Step Solution & Explanation
At PWP, suction is $15\text{ atmospheres} \approx 15,300\text{ cm H}_2\text{O}$. $\text{pF} = \log_{10}(15,300) \approx 4.18$. At Field Capacity ($1/3\text{ bar} \approx 340\text{ cm}$), $\text{pF} \approx 2.53$.