https://www.youtube.com/edit?ar=2&o=U&video_id=z5heaXpwdE0

Calculations:

PAW = FC – PWP

Horizon Oi:

PAW: 0.231 –  0.129 = 0.102

0.102 % water (7.62 cm) = 0.777 cm³ H₂O/cm³ soil

Horizon A:

0.187 – 0.0882 = 0.0988

0.0988 % water (22.86 cm) = 2.26 cm³ H₂O/cm³ soil

Horizons Bs1, Bs2, and Bs3:

0.162 – 0.0650 = 0.097

0.0970 % water (35.56 cm) = 3.45 cm³ H₂O/cm³ soil

Total PAW:

0.777+2.26+3.45+3.45+3.45= 13.387 cm³ H₂O/cm³ soil

The Welsh triangle estimates FC and PWP based on texture. However, it does not take into account rocks and soil organic matter. These factors could change the PAW in the Bullards Soil Series. Rocks take up surface area and decrease the PAW of a soil. This soil series has relatively low rock fragments starting with 0% in the Oi horizon and increasing gradually until it reaches 25% in horizon Bs3. Organic matter increases the PAW of a soil. This soil series has some organic matter in the Oi horizon but overall does not have a great amount of organic matter.

 

Saxton, K. E., Dr. (1997, February 18). Soil Texture Triangle: Hydraulic Properties Calculator. Retrieved October 17, 2018, from
http://resources.hwb.wales.gov.uk/VTC/env-sci/module2/soils/soilwatr.htm