A soil has a bulk density of 1.5 g/cm³ and a particle density of 2.65 g/cm³. What is the percentage total porosity of the soil?

Total porosity (%) = [1 − (bulk density / particle density)] × 100 = [1 − (1.5 / 2.65)] × 100 = [1 − 0.566] × 100 = 0.434 × 100 = 43.4%. Option B (56.6%) is the complement error where candidates subtract porosity from 100 incorrectly. A porosity of 43.4% is typical of a moderately compacted agricultural soil.