🌱 Soil Profile

θ surface—
Field capacity—
Wilting point—
Wetting front—
Nutrient leach.—
van Genuchten (1980)
θ(ψ) = θr + (θs−θr)/[1+(α|ψ|)^n]^(1−1/n)
Wetting front advances by Darcy flux; nutrient leaching proportional to flux × concentration.