(=) Soil water-storage capcity 1、 Water deepth(D) Dy=horD0=∑h 2、 Water fang(方)(m3) VFang ha =1od VEang/mu(亩=23D
（三）Soil water-storage capcity 2、Water fang(方)（ m3） VFang/ h a =10Dw VFang/mu(亩)＝2/3Dw 1、Water deepth（DW） DW =V·h or D h w i n i ,100 1 1 = • = mm
Estimating water contents Gravimetric method: The soil sample is dried in an oven at 105 C and the mass of dry soil recorded Neutron scattering method ime Domain Reflectometry(TDR)
三、Estimating water contents • Gravimetric method: The soil sample is dried in an oven at 105°C and the mass of dry soil recorded. • Neutron scattering method • Time Domain Reflectometry (TDR)
Section 2 Soil Water Potential Total soil water potential and individual potentials Soil Soil B Sand Clay Soil Soil 10 150 Where does water flow?
Section 2 Soil Water Potential 一、 Total soil water potential and individual potentials Soil A Sand Soil 10% Soil B Clay Soil 15% Where does water flow?
Water moves from areas of high potential (wet soil : -2 or-4) to areas of low potential (dry soil -8) 7 8 Root Soil
Water moves from areas of high potential (wet soil : -2 or -4) to areas of low potential (dry soil -8) Root Soil Soil -7 -2 -3 -.4 -8