南京农业大学：《土壤学》（双语版） Charter 5 Soil Water

Charter 5 Soil Water

Charter 5 Soil Water

Section 1 The types of soil water and measuring soil moistueeeaoi

Section 1 The types of soil water and measuring soil moisture content

The importance of soil water Effect on soil formation,erosion, and structure stability It is the ma jor constituent of plant protoplasm It is essential for photosynthesis and conversion of starches to sugar It is the solvent in which nutrients move into and through plant parts

The importance of soil water： • Effect on soil formation,erosion, and structure stability • It is the major constituent of plant protoplasm. • It is essential for photosynthesis and conversion of starches to sugar . •It is the solvent in which nutrients move into and through plant parts

The types and available of soil moisture 1 Classification of soil water Adsorbed water Membranous water Capillary water ● Numerical Gravitational water method

一、The types and available of soil moisture 1、Classification of soil water • Adsorbed water • Membranous water • Capillary water • Gravitational water •Numerical method

(1) Soil adsorbed water held by strong electrical forces low energy little movement- held tight by soil exists as a film unavailable to plants removed from soil by drying in an oven

（1） Soil adsorbed water ： •held by strong electrical forces - low energy •little movement- held tight by soil •exists as a film •unavailable to plants •removed from soil by drying in an oven

(2) Soil Membranous water held by hydrogen bonding liquid state in water film major source of water for plants greater energy than adhesion water

（2）Soil Membranous water ： • held by hydrogen bonding • liquid state in water film • major source of water for plants • greater energy than adhesion water

Sketch map of membranous water

Sketch map of membranous water

(3) Soil capillary water Capillary water- The water held in the capillary"or small pores of a soil usually with a tension >60 cm of water Capillary water includes capillary hanging water and capillary rise water

（3） Soil capillary water ： Capillary water-The water held in the “capillary” or small pores of a soil, usually with a tension >60 cm of water. Capillary water includes capillary hanging water and capillary rise water

Capillarity 0.1-1mm Capillarity obvious 0.05-0.1mm Capillarity strong 0.05-0.005mm Capillarity very strong 〈0.001mm Capillarity disappears Water is drawn up into the capillary tube

Capillarity： 0.1-1mm Capillarity obvious 0.05-0.1mm Capillarity strong 0.05-0.005mm Capillarity very strong 〈0.001mm Capillarity disappears Water is drawn up into the capillary tube

Capilla hanging water sketch map Soil particle

Soil particle Capillary hanging water sketch map