Abstract
It is important for the studies on the relation of soil-water system to plants that soil water holding capacity is discussed on a view of pF curves.
Fresh soil particles change their nature of water holding capacity when they are dried to air-drying state (≅pF 6) . On the contrary, before air-drying the change of soil water holding is based not one the changes of the water holding capacity but on the structural changes of soil particles. Namely, when not dried so intensely as air-drying, soil. particles do not change their nature of water holding capacity, but they gather themselves to make massive particles. As massive particles have less specific areas which hold water than individual particles, soil water holding capacity decreases on increasing a proportion of massive particles in soil.
Massive particles once gathered are not dividedd to individual ones adding water again, then soil, as. a whole, seems to decrease as much water content as specific areas decreased. But, when massive particles are dispersed by supersonic wave, they become individual ones and have same water holding capacity as fresh soil particles. Once air dried, soil particles have different nature of water holding capacity from one of particles of same fresh soil.
