Show scientific CULTURE OF SOIL interesting paragraphs taken from prof Tin article on an soil moisture daffe different rent terms that the philosophy of scientific sol soil culture may inny be thoroughly understood the following paragraphs are from an article written by prof J D tinsley of the new mexico experiment exper imen station water in the soil may tako take the form of free water capillary water or hygroscopic water tree free water Is water under the influence luence Int of gravity percolating through the spaces in the soil and seeking a lower and lower level ultimately it forms films around the soil particles and tills fills in the minute spaces between them in this condition it no longer tends to sink deeper into the ground it la is no longer influenced by gravity it has in fact ceased to bo be free water but has become capillary water when every soil sell grain has been ca covered vered with a filmor capillary wa ter and all the spaces are filled the soil Is said to be saturated it t will hold no more moie arid and any excess is labree free water sinking deeper into the sol soil arid and saturating it to still greater depth the 1 ho capillary water Is held to the s surface of each minute grain of soil boll by the force of adhesion its tendency is to move toward the place where the soil Is drywat whether that be up lip down or horizontally this movement along the soil particles li is sim liar to the movement of oil along a lamp wick and is what Is meant when the term capillary attraction or capillarity Is used if oue one end of a small mall s tube be immersed in water it will be noticed that the liquid will rise higher in the tube than in tho the vessel in which the water Is contained this also is due to capillarity experiment shows that the smaller the tube the higher the water will rise but the larger the tube the taster faster the move ment now the soil may be imag ined as filled with multitudes of these thesa tiny tubes through gl which capillary water rises to the surface when the surface becomes dry enough to attract tr let it this fore of capillarity la Is the one thing upon which the farmer must depend to bring the water in the soil close enough to the surface to be reached by the roots of crop plants at the same time his greatest care must be to prevent the moisture from being lost by evaporation which proceeds eds with extraordinary rapidity in ili the excessively dry atmosphere of semiarid semi arid america from the capil lary water the plant roots derive their supply of water and wah it they take up the soil elements necessary to their growth the third form of soil moisture Is hygroscopic water this la Is water that cannot be dried out or re moved from the soil by natural evajo ration it is a wholly negligible quantity |