02 Rural School Leaflet. 



WATER HOLDING POWER OF SOILS 



E. O. PIPPIN 



One of the most important properties of a soil is its capacity to retain 

 water. Plants require a large amount of water for their growth. They 

 build it into their tissues in large amounts, and still larger quantities 

 are evaporated by their leaves. You can see something of how much 

 water is required for this purpose by turning a cold glass jar over a grow- 

 ing plant. A quart glass fruit jar may be used to enclose the stem and 

 leaves of any of the smaller plants whether they be growing in pots 

 or in the garden. In a short time beads of water will collect on the 

 glass and run down the sides. This water has been pumped out of the 

 soil by the plant, and given off into the air through the leaves as water 

 — or invisible steam. This water carries the food from the soil into the 

 plants and distributes it to the different parts requiring nourishment. 

 This is the transfer system of the plant and the water is the carrier. 

 If the water be withheld the plants will not only become flabby and 

 weak, but they will not receive their food properly. We say they wilt. 



This wilting calls attention to the other service of water to the plant. 

 The tissues of a living plant are spong}^ and porous. In their growing 

 condition they are gorged with water so that they stand out straight 

 and stiff. It gives the crisp, fresh condition to the corn leaf, or the gera- 

 nium. If more water is evaporated than is taken in by the plant roots 

 the plant lops down, — ^w'ilts. The water acts on the leaf like the gas 

 in a balloon to hold it up. So that when a leaf wilts it means that the 

 plant is thirsty. Some idea of how much water a plant contains may be 

 gained by weighing some fresh stems and leaves as soon as they have been 

 cut. Then carefully dry them on a sheet of paper in a warm place, and 

 after a few days weigh them again. From three-fourths to five-sixths 

 of ordinary plants consist of water. The pumpkin is over ninety per 

 cent water. 



Now all these different uses require large amounts of water, all of 

 which must be supplied by the soil. For each pound of dry material 

 a plant contains, from 300 to 500 pounds of water must have been used 

 in its production. This gives some idea of the great importance of the 

 water a sbiVcan hold. If the soil retains but a small amount of water 

 it must be frequently wetted when plants are growing in it. In the 

 greenhouse or window garden this can be easily done, but in the field 

 where acres of crop must be watered the process is very laborious and 

 expensive. It is practiced in some of the very dry regions of the countrs' , 

 in which it is called irrigation. But in New York and most other parts 

 of the world plants must depend on the water held in the soil from the 

 occasional rains and snow. If the rains are far apart it is very essential 



