HOW TO CARE FOR SOIL 329 



dam is the low diversion dam which turns the water 

 through a tunnel 3^ miles long into the main canal, 

 which can supply water for 164,122 acres of land. 



The crops grown on the Shoshone lands are alfalfa, hay, 

 wheat, oats, barley, potatoes, sugar beets, fruits, and 

 green vegetables. Dairying and bee culture are also 

 increasing, the products having a high market value. 



226. Effect of Sun's Heat on the Soil. The sun warms 

 the soil so that it is possible for plants to grow; it also 

 causes excess water to evaporate. While this evaporation 

 is taking place rapidly, the soil is not warmed very much. 

 If the soil is not properly cared for, the sun's heat will 

 evaporate the water that should be retained for the crops. 



If the soil that has a high per cent of clay, or is all clay, 

 is plowed while wet, instead of moist, the sunshine will 

 dry it so quickly on the surface that it will become very 

 hard, and it is then very difficult to pulverize it, and it 

 also often loses much of its fertility. Sandy soil, or soil 

 with a large amount of humus in it, will not be easily 

 baked by hot sunshine. 



Clay soil, if it is not stirred on the surface after a rain, 

 will dry hard and crack. These cracks, running in all 

 directions over the surface, permit the soil water to 

 evaporate rapidly and in a few days the crop will be 

 suffering because of insufficient water. Clay soils should 

 be stirred on the surface as soon as dry enough after each 

 rain and the water will be held for the use of the crop. 



227. Erosion. Erosion is a wearing away of the land 

 by the wind and water. You have seen clouds of dust 

 in the streets of cities and on country roads or even in 

 dry fields. This dust may not appear to amount to very 

 much, but tons of solid matter are moved from place 

 to place by strong winds, even in climates of moderate 



