TILLING THE SOIL 



143 



powdery just like the powdered sugar. Such a layer of 

 loose soil is called a mulch. It is only by mulching that 

 the moisture can be kept in the soil. In those countries 

 in which there is very little rain in summer the farmer 

 is able to raise good crops by the proper amount of 

 mulching. 



The first illustration shows that soil which is not 

 mulched cracks open and 

 allows . evaportion to take 

 place far below the sur- 

 face. Soil under such 

 conditions will dry very 

 quickly and be of no use for farming. The second illus- 

 tration shows soil which has been properly mulched and 



the moisture preserved. 

 It is very much like the 

 cube sugar and the pow- 

 dered sugar: the lower 

 soil continues to bring up 

 water from below, while the dry mulch prevents its loss 

 when it comes near the surface. The soil must be 

 mulched soon after each rain, as the water opens the 

 pores of the former mulch and causes it to be of no use. 



Tilling, as has been noted, kills weeds. This is 

 accomplished by the tearing up of the weeds and saves a 

 large amount of water. Weeds, like other plants, use 

 vast quantities of water but they give no return to the 

 farmer. Thus all the water which weeds use is a total 

 loss to the farm. Weeds should be killed for other reasons, 

 the chief one being that they are liable to kill the crops 

 and their seed or stalks may spoil some crops. 



Cuts supplied by the International Harvester Co. 



