THE PROPERTIES OF SOIL 33 



cultivation assuming the crop is drilled 

 so that as little water as possible shall be 

 allowed to escape into the air, except through 

 the leaves, and such water, of course, has 

 done all the work of which it is capable. 

 If, on the other hand, the soil is allowed to 

 become encrusted, water rising from the sub- 

 soil by capillarity has no difficulty in reaching 

 the surface and is uselessly evaporated into 

 the air. It may be that such loss of water 

 is increased by the growth of weeds, which 

 not only rob a crop of its food, but also 

 deprive it of a certain proportion of the 

 water which is vital to its existence. The 

 importance of water-conservation has been 

 more recognized of late years by farmers, but 

 in this respect gardeners certainly led the 

 way. Most gardeners know that the require- 

 ments of plants for moisture are almost as 

 well met by the use of the hoe as by the use 

 of the watering-can, in fact in some cases it 

 may be said that the hoe supplies water 

 more satisfactorily than the watering-can, 

 because whereas water falling from a can 

 consolidates the surface, water rising from 

 below produces no such undesirable results. 



We are apt to associate surface attraction 

 or capillarity with the vertical movement of 

 water, but the same force is equally operative 



