496 Agricultural Experiment Station, Ithaca, N. Y. 



SUMMARY. 



1. The average annual rainfall in Kew York is sufficient for the 

 growth of profitable crops. Owing to its unequal distribution and 

 to the loss of nearly one-half of it by surface drainage, crops usually 

 suffer from droughts. 



2. The first step towards conserving moisture is to put the 

 soil in such a physical condition that it will be pervious to water, 

 or afford a reservoir for it. 



3. Water exists in the soil as free, capillary or hygroscopic. 

 The free water within eighteen inches of the surface is injurious 

 to the growth of cultivated plants. The capillary water is the 

 direct source of their supply and should be conserved by all pos- 

 sible means. 



4. Capillary action of the soil depends upon the fineness of 

 its particles and the closeness of their relation to each other. In 

 coarse, loose, sandy or gravelly soils the action is weak; in fine, 

 well-compacted soils it is strong. 



5. When the capillary interstices or pores in the soil are con- 

 tinuous from the moist under soil to the surface, the moisture 

 rises uniformly and passes off into the atmosphere by evapora- 

 tion. If, however, these interstices or pores are made very much 

 larger near the surface, the moisture is arrested in its upward 

 movement, a result which is accomplished by light surface culti- 

 vation which produces a " soil mulch." This mulch of loose 

 soil answers much the same purpose as a board or carpet would 

 in cutting off the direct connection of the capillary soil with the 

 atmosphere. As soon as the soil becomes baked or encrusted, 

 the capillary connection with the atmosphere is renewed, and 

 another tillage is required to re-establish the soil mulch. 



6. A large amount of water is necessary for the plant, as its 

 food is in a very dilute solution, and water is also used in build- 

 ing plant tissue. 



7. Moisture in the soil is necessary that nitrification and de- 

 composition of organic matter may take place. Without it the 

 action by which the roots are able to corrode the solid rock and 

 set free plant food cannot take place. 



8. The distribution of rainfall cannot be controlled by any 



