94 DRY LAND FARMING 



supply of plant food in the soil in a readily available 

 form. This in dry areas may be accomplished meanwhile 

 by that high-class cultivation which will insure the abun- 

 dant liberation of fertility. 



While not very much can be done to regulate the 

 amount of water transpired by individual plants, the 

 farmer can do much to regulate the amount of water 

 taken from the soil in the aggregate, by regulating crop 

 growth, and he can increase the amount of water avail- 

 able for transpiration. He may influence the amount of 

 water that shall be taken from the soil : First, by decid- 

 ing as to the crops that he will grow, some of which take 

 more and some less moisture from the soil. Second, he 

 may regulate the thickness or the thinness of the stand 

 of the plants in a given crop. Third, when he finds that 

 a crop that has been sown inopportunely is not going to 

 prove remunerative, he should at once remove or bury 

 it, and thus stop the drain on soil moisture to no pur- 

 pose that is being made by the plants that compose the 

 crop. The amount of water available for transpiration 

 may, of course, be increased by that cultivation which 

 will encourage the entrance of water into the soil and 

 which will retard its escape when it has so entered. 

 Experiment has shown that the amount of water called 

 for to produce a pound of dry matter in various soils is 

 much greater in those that are not well cultivated than 

 in those which are. Experiments conducted in Utah 

 have proved that the summer-fallow materially reduces 

 the amount of water called for by plants as compared 

 with land that has been continuously cropped. 



As cultivation extends in dry areas and as it becomes 

 more carefully conducted, the store of moisture in the 

 soil will increase ; as the crop area increases, transpira- 

 tion through the growing of crops will also increase. 

 To such an extent will this increase prevail, that it should 

 exercise a material influence by increasing the humidity 



