412 DRY LAND FARMING. 



than when not so managed. Farm manure not only 

 brings plant food to the soil, but it increases the vege- 

 table mold in the same, and it facilitates the liberation 

 of fertility through chemical agency. The beneficial 

 effects of manure on the soil and crops are present for 

 a much longer period in dry than in humid areas, be- 

 cause of its slower decay in the soil. When live stock 

 are kept in any considerable number on dry farms, the 

 maintenance of fertility on these will not be a very 

 serious question. 



The use of artificial fertilizers in dry areas will not 

 assume large proportions for many years to come, and 

 for the reason that the expense incurred would probably 

 be greater than the benefit accruing. There may be 

 instances in which such nitrogenous fertilizers as .nitrate 

 of soda may be applied with advantage and profit, but 

 usually nitrogen may be brought to the soil more cheap- 

 ly by growing legumes. Phosphoric acid and potash 

 will not be much needed for many years, in some in- 

 stances for an indefinite period. 



In various ways the available supply of fertility 

 may be increased without adding fertilizer to the soil 

 directly. Among these are the following: (1) Cultivating 

 the soil so as to expose it more effectively to those 

 weathering agencies which unlock inert plant foods. 

 These include sun, air, frost and rain. (2) Supplying 

 the soil with vegetable matters which in process of 

 decay produce various acid substances which act upon 

 the soil grains so as to set free more or less of the 

 plant food which they contain. Such action is present 

 in degree in the decay of all kinds of plant food in the 

 soil, whether it has been produced above or below the 

 surface of the same. (3) Keeping the soil in a condi- 

 tion so that water will move through it freely. Plant 

 food is thus dissolved to feed the plants, and though 

 carried downward it is again carried in dry areas to the 



