Arizona Agricultural Experiment Station 577 



CHARACTER OF ARIZONA RAINFALL 



The character of the rainfall for the two years just ended 

 is, in general, what stockmen should count upon and plan for 

 in the future, if their business is to be run on a moderately 

 safe basis — very heavy for one year and very light for the 

 following year or two years. In the proper sense of the term 

 we do not have in Arizona what may be called a "normal" rain- 

 fall. The rainfall for one year cannot be taken as any indi- 

 cation of what may be expected the next year. Years of aver- 

 age rainfall may be followed by dry years or wet years. The 

 rainfall at Tucson for the year ended June 30, 1920, was 20.54 

 inches or more than three times the amount for the twelve 

 months just closed. The former was the heaviest annual rain- 

 fall for this location during a perior of thirty-nine years, the 

 latter the lightest rainfall over a period of seventeen years. 

 Other years or seasons within the memory of Arizona stock- 

 men that were nearly or quite as dry as the one just ended, 

 with the usual heavy losses of stock from starvation, are as 

 follows: 1894-1895, with a rainfall at Tucson of 5.65 inches; 

 1899-1900, with a rainfall at Tucson of 7.42 inches ; 1901-1902, 

 with a rainfall at Tucson of 6.99 inches; and 1903-1904, with 

 a rainfall at Tucson of 6.26 inches. 



BROWSE PASTURES VERSUS GRASS PASTURES 



The present drought has taught some good lessons relative 

 to forage conservation during periods of abundant feed and to 

 the classes of grazing ranges that in the long run are most 

 desirable for general grazing purposes. Losses of stock were 

 relatively light and in addition the animals mostly came 

 through the year in fair condition on ranges having a growth 

 of browse plants along with the usual growth of grass and mis- 

 cellaneous herbs or weeds. This was noticed on ranges in 

 southern Arizona where such plants as scrub-oak, mesquite, 

 cat's-claw, mesquitilla or ramita (Calliandra), deer browse 

 (Cercocarpus), and bear grass (Nolina) were abundant; also 

 on grazing ranges in central and northern Arizona, in particu- 

 lar, those about Mayer, Prescott, Payson, and Grand Canyon, 

 where the growth of such shrubs and small trees as scrub- 

 oak, {Quercus turbinella), post-oak (Quercus utahensis) and 

 (Q. submollis), mulberry {Moms celtidifolia) , hackberry or 

 palo bianco (Celtis reticulata), Apache plume (Fallugm para- 

 doxa), cliff rose or quinine bush (Cowania Stansburiana) , deer 



