26 



BULLETIN 367, U. S. DEPARTMENT OF AGRICULTURE. 



of the first year. Since the first cutting always contains some old 

 grass, the actual reduction of forage due to repeated cutting is less 

 than the amount indicated, but is certainly quite large. 



Evidence not c|uite so conclusive is shown by the cuttings made by 

 Mr. Proctor on the larger areas, probably less conclusive because it 

 has been his habit to cut over some ground each year that had not 

 been mowed before. Records for 1911 on the 29.9 acres were not 

 obtained, because considerable of the hay was spoiled by rain. The 

 average production in 1912 of 21.5 acres (most of which had been 

 mowed the two previous seasons) was 688 pounds per acre. In 1913, 

 9.8 acres of this same land gaA'e 669 pounds per acre, while 21.9 

 acres, j)art of which had not been cut previously, gave 712 pounds 

 per acre. Early in June, 1911, a fire burned all the old grass in the 

 region Proctor usually cuts, so there was no old gi'ass to be had that 

 season. The average production on the 26.88 acres that he cut that 

 year was 478 pounds per acre, which is about 100 pounds per acre 

 lower than the general average. Doubtless this was the result of the 

 fire, which was more than normally effective because growth of the 

 grass had already begun when it occurred. The records for the 

 three years show a decline in productivity, which is doubtless at- 

 tributable to continued cutting. 



The only other factor which might influence these results would 

 be the seasonal rainfall. From what has already been said about the 

 '' spotted " character of the rainfall, it f oIIoavs that our records taken 

 only a few miles away do not tell the actual facts with regard to the 

 amount of water that fell upon these areas during the different 

 growing seasons. But since the total seasonal rainfall on each plat 

 was probably closely parallel to the records obtained at MacBeath's 

 and at McCleary's, it is well to compare these figures for the dif- 

 ferent years under consideration. Since it is the seasonal rainfall 

 only that affects the amount of forage here considered, it will be im- 

 portant to note the records of precipitation for June, July, August, 

 and September, in the years 1910-1914, inclusive, as shown in 

 Table VI. 



Tap.le VI. 



-Coinparison of summer rainfall records at tivo points on the Santa 

 Rita Range Reserve, Ariz., 1910 to 19 IJf, inclusive. 



Month. 



McCleary's house. 



MacBeath's house. 



1910 



1911 



1912 



1913 



1914 



1910 



1911 



1912 



1913 



1914 



June . . . . 



0.69 



5.10 



4.41 



.51 



1.51 

 8.40 

 1.17 

 1.56 



0.56 

 8.62 

 3.49 

 



1.46 

 3.58 

 3.51 



.67 



1.55 

 4.99 

 3.79 

 1.21 



0.57 

 4.64 

 3.94 

 L02 



2.04 

 5.05 

 2.96 

 3.79 



0.27 



5.89 



3.69 



.70 



0.42 

 5.15 

 4.59 

 1.94 



3 44 



July.... 



4.09 



August 



6.48 



September 



4 08 







Total 



10.71 



12.64 



12.67 



9.22 



11.54 



10.17 



13.84 



10.55 



12.10 



18 09 







