18 BULLETIN 1031, U. S. DEPARTMENT OF AGRICULTURE. 
plan of management in order to avoid local overstocking to the 
detriment of stock and range. 
The possible extent of this local variation in precipitation is ap-_ 
parent from observations at the Jornada Range Reserve and vicinity 
from 1915 to 1919. In 1918 four additional rain-measuring stations 
were established on the reserve at distances of 7 to 13 miles apart. 
Table 5 shows precipitation at these stations in addition to the head- 
quarters and State College stations. 
TABLE 5.—Annual and seasonal (July, August, and September) precipitation for 
New Mezxico State Agricultural College and five rain stations on the Jornada 
Range Reserve, showing variation in amount within comparatively short 
distances. 
aE Lena South Well. | Red Lake. | West Well. | Ropes Spring. 
Year. IPS ae SSI aoe OD : 
An- | Sea- | An- | Sea- | An- | Sea- | An- | Sea- | An- | Sea- | An- | Sea- 
nual. | sonal.} nual. | sonal. } nual. | sona?.| nual. | sonal.| nual. | sonal.| nual. | sonal. 
Inches.| Inches.| Inches.| Inches.| Inches.| Inches.| Inches.| Inches.| Inches.\| Inches.| Inches.| Inches. 
ON UG a ea es Seu E38 4.67 |}17. 41 ASG: sts, heratscelle cs coec cles | em tare secession rere eset erect aoe epee | 
1OLGR eee TAA Beth tar’ ae (Wa ta So a panto yl [epee ae call ee cen J) BI yaa | Pega a ee Be Ps ee yuna ev Bg 
ie ee eee 5. 58 4.91 3. 54 PFC ae ny een | emer) Wee Aa a Sn ren a I ee ee ee ee eee ee lee Dk os 
TO) Eee SERS ete 7.23 Zed: 8.76 4.41 5.47 2. 39 7.06 3. 88 5. 87 3. 16 8. 89 3.70 
LQG ss a be 8. 05 4.20 | 12.78 8. 20 Us 4.67 | 11.52 6. 42 7.91 4.96 | 16.37 5. 85 
1 Approximate. 
Although no precipitation records are available, it is known from 
observations that the range unit adjoining the reserve on the south 
received more precipitation during 1917, a year of the recent drought, 
than fell on the reserve. In 1919, however, it probably received less 
precipitation than the reserve by an amount sufficient to make a dif- 
ference in the current year’s forage and in recuperation of range. 
The range unit north of the reserve received earlier rains and a 
greater total precipitation than the reserve in 1918 and 1919, a dif- 
ference of sufficient importance to warrant a change from the pre- 
arranged plan of grazing the unit. 
This possible variation is pointed out merely as one of many 
warnings against too heavy stocking of a range unit as a whole or a 
plan of management which is not reasonably flexible to meet such 
a situation by shifting stock from a local dry area to one of more 
abundant rainfall without disarranging the whole plan. 
VARIATION IN FORAGE PRODUCTION. 
Some measure of the volume of range forage which may be figured 
on seasonally, annually, and over a period of years, and the main 
factors responsible for variation, are fundamental in deciding the 
classes, numbers, and management of live stock. Drought and im- 
