NORTHERN GREAT PLAINS FIELD STATION IN 1923 17 
Flies and mosquitoes were worse during July than they have been 
since the experiment started. The gains of the cattle during July 
were the lowest that have been obtained for that month. The total 
gains for the season were slightly below normal. 
Table 8 gives the average gains of the cattle for 1923 and for the 
period from 1916 to 1923, inclusive. 
The botanical studies in connection with the experiments were 
conducted along the same general lines as during previous years. The 
number of plants of pasture sage {Artemisia frigida) per unit area 
in the 30-acre pasture has increased about tenfold. This increase 
has been caused by overgrazing. The individual plants are also more 
robust in this pasture than in any of the others. There has been an 
increase in the number of plants of this sage in the 50-acre pasture 
and slight or no increase in the other pastures. Cattle do not like 
pasture sage, and they lose weight although a large quantity of it is 
available for grazing. 
The results of the grazing investigations for the period from 1916 
to 1921, inclusive, are given in more detail in another publication.* 
The follo^ving general conclusions based upon the gains of the cattle 
and the general condition of the pastures are drawn from the results 
of the grazing experiment to date: 
The 100-acre pasture, which is grazed at the rate of one steer to IQ acres, 
provides more land than is necessary to allow the maximum gain per head. The 
pasture is annually undergrazed. 
The 70-acre pasture, which is grazed at the rate of one steer to 7 acres, provides 
approximately the area of land required to produce the maximum gain per head. 
This pasture is grazed as heavily as it should be for a system of continuous grazing. 
The vegetation, however, is not utilized so completely as it can be with a different 
system of grazing. 
The 50-acre pasture, which is grazed at the rate of one steer to 5 acres, does 
not provide enough feed to produce a maximum gain per head during a period 
of five months. It is overgrazed, and this fact is shown by the decreased gains 
of the cattle and the increase of pasture sage. 
The 30-acre pasture, which is grazed at the rate of one steer to 3 acres, is too 
small to provide enough feed for the cattle for a period of five months. This 
pasture is severely overgrazed. The eflfect of overgrazing is shown by the marked 
decrease in the gain per head of the cattle as compared with the other pastures 
and the increase in the number and size of the plants of pasture sage. 
The 70-acre rotation pasture, which is grazed by a system of deferred and 
rotation grazing at the rate of one steer to 4.4 acres, provides enough feed to 
allow the cattle to make gains about 10 per cent below the maximum gains ob- 
tained in any of the other pastures. This system of grazing affords the maximum 
utilization of the vegetation without serious injury to it from overgrazing. 
The 35-acre bromegrass pasture, which was grazed at the rate of one steer to 
2.2 acres in 1923, did not provide enough feed to allow the cattle to make good 
gains. It was grazed too heavily for the season. 
< Sarvis, J. T. Effects of different systems and intensities of grazing upon the native vegetation at the 
Northern Great Plains Field Station. U. S. Dept. Agr. Bui. 1170, 45 pp., illus. 1923. 
