46 CIRCULAR 491, U. S. DEPARTMENT OF AGRICULTURE 



Similar work was conducted by the same Division at Ardmore, 

 S. Dak., but the advantages of rotation grazing were much less 

 apparent, according to Cole and others {17). At Ardmore the rota- 

 tion pasture was divided into two parts, which did not provide an 

 opportunity for the same degree of advantage in rest periods that is 

 possible by the three-division method. Black and others (7. pp. 16, 

 18) reported as follows in 1937: 



Vegetation of the type [short-grass, composed of a high percentage of buffalo 

 grass] making up the pastures at Ardmore is not likely to be damaged if it is 

 not grazed so closely that the animals grazing it suffer severe loss in weight. 

 * * * In the last 3 years of the investigation, steers on pasture alternately 

 grazed made significantly greater gains than steers grazed on pasture contin- 

 uously at the same rate of stocking. 



Grazing investigations of this nature are also in progress at Miles 

 City, Mont., Manyberries. Alberta, and Swift Current. Saskatche- 

 wan, but practically no work of this kind has been conducted in the 

 drier parts of the central and southern Great Plains. Some grazing 

 studies are in progress at Manhattan. Kans., Fort Collins, Colo., 

 Sonora. Tex., in eastern Oklahoma, and at the Jornada Experimental 

 Range in southern New Mexico. All of these experiments are con- 

 ducted outside the so-called dust bowl. Consideration is being given 

 plans to undertake grazing investigations at Woodward, Okla., and 

 on sandy and heavy soils in the "center of the dust bowl" as well as 

 elsewhere in the drier parts of the high plains. 



Until more definite information is available, it is suggested that 

 light, deferred, and rotation grazing may be expected to promote 

 recovery on most pastures in the region, especially on sandy or semi- 

 sandy soils where the vegetation is represented in large measure by 

 tall and midtall grasses. The results of range surveys conducted in 

 the central and southern Great Plains in 1935 and 1936 (58) and 

 other work reported by Clements and Weaver (16) indicate that 

 these grasses are damaged 'more by overgrazing than the short spe- 

 cies. Since the results also showed that blue grama responds well 

 to protected grazing and is an important constituent of all "hard- 

 land" pastures, rotation grazing may be adopted as a fairly sound 

 practice on most classes of soil and vegetation in the area. The 

 rotation system employed so advantageously during the growing 

 season at Mandan may be adapted to year-long grazing in the south- 

 ern Plains. A farmer or rancher may divide his grazing area into 

 two nearly equal parts, if watering facilities permit, saving slightly 

 more than half of the area for continuous winter grazing and divid- 

 ing the remainder into three equal parts for deferred and rotation 

 grazing during the growing season. 



In reference to range improvement on the plains of western Can- 

 ada, Kirk (40. p. 30) states that— 



On the dry range lands of the short grass plains * * * over-grazing has 

 been responsible more than any other factor for the depleted condition of cer- 

 tain range areas. It seems clear also that the most economical way of restor- 

 ing depleted pastures * * * is to protect them during the spring and sum- 

 mer months and then graze them in the fall and winter after the seed has 

 been shed. If the pasture is badly depleted this method of deferred grazing 

 should be adopted for several years in succession. 



Clements and Weaver (16) challenged the commonly accepted be- 

 lief that the short grasses (buffalo grass and blue grama) were al- 



