THE ROOT SYSTEMS OF CEREALS. 109 



tively. The rye was drilled at the rate of 30 pounds per acre about the 

 last week in September. The wheat was drilled late in August and at 

 the same rate. Both came up well in the fall. At the time of harvest 

 the rye averaged 2.3 feet in height and the wheat only 2.1 feet. The roots 

 were excavated on July 20. The very compact, chocolate brown silt- 

 loam was well filled with the abundant much-branched wheat roots to a 

 depth of 2.1 feet, while a few reached a maximum depth of 2.3 feet. 

 The rye roots reached a working level of 2.2 feet, while some penetrated 

 about 0.6 foot deeper. The soil was less compact than that in the un- 

 broken sod (plate 9, a), and was fairly moist to a depth of 6 feet. At 3.6 

 feet occurred the grayish layer locally known as "hardpan" (c/. p. 75). 



The open-mat type of buffalo and grama sod near Sterling, Colorado, 

 has already been described (p. 42 ; plate 2, a) . Five miles northwest of 

 Sterling, the soil on which a field of Turkey Red wheat was growing 

 consisted of a stiff loam slightly intermixed with sand. It was chocolate 

 brown in color and very uniform to a depth of 2.8 feet, where there was 

 a layer of gravel with some pebbles an inch in diameter, the whole con- 

 siderably intermixed with sand and rather firmly cemented together, 

 probably with compounds of calcium and magnesium. At the time of 

 examination on July 21, several weeks after harvest, the soil was quite 

 moist to the layer of gravel, which throughout its extent of about 10 

 inches was very dry, as was also the underlying sand. The soil had been 

 farmed for 7 years and cropped with wheat during 1917 and 1918. The 

 1919 crop was quite thick, and gave a good yield, the plants at maturity 

 standing 2 feet high. Many profusely branched roots, with long, 

 widely spreading laterals, penetrated the soil to a working depth of 2.7 

 feet. Only a few roots entered the hard, gravelly layer, and these 

 penetrated it only a little. It is interesting to note that in this dry 

 subsoil the old roots of buffalo grass were easily identified. They were 

 traced about a foot through the sandy layer and probably extended 

 much deeper. 



At Flagler, Colorado, about 100 miles east of Colorado Springs, the 

 vegetation is also of the short-grass type. Here, again, mats of buffalo 

 grass alternate with those of grama, leaving many intervening bare 

 areas. Buffalo grass is somewhat more abundant than the grama and 

 takes complete possession of low areas ("buffalo wallows"), where 

 the run-off water from melting snows or heavy rains collects and 

 stands. Muhlenbergia gracillima, Festuca octoflora, Aristida purpurea, 

 and in disturbed areas Schedonnardus paniculatus occur more or less 

 abundantly over the level or slightly rolling lands. These are accom- 

 panied, usually sparingly, by Psoralea tenuiflora, Gutierrezia sarothrce, 

 Opuntia camanchica, 0. polyacantha, 0. fragilis, Chrysopsis villosa, 

 Artemisia frigida, and Plantago purshii. In rougher land as along 

 small canyons, the greater water penetration is indicated not only by a 

 greater abundance and better development of most of the above herbs, 



