THE ROOT SYSTEMS OF CEREALS. Ill 



drifts of snow (cf. p. 116). The oats had an average height of 2.2 feet, 

 which was 0.5 foot greater than the working depth of the roots; only 

 rarely did roots extend to 1.9 feet. 



About 1.5 miles further eastward, and just north of Flagler, a field of 

 Turkey Red wheat growing on sod was examined. The land had been 

 broken in the spring of the preceding year and the wheat was diilled in 

 September. The straw was very short, the maximum height scarcely 

 exceeding a foot, while considerable grain was left in the field, being too 

 short to be caught by the header. The roots were developed very much 

 as if growing in a large flowerpot, for the soil was moist onty to a depth 

 of 1.3 feet, where a very tenacious "hardpan", 0.8 foot thick, occurred. 

 Below this the soil was less compact but powdery. The dense masses of 

 compacted roots practically all ended at a depth of 1.4 feet; only a very 

 few penetrated slightly deeper. 



From these four soil examinations, none of which were made more 

 than 3 miles apart, it is clear that the depth of the "hardpan" varies 

 considerably. This frequently greatly hinders the penetration of 

 moisture and gives rise to "spotted" soil conditions. Indeed, when the 

 land is broken and farmed, local variations in the height and luxuriance 

 of the crop are often very evident, even in the same field. Shantz 

 (1911:47)has shown that in short-grass plains the run-off, even on 

 slopes having the same inclination and in areas only a few feet apart, 

 may be five times greater in one place than in another. The areas of 

 greater moisture penetration were marked by a growth of Psoralea 

 tenuiflora. When the land is broken these moist spots would have a 

 marked effect upon crop growth. Corn growing in "buffalo wallows" 

 is frequently a foot higher than that in the surrounding fields. How- 

 ever, it should be stated here that this is the only case out of 15 ex- 

 aminations made throughout the short-grass plains where the crop 

 was so shallow-rooted. Continued farming, with the use of proper 

 methods of dry-land agriculture, providing the rainfall is sufficient to 

 warrant the initial breaking of the sod, should lead to the disappearance 

 of the "hardpan" and consequent deeper moisture and root penetration. 

 Under natural conditions, as has been repeatedly pointed out in pre- 

 ceding pages, practically all species of the short-grass plains examined 

 (except the cacti, which possess water -storage organs) have extensive 

 roots which easily penetrate below the "hardpan" layer and often 

 many feet into the drier soil. Available moisture must be present, at 

 least during certain periods, to a considerable depth. This may occur 

 only during wet years of a climatic cycle. Whether living roots are 

 to be found in the deeper subsoil only during each successive wet period 

 or whether they continue to live but absorb little or no water through- 

 out the dry periods of several years (assuming that available water is 

 entirely exhausted), remains to be determined. 



