THE ROOT SYSTEMS OF CEREALS. 103 



roots penetrated the wet, sticky subsoil to a depth of 3.4 feet, but only a 

 few reached this depth. However, the}' were very abundant to the 

 working level of 2.6 feet. The maximum lateral spread was somewhat 

 less than a foot, most of the roots penetrating more or less vertically 

 downward or running obliquely downward at such angles that surface 

 laterals were rare. The great masses of roots, their lateral spread, 

 copious branching, and depth of penetration are shown in figure 32. 

 The upland plats, located on a level tract of land about half a mile 

 distant and about 80 feet higher, were on a rather shallow Marshall 

 silt-loam underlaid at a depth of about 1.2 feet with heavy loess. 

 Physical and chemical analysis of the soil, together with its seasonal 

 water-content, may be found on page 140. Here the preceding crop 

 had been Sudan grass. The soil was double-disked to a depth of 4 

 or 5 inches just preceding planting on April 24. White Kherson oats 

 were sowed at the same rate as in the preceding case. On July 8 the 

 grain was very ripe, had an average stem-height of 2 feet, but was 

 only about two-thirds as thick as that on the lower plat. The soil 

 was fairly moist, but not wet all the way down (see table 19). Some 

 of the roots had reached a maximum depth of 4.1 feet, while a work- 

 ing depth of 3.1 feet was determined. 



The White Kherson oats examined in the fields at the State Univer- 

 sity farm were a crop in the four-year rotation scheme, being preceded 

 by corn and followed in succession by winter wheat and red clover. 

 They were planted on April 1 at the rate of about 56 pounds per acre. 

 Although the field was quite level, the soil was found to be somewhat 

 variable. In the trench dug in the oat field, the black Marshall silt- 

 loam was underlaid at a depth of 2.3 feet with a compact subsoil of 

 loess intermixed with clay. It was quite moist at all depths examined. 

 The crop had reached an average height of about 2.8 feet. The roots 

 were examined on August 12, several weeks after the grain had been 

 harvested. While some reached a maximum depth of 3.8 feet, the 

 average working depth was determined at 3.2 feet. 



The root system of Turkey Red winter wheat, Triticum cestivum, 

 was also studied in this same field on a plat about 100 feet distant. Here 

 the dark-colored silt-loam at a depth of 2.3 feet intergraded into a very 

 hard tenacious subsoil of clay intermixed with chalky spots and streaks 

 below 4 feet. The wheat, which had been preceded by oats, was sown 

 at the rate of 75 pounds per acre on September 19. At the time of 

 harvest it had reached an average height of about 3.3 feet. Roots 

 were excavated on August 12. The working depth was at 3.2 feet; not 

 many roots penetrated below 3.5 feet, although a few had a maximum 

 penetration of 4.7 feet. The abundance of roots, amount and length of 

 branching, as well as the depth of penetration, are quite variable for all 

 of the smaller cereals in different soil types and when grown under vary- 

 ing degrees of water-content. Following is a typical example of Turkey 

 Red wheat roots when grown in moist silt-loam. 



