VI. THE ROOT SYSTEMS OF CEREALS. 



The detailed study of the root systems of cultivated plants has been 

 grealty neglected in the past, in spite of the importance of the root 

 in the utilization of water and solutes in the soil. Comparatively too 

 much attention has been devoted to the above-ground portion of the 

 plant, and it has been all but forgotten that a large part of every crop 

 consists of the root system, which is of great importance in determining 

 yields, although out of sight. Except for the early work of King (1892) , 

 Headden (1896), Goff (1897), TenEyck (1899, 1900, 1904), and Shepherd 

 (1905), at the Wisconsin, Colorado, Kansas, and North Dakota Ag- 

 ricultural Experiment Stations, respectively, a study of the literature 

 shows that the work done on the extension and development of root 

 systems in the United States has been surprisingly little. The excel- 

 lent work by Miller (1916) on the root systems of corn and the sor- 

 ghums, and by Howard and Howard (1917) on the root development of 

 agricultural plants in India, are conclusive evidence of the great wealth 

 of both purely scientific and practical values to be obtained from a 

 thorough investigation of root habits. A summary of the literature 

 on the root systems of agricultural plants has recently been made by 

 Miller (1916a), to which the reader is referred. The purpose of these 

 studies is primarily to find the relation between the root development 

 of crop plants and the native species and to determine what correla- 

 tions, if any, exist between the two. In this way a much broader basis 

 for the use of the natural vegetation as an indicator of crop possibilities 

 can be established. A knowledge of root habits should help us to 

 select and breed varieties better adapted to the various regions de- 

 limited by the natural vegetation, since the chief limiting factor to 

 crop production is soil-moisture in the grassland area west of the 

 Missouri. 



ROOT DEVELOPMENT IN TRUE PRAIRIE. 



The root development of rye, Secale cereale, was first examined in the 

 sandy soils near Central City, Nebraska. On page 64 it has been 

 pointed out how continued overgrazing initiated the blowing of the 

 sandy soil, which, as a result of successive movements, is often some- 

 what stratified, and how it is being reclaimed by growing rye and other 

 crops, which more or less efficiently prevent soil movement (plate 10, a) . 



The development of the rye, both tops and roots, varied greatly 

 with the type of soil, the stand being thin, the stalks short, and the root 

 system meager in pure sand. Two areas were carefully selected 

 typical respectively of the better and poorer development of the crop 

 On both the crop was drilled at the rate of 56 pounds per acre early in 

 September of 1918. The plants were examined on June 6, 1919, when 

 in full bloom. A long trench was dug just within the field, where the 



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