THE INFLUENCE OF THE SOIL TYPE ON THE PLANT VARIETY. 



By J. L. BuEGEss. 



Part I. 



THE PLANT ENVIRONMENT, 



Environment of any plant is composed of but two elements, namely: 

 Climate, or the combined effect of light, heat, air, moisture, etc., into 

 which the stalk rises and the leaf spreads ; and Soil, or the medium into 

 which the plant sends its roots in quest of food and drink. 



SOIL TYPE. 



In general, what the farmer terms "a kind of land" is technically 

 known as a type of soil, possessing distinct characteristics as regards 

 crop production. The soil type has, as a whole, definite texture, struc- 

 ture, color, origin, depth of soil and subsoil, topographic and drainage 

 features, organic and mineral composition, native vegetation, and natural 

 productiveness. It may be said that any factor which materially influ- 

 ences crop production on a given soil type in a given locality may be 

 considered an element serving to differentiate between the given soil 

 type and another in a distant locality, otherwise identical with the first, 

 but not influenced by the same factor in the same degree. 



The number of distinct soil types that have been recognized in differ- 

 ent parts of the country is very great. Variations in any of the above 

 characteristics may necessitate the establishment or recognition of a new 

 type. For example, allowing texture, which deals with the size of the 

 soil particles, to remain unchanged, variations in one or more of the 

 other characteristics have enabled the United States Bureau of Soils to 

 name over fifty types of clay soil; upwards of sixty different silt loam 

 soils; more than 164 sandy loam soils, etc., each type differing from the 

 others in some one or more essential qualities. 



Every farm has one or more types of soil on it. Most farmers recog- 

 nize this and, in general, soils are differentiated into types according as 

 the best farmers perceive them to have different crop values. On close 

 examination, however, most farms will reveal more types than their 

 owners have suspected to exist. The United States Bureau of Soils has 

 recognized and mapped upwards of 400 types of soil in the United 

 States and the number goes on increasing as the subjects of soil classifi- 

 cation and crop adaptation are studied more and more carefully. 



ADAPTATION TO ENVIRONMENT. 



Much has been done in this and other countries to discover- the en- 

 vironmental conditions of both plant and animal life best suited to the 

 fullest interaction of all parts of the organism. 



