TEXTURE AND CROP RELATIONS 



79 



This means that, while sandy loams 

 a class are similar in texture, they may 

 other properties of importance in plant 

 complete series is one in which all the 

 are represented. 



Some idea of the relation of these c 

 crops is given by the following curves, 

 especially suited to the production of 

 which they are associated. 



or silt loams as 

 differ in many 

 production. A 



possible classes 



lasses of soil to 

 These soils are 

 the crops with 



7 

 CLAV 



12 3 4 5 6 



FINE GRAVEL COARSE SAND MEDIUM SAND FINE SAND VERY FINE SAND SILT 



SOIL SEPARATES 



Fig. 25. Curves showing the relation of soil texture to crop adaptation 



27. Some physical properties of arid and humid 

 soils. In discussing the formation of soils, attention 

 was directed to the effect of climate upon the process, 

 and it was noted that under arid conditions physical 

 disintegration is likely to predominate over chemical 

 decomposition, which results in an average coarser text- 

 ure of the soil. This appears especially in the greater 

 proportion of soils of the sandy and loam classes to 

 those of the silt and clay classes. 



Climate also exercises a modifying effect as between 



