THE FARGO CLAY LOAM. 7 



have been established tributary to these ditches in order still further to 

 improve the internal drainage of the soil and subsoil. None of these 

 latter installations have been in place for a sufficient period of time 

 to demonstrate fully the beneficial effects of tile drainage for the 

 Fargo clay loam. It may be said, however, that such installation of 

 proper systems of tile, not only on the Fargo clay loam, but also upon 

 other soils of this general class has been demonstrated to be followed 

 by increases in crop yields amounting to 25 or even 50 per cent above 

 the yields secured upon areas not thus treated. The beneficial effect 

 of the tile drain is most evident during seasons of excessive rainfall, 

 when crops are practically ruined upon areas of inadequate drainage, 

 while a fair to a good crop is produced where the open ditches and 

 supplementary systems of tile have been installed. Even in years 

 of normal rainfall, when the undrained soils produce their best yields, 

 the tile-drained fields are also found to produce slightly larger crops, 

 even though the yields are not so markedly superior as in years of 

 heavy precipitation. 



Even smaller increases in crop production than those which have 

 been obtained through the tile drainage of the Fargo clay loam are 

 sufficient to pay a very high rate of interest upon the investment 

 involved. The additional consideration should also be held in mind, 

 that not only does tile drainage increase the crop year after year, but 

 in years of unusually heavy rainfall drainage alone makes the produc- 

 tion of any crop possible. The drainage of the Fargo clay loam 

 through the installation of tile is still in its initial stages, and there 

 remain a number of engineering problems to be solved with regard 

 to the best depth for the laying of the tile, the size of the tile to be 

 installed, and the frequency of interval at which the tile lines are 

 to be laid. The systems already installed have also developed the 

 fact that in certain instances the seemingly homogenous subsoil mate- 

 rial undoubtedly possesses local variations in the deeper subsoil which 

 give rise to inequalities of drainage not evident from any considera- 

 tion of surface slopes, or from the consideration of the texture of the 

 surface soil and shallow subsoil. Thus the adequate drainage of the 

 Fargo clay loam constitutes an intricate and difficult problem for the 

 drainage engineer, but a problem which is of vast importance in the 

 more diversified and more profitable occupation of very extensive 

 areas of this type. 



Second only in importance to the perfection of drainage systems 

 upon the Fargo clay loam is the adoption of proper systems of crop 

 rotation. The wonderful natural fertility of this soil, its broad 

 expanse of level area, and its climatic surroundings all tended to 

 lead the pioneer farmer toward the adoption of a single small-grain 

 crop, spring wheat. In the earlier days this crop was seeded over 

 areas measured by the square mile, and was produced year after year 



