148 FARM DEVELOPMENT 



drain may divert this water so as not to necessitate the 

 draining of a large area. 



The stratification of the soil where spring or seepage 

 water occurs should be studied when practicable to do so. 

 This can sometimes be done effectively by making holes 

 several feet deep in the wet area with a posthole anger. 



Lands not needing drainage. Where Nature has so 

 formed the surface of the ground that the excess of 

 water easily runs off, or has put together the particles of 

 the soil and subsoil so that the water can readily per- 

 colate downward, there is usually nothing to be gained 

 by a system of drainage. Hillsides with open subsoils 

 do not need drainage. In localities where there is not 

 a very large amount of rainfall, drainage has very little 

 effect, even in heavy soils on hillsides. 



Level lands through which water can easily percolate 

 do not need artificial drainage, since the drainage down- 

 ward is sufficient to carry off the excess water. It is 

 desirable for the water to seep through the soil, rather 

 than to run over its surface. 



Heavy lands in dry climates, whether rolling or flat, 

 usually do not need draining, or only a sufficient amount 

 to prevent flooding in case of unusual storms. Here it 

 is desirable to let the water from rains lie on the land 

 for a short time, giving it an abundance of time to be 

 absorbed, and preventing as much from running off the 

 surface as possible. The soil and subsoil are great 

 reservoirs which must be relied upon to store up water 

 to be used during periods of drought. In regions of 

 slight or irregular rainfall, it may be advisable to risk 

 the crops suffering some during wet periods, even if the 

 water stands on the fields. This water will go deep into the 

 subsoil and be held available for crops at a future time. 



Drainage and rainfall. The greater the rainfall the 

 greater need there is of drainage. In western Dakota, 

 Montana and other semi-arid districts, drainage is very 



