128 



DRAINAGE AND IRRIGATION 



system of drainage. Miles of acres of this type of land have been 

 improved by some system of cooperation among land owners 

 and by the work of state drainage officials who are sometimes 

 authorized under certain conditions to drain the land and assess 

 the cost in the form of a tax against the owners. 



Value of Drained Land. Usually any area requiring drainage 

 is rich in plant food. The very conditions which make drainage 

 desirable have brought to the areas an abundance of plant food 

 and organic matter during past ages. When soils are very rich and 

 conditions may be made favorable for the production of enormous 

 crops of high money value, by simply draining them, the results of 

 drainage may be very profitable. The amount of profit which 

 may result from the drainage of land is dependent upon the kind 



FIG. 84. Students may have practice in surveying for drainage lines. 



of crops which the owner may desire to grow and the facilities 

 for marketing such crops. Very often the soil after being drained 

 is well suited to the growth of* market garden crops, such as 

 cauliflower, celery, spinach, onions and cabbage. If the railroad 

 or other facilities for marketing such valuable crops are favorable, 

 the money expended in draining the land will be amply repaid. 

 On the other hand, if the area is to be used for a general farm crop, 

 and if the cost of drainage per acre is found by calculation to be 

 very great, the project would probably not be a profitable one. 



Profits from Drainage. Several things must be considered in 

 determining the cost of draining a given area. This should always 

 be determined as closely as possible before the work is undertaken. 

 By the use of the carpenter's level or an inexpensive farm level 

 (Fig. 84), any one can determine whether or not drainage is pos- 

 sible. In doing this the distance for each line of drain may be 



