156 THE APPLE 



and are expensive to maintain. Some of these objections can be 

 lessened, if not removed, by locating such drains along the lower 

 boundary of the tract. When this plan is followed, covered drains 

 are frequently laid among the trees and discharged into the open 

 drains. Sometimes the source and direction of the waste water 

 that is water-logging an orchard can be traced beneath the sur- 

 face. In this event it is well to try to intercept its passage before 

 it reaches the trees. This can be done by an open drain, but a 

 covered pipe drain of the required size is preferable. Where dur- 

 able lumber is cheap, box drains may be used ; where lumber is 

 high it will be more economical to use pipe drains made of either 

 clay or cement. For pipe drains ranging from 4 to 8 inches in 

 diameter, clay is most often used; for sizes 10 inches and over, 

 cement. The clay or tile drains are made 1 foot in length, but 

 for the larger sizes of cement the length may be increased to 2 

 or even 3 feet. 



The drainage of irrigated lands differs in many respects from 

 that of land in the humid states of Iowa, Illinois, and Ohio. In 

 irrigated districts the drains are larger and are laid deeper. While 

 4-inch tile drains may be used in places, 6-inch drains are to be 

 preferred, and should be considered the smallest desirable size. 

 The depth at which they are laid ranges from 4 to 7 feet, and a 

 depth of 5 or 6 feet is required for orchards. A grade of 5 feet 

 to the mile is about the least that should be used, and wherever 

 practicable it should be increased to 10 feet to the mile. 



In laying drains that are likely to become clogged with silt or 

 roots, or both, a small cable is laid in each line, and at distances 

 of 300 to 500 feet sand boxes are placed so as to facilitate cleaning 

 the tiles with suitable wire brushes. 



Drainage in unirrigated orchards. The question usually asked 

 is, What should I gain by drainage ? To become a successful 

 orchardist every fruit-grower should be familiar with the reasons 

 for soil drainage. Drainage removes from the soil the surplus 

 water, which, if allowed to remain, would be very injurious to 

 the plant because it excludes the air which contains oxygen — an 

 element that helps to make plant food available. Drainage also 

 removes the injurious salts which, if allowed to accumulate, often 

 make land unproductive. 



