56 MODERN STRAWBERRY GROWING 



4. Tile costs about ^90 per acre, where 

 they are laid in rows five feet apart, and in 

 good digging not less than $20 per acre is 

 required to lay the same; therefore too ex- 

 pensive. 



5. Rains fall from above and soak into the 

 soil, drawing air down into the soil, causing 

 the soil to be aerated. Sub-irrigation lessens 

 this process as the water does not draw so 

 much air into the soil. 



Overhead system. — ^To date, this may be 

 called the best system as it has many of the 

 advantages of the former methods and more 

 advantages of its own. It is very economi- 

 cal of labour and water, resulting in great 

 savings where these two items are costly. 



The Skinner system is typical of this 

 method, and was first used by the inventor 

 in the spring of 1897, and has been in con- 

 tinuous operation since. It was first given 

 to the public in 1904, 



The system consists of parallel lines of pipe, 

 in which are inserted especially devised 

 nozzles, located in the pipe at distances ap- 

 proximately four feet apart. The nozzle lines 

 are from forty to sixty feet apart, depending 

 upon the local conditions. The water is 



