136 



THE APPLE 



Methods of Irrigation 



Furrow irrigation. The usual method of irrigating orchards is 

 by means of furrows, which vary in depth, length, and distance 

 apart, but do not for this reason require different kinds of treatment. 

 The division of this subject is due rather to the means employed 

 in carrying water from the supply ditch to the furrows. In some 

 cases the distribution is effected by making openings in an earthen 

 ditch, in others by inserting wooden or iron spouts in the ditch 



Fig. 58. Head-ditch constructor 

 The use of an A-scraper in building head ditches 



banks, while in many others flumes having the desired number of 

 openings, or pipes with standpipes, divide the supply among the 

 furrows. These different means of transportation will be described 

 under their respective headings. 



Earthen head ditches. Permanent ditches at the head of orchard 

 tracts should be located by a surveyor. The proper grade depends 

 chiefly on the soil. If the soil is loose and easily eroded, a slight 

 grade is best. On the other hand, the grade must be such that the 

 velocity of the water will be sufficient to prevent the deposition 

 of silt and the growth of water plants. In ordinary soils a grade 



