114 HORTICULTURE, FORESTRY, FLORICULTURE 



often not possible to obtain a fall greater than 1 inch to 100 feet, 

 while on steep slopes the fall may reach 20 inches per 100 feet. On 

 ordinary soils a grade of 3 to 4 inches is to be preferred, and where 

 the fall exceeds 8 to 10 inches to 100 feet the trees should be set out 

 in such a way as to decrease the slope of the furrows. 



The number of furrows in orchards depends on the age of the 

 trees, the space between the rows, the depth of furrow, and the char- 

 acter of the soil. Nursery stock is irrigated by one or two furrows 

 and young trees by two to four. A common spacing for shallow fur- 

 rows is 2Mj feet, while deeper furrows are made 3 to 4 feet apart. 

 The general trend of orchard practice is toward deep rather than 

 shallow furrows, a depth of 8 inches being frequently used. 



The furrowing implement most commonly used by the orchard- 

 ists of Orange County, Cal., consists of a sulky frame to which are 

 attached two or three double moldboard plows. Those who prefer a 

 small number of deep furrows use a 12 to 14 inch corn lister. A 

 simple furrower may be made by attaching an arm to a cultivator 

 and then fastening two shovels to the arm. The space between the 

 furrows is 4% feet and the depth is regulated by the lever arm of 

 the cultivator. 



Applying Water to Furrows. In the Payette Valley, Idaho, 

 200 or more miner's inches are turned into the head ditch and di- 

 vided up by means of wooden spouts into a like number of furrows. 

 On steep ground much smaller streams are used. The length of the 

 furrow varies from 300 feet on steep slopes to 600 feet and more on 

 flat slopes. The time required to moisten the soil depends on the 

 length of the furrow and the nature of the soil. 



For the most part, the furrows are made parallel to the rows 

 of trees. An arrangement of this kind is satisfactory in young or- 

 chards, but as the trees reach maturity their branches occupy more of 

 the open space between the rows and prevent the making of furrows 

 near the trees. A space of 6 to 12 feet square, according to the size 

 of the trees, is not furrowed. This space usually becomes so dry that 

 it is worthless as a feeding ground for roots. In order to moisten 

 these dry spots, a larger stream is often carried in the two furrows 

 next to each row of trees and the surplus is led across in short fur- 

 rows in the manner shown in figure 20. Instead of continuing 

 straight and cross furrows, use is frequently made of diagonal fur- 

 rows, to moisten the dry space between the trees. This last method 

 is best adapted to grades of 5 inches to the 100 feet or more. 



A method and the cost of one irrigation is described as follows : 

 The implement used to make furrows consists of three shovels at- 

 tached to a beam which is mounted on a pair of low wheels. The 

 driver sits on a riding seat and by operating a lever can regulate the 

 depth of the furrows. A man and two horses will furrow out 10 

 acres in a day. For a distance of 150 feet from the top of the orchard 

 the furrows are straight. They are then zigzagged to within 60 or 

 70 feet of the bottom, where the last three rows of trees are irrigated 

 by basins which catch the surplus. In the case described the depth 

 of furrow was 6 inches, length 800 feet, and distance apart 3 feet. A 



