124 



OFFICIAL REPORT OF THE PROCEEDINGS OF THE 



one ton of dry matter. My investigations lead me to think that it takes 

 much less to raise fruit — about 200 tons of water to raise one ton 

 of oranges or lemons. Now, allowing 20,000 pounds of fruit per acre, 

 let us see how far one inch of water would take us. Oranges contain in 

 round numbers 18 per cent of solid matter and 82 per cent of water; 

 therefore, 20,000 pounds of fruit would contain 3,600 pounds of dry 

 matter. If we multiply this factor by 200, the number of pounds of 

 water it takes to raise one pound of dry fruit, and, with this result, 

 namely, 720,000, divide the total number of pounds in an annual inch 

 of water, we would get 54.5, which would represent the number of acres 

 of oranges producing 20,000 pounds of fruit per acre, that one inch per- 

 petual flow would supply, making no allowance for water put into the 

 ground by winter rains. 



Surface Irrigation. — There are four systems of surface irrigation in 

 general use in Southern California. The first method is a basin method, 

 where they cover the whole of the ground. A double furrow runs down 

 between every other row of trees, the furrow being large enough to carry 

 from 15 to 50 inches of water. Let us trace this stream starting from 

 the head ditch: The attendant breaks down the furrow enough to let 

 all the stream flow into the first basin, requiring from one to three 

 minutes to fill it, according to the size of the stream and basin. Every 

 other tree is irrigated until the last tree is reached, when the attendant 

 works back, irrigating the trees he omitted on his downward course; thus, 

 when the last tree is irrigated in both rows, the attendant is back at the 

 head ditch, where he can turn the stream between other rows without 

 loss of time. The cost of making these basins is variously estimated 

 from $1.50 to $2.50 per acre. 



The second method is also a basin method, the basins covering the 

 whole of the ground, but without furrows. The water is run into the 

 first basin until it is filled; then a portion of the lower side is broken 

 down and the water allowed to flow into the next basin; and so on down 

 through the whole row. When the last basin is filled and while the 

 water is still running, the attendant goes back to the head ditch and 

 turns the water into the next row of basins. 



The third method is where the basins are made only over a portion 

 of the ground, thus omitting to irrigate a part of the land. 



The fourth method is called the "Modern Method." It consists in 

 having a head ditch at the highest side of the orchard and running the 

 water down through small furrows to the lower end. The number of 

 furrows used varies from one to eight. It is an easy, convenient, and 

 cheap method. 



Inasmuch as the roots of trees in an orchard form a perfect network 

 through the whole soil, it is necessary to get an even distribution of the 

 required amount of water over the whole of the land, i. e., where surface 



