704 



THE IRRIGATION AGE. 



Fig. 30. Box Drain. 



shown in figure 30 may be used. Where lumber is 



high in price, it 

 will be more eco- 

 nomical t o use 

 pipe drains made 

 of either clay or 

 cement. The for- 

 mer is most fre- 

 quently used for 

 sizes ranging 

 from 4 to 8 inches 

 in diameter and 

 the latter for 

 sizes 10 inches 

 and over. The 

 clay or tile drains 

 are made 1 foot 

 in length, but in 

 using cement for 

 the larger sizes 

 the length may be increased to 2 and even 3 feet. 



The drainage of irrigated lands differs in many re- 

 spects from that common to the humid states of Iowa, 

 Illinois or 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 as the smallest desirable size. The 

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

 5 to 6 feet are 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 sim- 

 ilar to figure 31 are placed so as to facilitate cleaning the 

 tiles with suitable wire brushes. 



Growing Crops Between the Tree Rows. 



The large majority of California fruit growers do not 

 grow marketable crops between the trees. They believe 

 in clean culture, except where leguminous crops are used 

 to renovate and fertilize the soil. From the standpoint of 

 the large commercial orchard and the well-to-do pro 

 prietor, this prac- 

 tice has much to 

 recommend i t . 

 The planting of 

 such an orchard 

 is regarded as a 

 long time invest- 

 ment. Little, if 

 any, 'returns are 

 expected for the 

 first few years, 

 but when the 

 trees approach 

 maturity and are 

 in full bearing 

 the anticipated 

 profits are sup- 

 posed to compen- 

 sate the owner 

 for all the lean 

 years. Any treat- 

 men t, therefore, 

 which tends to 

 rob the soil of its 

 plant food when 

 the trees are 

 young or to re- 

 tard their growth 

 is pretty certain 

 to lessen the 

 yields and the 

 consequent prof- 

 its in later years. Prof. E. J. Wickson, director of the 

 California Experiment Station, tersely expressed the pre- 

 vailing opinion on this question in California in his work, 

 "Californa Fruits and How to Grow Them," in the fol- 

 lowing language: "All intercultures are a loan made by 

 the trees to the orchardist. The term may be long and 



need restitution to the soil of the plant food removed by 

 intercropping." 



Mr. S. W. McCulloch, who controls 150 acres of citrus 

 orchards in southern California, goes further in stating: 

 "It is always detrimental to the development of an 



Fig. 32. Orchard Showing Strawberries Between Rows of Trees. 



Fig. 31. Sand Box in Tile Line. 



orchard to grow crops between the trees. In some cases 

 the effect is not marked aside from securing less rapid 

 growth, but it will affect the crops of fruit for several 

 years and in the end nothing will be gained." 



Notwithstanding all this, the poor man must needs 

 make the loan or his children may starve. The settler on 

 a small tract set out to young trees can not afford, if his 

 means are limited, to wait four or five years for 

 the first returns. He must product crops between 



the rows, and the 

 question for him 

 to consider is 

 how this can be 

 done with the 

 least possible in- 

 jury to the trees. 

 A plentiful sup- 

 ply of water and 

 a deep rich soil 

 are the essentials 

 of intercropping. 

 In districts that 

 depend on a 

 meager rainfall of 

 15 to 20 inches 

 per annum, o r 

 where irrigation 

 water is both 

 scarce and costly, 

 the practice be- 

 comes of doubt- 

 ful value under 

 any circum- 

 stances. In most 

 of the fruit dis- 

 tricts of the West 

 water for irriga- 

 tion is still rea- 

 sonably low in 

 price, and the 

 extra amount re- 

 quired for intercropping represents but a small part of 

 the net gains from such crops. 



Shallow-rooted plants are considered the most desir- 

 able for this purpose. Squash, melons, sweet potatoes, 

 tomatoes, and peanuts are the most common in Califor- 

 (Continued on page 712.) 



