HORTICULTURE 119 



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 in- 

 creased 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, to obviate trouble, 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 stand- 

 point of the large commercial orchard and the well-to-do proprietor, 

 this practice has much to recommend it. The planting of such an 

 orchard is regarded as a long-time investment. 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 supposed 

 to compensate the owner for all the lean years. Any treatment, 

 therefore, which tends to rob the soil of its plant food when the trees 

 are young or to retard their growth is pretty certain to lessen the 

 yields and the consequent profits in later years. One writer tersely 

 expressed the prevailing opinion on this question in the following 

 language: "All intercultures are a loan made by the trees to the 

 orchardist. The term may be long and the rate of interest low, but 

 sooner or later the trees will need restitution to the soil of the plant 

 food removed by intercropping." 



Notwithstanding 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 produce crops between the 

 rows, and the question for him to consider is how this can be done 

 with the least possible injury to the trees. A plentiful supply of 

 water and a deep, rich soil are the essentials of intercropping. In dis- 

 tricts that depend on a meager rainfall of 15 to 20 inches per annum, 

 or where irrigation water is both scarce and costly, the practice 

 becomes of doubtful value under any circumstances. 



Shallow-rooted plants are considered the most desirable for this 

 purpose. Squash, melons, sweet potatoes, tomatoes, and peanuts are 

 the most common in California. The cultivation is done with one 

 horse and a small cultivator. A clear space 3 to 4 feet wide is left 

 on each side of the young trees. In the Verde River Valley of Ari- 

 zona, strawberries, lettuce, onions, and melons are raised in the 

 young orchards. In parts of Idaho, alfalfa fields are frequently 

 plowed under to plant trees. When this is done, berries, beans, 

 melons, onions, and tomatoes can be grown between the rows for 

 several years without any apparent injury to young trees. In north- 

 ern Colorado, raspberries, gooseberries, currants, as well as corn, 

 beans, and peas are often planted in orchards, while in southwestern 

 Kansas it is usually cabbage, melons, and sweet potatoes. 



In the young apple orchards of Hood River Valley, Oregon, 

 strawberries are frequently planted between the rows. The manager 



