THF IRRIGATION AGK. 



best fruit use three feet if they can 

 get it. 



FIELD AND GARDEN CROPS. 



For corn and most garden stuff six to 

 twelve acre inches, but on twenty inches 

 of rain more of these are raised without 

 water than with it. But the rule is the 

 same as for deciduous fruits above men- 

 tioned and may be taken without excep- 

 tion for almost anything that whatever 

 you can do without irrigation you can 

 far surpass with it. 



On this rainfall grain is not irrigated 

 at all except in a very few places and 

 there six acre inches seem the greatest 

 amount used. 



For alfalfa in small patches for home 

 use one to two acre feet. In large fields 

 to get a series of heavy crops from three 

 to five acre feet. 



Where the rainfall is only ten inches 

 these amounts are increased about twenty 

 per cent, except for alfalfa. Straw- 

 berries and many such things need water 

 at a rate much in excess of this, and 

 so does a lawn if sprinkled, but not if 

 flooded, but no one keeps any account of 

 the amount used for berries, lawns etc., 

 and at the w r ater company's office the 

 books show only what is taken for the 

 whole place. 



The larger figures above given repre- 

 sent much waste. Except on very por- 

 ous soil or a very hot and dry locality 

 the average of the two sets of figures is 

 enough. On many soils where the air 

 is not too hot and dry the smaller figures 

 are enough for almost anything but 

 heavy crops of alfalfa, oranges, lemons 

 or berries, provided the water is carefully 

 used and good cultivation kept up. The 

 whole subject is full of qualifications 

 that make conclusions taken from one 

 place almost worthless for the next. For 

 instance there is much alfalfa land that 

 is naturally moist and still more so open 

 that the roots will reach standing water 

 below. This w r ill give very good crops 

 without any irrigation if the gophers 

 are drowned out regularly. A six inch 

 flooding twice a year will generally do 

 this and a nine inch one is quite sure to. 

 Much of this moist land is so easily kept 

 free of gophers that one six inch flood- 

 ing a year will do, but many will put 

 live feet of water on such a soil because 

 they have it, the soil is so open that it 



drains away beneath leaving apparently 

 no bad results. The yield under such 

 watering is very heavy but it is certain 

 that no such amount of water is needed 

 on that kind of ground. 



A RAINFALL OF TEN INCHES. 



In the few parts of Southern Cali- 

 fornia where the rainfall is below ten 

 inches there is little, if any, more water 

 used than where it is ten. Where it is 

 practically nothing, as on the Mojave 

 and Colorado deserts, there is no settle- 

 ment from which any reliable data can 

 be had. But from experiments I have 

 made in a few places with the soil there, 

 from the irrigation on the few places 

 there are, from the results of overflow 

 in some years and unusual rain fall at 

 others, there is the best of reason to 

 believe that if the ground were once 

 well filled w r ith water and the subsoil 

 kept full by winter irrigation ( that is 

 put in the same condition it would be in 

 on the western slope after good winters ) 

 it would not require for the hottest and 

 driest parts, having the longest spells of 

 hot weather more than thirty per cent, 

 more summer, water than on the western 

 side of the mountains. And on all that 

 portion which lies 2,000 feet or more 

 above the sea, like much of the western 

 side of the great plains of the Mojave, 

 it would not require any more water 

 than the average of the country on the 

 Pacific Slope. I believe this principle 

 will apply to most all the desert sections 

 of the Union. The loss from the top 

 soil by the hotter sun of some of the 

 hottest parts amounts to almost nothing 

 if the soil is well cultivated. The loss 

 by the transpiration from the leaves 

 during the hotter and longer weather 

 is about all that need be considered. 

 For late fruits thisi amounts to some- 

 thing but is not so much in excess 

 of what it is in the cooler countries 

 as one would imagine. Neither is the 

 difference in the dryness of the air of 

 half as much consequence as one would 

 suppose. Thirty per cent, more water 

 will balance these anywhere if the other 

 points are attended to. The land that 

 in Arizona, New Mexico. Utah. Texas. 

 Nevada and other states now looks so 

 thirsty that a young river would hardly 

 seem enough to give drink to a farm. 

 really needs but little more summer 



