THE ART OF IRRIGATION. 



them, three tons of such hay are almost 

 as certain as any crop in the world. 



If allowed to grow into grain the stand 

 would make about such crops as those on 

 San Marcos. 



Where the winter -rains reach twenty 

 inches, crops of corn of thirty-five to 

 fifty bushels to the acre without a parti- 

 cle of water from any source after the 

 planting of the seed are a common sight 

 on the good uplands, while potatoes, pea- 

 nuts and all manner of garden truck, 

 with crops of pumpkins and squashes 

 quite paralyzing to a tenderfoot, and 

 other stuff too numerous to mention. 

 may be seen in thousands of places, and 

 this is not done by moisture rising from 

 any sheet water below or on fog or moist- 

 ure in the air. though cool, cloudy weather 

 for a period in the spring materially 

 helps the filling of grain, [t is done 

 entirely by the moisture m the ground 

 retained by cultivation until the roots 

 take it out. 



These instances cannot be used as 

 guides for all parts of the United States. 

 The soil of the greater part of California 

 has a great power of retaining moisture, 

 especially the adobes, and a porous sub- 

 soil very deep and holding w r ater with a 

 wonderful grip is all but universal beneath 

 the arable lands of the state. But I am 

 certain that I have seen as large crops 

 raised in Minnesota, Wisconsin and Illi- 

 nois on the sanie amount of rain w r here 

 the distribution was good, the crops well 

 put in, and the weather good for ripening 

 up the grain, but in many other sec- 

 tions that I have seen that are under- 

 laid by rock floor, or where the soil is too 

 "leachy" and will not hold moisture up 

 to the surface under cultivation, or where 

 the subsoil is too gravelly and will not 

 retain the moisture long enough, it can- 

 not be done. But the cases given to 

 prove that the amount of water needed 

 under certain conditions which are very 

 common is much less than is calculated 

 by officials from the ordinary data taken 

 from large areas where all carelessness 

 and waste are counted against w T hat is 

 the real wealth of the country. 



On the "other hand they do not prove 

 that it may not pay to use for some crops 

 double or triple the quantity. The 

 quantity needed for a fine crop of apples 

 is no test of the requirements of a fine 



crop of oranges, or lemons, nor is the 

 amount that will produce a good crop of 

 grain any criterion of the amount it will 

 pay to use if you w r ant to work an alfalfa 

 patch to its fullest capacity. But the 

 fact that the duty of water is over- 

 estimated for so many things leads us 

 to suspect that it may be for all. 



SPECIFIC INFORMATION. 



While the following figures are far 

 from perfect they are probably the best 

 attainable for I have compared notes 

 with many of the best irrigators w r ho 

 have traveled much and studied the sub- 

 ject extensively. They are pretty safe 

 for all those sections of the union wrhere 

 the soil is not too open, or the climate 

 unusually hot and dry for a long time. 

 In plenty of places less water will suffice. 

 These are the amounts delivered on the 

 land during the year and not the rate at 

 which the water is used during the irri- 

 gating season. They are also in addition 

 to the rainfall and represent average 

 years, they mean also good work, wet- 

 ting the whole ground and following it 

 up with good and continuous cultivation 

 for such things as can be cultivated. 



FRUITS. 



Under an average rainfall of twenty 

 inches, for deciduous fruits of all kinds, 

 from six to twelve acre inches. On this 

 rainfall many do not irrigate at all yet 

 raise profitable crops. But with very 

 few exceptions the profits for any year 

 except the very wet ones will be doubled 

 and often tripled where the trees are 

 very old and heavily loaded, and the 

 certainty of the crop for the next year 

 will be almost assured by one or two 

 irrigations after the fruit is taken off. 

 The best results are obtained with the 

 larger quantity of water and I nave 

 never yet seen anything damaged by a 

 foot and a half for old trees if properly 

 used. Nevertheless the average seems 

 about nine inches in depth. 



For oranges and lemons in full bear- 

 ing from one to three acre feet, the 

 average is about two. One foot is rarely 

 enough for old orange trees in full bear- 

 ing and will never give the same profits 

 that three w T ill if carefully used. The 

 wide difference is explained in the pre- 

 ceding chapters. The growers of the 



