THE IRRIGATION AGE. 



209 



tree was thus kept working for nothing. It was also 

 difficult to secure in this way an even wetting of any 

 of the ground. About the center there was quite 

 certain to be too much water, and it was a long time 

 before people learned that water should never touch 

 the stem or stalk of anything if it can as well be 

 avoided. Many trees were thus injured, and the 

 orange and lemon especially suffered from gum dis- 

 ease or foot rot. 



This method also trained the roots into the form of 

 a brush, and down into the colder and more "sour'* 

 soil, instead of outward into the warm, rich topsoil. 

 It crowded them together so much that unless fully 

 supplied with fertilizers the tree would soon be starv- 

 ing. Under no circumstances could the ground about 

 the roots be well supplied with air, because they were 

 trained so far down that any loosening up of the soil 

 without destroying too many of the fibrile or feeding 

 roots was impossible. 



In spite, however, of its disadvantages, it was in 

 many respects remarkably useful, as we shall see 

 elsewhere, and, though it should not be used when 

 anything better can be had, it is by no means to be 

 despised, especially when well done. The worst irri- 

 gation thus far described generally surpassed no irri- 

 gation, and that is why people cling so persistently to 

 wrong methods. Partial success makes people ex- 

 tremely obstinate on these points. You can see in parts 

 of California to-day the basin method in its very worst 

 form in use by people who have had the best of op- 

 portunities to learn the evils of it, but still follow it at 

 a steady loss. 



The difficulty of spreading water evenly over the 

 top of the ground and the annoyance and ruin some- 

 times caused by the baking of the ground under the 

 hot sun a few days, and often only a few hours, after 

 the water was taken off, naturally led some to think of 

 applying the water beneath. Two good object lessons 

 in sub-irrigation were already at hand. There were 

 places where the water in valleys stood in a sheet 

 below at about the same leve year in and year out. 

 Marvelous corn, pumpkins and other crops grew on 

 such land. Some tracts that used to be dry were made 

 wet below by water soaking from the ditches, and 

 land that was once desert showed .wonderful fertility 

 when the water rose to a few feet from the surface. 

 In other places the soaking of water beneath the soil 

 down a slope below a small spring developed a re- 

 markable growth of vegetation during the dry sea- 

 son. In some places the same effect was found 

 where the water from the winter rains followed a 

 sheet of clay, hard-pan or even the bedrock of the 

 hills down some long, smooth slope. 



From these two things it was natural to conclude 

 that if the water could be distributed underground 

 all the annoyances of irrigation would vanish. The 



first movement of any importance in this direction 

 was a system of continuous pipe of cement and sand 

 laid in a trench and covered over. Openings were 

 madeat the proper places for the issuance of water 

 which, from that time, was supposed to do its own 

 spreading in all directions and with proper evenness. 

 This should have seemed a very violent supposition 

 to one who knew anything of water, the most contrary 

 of all things. But upon this principle was based and 

 must be based all sub-irrigation theories. All the ar- 

 rangements for the carrying and delivery of the wa- 

 ter in the pipes were good enough, though quite ex- 

 pensive, and the cry of "Eureka" went far and wide 

 in California, the only place in which it was tried to 

 any extent. 



One thing alone would have made a failure of it in 

 any country having a long, dry season. Roots will 

 enter any place where there is water or even moist- 

 ure, and there they will stay and spin threads and 

 skeins and all sorts of beautiful network. And the 

 distance they will go to indulge this taste is quite 

 wonderful. The openings of the pipes were soon stop- 

 ped by snarls of fine roots and the expense of clean- 

 ing thf>m out was so great that the system was aban- 

 doned. The roots also went through the slightest 

 crack in the body of the pipe, and as cement is sure 

 to crack sooner or later this always added to the diffi- 

 culty. 



But there were other objections which in any way 

 of applying water under ground, except for a few 

 things, seem insuperable. It is now well known that 

 though berries and some few kinds of vegetables will 

 do well on the hillside having a sheet of water sliding 

 down the bedrock or hard pan beneath, the majority 

 of things will not do as well as where the water is ap- 

 plied to the surface only with the ground open enough 

 below to carry off quickly any surplus of water. The 

 same is true of bottom or valley land irrigated by a 

 sheet of water rising from below. Alfalfa, corn and 

 some other things do very well on it. Grapes are 

 apparently not injured unless needed for wine. Pear 

 trees stand it quite well. But it is death to some 

 things, sickness to others, and more or less of an in- 

 jury to nearly all valuable products. Without very 

 expensive appliances sub-irrigation cannot be used 

 to any extent unless there is some sort of [a hardpan 

 below to hold the water. And that is exactly what 

 you do not want for most things. If there is anything 

 of that sort it should be broken through with dyna- 

 mite so as to let the surplus water out. 



Unless there are several openings for the water and 

 distributed properly over a certain space, it is nearly 

 impossible to get a uniform wetting of^the ground by 

 delivery of the water underneath. Some parts will 

 be too wet and some too dry. At the next irrigation it 

 is not certain that the same part that was wet enough 



