276 



THE IRBIOATION AGE. 



through subterranean conduits, for the purpose of 

 moistening the fields in dry periods, when the spongy 

 soil of the gardens commenced to dry and crack, and 

 when the turf was not sufficiently packed to permit sur- 

 face irrigation. 



These underground conduits were so arranged as to 

 serve two purposes : to carry off drainage water, or to 

 retain it for moistening the soil. To accomplish this 

 end the pipes were cut at fixed points by a mass of clay 

 which was traversed by a drain which served as a com- 

 munication between the ends of the conduit, and which 

 could be closed by means of a movable plug or valve. 

 To cause the water to ascend or flow into the soil, it 

 sufficed to stop or plug up the tubing below the point 

 to be irrigated, and the water flowing through the drain 

 rose to its level and flowed into ground by infiltration. 



The idea was approved in England, and in 1839 

 Fellenberg's system was adopted, and irrigation by in- 

 filtration came into common use, largely, however, for 

 the purpose of flowing liquid manures through pipes to 

 fertilize the sub-soil of arable land. The system was 

 afterward enlarged and developed into a system of sub- 

 irrigation where surface irrigation could not be prac- 

 ticed. It was carried to the United States and is now 

 quite common where water is scarce, and in orchards, 

 vineyards and for deep rooted plants generally. 



SUB-IRRIGATION AND DRAINAGE COMBINED. 



In every properly arranged system of irrigation the 

 ditches or other conveyers of water are equivalent to 

 open drains devised for the purpose of flowing water 

 from the surface along lines and in directions carefully 

 surveyed. 



According to the common understanding, drainage 

 means carrying off an excess of water from swamps 

 and cold, over-moist soils for the purpose of reclaiming 

 them, or converting them into fertile fields. But since 

 irrigation plays so important a part in farm economy 

 and profitable plant culture, indeed, since it has become 

 an absolutely essential element of success in the arid 

 and sub-humid regions of the United States, and is 

 gaining ground in the humid regions, it has been dis- 

 covered through costly experience that drainage and 

 irrigation are inseparable systems. 



Originally, the pioneer farmer on arid and semi- 

 arid lands, finding none at all or very little water or 

 even moisture in the sub-soil, disregarded drainage if 

 he ever even thought of such a thing, and went on pour- 

 ing water upon the soil and into it faster than it could 

 evaporate. 



The surplus accumulated little by little, until after 

 a few years he discovered that his vines, trees and even 

 small fruits were beginning to die at the tops. Investi- 

 gation disclosed the curious fact in an arid region, that 

 there was too much water in the soil ; that a water table 

 had formed, in some cases within two and four feet of 

 the surface, and that no means of drainage having been 

 provided, this water table was constantly rising, and, in 

 the course of a very few years his land would become a 

 valueless swamp. A ridiculous thing in a rainless 

 region, but one that was quite common. 



Again, the advent of an enormous ditch or canal 

 was hailed with joy. It meant water, and water in the 

 arid regions, it must be confessed, means everything. 

 As years went on, the water in the canal was insidiously 

 working its way through the sub-soil by infiltration or 

 seepage and dissolving the deleterious alkalis in the soil 

 through which it passed, carried the solution down to 



the low lying lands, saturated them and evaporating, 

 left a whitened soil dead, so far as useful vegetation 

 was concerned. Quite naturally there was much con- 

 sternation, and various remedies were thought of. Beets 

 and sorghum, and other gross (feeding plans, were 

 recommended as alkali destroyers. Then ditches were 

 dug to carry off the seepage water from the bottom 

 lands or to prevent further infiltration from the canals. 

 An unconscious recognition of the necessity for drains. 



Still the insidious infiltration went on, and by and 

 by barren black or white patches began to appear higher 

 up the sloping land, until seepage water became the bane 

 of the irrigation farmer. Then came the idea of cement- 

 ing the great ditches to prevent seepage, a good policy 

 where water is to be transported long distances but if all 

 ditches were cemented there would be no infiltration and 

 many lands would revert to an arid condition and 

 pioneering would have to begin over again. The great 

 aim of converting arid lands into fertile, moistened 

 soil would be defeated if seepage or infiltration were to 

 be stopped entirely. 



Out of this condition grew the idea of drainage 

 systems which it was supposed would more or less ob- 

 viate the alkali trouble, but this also deprived the land 

 of seepage water from canals and ditches in which the 

 water was good irrigating water, and so wasted it. 



Scientists came to the rescue and gave the patent 

 opinion that the good water became bad by associating 

 with the deleterious elements in the soil, picking them 

 up in solution and carrying them along down to the 

 lower levels, and then backing up, on the principle that 

 it is the nature of water to seek its own level, carried up 

 the deadly ingredients to the surface, and there 

 abandoned them in a cowardly fashion and evaporated, 

 leaving alkali and other impurities behind to destroy 

 vegetation, ruin fertility. 



But this did not dishearten the farmer, for if one 

 tract of land ceased to be productive by reason of an 

 excess of alkali deposits, he selected a virgin tract out of 

 his numerous broad acres and went on as before. But 

 now he is confronted with the alkali fiend on all sides 

 in certain regions and seeks a remedy against it. The 

 demand now is for small farms, every foot of which 

 may be made productive, and be more profitable than 

 a large ranch cultivated in patches. 



Years, nay, ages ago, in other arid regions than 

 those of the United States, the same difficulties en- 

 countered by the western irrigation farmer were ex- 

 perienced and sought to be overcome by means of drain- 

 age. It was soon discovered that by drainage alone, the 

 vegetating stratum above the drain pipes no longer pre- 

 sented its natural cohesion, but dried and cracked into 

 fissures to such an extent that surface irrigating water 

 cut gullies into the soil through which it rapidly dis- 

 appeared on its way to the drains to be wasted or to 

 obstruct the drain pipes. These inconveniences were 

 grave in the case of small irrigating ditches, but were 

 aggravated when the main supply ditch or canal crossed 

 the line of drains. A remedy was sought by giving the 

 drains a steeper incline to create a strong, rapid current 

 through the pipes, or by using light conduits with ver- 

 tical wells or tubing at certain fixed points, up which the 

 excess water might rise and thus regulate the flow, or 

 again by isolating the drains and the irrigating ditches. 



In drained fields two experiments were tried : 



First. The drains were buried only about four 

 inches below the turf, and the surplus water allowed 



