246 



THE IRKIQATION AGE. 



in this, as in all others, the soil must be kept open to 

 retard evaporation, otherwise constant applications of 

 water are necessary to keep plants growing. 



Where water is not obtainable from pipes and 

 hydrants, a tank on a two wheeled cart, with a pro- 

 jecting sprinkler is commonly used. In ordinary vege- 

 table gardens hand sprinklers are used, the water being 

 run into a convenient reservoir, which may be a barrel 

 sunk into the ground, and the water dipped out. With 

 one or with one sprinkler in each hand, the irrigator 

 walks along the rows, slowly sprinkling the plants with 

 water until it runs off the ground as in a rainfall. Many 

 plants are benefited by this system of irrigation. Flow- 

 ers, small bush fruits, strawberries, and even trees, the 

 spraying of water upon which washes the leaves and 

 freshens them, or as it is sometimes expressed, "gives 

 them a drink." 



In market gardens in proximity to cities, hydrant 

 water is plentiful and this is used for sprinkling or 

 any desired system of irrigation. Lawns are watered 

 by means of a rubber hose with all sorts of attachments 

 intended to scatter the water over the largest space. 

 Where windmills are in use and elevated tanks common, 

 all the advantages of hydrant water may be secured at 

 small expense, and the same is the case where the 

 farmer is so fortunate as to have an elevated acre or 

 two of ground in which to dig a catch reservoir. There 

 are some doubts as to the proper time during the day to 

 irrigate crops or plants by sprinkling. Some contend 

 that the evening or the early morning is the best time 

 while others, again, contend that it does not make any 

 difference. It does make a difference, when one stops 

 to think. In the early morning the water is chilled after 

 the hours of the night, and when water is applied after 

 sundown it becomes cold and where the water is colder 

 than the plant it is not beneficial, but stops growth. To 

 recur again to the everlasting Chinaman, whose ideas are 

 founded on centuries of success in growing anything he 

 attempts, he can be seen religiously pouring water on 

 his plants, even the most delicate, while the hot sun is 

 shining down upon them with a burning heat. One 

 looks in vain for the plants to droop and wither under 

 such treatment, for they keep on growing vigorously 

 and luxuriantly under the influence of the heat and 

 the watery vapor engendered by the heat of the sun. 



There can be no doubt that by the constant or regu- 

 lar application of water to the soil, in quantities to equal 

 evaporation, the ground will be maintained in a moist 

 condition favorable to plant growth. Moreover, there 

 is always less water required for a second application 

 than for a first one, and the quantity diminishes with 

 each application, until a modicum of water will be 

 reached and a profitable crop raised economically. Where 

 there is- no water in the subsoil, or at least none attain- 

 able by capillary motion, irrigation creates an artificial 

 one which may be drawn upon by aeration of the soil 

 by deep cultivation. Where there is a water table al- 

 ready within serviceable distance of the surface, irriga- 

 tion may be so regulated as to keep the soil open and 

 aerated by the flowing of water through it, and when 

 that object has been attained, the labor of irrigation will 

 have been reduced to an economical minimum and pro- 

 duction astonishingly increased. 



We shall have more to say on the subject of sub- 

 irrigation in a special chapter devoted to the system. 



DRAINAGE OF FARM LANDS. 



Results of Careful and Extended Investigations by the Gov- 

 ernment for the Benefit of the Fanners. 



BY C. G. ELLIOTT, 

 Expert in Drainage and Irrigation, U. S. Department of Agriculture. 



From Farmers' Bulletin No. 187, Courtesy U. S. Department of 

 Agriculture. 



(CONTINUED.) 



The capacity of drains for carrying water may be 

 computed quite accurately, but the modifying condi- 

 tions and the quantity of water it is desired to remove 

 in a given time are just as important elements in any 

 determination of the problems. Any table which can 

 be computed will apply only to the conditions assumed, 

 whereas each drain presents a problem which should 



Fig. 11. 

 Grading Scoop. 



be solved with all its peculiarities considered. The fol- 

 lowing table has been computed to serve as a guide in 

 adjusting the size of mains to the area which is to be 

 drained. Two cases only are considered one in which 

 the mains are 1,000 feet long, and the other in which 

 they are 2,000 feet long. Lateral drains should be three 

 inches and four inches in diameter. Submains or large 



Fig. 12. 

 Grading by Line and Gauge. 



branches which themselves receive the drainage of lat- 

 erals should be regarded as mains in considering their 

 The table is computed for removing one-fourth 



size. 



inch of water in depth each twenty-four hours from 

 the area drained. Should the conditions be such as to 

 require the removal of a greater depth of water in 

 twenty-four hours, a proportional reduction in the num- 



Fig. 13. 

 Tile Hook. 



ber of acres given in the table may be used ; that is, if 

 it is desired to remove one-half inch of water instead 

 of one-fourth inch, the sizes given in the table will 



