834 



IRRIGATION 



throwing up slight riiiges, with a pluw or other imple- 

 ment, and tile water turned into these basins in succes- 

 sion and allowed to accumulate to a sufficient extent. 

 This method is particularly applicable to fru t t ees 

 although it is occasionally used in other crops In very 

 sandy soils the water is occasionally cir e 1 tl ro ^1 

 the field in wooden troughs, which a 1 t ot 11 t 



seepage to water the land. This pr t tl e 1 



seepage which might occur in such so 1 t tl t 



flowed over the surface. Another metl J to I 

 tribute the water through the field n ir u p pes v. th 

 openings at frequent intervals, in wh ch nozzles can be 

 attached to deliver a fine spray over a small area W th 

 four or five such nozzles an attendant can water a con 

 siderable area of ground in the co rse of a day Such 

 an irrigating outfit in Florida was supplied with a 

 power equivalent to about one horsepower per acre. 

 The mains and laterals were of 1-inch or IK-inch iron 

 pipes laid near the surface of the ground, the laterals 

 about 100 feet apart, with hydrants every 50 feet. 

 Tanks were originally used, but it was found desirable 

 to pump directly into the mains to insure a sufficient 

 pressure. 



Care should be exercised in applying water to the 

 land. Where water is plentiful there is a common prac- 

 tice of using such an excess as to injure the flavor of 

 fruit, increase the liability of disease, and eventually in- 

 jure the land by the accumulation of seepage waters and 

 of alkali. As a rule, there has been very much more 

 damage from over-irrigation than from the use of too 

 little water. The first two or three years a soil usually 

 requires a considerable amount of water, but after be- 

 coming well moistened to a considerable depth it should 

 require comparatively little water thereafter to maintain 

 its fertility. As it is not easy to apply just the proper 

 amount, the excess should be provided for. If there is 

 any reason to fear lack of drainage, the land should be 

 thoroughly underdrained before Irrigation is started, or 

 at any subsequent time when the need of it becomes 

 apparent. 



Irrigation always should be supplemented by the 

 most thorough cultivation. After going to the expense 

 of watering the soil in this way, it is poor economy to 

 allow the water to escape by evaporation or otherwise; 

 therefore every precaution should be used in thorough, 

 subsequent cultivation and in the exclusion of weeds, 

 to conserve the moisture so applied. The intelligent 

 horticulturist will find that in the use of this expensive 

 method of maintaining a proper water supply in the 

 soil, it is incumbent upon him, even more than if the 

 method were not used, to give careful attention to all 

 the ordinary methods of preparation and cultivation in 

 order to maintain the advantages he has established by 

 the Irrigation plant. Milton Whitney. 



SuB-iREiOATioN IN THE GREENHOUSE.— The term sub- 

 irrigation is used to describe a method of supplying 

 water to the roots of plants by means of some form of 

 conduit placed below the surface of the soil. In green- 

 house operations, the essential features of the plan are 

 a level, water-tight bench-bottom, and tile or pipes to 

 serve as conduits for the water. The tile, or pipes, are 

 laid diiT.ilv (m iln l.rm'h bottom, and over these the 

 soil i^ M ■' ' ' i i' I" the depth of about 6 inches. 

 When ^^ ■ : I '.hiced in sufficient quantities 



throu^li 111. Hi. r [.i|i."-,it passes out at the joints or 

 perforaliuus ml., ilic ^uil. 



When applied to greenhouse operations, the term sub- 

 watering has been proposed by Gofif and Cranefield for 

 the reason that Irrigation is used to denote watering on a 

 large scale out-of-doors. It may be said, however, that 

 the words watering and Irrigation do not indicate the 

 scale of operations with any degree of accuracy, hence 

 it seems as well to use an old word as to coin one, es- 

 pecially when the familiar word expresses the meaning 

 intended. 



Experiments in watering plants by this method were 

 begun in the winter of 1890 and 1891, at the Ohio Ex- 

 periment Station. The suggestion came from the re- 

 sult obtained in nn offnrt to check the lettuce rot. Water 

 was intro.hic.d to tlie soil in boxes by means of a pipe, 

 in a similar iiianin r t.> the method often employed in 

 watering hilN ..f iiulons and cucumbers. When the 

 plants were watered in this manner, the lettuce showed 



IRRIGATION 



BO much more vigor than that watered in the ordinary 

 way that operations were begun at once on a larger scale : 

 first in a bed on the ground having a clay bottom, then 

 on a ater t ght ben h ua le of 1 1 er ai d finally on 



I tect apart 



t eld have 



f,hto 



I 1 in ze 1 



1 1 1 1 1 1 I \ I I I re 1 off 



the corn till t 1 tl e flow of 



water 11 1 I I I 1 ) 1 1 j u ng 



com uon 1 111 1 tl co^ r ng 



the ent re ben h I otto tea I of a 1 i oft le e-( ery 



2 feet, as at first. 



Benches made of lumber have proved unsatisfactory 

 because of the swelling .ind warping of the lin.irds. 

 Solid beds on the gi-.niTvl hrv,- vt h. . -i .:,,-,■, -ufi,l. ex- 

 cept where an imii.T'-.':- . I ■ i,..'...M. , .-.,,! i,:.ha- 

 nized-iron adds gn ;i: . in.l 



lasts only a short t.. i ■ : i..r 



greenhouse sub-irri;:,.! i- .-n.' in;..].' .t iimi. luils 



which are not acted upon by watir. 



A well-made tile- and cement-bench seems to be the 

 only form of construction that will meet the require- 

 ments. Such a bench does not ci.st so niiich as to pre- 

 clude its use, and nil! l::-t n- h ir: ..^ ;iii\ ..iIjit part of 

 the greenhouse. In .i' - ;: ! :. i . ' . li. it will not 



be necessary to ent. I ■ ' .. i n. 1 1 as relate 



to the method of wai. i in n i .i i . n - - !..ii. The bench 



must be water-tiglit, ur marli .s... aii.l iiii> condition is 

 secured by spreading a layer of cement, an inch or more 

 in thickness, over the tile bottom. It is not a matter oi; 

 any moment whether flat tile or common drain-tile are 

 used, except in the quantity of cement required. The 

 cement must be spread with care, so as to secure a per- 

 fectly flat, level bottom, otherwise the water will not 

 flow uniformly in all directions. The sides of the 

 benches are made of cement also, but need be only 2 or 



3 inches high, or of sufficient height to merely retain 

 the water. Boards or slate are placed outside the ce- 

 ment wall to retain the soil. The tile-bottom may rest 

 on iron or wood cross-pieces. Wood has been in use 

 for this purpose at the Ohio Station for seven years and 

 shows no signs of decay, because it is out of reach of 

 the water. 



Nine years' experience shows that a perfectly con- 

 structed bench bottom, with the tile laid 2 feet apart, 

 will serve satisfactorily in distributing the water to all 

 parts of the bed, provided the tile are straight, so as not 

 to impede the flow of water. The tile are laid in the 



118S. Sub-irrigation with 



of tile. 



as tile-drains, and lengthwise or crosswise 

 the bed, as preferred. Better results are usually se- 

 cured if they are laid crosswise than lengthwise, as it is 

 difficult to secure an even flow through long lines of tile. 

 A little cement or mortar is used at each joint merely to 

 hold the tile in place when the soil is put in the bench, 

 but not enough to impede the flow of water from the 



