IKRIGATION 



joints. The first tile where the water is introduced is 

 laid at an angle, one end resting on the edge of the 

 bench side. This leaves a wide opening at the first 

 joint, which is closed with cement. A better plan is to 

 use a curved sewer-pipe for the inlet, but this is not 

 always available. The picture (Fig. 1182) shows how 

 the tile is laid on the bench bottom, being a view of a 

 side bench in a carnation house. 

 Following Goff s suggestion m the use of brick tiles 



IKRIGATION 



835 



ntii 1 II h h tt m with good 

 I 1 I ' th ,t this -nill be found 

 I II 11 ui tion as it appears 



in \ H distribution of ■ 

 n 111 IS The same as above de 

 10 pHns diffei only in the number 

 of tiles employed to distiibute the water When the 

 bench bottom is cnvored with tih placed near enough 

 together so that tli I ill ii t t ill between it will be 

 readily seen thit \ i i I it any point will flow 



to all parts of til I i .n 1 the tile It needs 



simplvto bebroii.l 1 I \ el that it will reach 



the soil whencipM i n n n will complete the dis 

 tribution Fig lis sh w s •» In nth m i tomato house 

 constructed after this plan A'^ aie the inlets B the 

 irrigating tile from which the soil has been removed 

 C is the tile bench bottom covered with cement The 

 same size of tile mz 2^-^ oi 3 imh is used both above 

 and below D is the cement side which his been broken 

 away to show the method of construction The outer 

 boird has been removed also 



The cost of construction need not be discussed here, 

 except to state that the only items extra, more than are 

 required in any well-constructed greenhouse, are the 

 cement bottom and the tile in which the water is dis- 

 tributed. 



A plan has been devised for applying water to small 

 plants in flats which mav properly be mentioned under 

 this head. The flats are shallow boxes with slatted bot- 

 toms. When the plants require water, the flats are 

 placed in a shallow vat of water and allowed to remain 

 until the surface of the soil appears to be damp, or even 

 wet. 



A watering in this manner is far more efiicient than 

 by the ordinary method. Taken in connection with sub- 

 irrigation in the benches, a crop of lettuce can be 

 brought to marketable size nearly two weeks earlier 

 than when surface watering is practiced. Anything like 

 a full discussion of results of experiments in watering 

 plants in the greenhouse by sub-irrigation would be too 

 voluminous for an article in this connection. A brief 

 review of the results obtained at some of the stations, 

 together with a short discussion of some general prin- 

 ciples, will serve the purpose intended. The increase in 

 weight of lettuce from sub-irrigated plats over those 

 watered in the ordinary manner has been reported bv 

 Rane, of West Virginia, as 25 per cent and bv Goff anil 

 Cranefleld as 26 per cent. At the Ohio Station the 

 range has been from 25 to 100 per cent. In the Latter 

 case the result was obtained by commencing with the 

 plants as soon as taken from the seed-bed, and carrying 



the two lots through to the termination of the experi- 

 ment, one by watering altogether on the surface of the 

 soil, the other by sub-irrigation. Each of the experi- 

 menters speaks of a gain in earliness of several days 

 by sub-irrigation. Rane secured similar results with 

 long-rooted radishes by this method of watering, but 

 not with the turnip-rooted sorts, while Munson, of 

 Maine, doubled the crop by watering below. Better re- 

 sults have usually been secured at the Ohio Station with 

 the turnip rooted than with the long varieties, but in 

 all cases there has been a gain in favor of sub-irriga- 

 tion varjing from 50 to 100 per cent. Rane found that 

 sub irrigation increased the yield of tomatoes, but the 

 gam was not large Essentially the same results have 

 been secured in Ohio. The tomato crop has not been 

 greatly influenced by the manner in which the water 

 was applied and the same is true of beets, while sub- 

 irrigated cucumbers and parsley have shown a decided 

 gain over surface watered. Carnations, roses, chrysan- 

 thnmums sweet peas, violets and smilax have been un- 

 1 1 experiment by the two methods of watering, and 

 ^\ liile no such marked results have been secured as with 

 1< ttuce and radishes, the sub-irrigated plots have shown 

 upenority over those watered in the ordinary manner, 

 m nearly all cases With carnations the improvement 

 h I been mainly in length and stiffness of stem. 



^side from the increase of crop secured by sub-irri- 

 t ition there are other considerations which may be 

 urged m its favor and these are embodied in the follow- 

 ing general propositions: 



(1) }fate>in(i by sub-irrigation in the greenlwuse 

 salts laboi the amount of labor saved depends 

 mosth on tht ompleteness of the arrangements for 

 watering but there is a saving in the number of appli- 

 cations as well It is possible to reduce the time em- 

 ployed m watering a house, or series of houses, to one- 

 hfth th tim 11 iHv rr-.-piirod. 



(-1 II ' "■■■'" linn asstires an abundant 



anJ : I ' ' . /■ to all parts of the bed. 



Pert 1 II II , I ,, lunches is assumed in this 



cast- lilt will I h . ■ii-iiiirtion watering becomes al- 

 most HUtoni iti the only care necessary being to look 

 after such portions of the beds as may, by position, be 

 subiect to unusual conditions of air or sunlight. 



(3) Where uib irrigation is practiced in the green- 

 house the surface of the soil does not hrrnm, r„„ii„i,-trd , 

 but retains Its anginal loose, friable ,;.,i,l ,i;„u . It is 

 true that where fiequent syringing is prariici ,1 iIh- sur- 

 face of the soil becomes more or less liin-di-ni <i. Imt imt 

 to the extent that occurs in surface-watfriiig. mid ihe 

 condition is easily remedied, whereas in the other case 

 It is uot It follows that a heavier soil may be used for 

 sub irrigation than with surface-watering. 



Still other considerations might be urged in favor of 

 this method of watering, but many of them would apply 

 to special cases only. Regarding the effect of the 

 method upon insects and diseases, but little can be 

 said. Lettuce rot is less prevalent upon sub-irrigated 

 plots than upon those which are surface-watered, but in 

 extreme cases plants succumb to the disease, whichever 

 method of watering is practiced. Munson found that 

 radishes suffered more from the attacks of millipedes 

 upon sub-irrigated plots than upon plots watered in the 

 usual manner. Nematodes work upon the roots of 

 roses, whichever way the plants are watered. The man- 

 ner of watering has no apparent effect upon the red 

 spider. Even in houses watered wholly by sub-irriga- 

 tion this pest is no worse than in houses in which the w.a- 

 ter is applied to the surface of the soil. It may be said, 

 however, that nearly all classes of plants are more easily 

 kept in a healthy growing condition, and are thus better 

 able to resist enemies of all sorts, when sub-irrigated 

 than when supplied with water in the ordinary way. 



This method of applying water to plants in green- 

 house benches, has now been sufficiently tested to de- 

 termine its value. All that now remains is to devise 

 ways and means to utilize what is known concerning it. 

 The adaptation to suit particular cases must be made by 

 individu.als, but this will be far easier in the future 

 than in the past, because better methods of construction 

 prevail than formerly. The success of sub-irrigation in 

 the greenhouse is now simply a question of mechanics. 

 W. J. Green. 



