72 MINNESOTA STATE HORTICULTURAL SOCIETY. 
beneath the soil deep enough not to interfere with the prosecution 
of the usual gardening operations. 
The advantages claimed for this method are economy in amount of 
water, and applying itin sucha way that there is no loss from evap- 
oration, and that the surface is always in condition to be worked; 
the disadvantages are, of course, in the question of expense, though 
it may be said that to properly prepare ground for surface irriga- 
tion also involves considerable expense. 
For lawn purposes this method is in considerable use, both in the 
East and in California, and in many places is so adapted as to be in 
wet seasons a method of drainage also. 
Our usual methods of sprinkling lawns has the disadvantage of 
drawing the grass roots to the surface, as the moisture does not 
penetrate to any depth, and if neglected for awhile the hot sun soon 
does its disastrous work, while if sub-irrigated the roots penetrate 
to a greater depth and are more favorably situated to resist drought. 
For lawn purposes the tile should be two to four inches, laid about 
twelve inches deep and ten feet apart, the lower half of the joints 
cemented but the tops open; laid on a level if possible, or nearly so, 
and at the upper end connected with an upright pipe through which 
the water may be introduced, and, if drainage is desired, at the lower 
end with au outlet drain which may be opened or closed as occasion 
may require. 
The last report of the Ohio State Horticultural Society gives ac- 
counts of experiments in this line, some of them in rather a tempor- 
ary fashion, which still gave good results. One cultivator of celery 
laid tile on top of the ground between the rows, by which means he 
applied water without washing the surface. In banking up the 
plants the tile were also buried, and water still applied through 
them with good results. Another, a cultivator of small berries, I 
believe, dug trenches between his beds in which he buried a foot or 
so of cornstalks laid lengthwise, in lieuof tiles, and covering them, 
applied the water through them. 
At Cornell University experiments have been made in connection 
with bench work in the greenhouses, by means of two tiles, and the 
results were quite marked. 
Briefly to enumerate the results, I may say that at Cornell the sav- 
ing in amount of water was about one-half, and plants subject to 
rot and injury from excessive dampness were in much better condi- 
tion. This last item in connection with fruits and vegetables is also 
noted from California. 
Experiments in California in trial beds where the tile were very 
closely laid and planted with early beets, onions, potatoes and string 
beans, the results were as follows: Early beets no special gain as 
the season itself was quite wet; onions and beans were watered five 
times. Increase of onions fifty per cent.; increase of beans over one 
hundred per cent. in weight, and season much prolonged. 
The Michigan Agricultural College reports: It is enough for any 
crop in any soil to apply 1200 bbls. per acre, once a week. In many 
soils sub-irrigation will require only one-third to one-half this 
amount. 
