158 VEGETABLE FORCING 



be considered : First, the tile lines must be laid level, and, 

 second, there must be water-tight walls around the beds, 

 which may be of any convenient size. Beds need not be 

 more than 6 inches deep, though 8 to 10 inches will give 

 better results, and some growers prefer them even deeper 

 than 10 inches. 



Pipes of various sizes may be used, but tile are more 

 satisfactory as well as more economical. Tile 2^ inches 

 in diameter are preferred if they must be laid near the 

 surface of the beds, and 3-inch size is best if they are to 

 be placed 4 or 5 inches or more below the surface of the 

 ground. In shallow beds the tile need not be covered with 

 more than an inch or two of soil. If the soil is light, open 

 and porous, it is better to place the tile near the surface 

 of the beds rather than at a depth of 10 inches or more, 

 because less water will be required. In shallow beds of 

 light soil, the first line of tile should be 10 inches from 

 the wall of the bed, and the interior lines should be about 

 2^ feet apart, though 3 feet is permissible. In the 

 deeper beds it is customary to place tile 18 inches to 2 

 feet apart. The concrete walls, if well made, need not be 

 more than 2^ inches thick. 



A little mud mortar placed at each joint will hold the 

 tile in place while they are being laid and until the beds 

 have been filled with soil. Deep beds require more water 

 than shallow ones, but applications need not be so fre- 

 quent. There does not seem to be any uniform practice 

 in regard to the length of the lines of tile. If they are 

 carefully placed, with the joints as close together as 

 possible, and there is an abundant flow of water, the lines 

 may be 50 feet long. At the ends of such lines, elbows 

 are used to provide outlets above the surface of the 

 ground, and pipe headers may be used to connect with 

 several lines of tile. It is then possible to water a 9 x 50 

 bed in five hours or less, the time depending upon the 



