PROCEEDINGS OF THE SUMMER MEETING. 63 



amount of water at hand and the character of the soil, as the deeper and 

 further apart they are the more water they will require. In an open sandy 

 soil some of the water will be lost in the subsoil, but the system is parti- 

 cularly adapted to land with a stiff subsoil which will retain it until it is 

 all absorbed. While good results can be obtained upon a sandy soil, 

 especially if it is rich in organic matter, the system of applying the water 

 to the under soil is decidedly preferable upon a clay soil to any system of 

 surface irrigation, as there will be no trouble from the baking of the sur- 

 face, and if an occasional stirring of the soil is given the surface will be' 

 kept light and open and will form an almost perfect mulch, which will go 

 far to prevent loss from evaporation. On scraping this away, the under 

 soil will be found full of moisture, while in unirrigated land it will be as 

 dry as dust. As showing the conserving effect of the earth mulch, it may 

 be stated that footprints in the light surface soil show up almost black, as 

 compared with the light color of the loose, dry soil, in the morning, before 

 the water that has been brought up from below is evaporated. This is of 

 course a common occurrence in any soil, but is particularly noticeable 

 upon irrigated soils in dry weather. 



In sandy soil it will be best if the tiles are not more than twelve or 

 or fifteen inches below the surface and unless there is an abundance of 

 water, under a good head, the nearer the tiles are together, down to a dis- 

 tance of ten feet, the better, and a saving of water can often be made if they 

 are even nearer. When as near the surface as this, unless the soil is well 

 drained, care should be taken that the lower ends of the tile are open, that 

 the water may run out in winter and not burst the tiles by fr^zing. 



Three-inch tiles will answer for the laterals (a smaller size may be used) 

 and a number of them may be connected by a larger size, into which the 

 water can be turned through a line of hose or directly from the supply 

 pipe. When this method is employed in the orchards of California, 

 cement or sheet iron pipes are used with a small hole near each tree 

 through which the water is supplied to the roots. When a moderate pres- 

 sure can be obtained a circle sixteen feet in diameter is watered through 

 each opening. For use in young orchards, where the trees do not occupy 

 all of the ground, a saving of water could be made if, instead of leaving all 

 of the joints between the tiles open, those between the trees are closed 

 with cement. 



In soil that is inclined to be wet in spring or that is likely to be satu- 

 rated by heavy rains during the summer, the pipes used for sub-irrigation 

 can be so laid as to serve for the removal of the surplus water. If placed 

 at a depth of from twenty to twenty-four inches it will only be necessary 

 to connect the lower ends of the lines of tile to a main drain, and have it 

 so arranged that the water can be held in them or let out, as is desired. 



It may be well to note here that on stiff soils the best results can not be 

 obtained from irrigation unless some efficient means of drainage is com- 

 bined with it, and when the combined bed and furrow method of watering 

 is used for garden crops it is often desirable to have a line of tile beneath 

 each of the dead furrows between the beds to take off any surplus water. 

 The system of sub-irrigation described above will serve for both purposes 

 with little extra expense, and if at any time the water in the soil is present 

 in excessive quantities, either from rainfall or careless watering, it can be 

 readily removed. 



Another advantage of sub-irrigation is that considerably less water is 

 required than with any other system of watering. With a stiff subsoil 



