12 vegetajdLe gardening. 



for some crops unless fi.'st pumped into a reservoir. A tern 

 perature of 60 degrees is desirable, though not always necessary 

 for the best results. 



Aim to wet the roots of the plants and avoid getting water 

 on the leaves. 



Wooden troughs afford the cheapest conduits for water anc 



Figure 1.— One method of irrigating crop planted in rows. 



should be used whenever practicable. Iron pipe is expensive 

 and much more difficult to manage than wooden troughs. 



Sub-irrigation is a new term that refers to the application 

 of water to the roots of plants by means of underground chan- 

 nels, such as tile or other drains. It works best in sandy soils. 

 In clayey soil the water runs too slowly through the sides of 

 the tiles. Land tiles make as good channels as any for this 

 purpose. They should be buried a few inches below or by the 

 side of the plants to be watered, being laid level with open 

 joints. Some experiments seem to show that it is a very waste- 

 ful way of using water, while others have shown this^ system 

 to be economical. As practiced for v/atering plants in green- 

 house benches, especially for lettuce, it has given excellent 

 results. 



