GREENHOUSE EXPERIMENTS 11 



so successful both in the greenhouse and out of doors during 

 the past few years, we have a system, which, as its name signi- 

 fies, applies the water to vegetation from beneath through pipes 

 laid below the surface of the ground,* and, in case of out-of- 

 door irrigation, at a depth beyond the reach of the plowf. 

 The ground is watered by capillary attraction. These pipes 

 are used indefinitely from year to year. One of the advantages 

 claimed for sub-irrigation over surface-irrigation is the econ- 

 omy of water. Some advocates say that it does better work 

 with half the water, while others go so far as to state that it 

 saves from three fourths to nine tenths. In our own experi- 

 ence, as far as the greenhouse is concerned, when we have 

 water-tight bottoms in the benches, there is no question as to its 

 saving both water and time. But from experiments carried on 

 during the past two years, we have found that the percentage 

 of water saved is greatly reduced when this system is applied 

 to out-of-door crops, and even to crops in the greenhouse where- 

 the water-tight beds, or those practically so, are not used. 



EXPERIMENTS IN GREENHOUSE 



To test this point as to greenhouse beds, an experiment was 

 conducted by myself during the season of i8o,3-'q4. at the West 

 Virginia station. Two beds, each eight by fifty feet, were 

 made, in each of which three rows of tile were placed equi- 

 distant and running lengthwise of the bed. The conditions of 

 each bed were similar except that one had a perfectly water- 

 tight bottom of matched flooring, while the other rested on the 

 ground. The soil, method of watering, etc., were the same. 

 The ground upon which the bed rested was a reddish, hard 

 clay, which had been unused until the soil was put in. It 

 had become very hard and dry from the heat in the house ; in 

 fact it made such a good walk that we did not cement it until 

 it began to show wear. After watering a few times we noticed 

 that the moisture was not sufficient in the latter bed, and we 

 were compelled to resort to surface-watering. However much 



* Agr. Science, Vol. vii, page 383. 



* West Virginia Expt. Station, Bulletin 33, Vol. 3. 



* Ohio Station Bulletin, Vol. V., No. 6, page 101. 

 tAmerican Gardening, Nov. 10, 1894. 



