76 CELERY CULTURE 



pass on to the next tile. The water entering the 

 tiles finds its way to the soil through the openings 

 between them and gradually works down the slope 

 toward the next line of tiles. During rainy seasons 

 the wells are closed down, the check gates and over- 

 flows all removed, and the irrigation system is made 

 to serve as a means of draining the land. A plan of 

 this system is shown in Fig. 30. 



Temperature of Water for Celery Irrigation. 

 As celery thrives best under cool conditions it is 

 desirable to use water at a rather low temperature 

 for irrigation. Warm, stagnant water, that has lain 

 for days exposed to the heat of the sun, should not 

 be used for irrigating celery. Water that is pumped 

 direct from wells and which has a natural tempera- 

 ture of from 50 to 60 degrees is preferable. 



