Rice Irrigation 369 



average amount used equal to a flooding of the field 

 6 inches in depth once every 10 days, and since so 

 much water must be used on this crop, the means 

 for handling it must be constructed with ample pro- 

 portions. 



In South Carolina, at the mouths of the Santee 

 river, where the natural conditions for rice culture 

 exist in almost ideal perfection, the fields have been 

 laid off into flooding basins, varying in size from 

 a few acres to thirty and more. Each basin is sur- 

 rounded by a dyke, at the foot of which is a main 

 distributing ditch 4 to 6 feet wide and 30 to 36 

 inches deep, much as has been described for cran- 

 berry irrigation, but on a larger scale, and the 

 resemblance is made still closer by the division of 

 the fields into narrow lands 20 feet in width by 

 parallel ditches 36 inches wide and 36 inches deep, 

 which are at once the ultimate distributaries and 

 the drainage channels. Trunks or sluices are pro- 

 vided controlled by semi-automatic tide gates, which 

 may be raised at will, on the sea side, to admit 

 the water to these ditches and flood the fields to 

 any desired depth, and then closed and the water 

 retained ; or the gate on the field side may be raised 

 and the water withdrawn. 



After the fields have been plowed and seeded in 

 the spring, they are flooded to a depth of ,6 inches 

 and allowed to so remain until the seed has germi- 

 nated and the first three roots formed. At this 

 stage the water is let off for three days to force 

 rooting, when flooding again occurs to overtop the 



