336 



FORESTRY AND IRRIGATION 



July 



too salt or the lands are above tidewater, 

 the planter must depend on water taken 

 from inland streams, lakes, or reservoirs. 



Almost all the irrigation in the Caro- 

 linas and Georgia is of a simple nature. 

 When reservoirs are required a small 

 stream is dammed, so that the water 

 backs up to form a reservoir, while the 

 land below is irrigated by direct flow 

 from the dam through suitable ditches 

 or canals. 



In the case of irrigation from tide 

 water, banks or levees are thrown up, 

 and these are pierced by " trunks," or 

 long boxes made of heavy timber and 

 closed by a sort of gate at each end. 

 These trunks are placed at an approxi- 



to drain the field, the inner gate is held 

 permanently open, while the outer one 

 closes when the tide is up, thus pre- 

 venting any inflow. 



Drainage forms an essential part of 

 rice culture, being absolutely necessary 

 at the time of harvesting. Undertiling 

 is of advantage in the Atlantic coastal 

 fields only when the water is supplied 

 from reservoirs or lakes. The rivers 

 carry too much sediment during the 

 freshet season to make a system of 

 tinder-drainage successful, as the tiles 

 would soon become clogged ; yet the 

 slopes are for the most part fit for good 

 drainage with but little grading. A 

 system of low dikes and small ditches 



Courtesy Department of Agriculture. 



COMBAHEE RIVER, SOUTH CAROLINA, A TIDAL STREAM OX WHICH THE MOST EXTENSIVE 



CAROLINA RICE PLANTATIONS OCCUR. 



mately mean distance between the limits 

 of high and low tides, so that the water 

 of high tide will flow through them onto 

 the fields to be flooded, or so that the 

 flood \vater may be turned off at the 

 time of low tide. The gate at either 

 end of the trunk is so arranged as to 

 act as a valve, the pressure of the water 

 against it serving to keep it shut unless 

 it is held open by a lever provided for 

 that purpose and worked from the top 

 of the retaining bank or levee. Water 

 flowing in at a time of high tide can be 

 retained on the field for as long a time 

 as is desirable, for when the tide drops, 

 the water inside of the levee is held by 

 the automatic closing of the inner gate. 

 In the same manner, when it is desired 



through the field accomplishes the de- 

 sired results of equable application and 

 depth of water, with rapid run-off when 

 a draining of the field is desired. 



Rice is a shallow 7 feeder. Its mass of 

 roots spreads out just below the surface, 

 and none of them strike down to any 

 great depth. On this account all plow- 

 ing is shallow, generally not more than 

 3 or 4 inches deep, though a greater 

 depth might be advantageous as giving 

 more plant food. In some places the 

 ground is so stiff that it is flooded before 

 plowing. Afterwards it is put in con- 

 dition by disc harrow and roller. 



On lands flooded by rivers which carry 

 rich sediment fertility is easily assured, 

 but in many instances, and particularly 



