March 1908.] 



217 



Edible Products. 



The Louisiana experiment station 

 collected the opinions of a number of the 

 most prominent rice growers, who agreed 

 in the main on the following methods :— 

 The land is broken with four-mule gang 

 ploughs, reaching about 3 inches. Disc 

 and spring-tooth harrows are used, and, 

 when necessary, complete pulverisation 

 is secured by the use of a smoothing 

 harrow. Should the ground be too hard, 

 water is turned on to soften it. The 

 growth is found more uniform where a 

 drill is used, although the rice may be 

 sown broadcast. In moist, warm weather 

 water is not turned on for from four to 

 six weeks, and then care is taken not to 

 cover the tops. An average season re- 

 quires three months' flooding. The water 

 is withdrawn from the field when the 

 heads begin to turn and the rice is passing 

 into the " dough stage." This is usually 

 from 10 to 14 days before harvest begins. 



Three horses with a modern self-binder 

 will harvest from 5 to 12 acres daily. 

 The same thresher used for oats will 

 thresh rice. Where the farmer supplies 

 the hands the thresher usually charges 

 2-|- c. per bushel. In threshing from the 

 shock something like seventeen men are 

 required. 



Irrigation Control.— The part played 

 by water being of importance where 

 irrigation is necessary, the following 

 description of the arrangement at a 

 certain station may be of interest : — 



The instruments used to regulate the 

 flow of water were placed upon a small 

 tract containing 37 '96 acres of land. The 

 middle branch of the main canal, 80 feet 

 wide at the point of diversion, was tap- 

 ped by a small flume 2\ feet wide and 40 

 feet 6 inches long. The levee, which is 

 &\ feet high, was cut and aprons of sheet 

 piling driven through the levee and into 

 the virgin soil. These aprons furnished 

 ample provision against leakage and 

 wash at the sides of the flume. A 

 standard water register was used to 

 keep a continuous record of the depth of 

 the water passing through the flume and 

 the times when water was applied to 

 the rice. 



The evaporating tank was established 

 in such a manner as would reproduce 

 conditions which prevailed in the rice 

 field. It was set in a pit and partly filled 

 with soil. Water was poured in until its 

 level was about 4 inches above the sur- 

 face of the soil. About one foot above 

 the water surface in the tank a light 

 wire netting was placed horizontally, 

 being stretched over a square frame 

 which rested upon posts at the corners. 

 The wire screen was used as a support 

 for grasses and rice straw, which 

 were increased in quantity as the 

 rice matured in the field, so that the 



depth of shade cast over the water 

 by the growing rice was reproduced, as 

 nearly as possible, in the tank. There is 

 no question whatever that the evapor- 

 ation from a tank placed upon the top of 

 the ground, and exposed to the direct 

 rays of the sun would be far greater than 

 that shown in this experiment. 



The raingauge was a double tube 

 securely mounted upon a post, the top of 

 the gauge being about 4 feet above the 

 ground. 



By the means above described, a record 

 of the evaporation, the rainfall and the 

 times when irrigation took place was 

 kept. From the continuous record of the 

 depth of water which passed through 

 the flume kept by the register the volume 

 of water used on the rice-field was 

 determined. These records covered a 

 period of 71 days. During this period 

 the experiment field containing 37*9t5 

 acres of rice received from the canal 

 enough water to cover it to a depth of 

 19 66 inches, and enough lainfall to cover 

 it to a depth of 915 inches. The evapor- 

 ation during the same period was 16 03 

 inches, leaving a net depth of water to 

 promote the growth of the rice crop 

 and supply the volume taken up by the 

 soil amounting to 12'78 inches. The 

 following table shows the water received 

 by the crop duiing the several weeks of 

 the irrigating season : — 



Week ending- 

 June 29 

 July 6 



„ 13 



„ 20 



„ 27 

 August 3 



„ 10 



., 17 



„ 24 



„ 31 



Flood 

 Water, 



Rain- 

 fall. 



Evapor- 

 ation. 



Inches. 



Inches. 



Inches. 



3 42 



0-42 



1-90 



0-47 



0-66 



3-36 



8-10 



0-36 



2-04 



2 39 



216 



0-12 



0-30 



1-56 



1-20 



0'58 



2-70 



1-10 



0'90 



0-96 



3'24 



3-19 





1-20 



0-20 



0-30 



1-08 



0-05 



0-03 



079 



19-96 



9-15 



16-03 



Summary. 

 Area irrigated ... ... Acres 37'96 



Depth of water received 



from irrigation ... inches 19 66 



Depth of rainfall ... ,, 915 



Total depth of water re- 

 ceived by the land 

 Evaporation 



New depth of water re- 

 ceived by the land 



28-81 

 16-03 



12-78 



