WET LANDS OF SOUTHERN LOUISIANA. 



11 



Results of soil tests on Lafourche drainage district No. 12, subdistrict No. 



Raceland, La. 





Depth 



of 

 sample. 



Num- 

 ber of 

 days 

 since 

 rain. 



Weight per cubic foot. 



Water in soil by volume. 



Depth 



of 

 water 

 table. 



No. of sample. 



Nor- 

 mal. 



Satu- 

 rated. 



Dry. 



Nor- 

 mal. 



Satu- 

 rated. 



Gain. 



Turf: 



12 



Inches. 

 4-10 

 4-10 

 4-10 

 4-10 

 5-10 

 5-10 

 3- 8 

 3- 8 

 6-10 

 6-10 



8-12 

 8-12 

 12-16 

 12-16 

 3- 7 

 3- 7 

 3- 8 

 3- 8 



7 

 7 



10 

 10 

 10 

 10 

 14 

 14 

 14 

 14 



7 

 7 

 7 

 7 

 7 

 7 



10 

 10 



Pounds. 

 45.8 

 54.4 

 44.0 

 45.8 

 43.9 

 46.7 

 41.3 

 41.3 

 51.2 

 47.3 



57.9 

 61.4 

 64.0 

 66.0 

 53.7 

 56.2 

 54.8 

 46.7 



Pounds. 

 61.5 



Pounds. 

 7.0 

 8.7 

 9.4 

 12.4 

 10.7 

 14.0 

 7.6 

 7.9 

 7.9 

 7.3 



21.2 

 22.8 

 29.5 

 30.0 

 14.9 

 16.9 

 16.9 

 8.7 



Per cent. 

 62.1 

 73.1 

 55.4 

 53.4 

 53.1 

 52.3 

 53.0 

 53.4 

 69.4 

 64.0 



58.7 

 61.8 

 55.2 

 57.5 

 62.0 

 62.9 

 60.6 

 60.8 



Percent. 



87.2 



Per cent. 

 25.1 



Inches. 

 18 



13 



18 



22 









20 



23 



62.3 



79.8 



26.4 



20 



24 



20 



25 



60.7 

 61.5 



74.7 

 86.2 



22.4 

 32.3 



20 



30 



20 



31 



20 



32 









22 



33 



57.6 

 71.3 



80.5 

 80.5 



16.5 

 21.4 



22 



Turf with silt: 



10 



20 



11 



20 



14 



77.6 



77.0 



21.8 



18 



15 



18 



16 i 



67.9 



84.8 



22.8 



20 



171 



20 



26 1 









24 



27 1 



64.9 



89.9 



29.1 



24 







Turf and silt after being mixed by two years of cultivation. 



The above samples were taken from the soil on subdistrict No. 2, which lies 

 about 5 miles from Bayou Lafourche and the same distance from Raceland. 

 This district is a part of the open, grass-covered prairie and had been well 

 drained for about three years. Its elevation is perhaps a foot above mean tide 

 level, and the soil probably w T ould be classed as Galveston clay. The fields from 

 which these samples were taken were in cultivation in 1909 and were planted to 

 corn or sugar cane in the spring of 1910. The original vegetation was a wild 

 prairie grass, locally called "paille fina." The muck or turf was formed from 

 this grass. The soil of the top 4 to 5 inches was quite soft and dry, having 

 been recently cultivated. Just below the depth of cultivation the soil became 

 moist, and water would drip from it when compressed. The muck here was of 

 a dark-brown color and very light and spongy ; after drying it became much 

 darker in color. It seemed to be a mass of partially decayed grass and grass 

 roots and had very little, if any, silt in its composition. The depth of the 

 muck on this tract varied from 6 to 18 inches. Below this came a layer of 

 mixed turf and silt about 1 foot in thickness, and from there on down to a 

 great depth occurred pure silt which would be classed as Sharkey clay. The 

 ground-water level stood a little less than 2 feet below the surface, which is 

 about the average depth of drainage secured on this tract. The first 10 sam- 

 ples in the table were taken from the layer of pure turf ; the next four, Nos. 

 10, 11, 14, and 15, from the layer of mixed silt and vegetation just under the 

 layer of pure turf ; and the last four, Nos. 16, 17, 26, and 27, from a field on the 

 same tract that had been cultivated for two years, but that .had not been culti- 

 vated in 1910 when the samples were taken. The last four samples show the 

 result of deep plowing, thus mixing the silt and the pure turf, and give an idea 

 of the conditions that may be expected after the fields have been cultivated 

 for a time. 



The following table gives the results of tests of the muck on Lafourche 

 Drainage District No. 12, subdistrict No. 3, which lies a little farther out from 

 Bayou Lafourche than does subdistrict No. 2. 



