WET LANDS OF SOUTHERN LOUISIANA. 



13 



the combined water capacity of the two varieties, for many of the planta- 

 tions have a mixed soil much like that of the Smithport Plantation. 



The samples recorded in the following table were taken in Bayou Lafourche 

 sandy loam near Lockport and about one-fourth mile back from the bayou. 



Results of soil tests near Lockport, La. 



Number of sample. 



Depth of 

 sample. 



Number 



of days 



since 



rain. 



Weight per cubic 

 foot. 



Water in 

 soil by 

 volume. 



Depth 



of water 





As taken. 



Dry. 



table. 



Sandy loam: 



36 



Inches. 

 3-8 

 3-8 

 6-11 

 6-11 



14 

 14 

 14 

 14 



Pounds. 

 105. 9 

 105. 4 

 105.9 

 105.4 



Pounds. 

 81.2 

 80.6 

 75.4 

 78.1 



Per cent. 

 39.5 

 39.7 



48.8 

 43.7 



Inches. 



40 



37 



40 



38 



40 



39 



40 







The soil in this tract is representative of the average soil conditions in the 

 bayou-front plantations. It also is of much the same nature as the ridges of 

 silt that occur in many of the turf or muck lands. The soil had been cultivated 

 for a great many years, and little vegetable matter was present. It already 

 had been cultivated in 1910 when the samples were taken. The ground was 

 quite moist to the touch, but was perhaps a little drier than usual. The soil 

 was much the same to a very great depth. The tests were made for the pur- 

 pose of comparison with the tests of the muck. 



It will be noted by comparing samples 40 and 42, in the summary of re- 

 sults of soil tests on the Smithport plantation, with samples 36 to 39, inclusive, 

 taken near Lockport, that the muck soil seems to be more retentive of moisture 

 than the sandy loam of the bayou ridge. The samples of each class of soil 

 were taken at approximately the same depth and on the same date, yet the 

 muck contained nearly 50 per cent more water than the sandy loam. Later in 

 this same season, which was unusually dry, the crops on the muck soil with- 

 stood the effects of the drought better than did those on the sandy ridge soil. 



In general, the layers of turf or muck of southern Louisiana having been 

 formed on an alluvial deposit, and in many cases mixed with silt, the turf after 

 a few years of cultivation works up into a most excellent soil which is well bal- 

 anced in chemical composition. This is proved by the excellent yields of both 

 truck and general field crops on such lands near Lockport and RacelamL* The 

 muck of the cultivated fields' has a greater density and a darker color than 

 that where the land is undrained and uncultivated. In its original state the pure 

 turf is a light brown, but as it dries and decays it becomes darker and finally 

 is almost black. When first drained it is very light and spongy and when 

 plowed breaks up into rather large pieces, sometimes as much as a foot square, 

 which are pushed ahead of the plow instead of being turned in a furrow. After 

 the second year of cultivation, the muck loses its fibrous nature and resembles 

 old sawdust in texture, although a little darker in color. As cultivation con- 

 tinues the muck mixes more and more with the underlying silt, and a much 

 heavier and more impervious soil results. 



SUBSIDENCE OF SOILS. 



It is well known that swamp lands having soils containing a large percentage 

 of vegetable matter subside when drained and cultivated. This subsidence 

 in due to three main causes — drying, decay, and cultivation. Shrinkage and 

 the consequent subsidence, due to drying, affects mostly the top layer but ex- 



