70 



nificant differences, however, between the alkivial lands at the 

 northern edge of the state and those in the latitude of New 

 Orleans. The soil of extreme northeastern Louisiana is hardly 

 surpassed in productiveness anywhere in the world ; but there is 

 a progressive decrease in fertility going downstream from there, 

 for two different — but not wholly independent — reasons. First, 

 on approaching the mouth of the river the seasonal fluctuation 

 of the water diminishes, and with it the opportunities of the soil 

 for aeration ;* and second, because of the pronounced increase of 

 late summer rainfall toward the Gulf coast, the soils in that direc- 

 tion must be more thoroughly leached. f The variations in soil 

 fertility are brought out very well by census statistics on the use 

 of commercial fertilizers. ij: In 1909 the farmers in the alluvial 

 parishes above Baton Rouge spent only 7 cents for fertilizers for 

 every acre of improved land in 1910, those between Baton Rouge 

 and New Orleans $1.23, and those below New Orleans $2.22. 



In northern Louisiana the alluvial lands are largely devoted 

 to cotton, while about Baton Rouge sugar-cane becomes the lead- 

 ing crop, and that gradually gives way to rice lielow New Orleans. 

 A northeast-southwest line drawn across the delta a little above 

 Baton Rouge separates the cotton and sugar-cane regions pretty 

 well, and the difference is reflected in the vegetation, as will be 

 shown farther on. 



The Sugar-cane Region 



From New Orleans to Baton Rouge (88 miles) and about ten 

 miles west of the latter place, or about to the boundary between 

 the parishes of West Baton Rouge and Pointe Coupee, I was in 

 the sugar-cane region, where vast fields of cane, hiding all but 

 the roofs of the one-story houses, are the most conspicuous fea- 

 ture of the late summer landscape. Corn and rice rank next to 

 cane in acreage, the former often planted with velvet beans or 

 sugar-cane in alternate rows. Rice was being threshed at the 

 time I passed by, and the piles of chaff were often burned to get 



* See Torreya 11: 223. 191 1. 



t See Science II. 48: 208-211. Aug. 30, 1918. 



t See Science II. 42: 500-503. Oct. 8, 1915. 



