37 



of sodium and magnesium. The third reason why the cane will at this 

 place stand more salt than at others, is the high nitrogen content of the 



black vegetable mould. 



THIRD SERIES OF ANALYSES. 



In order to get more data on the subject which might enable us to 

 fix numerically the limit of tolerance for salts in these marsh lands, 

 another series of samples was taken in the Cane de Tiburones, in April 

 1912. The area investigated at this time was situated in that part of the 

 marsh which is controlled by Central Cambalache. It is located in the 

 south-west quarter of the marsh, near the railroad station Santana. Here 

 cane had been planted one season before, and the crop had been cut and 

 allowed to ratoon wherever the condition of the cane warranted this 

 policy. In other parts it had been left standing without cutting. 



Sample No. 1 was taken in field No. 2. The cane here was ratoon cane, 

 quite vigorous and healthy, and had attained a height of from seven to 

 eight feet. 



No. 2 came from field No. 4, also in ratoon cane. The cane here was 

 apparently healthy, but it was not as good as in location No. 1, having 

 grown to a height of only five feet. 



At location No. 3, also in field 4, the cane had likewise been cut 

 and allowed to ratoon. But it was only about three feet high and showed 

 marked signs of suffering. 



In place No. 4, located in field No. 8, the cane, when first planted, 

 bad germinated, but most of it subsequently died. 



In location No. 5, in field 5, the cane did not even germinate. 



It is important to note here that in locations No. 1, 2 and 3 the 

 ground water was low enough to be out of reach of the cane roots, whereas 

 in Nos. 4 and 5 it was quite near the surface. 



Table No. XIV gives the analyses of the soils from the 5 places, to 

 the depth of two feet. 



