10 VALUE OF SWAMP LANDS. 



will notice that where the kainit was used the proportion 

 of poor corn is lowest. It is always the rule that an 

 abundant supply of potash ensures a plump ear, well filled 

 to the tip. The benefit was not confined to the first year. 

 For ten years after the kainit was used there was an in- 

 crease in yield. In n years this gain over the natural soil 

 amounted to 594 bushels per acre, which represents the 

 gain from using one ton of kainit. At the average selling 

 price of 35 cents per bushel this means $207.90. In every 

 case where potash has been used on these black, unproduc- 

 tive soils the gain in the crop yields has been remarkable. 



The results on similar soils in Illinois, as recorded in 

 Bulletin No. 93 were just as marked. In every case where 

 potash was used the yield of the corn was increased. 

 Analysis of this Illinois soil showed much the same con- 

 dition as was found in Indiana, the black or swamp soil 

 contained several times as much nitrogen as the best soils 

 in the corn belt and also an abundance of phosphoric acid. 

 It was, however, almost entirely deficient in available potash. 

 It was this lack of potash, combined with poor drainage, 

 that made these soils unproductive. The use of lime alone 

 did not increase the yield greatly because it did not add 

 potash. These Illinois experiments were even more elabo- 

 rate than those in Indiana. One soil thus tested consisted 

 of about 16 inches of black peat, then 14 inches of lighter 

 soil, with a sub-soil of coarse sand. This soil was a failure 

 at producing ordinary crops, particularly corn While 

 analysis showed a lack of potash it was determined to try 



