192 2] WOOD ARD— SOIL FERTILITY 87 



cropped as in the virgin land in both surface and subsoil. The 

 cultivated soils had been cropped for thirty to forty years. 



Lyon and Bizzell (44) found an increased loss of sulphur in 

 the drainage when burnt lime was used, while MacIntire, Willis, 

 and Holding (47) found the loss greater for calcium carbonate 

 than for calcium oxide. It seems the carbonate favors bacterial 

 action much more than the oxide. 



Robinson (59, 60) analyzed a large number of soil samples 

 from different parts of the United States for sulphur and phos- 

 phorus. Most of them were low, some extremely low, in both 

 phosphorus and sulphur. Many of the samples were much lower 

 in sulphur than phosphorus. Brown and Kellogg (ii) analyzed 

 samples of Iowa soils and found the sulphur content varied from 

 719 to 938 pounds per acre in the surface soil, while the phosphorus 

 content varied from 1289 to 1538 pounds per acre. Shedd (62) 

 analyzed samples of Kentucky soils and found the sulphur content 

 in the surface soil varied from 213 to 1080 pounds per acre in virgin 

 soil, and from 180 to 560 pounds per acre in cultivated soils. The 

 phosphorus content in the surface soil ranged from 320 to 5860 

 pounds in virgin soil, and from 320 to 7 240 pounds in cultivated soil. 



Some sulphur is brought down from the air in rain water. 

 The amount is probably greater during periods of heavy rainfall 

 than when the precipitation is slight. Near cities, where a large 

 amount of coal is burned, the amount is probably much greater 

 than in country districts far from cities and railroads. The data, 

 however, are too meager to form any definite conclusions. Hall 



(26) reports sulphur analyses of rain water at Rothamsted from 1881 

 to 1887 which give an annual average of seven pounds of sulphur 

 in the rain water per acre per year. Analyses by Hart and Peterson 



(27) at the University of Wisconsin for part of a year led them to 

 the conclusion that the amount in one year would be approximately 

 the same as found at Rothamsted, Stewart (67) analyzed rain 

 water at the University of Illinois and obtained as a seven-year 

 average 45.1 pounds of sulphur per annum. All of these analyses 

 are of rain water collected near cities. The water in the rain 

 gauges is Hkely to be contaminated by dust and soot and by the 

 droppings of birds which roost on the rain gauges. 



