1922] WOODARD—SOIL FERTILITY 95 



soil samples are also quite similar in texture. Here again we find a 

 high sulphur content with a high organic matter content, and a 

 low sulphur content with a low organic matter content. When we 

 compare different soil types or samples from the same type but 

 from fields which have been cropped differently, however, there is 

 little e\'idence of any relation. Samples 7 B and 9 B have approxi- 

 mately the same sulphur content, yet the volatile matter in the 

 latter is twice that in the former. Both these samples are sub- 

 soils from Ohio, and were taken from fields that were not far apart, 

 but 7 B is on upland silt loam while 9 B is a muck soil. Again, the 

 cropped soil (no. 15) and the virgin soil (no. 16) from Bentley's 

 farm, Indiana, differ only sUghtly in volatile matter, but differ 

 widely in sulphur content. Gentry and Curry's soil (no. 28) has 

 slightly less volatile matter than Sharp's soil (no. 30), but con- 

 siderably more sulphur. Sample 10 A from Wager's farm in Wis- 

 consin is a fine sandy loam soil with very little clay but a large 

 amount of organic matter, as may be recognized by its black color, 

 yet it contains considerably less sulphur than sample 2 A from the 

 Wah-Bee-Mee-Mee farm in Michigan, which is also a sandy loam 

 soil, containing considerable coarse sand with sufficient organic 

 matter to give a black color. 



It seems, then, that from the sulphur standpoint, as well as the 

 nitrogen standpoint, the character of the organic matter is of more 

 importance than the amount. Sulphur, like nitrogen, is mainly 

 present in the proteins, so that a small amount of high protein 

 organic matter, such as one would obtain by plowing under leg- 

 umes, would be more valuable than a larger quantity of organic 

 matter from wheat or oat straw or cornstalks. It seems probable 

 also that the proteins are more readily decomposed than the non- 

 protein organic matter, so that the sulphur and nitrogen would be 

 oxidized more rapidly than the carbon, and the sulphur and nitrogen 

 content might become quite low when there was still a consider- 

 able amount of carbonaceous organic matter in the soil. 



In all the samples analyzed, the sulphur content was less than 

 the phosphorus content. One of the samples from Ohio which 

 was taken in a low wet place was a muck, very high in organic 

 matter. This soil had nearly as much sulphur as phosphorus in 



