June i6, 1919 Sulphates Affecting Plant Growth and Composition 



93 



of the soil extracts is compared. The soil solution from A contains 

 twice as much sulphate sulphur as the soil extracts from B and C and the 

 total sulphur is three times as great. Apparently there is enough sulphur 

 in the soil solution compared to the other elements for straw production. 

 The development of the oat seed as shown in Table IV, agrees very well 

 with the weight increases of the straw as shown in Table III. In com- 

 paring the growth of the oats on the soils receiving sodium nitrate plus 

 calcium carbonate to those receiving sodium nitrate only, the calcium 

 carbonate appears to have an injurious effect upon growth, but in com- 

 paring the calcium carbonate-sodium-nitrate-treated soils to those receiv- 

 ing sulphur, sodium nitrate, and calcium carbonate, the sulphur has 

 caused increased growth in all cases. 



Table III. — Weight of oat straw and its percentage of sulphur and nitrogen on the different 

 soils and sand cultures obtained fro^rn the different fertilizer treatment 



o A=beaverdam soil or sand; B=Medford loam; C= antelope-clay-adobe. 



