96 



Journal of Agricultural Research 



Vol. XVII, No. 3 



of total sulphur and nitrogen would grow less as the plant developed, 

 until, at maturity, the nitrogen content would average about the same 

 for all the clover grown under the diflferent fertilizer treatments. In 

 certain pots, maturity, undoubtedly, would be reached sooner, but allow- 

 ing each group to grov/ until they all reached the same stage of develop- 

 ment, it would be of importance to know whether the sulphur had affected 

 the nitrogen content and the character of the compounds containing 

 nitrogen. Samples of alfalfa grown on sulphur-fertilized soils in Oregon,^ 

 as shown in Table IX, have shown a higher nitrogen content than those 

 grown on the same soil without sulphur application. Shedd (24) reports 

 increase in protein content of soybeans from ammonium-sulphate fertili- 

 zer and Ames and Boltz (i) report larger protein content in rape where 

 sulphates were in the fertilizer used. In this experiment available 

 nitrogen was present in the form of nitrates. It would be of interest 

 to know whether by maintaining the sulphate supply an increase in 

 nitrogen assimilation from the air could be brought about. 



Table VI. — Weightof clover roots expressed in gms. grown on the different soils receiving 



various treatments 



Treatment. 



Soil A.o 



Soil B.» 



Soil C. 1 



Calcium sulphate. 

 Sodium nitrate. .. . 

 Sodium sulphate . 

 Sodium nitrate. .. . 



Sulphur 



Calcium carbonate 

 Sodium nitrate. .. . 

 Sodium nitrate. .. . 

 Sodium nitrate. .. . 

 Calcium carbonate 

 No fertilizer 



I- 15 

 •95 



•93 

 .60 



• 51 



0.85 

 •36 

 .49 



•23 



. 21 



0.44 

 .28 



. 10 



13 



"Soil A=beaverdam; soil B=Medford loam; soil C= antelope-clay-adobe. 



Table VII. — Sulphur and nitrogen content at different stages of growth in clover 



grown on soil A 



'Reimer and Tartar. Unpublished data, Oregon Agricultiu-al Experiment Station. 



