icri^r 



Are Soils Containing Less than 0.02 % SO3 Benefited 

 by Special Manuring with Sulphates? 



BY 



G. DAIKUHAHA. 



Soils containing less than 0.02 % SO3 are rather frequent and since 

 such soils occur in Japan, it has some value to decide whether sulphates 

 would considerably increase the yields by furnishing easily assimilable 

 sulphur for protein formation. I selected for my test three soils which gave 

 the following numbers on analysis^^ : 



No. I came .from Sakamura in Hiroshima Prefecture and was a sandy 

 loam ; No. II came also from Heira-Mura in the same Prefecture and was 

 a clayey soil ; and No. Ill came from Hirono-Mura in Fukushima Prefecture 

 and was also of a clayey nature. 



Seventy-two zinc pots containing 13, 14 and 11 Kg soils resp. served 

 for this experiment, three pots for each trial. The general manure per pot 

 for these three soils was : 



Sodium nitrate fig, in two fractions. 



Double superphosphate^) 3g 



Potassium carbonate 2.5 g 



i). The analysis was carried out accwding Ulbricht's method with a hydrochloric acid of 

 10 %, a little modified by T. Katayama. 



2). Only the soluble portion of this preparation served for this experiment and contained 

 36.76 % P2O5, 0.81 % CaO and 0.83 % SO3 in the original sample. 



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