lO 



Journal of Agricultural Research 



\(A. VI, No. I 



Table IX. — Effect of carbon bisulphid on the growth of oats and corn in different types 



of soil 



The results of the nitrate determinations agree with those obtained in 

 previous experiments. At the time of planting the carbon-bisulphid soils 

 were lower in nitrate but higher in ammonia than the original soil. 



The data from Tables VIII and IX show that carbon bisulphid has a 

 much more beneficial efi"ect on mustard than on any other crop. Buck- 

 wheat and oats are benefited, but not so markedly as mustard. Corn 

 fails to show any improvement from treatment with carbon bisulphid. 



EFFECT OF CARBON BISULPHID ON BUCKWHEAT AND RAPE IN VARIOUS 



SOILS 



The five soil types selected for the study of the effect of carbon bisul- 

 phid on buckwheat and rape in various soils ranged all the way from a 

 very compact red clay to an open, sandy soil. After treating with 2 

 per cent of carbon bisulphid the soils were allowed to stand for three 

 months before planting. Bacteria counts and nitrate determinations 

 were made at the beginning and after two and three months. The effect 

 of the carbon bisulphid on the total number of bacteria is very evident. 

 In every case the carbon-bisulphid soil contained the most bacteria. The 

 maximum gain occurred in the clay-loam soil, the minimum in the Norfolk 

 sand. The increase due to the treatment was greatest after two months. 



Here, again, the treated soils gave a much lower nitrate content than 

 the controls. It seems safe to say that a rapid increase in numbers of 

 bacteria in a carbon-bisulphid soil is followed by a decrease in the 

 amount of nitrates. 



Three months after treatment the soils were planted to buckwheat. 

 Growth was slow at first, especially in the carbon-bisulphid series. The 

 crop was harvested when 60 days old. The results of this experiment 

 are shown in Table X. 



