Journal of Agricultural Research 



Vol. VI, No. I 



EFFECT OF CARBON BISULFHID ON THE HIGHER AND LOWER FORMS 



OF PLANT LIFE 



From the results of the preceding experiments it seems that carbon 

 bisulphid should exert a beneficial effect on the growth of higher plants. 

 At first this should be most marked with ammonia-feeding plants, and 

 later with nitrate-feeding plants. Unfortunately it is not possible to 

 secure plants that feed entirely on nitrates or ammonia. For this reason 

 it was thought best to study the relation of carbon bisulphid to the 

 growth of several different plants. Accordingly a combination study of 

 the effect of carbon bisulphid on higher plants and on bacteria was made. 

 A wide range of soil types, as well as different higher plants, was used. 



Before entering upon a study of the relation of carbon bisulphid to 

 soil type and various plants, it was desired to obtain some idea of the 

 influence of various amounts of carbon bisulphid on plant growth. The 

 procedure was as follows : Ten kgm. of field soil (Miami silt loam) were 

 placed in each of sixteen 2 -gallon jars. The carbon bisulphid was added 

 in varying amounts, from 0.5 per cent to 2 per cent. It was poured into 

 holes in the soil. These holes were closed immediately and the water 

 increased to half saturation. In order to overcome the injurious effect 

 of carbon bisulphid, the jars were then allowed to stand for two weeks 

 before planting. 



CORN AND MUSTARD IN MIAMI SII^T LOAM 



The results of the test with corn and mustard are given in Table IV. 

 It is evident from the data of the table that these plants do not re- 

 spond alike to carbon bisulphid. 



Table IV. — Effect of varying amounts of carbon bisulphid on the growth of corn and 



mustard 



In all concentrations except 2 per cent, carbon bisulphid injured the 

 growth of corn. Mustard, on the other hand, was greatly benefited by 

 the carbon-bisulphid treatment. An increased growth was observed 

 from all concentrations. The maximum gain was noted with 2 per cent 

 of carbon bisulphid. This beneficial effect on mustard is very evident 

 from Plate II, figure i. If this increase in growth is due to the larger 



