Apr. 3, 1916 Relation of Carbon Bisulphid to Plant Growth 



II 



Table X. — Effect of carbon bisulphid on the growth of buckwheat in different types of soil 



No. 



3 

 4 

 5 

 6 



7 

 8 



9 

 10 

 II 



12 

 13 

 14 

 15 

 16 



17 

 18 



19 

 20 



Soil. 



Cecil clay 



do 



do 



do 



Porters clay 



do 



do 



do 



Clay loam 



do 



do 



do 



Hagerstown loam 



do 



do 



do 



Norfolk sand 



do 



do 



do 



Carbon 



bisulphid 



added. 



Per cent. 



Control. 



Control. 

 2 

 2 



Control . 



Control. 



Control. 

 Control. 



Control. 



Control. 

 2 

 2 



Control. 



Control. 



Weight of first crop. 



Green. 



Gm. 



5 



15 

 10.5 



14-5 

 14-5 



5- 

 12. 

 28 



30- 

 27 



25 



17- 

 40. 



32 

 49. 

 12 

 17- 



Dry. 



Average. 



Gm. 



I. 2 



1-5 

 3 

 4 

 2 



3-5 

 3-7 

 3.7 

 I. 2 

 2 



6.5 



8 



6.2 



S 



4-5 

 7-5 

 8.7 

 10. 2 

 3 

 3-5 



Gm. 



1-35 



3-5 



2-75 



1.6 



7-25 



5-6 



6 



9-45 



3-25 



With one exception, Norfolk sandy soil, the carbon-bisulphid series 

 gave a larger yield. This was most marked in the case of clay-loam soil. 

 The data on p]^t growth agreed with the plate counts. 



The buckwheat was followed by a crop of Dwarf Essex rape. Unfortu- 

 nately the young rape plants suffered seriously from insects. Although 

 the tissue was too badly infested to save, a decided difference in growth 

 could be seen. The beneficial effect of carbon bisulphid on rape was 

 noted in every soil type. 



EFFECT OF CARBON BISULPHID ON VARIOUS CROPS IN ACID SOILS 



In order to study the effect of carbon bisulphid on the growth of higher 

 plants in acid soils, a series of experiments was made. Four types of 

 soil were selected for this work: Miami silt loam, Sparta sand, Colby 

 silt loam, and Marshfield peat. The neutral Miami silt loam was used 

 as a check for the acid soils. According to the Truog acidity test, Sparta 

 sand requires 0.5227 gm. of calcium carbonate per 100 gm. of soil, Colby 

 silt loam 1.021 gm., and Marshfield peat 4.43 gm. Four weeks after 

 treatment with carbon bisulphid, the soils were planted. 



RED CLOVER 



The effect of carbon bisulphid on medium red clover in acid soils is 

 clearly seen from the figures of Table XL The clover grew luxuriantly 

 in all soils except the untreated acid peat. Two crops were cut. Carbon 

 bisulphid in peat soil caused an enormous gain in the growth of clover. 

 This was very striking in both the first and second crop. 



