42 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



the third was kept surface-cultivated. The results are 

 recorded below : — 



Percentage of C0 2 in the soil gas from three different plots in the 



Botanical Area. 



It will be seen that the percentage of carbon dioxide in 

 the soil air is highest in the grassed plot and lowest in the 

 cultivated plot, the air iu the soil of the trenched plot being 

 intermediate in composition. During the first six months 

 of the jrear 1919 the carbon dioxide in the air of the grassed 

 plot was between 0-5 to 0-3 per cent., that in the trenched 



