E. J. Russell and A. Appleyard 



29 



Determinations of the amount of GOg in the soil air of grass land 

 are given in Table VII. The results show that more COg is usually 

 present than in arable land and the oxygen content is lower. But no 

 strict comparison with arable land can be made because of the great 



Table VII. Composition of soil air of grassland. Percentac/e by volume. 

 A. Pasture used for grazing. 



Da(u 



CO., 



Dec. 19, 1912 

 Jan. 13. 1913 

 Jan. 24 

 Feb. 11 ., 

 Feb. 26 „ 



1-5 

 0-7 

 31 

 0-7 

 2-0 



0., 



15-8 

 16-6 

 6-2 

 19-0 

 16-4 



N„ 



82-7 

 82-7 

 90-7 

 80-3 

 81-6 



CO., 



O., 



N, 



Bacterial N as 



numbers, nitrate, 



millions parts per 



per gram 1 million 



