20 



4 places, and in these mixtures the total nitrogen has 

 been determined by soda-lime. 



The same difficulty arose in the application of the 

 results relating to the subsoils, as in the case of the 

 wheat field subsoils, owing to the natural irregularity 

 in composition independently of the special history 

 of the plots ; so that only some of the results relating 

 to the surface soils have been published (No. 60, 

 p. 39, 1882). 



In 1882, the soils of 26 of the 29 barley plots were 

 sampled, in most cases at 4 or at 3 places, but in a few 

 at only 2 places, on each plot, and in each case to the 

 depth of 3 times 9 inches, or 27 inches in all. A por- 

 tion of each individual sample is preserved, but mixtures 

 were also made representing respectively each of the 3 

 depths of each plot. Determinations of nitrogen by 

 soda-lime have been made in the first depth mixtures 

 for each of the plots, and in the mixtures of the second 

 and of the third depth for most of the plots. The 

 carbon has been determined in all the first depth mix- 

 tures, and in a few of those for the other depths. 

 Chlorine has been determined in some cases, and the 

 nitrogen as nitric acid at the 3 depths on most of the 

 plots. All the nitrogen as nitric acid results have been 

 published and discussed in No. 64, pp. 28-33, 1883. 

 Some illustrations have been given from the results as 

 to the total nitrogen in the surface soils, but none as to 

 that in the subsoils, nor as yet have any of the carbon 

 or chlorine results been published in detail ; but a 

 reference to the carbon results is given in No. 68> 

 p. 24. 



If the exigencies of other work permit, it would be 

 desirable to sample the barley soils again after the 

 removal of the fortieth crop (in 1891), that is after the 

 removal of 10 crops since the last sampling ; and, as in 

 the case of the wheat field soils, the samples should be- 

 taken in most cases to the depth of at least 8 times 

 9 inches, and in some to 12 times 9 inches ; to the 

 greater depth more especially for the determination of 

 nitric acid, and perhaps of chlorine. 



