148 
INVESTIGATIONS ON EOTHAMSTED SOILS. 
CARBON, AND RATIO OF CARBON TO NITROGEN. 
The carbon was not determined in the earlier samples, but only in 
those collected in 1882. The following table shows the percentages of 
carbon side by side with the percentages of total nitrogen, and the 
ratios of carbon to 1 nitrogen, and of nitrogen to 100 carbon: 
Table 80. — Hoos fieldbarley soils, samples collected February- March, 1882— Nitro- 
gen and carbon in first, second, and third depths of 9 inches each, stated as per- 
centages of fine, dry soil; also ratios of carbon to 1 nitrogen, and nitrogen to 100 
carbon. 
Sec- 
tion. 
Plat. 
First 9 inches. 
Second 9 inches. 
Third 9 inches. 
Nitro- 
gen. 
Car- 
bon. 
Carbon 
tol 
nitro- 
gen. 
Nitro- 
gen to 
100 car- 
bon. 
Nitro- 
gen. 
Car- 
Car- 
bon to 
1 ni- 
tro- 
gen. 

Nitro- 
gen to 
100 
car- 
bon. 
Nitro- 
gen. 
Car- 
bon. 
Car- 
bon to 
1 ni- 
tro- 
gen. 
Nitro- 
gen to 
100 
car- 
bon. 
O 
A 
1! 
I 
Per 
cent. 
0.0930 
.0897 
.0970 
.1124 
Per- 
cent. 
1.021 
.957 
1.007 
1.154 
11.0 
10.7 
10.4 
10.3 
9. 11 
9.37 
9.63 
9. 74 
Per- 
cent. 
0.0652 
.0538 
Per 
cent. 
Per 
cent. 
0.0490 
.0409 
Per- 
cent. 
0.188 
9.1 
11.02 
0. 414 
10.1 
9.88 
.0837 
.0730 
.0900 
.1020 
.1040 
.1096 
1.026 
1.060 
1.007 
1.082 
11.4 
10.4 
9.7 
9.9 
8. 77 
9.62 
10.33 
10. 13 
.0660 
.0649 
.0553 
.0647 
.555 
8.6 
11.69 
.519 
8.0 
12. 47 
.0772 
.0620 
.1080 
.1078 
.1112 
.1057 
1.110 
1.171 
1.117 
1.119 
10.3 
10.9 
10.0 
10.6 
9.73 
9.21 
9.96 
9.45 
.0759 
.683 
9.0 
11.11 
.0639 
.521 
8.2 
12. 26 
.0683 
.0.536 
AAS - 
C 
fl 
2 
u 
i 
{I 
.1042 
.1135 
.1133 
.1023 
1.071 
1.198 
1.174 
1.098 
10.3 
10.6 
10.4 
10.7 
9.73 
9.47 
9.65 
9.32 
.0793 
.0636 
.0646 
.0685 
.1234 
. 1207 
. 1330 
.1306 
1.327 
1. 313 
1. 375 
1.355 
10.8 
10.9 
10.3 
10.4 
9.30 
9. 19 
9.67 
9.64 
.0633 
.0684 
.0613 
.0733 
.0537 
.0632 
.0.543 
.0631 
.643 
9.4 
10.65 
.507 
8.0 
12.47 
. 1798 
.2131 
2.032 
2.486 
11.3 
11.7 
8.85 
8.57 
.0811 
,0836 
.638 
.727 
7.9 
8.7 
12.71 
11.49 
(Hill.-. 
.0523 
.542 
.506 
9.0 
9.7 
~Ti7T6 
10.34 
The first point that we naturally look to in the carbon results is to 
sec how far the quantity of carbon on plat 4 of section O (the plat 
which grows the large quantity of the yellow trefoil as a weed) accords 
with the high proportion of nitrogen contained in that plat. We see 
at once that there is a close correspondence. 
The other plats do not differ much in carbon from those of section 
A (ammonium salts), but the plats of the two sodium nitrate se<-iions 
give uniformly a higher percentage of carbon than the ammonium 
sails plats, showing generally pretty clearly the, influence of greater 
crop residue accumulation following greater crops. 
On the rape-cake plats the actual accumulation of added organic 
matter is distinctly indicated by a decidedly larger carbon accumula- 
tion; and, as we should expect , we not ice t he same thing, but to a 
much larger extent, in the case of the two farmyard-manure plats, 
