THE BBOADBALK WHEAT SOILS. 
127 
Table 68.—Iiroadl>alk wheat -soils— Organic carbon, stated as percentages of fine 
dry soil and as pounds p< ■>• a<-n\ in samples collected October. 1SS1, and October, 
is 1 .'.;. 
First 9 inches. 
Second 9 inches. 
Third 9 inches. 
1881. 
lS'.CJ. 
1881. 
1S!(3. 
1881. 
1893. 
Per 
Pounds 
Per 
Pounds 
Per 
Pounds 
Per 
Pounds 
Per 
Pounds 
Per 
Pounds 
cent. 
per 
cent. 
per 
cent. 
per 
cent. 
per 
cent. 
per 
cent. 
per 
acre. 
acre. 
acre. 
acre 
acre. 
acre. 
Pint ";i 
711 
0.645 
17,880 
0.515 
14,376 
Plat 2b 
2. 182 
51,082 
8.880 
52,048 
ii. ,7 J 
lS.IKlT, 
.7 is 
19,981 

0. 518 
it." \m 
.492 
13,734 
Plat 3 . 
.977 
2.5. 3 in 
.888 
23,022 
.838 
16.848 
. 565 
15,093 
.468 
13.(104 
.483 
13.483 
Pl;it 1 
l.Ulli 
88, L86 
.\m 
23. .567 
. 587 
16,146 
.mi 
16,112* 
• M ri 
12.92.5 
. 463 
12,925 
Plat 5 
1. 
26. 
. 931 
21. 137 
. 8 8 
16, 288 
. 
1"). 6Sl 
. 4ti6 
13, m i> 
. 1 16 
12,450 
Hat 6 
1. KM 
:»l.*52 
ton 
26. 119 
.806 
16. Ins 
. 5*3 
15.574 
. 14» 
12.506 
.429 
11,976 
Plat 7 
1 . 267 
32, H49 
i. nu 
88,546 
. 599 
16,001 
.53(1 
14. l.> 
.4.50 
12,562 
.426 
11,892 
Plat 8 . 
L812 
84,015 
L188 
89 MM 
.•'46 
17.2.57 
. 61 I s 
16,242 
.470 
13,120 
.443 
12.3615 
Plat 9a 
1.250 
32, 
1. 162 
80,128 
. 655 
i7. m 
•Ml 
17.3-.ii 
. 163 
12. 825 
.535 
14.935 
Plat 0b 
i . i 15 
89,888 
1.IMIS 
26. 131 
JjlW 
16,242 
.640 
17,(>96 
. ».v> 
12,645 
. 524 
14,627 
Plat 10*. 
1.095 
88,888 
L048 
27. 197 
.620 
16,562 
06* 
17,844 
. 17.; 
13.2** 
.526 
14,683 
Plat lnl, 
1.088 
27,480 
.969 
85, 122 
.61* 
17,810 
.;■>.; 
17,681 
.521 
14.544 
.524 
It.. 127 
Plat 1 1 
1.176 
80, 180 
1. in? 
88,700 
.694 
18,680 
.643 
17.177 
.503 
14,041 
. 492 
13,734 
Plat 12 
1 . 885 
83.815 
1.12:$ 
88,116 
672 
17,861 
.♦•43 
17.177 
.501 
13. 9S5 
.526 
14,683 
Plat 18 
L.2B7 
82, 588 
L 181 
80,201 
. 664 
17.73* 
.630 
16, 328 
.4*1 
13. 127 
.477 
13.315 
Plat 1 1 
1 25t 
82, :»1 1 
l 187 
29, 178 
.641 
17. 123 
629 
16, *03 
. 193 
13. 762 
.502 
14.(113 
Plat 16 
i 810 
32.301 
1.17H 
80,381 
664 
17.7:^ 
727 
18, 421 
. 1*2 
13. 455 
. 535 
14.935 
Plat 16 
L080 
28,000 
LOBS 
27,611 
.5KH 
16,707 
. 882 
18.21* 
. 1st 
13.511 
.438 
12.227 
1.810 
:tl. :i71 
L.084 
> 363 
.612 
17. 160 
.850 
17.:$64 
. 17«.i 
13.371 
.492 
13,734 
ri.-it 
1.261 
32,693 
1 1 Mi 
2-.I.711 
J8B 
I7.IU3 
.6311 
16,828 
.442 
12.33X 
.478 
13.343 
Plat 1!' 
1.:*;: 
35,4*10 
1 - 
«.«, 
.717 
18, 158 
19,207 
:>ut 
14.1169 
.587 
16. 3S6 
Attention for the moment may be directed especially to the surface 
soils, representing the first 9 inches of each plat, in each of the three 
years. 
Having devoted so much time and space to the detailed considera- 
tion of the I s ' 1 -! samples, all we need here do is to see how far the 
results of the l\v.> previous samplings bear <»ut the conclusions gener- 
ally arrived at from those of later ones. You may be reminded that 
the three samplings represent the twenty-second, thirty-eighth, and 
fiftieth years of these continuous experiments. The continuously 
dunked plat, Jb, shows a steady gain in percent aire of nitrogen, which 
has increased markedly since 1 ss 1 , the three percentages being 0.1752, 
0.1836, and 0.2132. Between 1805 and 1881 the difference, expressed 
as pounds per acre, is less marked than in percentage, but this is 
because the surface soil has become lightened and weighs less for a" 
like depth. The organic carbon, between 1881 and 1893, shows an 
increase of 964 pounds per acre. 
The rape-cake plat (No. 19) was not analyzed in 1805. Between 
1881 and 1893, however, we see that it has accumulated 0.0079 per cent 
of nitrogen, or 191 pounds per acre. The farmyard manure and the 
rape-cake plat s, it will be remembered, are the onl} T plats that seem to 
accumulate actual mannrial nitrogenous matter as such. . 
Next we may consider plats :> and 4, the unmanured plats. Both 
show a steady decline in nitrogen and carbon from period to period. 
Closely behind them, both in nitrogen and carbon diminution, comes 
plat 5, with mineral dressings only. It has lost rather less nitrogen 
