138 
INVESTIGATIONS ON ROTHAMSTED SOILS. 
1881 results are compared with those of 1893, though in the second 
depth the difference between the figures for 1865 and 1881 is not in 
the direction that would be expected. 
POTASH (1865, 1881, AND 1893 RESULTS COMPARED). 
We may now in the same way briefly examine the potash results 
for the samples of the three periods. These are recorded in the fol- 
lowing table : 
Table 74. — Soils from Broadbalk wheat field, Rothamsted— Samples collected in 
1865, 1881, and 1893— Potash determinations. 
FIRST 9 INCHES OF SOIL. 
Dissolved by strong hydrochloric acid. 
Dissolved by 1 per cent solution of citric 
acid. 
1865. 
1881. 
1893. 
1865. 
1881. 
1893. 
Per 
cent. 
Pounds 
per 
acre. 
Per 
cent. 
Pounds 
per 
acre. 
Per 
cent. 
Pounds 
per 
acre. 
Per 
cent. 
Pounds 
per 
acre. 
Per 
cent. 
Pounds 
per 
acre. 
Per 
cent. 
Pounds 
per 
acre. 
Plat 3 .. 
Plat 4 
0.191 
4,952 
0.226 
5,859 
0.220 
.219 
.240 
.234 
.197 
.223 
.240 
.273 
.262 
.279 
.285 
.277 
5, 704 
5.678 
6,222 
6,067 
5.107 
5, 782 
0,222 
7.078 
6.793 
7.233 
6,652 
6.953 
0.0040 
104 
0.0032 

83 
0.0032 
.0052 
.0032 
.0040 
.0032 
.0040 
.0024 
.0188 
.0232 
.0308 
.0384 
.0330 
83 
1&5 
83 
104 
83 
104 
62 
487 
602 
799 
896 
828 
Plat lUa. 
Plat 10b. 
Plat 11.. 
Plat 12- 
Plat 14., 
Plat 13.. 
Plat 7 
. 226 
" "."228 
.232 
.244 
.269 
5,859 
" 5."9li" 
6,015 
6,326 
6,974 
.224 
.244 
.243 
.234 
.251 
.290 
5,807 
6,326 
6,300 
6,067 
6,507 
7,519 
.0040 
".0036" 
.0060 
.0036 
.0200 
104 
93" 
156 
93 
519 
.0020 
.0032 
.0020 
.0060 
.0044 
.0228 
52 
83 
52 
156 
114 
591 
Plat 5 
Plat 2b.. 
Plat 2a 
.273 
6,767 
.259 
6,206 
.0300 
744 
.0284 
681 
SECOND 9 INCHES OF SOIL. 
Plat 3... 
Plat 4 
0.336 
8,976 
0.407 
10,872 
0.335 
.414 
.394 
.359 
.367 
.371 
-.404 
.379 
.361 
.410 
.318 
.398 
8,949 
11.059 
10.525 
9,590 
9,537 
9,911 
10,792 
10, 124 
9,643 
10,952 
8. 495 
10,632 
0.0028 
75 
0.0044 
118 
0.0060 
.0060 
.0032 
.0052 
.0028 
.0040 
.0048 
.0136 
.0140 
.0224 
.0276 
.0168 
160 
160 
86 
139 
75 
107 
128 
363 
374 
598 
737 
449 
Plat 10a. 
Plat 10b. 
Plat 11 . 
Plat 12.. 
Plat 14- 
Plat 13.. 
Plat 7 
.360 
9,617 
.336 
.374 
.409 
.390 
.403 
.446 
8.976 
9.991 
10,926 
10, 418 
10, 765 
11,914 
.0048 
128 
.0024 
.0028 
.0024 
.0028 
.0040 
.0128 
64 
75 
64 
75 
107 
342 
.472 
.384 
.491 
.382 
12.609 
10,258 
13, 116 
10,204 
.0052 
.0040 
.0052 
.0120 
139 
107 
139 
321 
Plat 5 
Plat 2b.. 
Plat 2a 
.334 
8,922 
.366 
9, 777 
.0140 
374 
.0176 
470 
THIRD 9 INCHES OF SOIL. 
Plat 3... 
Plat 4 
0.459 
12,813 
0.466 
13,008 
0. 495 
.507 
.533 
.507 
.459 
.488 
.408 
.433 
. 459 
.472 
.415 
.499 
13,818 
14, 153 
L4,879 
14, 153 
12,813 
13, 023 
11,389 
18,087 
12,818 
18, L76 
1 1 . 5X5 
13.930 
0. 0032 
89 
0.0040 
112 
0. 0072 
.0044 
.0048 
.0036 
.0036 
.0088 
.0052 
i m 164 
.0064 
.0092 
.0128 
.0096 
201 
123 
134 
101 
101 
101 
145 
235 
179 
257 
357 
268 
Plat 10a 
Plat 10b. 
Plat 11. 
Plat 12 
Pint 14 
Plat 13 
Plat 7 
.511 
""."489" 
. 450 
.640 
.458 
14,265 
13^660" 
12,729 
15, 074 
12.786 
.475 
. 409 
. 452 
.006 
.646 
. 408 
13,260 
13,092 
12,618 
14,007 
15.242 
13, 762 
.0044 
123 
.0028 
.O02S 
.0028 
.0028 
.0050 
.0032 
78 
78 
78 
78 
156 
89 
.1X130 
.0048 
.0040 
.0044 
101 
134 
112 
123 
Pint 2b 
Pint 2n 
.410 
11,445 
.532 
14,861 
.0040 
112 
.0052 
145 
With regard i<> the hydrocWoric-acid-soluble potash little need be 
added to what has already been said in discussing the 1893 results. 
Such a met hod of analysis docs not serve to give consistent compara- 
tive results, i therefore now direct attention simply to the citric-acid 
figures. 
