140 
INVESTIGATIONS ON ROTHAMSTED SOILS. 
the known additions of manurial potash to the soil and the quant ity 
of potash, as ascertained by analysis, in the crops removed from each 
plat. 
Table 75. — Broadbalk wheat soils — Samples collected in 1865, 1881, and 1893. 
[Plats 11, 12, 13, 14, 7, and 5. Potash per acre dissolved by 1 per cent citric-acid solution.] 
AFTER TWENTY-TWO YEARS (1844-1865). 
Plat. 
Treatment since 1851. 
Found. 
More (+) or less 
than plat 11. 
(-) 
Estimated 
excess ( + ) 
or defi- 
ciency ( — ) 
compared 
with plat 
11. 
First 9 
inches. 
Second 9 
inches. 
Third 9 
inches. 
27 inches. 
First 9 
inches. 
Second 9 
inches. 
Third 9 
inches. 
27 inches. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Pounds. 
11 
Nitrogen and phosphates . . 
93 
139 
101 
333 
12 
Nitrogen and phosphates 
and sodium salts (some 
potash in earlier years) 
156 
107 
134 
397 
+ 63 
- 32 
+ 33 
+ 
64 
+ 309 
14 
Nitrogen and phosphates 
and magnesium salts 
(some potash in earlier 
years ) 
93 
139 
112 
344 


+ 11 
+ 
10 
+ 219 
13 
Nitrogen and phosphates 
and potassium salts. 
519 
321 
123 
963 
+426 
+182 
+ 22 
+ 
630 
+2,021 
AFTER THIRTY-EIGHT YEARS (1844-1881). 
11 
12 
Nitrogen and phosphates .- 
52 
64 
78 
194 
Nitrogen and phosphates 
and sodium salts (some 
potash in earlier years) 
156 
75 
309 
+ 104 
+ 11 

+ 115 
+ 159 
14 
Nitrogen and phosphates 
and magnesium salts 
(some potash in earlier 
years ) 
114 
107 
156 
377 
+ 62 
+ 43 
+ 78 
+ 183 
+ 54 
13 
Nitrogen and phosphates 
and potassium salts 
591 
342 
89 
1,022 
+539 
+278 
+ 11 
+ 828 
+3,222 
AFTER FIFTY YEARS (1844-1893). 
11 
Nitrogen and phosphates . . 
83 
75 
101 
259 
12 
Nitrogen and phosphates 
and sodium salts (some 
potash in earlier years) . 
104 
" 107 
101 
312 
+ 21 
+ 32 

+ 53 
+ 20 
14 
Nitrogen and phosphatec 
and magnesium salts 
(some potash in earlier 
62 
128 
145 
335 
- 21 
+ 53 
+ 44 
+ 76 
- 92 
13 
Nitrogen and phosphates 
and potassium salts 
487 
363 
235 
1,087 
+404 
+288 
+ 134 
+ 826 
+4,052 
Nitrogen phosphates, po- 
tassium, sodium, and 
magnesium salts 
(502 
374 
179 
1,155 
+519 
+299 
+ 78 
+ 896 
+3, 062 
5 
Potassium, sodium, and 
magnesium salts, but no 
nitrogen 
799 
598 
257 
1,654 
+716 
+523 
+ 15(5 
+1,395 
+5,242 
In the case of the continuously dunged plat 2b, the accumulation 
of potash from period to period is not at all indicated by the hydro- 
chloric-acid results, but is qualitatively brought out very clearly in a 
comparison either of the L865 and L893 cit ric-acid results or of those 
of L881 and L893, particularly if the second and third depths be taken 
into account., though the increase between IS(;5and I SSI is not what 
would have been expected. Nevertheless the gradual accumulation 
of potash in the t wo successive depths of subsoil by downward pereo- 
lation is clearly seen in t he analyses of the samples representing these 
two depths in the various years. 
