86 
INVESTIGATIONS ON ROTHAMSTED SOILS. 
increase of potash for a given weight of crop is accompanied by 
increase of chlorin. This is seen in the following table: 
Table 44. — Broadbalk wheat soils — Potash and chlorin in crops on various plats. 
Plat 3, unmanured. 
Plat 5, minerals 
only. 
Plat 10a, ammonium 
salts only. 
Plat 10b, ammonium 
salts only. 
Plat 11, phosphates 
and ammonium 
salts. 
Plat 12, phosphates, 
sodium, and am- 
monium salts. 
Plat 14, phosphates, 
magnesium, and 
ammonium salts. 
Plat 2, farmyard 
manure. 
Plat 13, phosphates, 
potassium,* and 
ammonium salts. 
Plat 7, full minerals 
and ammonium 1 
salts. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Potash per acre in produce, 
annually, over 40 years. . 
14.29 
19. 91 
20.37 
23. 07 
23.35 
35.01 
36.80 
50 
51. 57 
53.06 
Chlorin per acre in prod- 
uce, annually, over 40 
years 
1.32 
1.84 
2.40 
2.96 
2.99 
4. 76 
5.20 
6.30 
8.59 
9.28 
Potash contained in 1,000 
pounds of average prod- 
uce (grain and straw) 
annually 
5.85 
7.04 
7m 
8.97 
9.32 
9.40 
Chlorin contained in 1,000 
pounds of average prod- 
uce (grain and straw) 
annually 
. 75 
.96 
1.01 
1.09 
1.(50 
1.65 
ACTION OF AMMONIUM SALTS ON THE LIME OP THE SOIL. 
A paper "On the composition of waters of land drainage," by the 
late Dr. Augustus Voelcker, F. R. S., 1 gives the detailed results of 
the examination of a large number of samples of drainage water col- 
lected from the Broadbalk field and supplied to him for the purpose 
by Messrs. Lawes and Gilbert in the years 1866, 1867, 1868, and 1869. 
These results are the only ones in existence giving complete analyses 
of the mineral constituents of these drainage waters; and the results 
of Dr. Voelcker's analyses are summarized and expressed as parts per 
million in the Rothamsted paper "On the amount and composition of 
the rain and drainage waters collected at Rothamsted," already sev- 
eral 1 imes referred to. (See p. 49.) The results of the mean analyses 
arc given as follows: 
'Journal of the Royal Agricultural Society of England, 2. ser., 10 (1874), pp. 
132-165. 
