84 
INVESTIGATIONS ON ROTHAMSTED SOILS. 
salts every year containing 112 pounds of ehlorin per acre, the latter 
having received for ten years the same quantity of nitrogen as plat 
15, but in the form of sodium nitrate, we find the quantities of ehlo- 
rin contained in the eight depths examined to be, respectively, in round 
numbers, 232 pounds and 118 pounds per acre; the difference of 114 
pounds being almost exactly the quantity of ehlorin contained in a 
year's application of ammonium salts. On the sodium nitrate plat the 
quantity of ehlorin is almost the same as on plat 5, without ammo- 
nium salts. 
It will be noticed throughout that below the first two or three depths 
t here is comparative uniformity in the quantity of ehlorin found from 
depth to depth in each plat, and the differences are probably due to 
more or less of absorbent clayey matter, with corresponding varia- 
tions to the quantity of sand or gravel which, when in excess would 
tend to aid, and when in deficiency to retard, percolation. 
CHLORIN IN CROPS. 
It is interesting here to see the quantities of ehlorin contained in 
the crops produced on the various plats. The following table (Table 
43) shows this for some of the plats over a period of forty seasons, 
namely, from 1852 to 1891. The ehlorin, it should be observed, is 
mainly found in the straw as part of the miscellaneous unassimilated 
matters of the steins and leaf, the quantity in the grain itself being 
comparatively trifling. 
Table 43. — Broadbalk wheat plats — Chlorin per acre removed per annum in total 
produce {grain and straw). 
Chlorin in grain a.nd straw per acre: 
Average of 10 years— 
1852-1861 
1862 iH7i 
1K72 IKH1 
\m> mn 
Average 
Total produce per acre (grain and 
straw): 
I i years' average 
( Ihlorin per 1,000 pounds of produce 
i grain and straw), average 
Plat 2b, farmyard 
manure. 
Plat 3, unmanured. 
Plat 5, minerals 
only. 
Plat 7. full minerals 
and ammonium 
salts. 
Plat 10a, ammo- 
nium salts only. 
Plat 10b, a m m o- 
nium salts only. 
Plat 11, phosphates 
and ammonium 
salts. 
Plat 12. phosphates, 
sodium, and am- 
monium salts. 
Plat 13, phosphates, 
potassium, and 
ammonium salts. 
Plat 14, phosphates, 
magnesium, and 
ammonium salts. 
Lbs. 
Lb.*. 
Lbs. 
TM. 
Lb ft. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
Lbs. 
6. 78 
1.7] 
2. 59 
8. 52 
3.32 
4. 10 
:;. 59 
6.05 
8.27 
7.54 
7.26 
1.58 
2. 12 
9.33 
2. 70 
3.70 
4. 65 
5. 74 
9.81 
6.00 
.82 
1.17 
7. 03 
1.21 
1.38 
1.83 
3.04 
6. 58 
:; 19 
7.75 
1.15 
1.46 
12.25 
2.26 
2.64 
1.87 
I L9 
9.60 
4.06* 
6.32 
LOO 
1.32 
1,934 
0. 68 
1.84 
2, 242 
0.82 
9.28 
5,629 
1 . 65 
2.40 
3, 104 
0. 77 
2.96 
3,501 
0. 85 
2.99 
3,988 
0. 75 
4.76 
4.973 
0.06 
8.59 
5.365 
1.60 
5.20 
5.112 
1.01 
Ii is evident from the results given in this table that a high propor- 
tion of ehlorin in the crops is not merely related to an abundant sup- 
ply of ehlorin in manure. For instance, the produce of plat 5, whiofl 
receives aochlorids, contains, in relation to its weight, no less ehlorin 
