394 Experiments with different Top-dressings upon Wheat. 
measure so uniformly as not to get a difference of from f to 1 lb. 
in the weight of different bushels of the same corn. 
The following table exhibits the produce in straw : — • 
Table showing the Prod'Me in Straw of each i-acre Plot, and Produce 
per acre. 
Per plot. 
Per acre. 
Plot 
I. 
II. 
III. 
IV. 
V. 
VI. 
VII. 
If cwt. of nitrate of soda 
(■ 180 lbs. of nitrate of soda and 1 
4 cwt. of wheat-manure .. 
6 cwt. of wheat-manure .. 
cwt. qrs. lbs. 
5 3 0 
6 0 2 
6 0 12 
.<> 3 23 
6 3 2 
4 1 20 
4 0 20 
ton cwt. qrs. lbs. 
13 0 0 
14 0 8 
1 4 1 20 
13 3 8 
17 0 8 
0 17 2 24 
0 16 2 24 
For the sake of better comparison, the increase per acre in 
corn and straw over unmanured portions of the experimental 
field, is stated in the next Table. 
Table showing the Increased Produce per acre in Corn and Straw over 
Unmanured Plot, in lbs. and bushels. 
Increase in com. 
Increase in straw. 
Plot 
- lbs. 
bushels. 
cwt. qrs. lbs. 
I. 
786 
5 1 4 
II. 
660 
11 
6 1 12 
III. 
Nitrate of soda and salt 
816 
13,^ 
6 2 24 
IV. 
4 cwt. of Proctor's wheat-mauure 
750 
124 
6 0 12 
V. 
6 cwt. of ditto 
1032 
9 1 12 
produce. 
produce. 
VI. 
1620 
27 
17 2 24 
increase. 
decrease. 
VII. 
none 
1 0 0 
An examination of the preceding results suggests the following 
remarks : — 
1. The plot manured with chalk-marl furnished as nearly 
as possible the same amount of corn as the unmanured plot, 
and rather less straw. 7 he produce in the one amounted to 
1620 lbs. of corn, and in the other to 1618 lbs.; or each gave 
27 bushels of wheat. 
In some parts of England chalk-marl is applied with consider- 
able benefit to the wheat-crop, but as the soil of the experimental 
field contained 18 per cent, of carbonate of lime, it could not be 
expected that a marl, which owes its fertilizing properties almost 
entirely to the carbonate of lime and to a little phosphate of lime 
which it contains, should produce any marked effect upon the 
