396 Expcrimods icitk different Top-dressings tipo/i H'lieat. 
proved inefficacious or even injurious in relation to turnips, 
grown on a similar soil to that on which the wheat was raised — 
had a most marked and decidedly beneficial effect upon tlu- 
wheat-crop. 
It may not be amiss to contemplate these experiments in an 
economical point of view, and to ascertain to what extent the 
different top-dressings have repaid the outlay of money — which, 
it will be remembered, was 1/. 12s. 6rZ. per acre in all cases, 
except in the case of the larger dose of wlieat-manure, the appli- 
cation of which entailed an expenditure of 21. 8s. per acre. 
Leaving unnoticed the extra produce of straw, which in some 
cases was considerable, 1 shall only take into account the produce 
in corn. The present average price of wheat of ordinary quality 
is about 42s. per quarter. Taking 42s. as the price of wheat per 
quarter, we obtain the following money-value of the increase 
in produce, as the clear profit realized by the top-dressings after 
deducting the expense of the manures : — • 
Table sliowing the Money Value of Increase in Corn per acre over 
Unmanured Plot, and Clear Profit after deducting the price paid 
for Manures. 
Money in- 
crease iu com. 
Cost of 
Manure. 
Clear I'rofii. 
Pint, 
, £. s. d. 
£. s. d. 
£,. S. d. 
I. 
3 8 9 
1 12 6 
1 16 .". 
II. 
Nitrate of soda 
2 17 9 
1 12 6 
1 5 .■! 
III. 
Nitrate of soda and salt 
3 11 .5 
1 12 G 
1 IS 11 
IV. 
4 cwt. of wheat-manure 
3 5 7 
1 12 G 
1 1.3 I 
V. 
6 cwt. of wheat-manure 
4 10 4 
2 8 0 
2 2 + 
VI. 
.. .. 
loss. 
VII. 
none 
1 12 G 
1 12 <; 
It will be seen that, with the exception of the chalk-marl, all 
the top-dressings paid very well, and that the more liberal outlay 
for manure produced by far the best return in money. 
I purpose to note down the relative produce of next season s 
crop on each of the |-acre experimental plots, and hope thus to 
ascertain whether the efficacy of the various top-dressings was 
spent in one season or not. In estimating the profits arising from 
the use of these top-dressings, the condition in wiiich the land is 
left after the removal of the crop ought, by rights, to be taken 
into account. It appears to me that the productiveness of the 
different plots will be found to vary considerably. 
In nitrate of soda we have only two constituents, namely, soda 
and nitric acid. Soda has scarcely any fertilizing value, and in 
combination with nitric acid it is, moreover, readily removed by 
