602 Application of Sulphate of Ammonia to Wheat. 
20 rods each, and have this day caused the produce to be separately 
thrashed : the result is as follows: — 
Wheat. Straw. 
Bsh. Gals. lbs. * 
Salted land . . 4 2 . 274 
Unsalled . . 3 6 . 232 
Difference 0 4. 42 
£. J. f/. 
This gives, per acre, 4 bushels of wheat, at 6s. .14 0 
„ 3 cwt. of straw, at Is. • . 0 3 0 
£ 1 7 0 
The 5 cwt. of Sulphate of Ammonia cost, including 
carriage from London and expenses 
This being laid on 3 acres, gives the cost per acre . Ill 6 
Deduct difference of produce, as above . . .17 0 
Loss per acre . . . £ 0 4 6 
When wheat sells for 7*., instead of 6s. per bushel, the expense would 
just be covered by the increased produce. But, on the whole, the 
result of my experiment is, I think, in favour of the conclusion formed 
by Mr. Pusey, that these saline manures do not answer the purpose of 
the agriculturist.* 
I apprehend, however, that in estimating the value of these, and in- 
deed of other manures, we are apt to confine our attention too much to 
the immediate results. Manures differ exceedingly as to the condition 
in which they leave the land in ihe year following the first crop. Of 
stable-dung it is estimated that one half is left in the land after a crop 
of wheat. As to some other manures (lime, for instance), it seems to 
be now admitted by the most accurate observers that they ultimately 
exhaust the soil, though they produce an immediate benefit. In fact, 
manures of this class act as s/imv/atits merely ; they bring into an active 
and soluble form the humus previously existing in the soil, but add no- 
thing to the store of nutritive matter. Instead of leaving the land in 
better condition, they actually deteriorate it. That deterioration may 
indeed be comj ensated, or even more than compensated, by the imme- 
diate profit ; the farmer may gain such an increase of crop as, if laid 
out in the ])urcliase of manvire, n)ay place him and his land, on the 
whole, in a better jiosition than if tlie stimulating manure had not been 
applied. But it must always 1 e a most important question in what 
uaij does any given apjilication tend to increase the produce of the soil? 
And when 1 see comparative statements of the crops yielded by different 
manures, without any notice of the tendency of such manures to benefit 
4 14 7 
* Journal of Agricultural Society, vol. iii. p. 211. 
