44 Experiments on the Growth af Wheat. 
Table VI. 
Manures applied per acre 
in 4 Years. 
Inci'ease obtained per acre 
in 6 Years. 
Price 
per 
Ton. 
Corn. 
Straw. 
Cost 
of 
Value 
of 
Dif- 
Description. 
Quan- 
tities. 
Bushels. 
Price 
per 
Bushel. 
Cwts. 
Price 
. per 
Cwt. 
Manure. 
Increase. 
ference. 
l!ape-cake 
lbs. 
8000 
£. 
5 10 
46f 
«. A. 
7 0 
s. (2. 
1 3 
£. s. a. 
19 12 10 
£. s. d. 
21 I 4 
£. s. d 
18 6 
Siilpbatc of Ammonia 
JIm iate of Ammonia 
800 
800 
15 0 
20 0 
j 36 
7 0 
692 
1 3 
12 10 0 
IG 19 2 
4 9 2 
Peruvian Guano . 
21G0 
12 10 
45J 
T 0 
91 f 
1 3 
12 1 1 
21 13 2 
9 12 1 
indeed, much more than it is desirable to apply in ordinary 
practice. Nor should it be inferred from the plan and results of 
these experiments, that the practice of growing a series of corn- 
crops by means of artificial manures is to be recommended. But 
when these results are considered by the side of those obtained at 
Rothamsted, Holkham, and elsewhere, and with the light of the 
common experience of almost every arable district of the country, 
the practical conclusion undoubtedly is, that highly nitrogenous 
manures much increase the produce of grain-crops under the cir- 
cumstances in which these are generally grown in our rotations. 
Peruvian guano, which contains a large quantity of phosphates, 
as well as nitrogen-yielding matter, is one of the best artificial 
manures for wheat ; and 2 to 3 cwts. per acre, sown broadcast 
before the seed, and harrowed into the land, will generally be 
sufficient. When ammonia-salts are used, about 2 cwts. per acre 
may be employed, and 1 to 2 cwts. of superphosphate of lime 
should at the same time be applied. The above quantities are 
such as should generally be employed when the grain-crop is 
grown in the ordinary course of rotation, and the land is con- 
sidered to be not highly enough manured to carry as heavy a 
crop as the average of seasons will well ripen. 
But another great advantage to the farmer of the nitrogenous 
and phosphatic manures now in such general use is that, provided 
the land be well dunged once in the course of the rotation, he 
may, without injury to it, by their means frequently take an 
extra grain-crop in the course ; — for example, barley or oats 
after wheat, as the description and condition of the soil and the 
locality may indicate. In such cases, 1^ time or twice as much 
of the artificial manure should be used as when the crop is grown 
in the ordinary rotation. 
