342 
Home Produce, Imports, Consumption, 
in yield from that cause, it happened that, taken together, those 
eight seasons were of considerably more than average produc- 
tiveness ; so that, perhaps, we may assume the average produce 
of those eight years fairly to represent the standard produce of 
the unmanured land independently of material exhaustion. 
That produce was equal to 17 bushels, at the standard weight of 
61 lbs. per bushel. If now we calculate what should be the 
produce in each of the subsequent twenty-eight years, on the 
assumption that it fluctuated from the standard exactly in the 
proportion of the fluctuation from year to year of the adopted 
average yield of the country at large, and compare the result so 
obtained with the actual yield of the plot each year, we find 
that the latter shows an average annual deficiency over the 
twenty-eight years of 4| bushels. According to this mode of 
calculation, therefore, this represents the decline of produce on 
the unmanured plot, irrespectively of season ; and it may be ob- 
served that, supposing it to be uniform over the whole period, it 
would correspond to a rate of diminution, due to exhaustion, of 
between one-quarter and one-third of a bushel from year to year. 
It remains to be seen whether, with a return of good seasons, the 
decline will be as marked ; and also whether, in time, a point 
will be reached at which the produce will remain constant, 
excepting so far as it is influenced by the fluctuations of the 
seasons. 
Hie Farmyard-manure Plot. — If the unmanured plot is 
declining in yield and fertility, there can be no doubt that 
the farmyard-manure plot is increasing in fertility. Analysis 
at different periods shows that the surface soil has become more 
than twice as rich in nitrogen as the unmanured land. In fact, 
as we have shown on several occasions, a large amount of the 
constituents of farmyard-manure accumulates within the soil, 
and they are taken up very slowly by crops. It is, indeed, 
remarkable that, notwithstanding this great accumulation within 
the soil, the crops on the dunged plot never show over-luxuri- 
ance. During the last few years there has even been a con- 
siderable decline in produce, due to unfavourable seasons, which 
have greatly encouraged the growth of weeds, and especially of 
grass ; whilst, owing to the wetness of the seasons, it has been 
quite impossible effectually to clean the land, and what has 
been done to that end has not been accomplished without injury 
to the crop. 
If, as in the case of the unmanured plot, we were to adopt the 
average of the first eight years, from 1844 to 1851, to represent 
the standard yield of the farmyard-manure plot, irrespectively of 
material accumulation, the figure arrived at would be 28|^ bushels. 
This is certainly a surprisingly low produce to be obtained by 
