86 Home Produce, Imports, Consumption, and 
of the c 'untry at large, the produce that the unmanured plot 
should yield each year has been calculated ; and the difference 
between the result so obtained and the actual yield of the plot 
each year shows the excess or deficiency of the actual produce, 
and, if deficiency, indicates the decline due to exhaustion. 
In 1880, with the results for twenty-eight years then at 
command, such a calculation showed an average deficiency over 
the period of rather more than 4§ bushels. This, therefore, 
according to the mode of calculation adopted, represented the 
decline of the produce on the unmanured plot during that period 
irrespectively of season. The results further showed that, sup- 
posing the decline had been uniform over the whole period, it 
would correspond to a rate of diminution of between one-quarter 
and one-third of a bushel from year to year. It was suggested, 
however, whether with a return of better seasons the decline 
would be as marked. In reference to this point it may be 
stated, that the last nine of the twenty-eight years gave a lower 
average produce over the country at large than any equal 
period of the previous nineteen or of the succeeding twelve 
years ; and that they gave an average of only 9 bushels per 
acre on the unmanured plot against 12| bushels over the suc- 
ceeding twelve years. Following the same line of calculation 
for forty years, with, as above referred to, a return of better 
seasons, especially during the last eight or nine years, to 1891 
inclusive, the figures showed almost exactly the same average 
deficiency of actual produce, compared with the standard of 17 
bushels, over the forty years as was formerly found for the twenty- 
eight years, namely, 4^- bushels, against rather more than 4$ 
bushels over the twenty-eight years. This, if the decline had 
been uniform, would correspond to less than a quarter (about 
two-ninths) of a bushel per acre from year to year over the forty 
years, instead of nearly one-third of a bushel over the twenty-eight 
years. But even this reduced rate of decline, due to a return of 
better seasons, indicated a calculated produce on the unmanured 
plot of only about 8 bushels in the fortieth year, against an 
actual produce over the last three years of about 1 3 bushels ; and 
it showed an average of only about 9 bushels over the last ten 
years, against an actual average of nearly 12^ bushels. 
It was concluded, therefore, that the adopted standard of 17 
bushels showed a greater decline than was indicated by the 
actual produce obtained, and that that standard was too high. 
Accordingly, the calculations have now been made on the as- 
sumption that the standard unmanured produce with which to 
compare the actual produce, as influenced by exhaustion, was 
only 16 bushels. 
