294 
MESSRS. J. B. LAWES AND J. H. GILBERT ON THE RESULTS OF 
should serve as direct models for practical agriculture, but such as should provide the 
data both for interesting scientific generalisation, and for useful practical deduction. 
Accordingly, the present section of our report will be devoted mainly to a description 
of the influence of different manures, and of different seasons, on the amounts of produce 
obtained—that is, on the activity of accumulation and growth —with only such general 
references to the botanical, the chemical, or the economic character .of the herbage, as 
may be necessary to prevent erroneous, and lead to correct interpretations and 
conclusions. 
The experiments were commenced in 1856, so that the season of 1875 completed 
the twentieth, and the present season (1879) completes the twenty-fourth year of their 
continuance. They have been conducted on a portion of the Park at Pothamsted, 
where the land has probably been in grass for some centuries. No fresh seed has been 
artificially sown within the last 50 years certainly, nor is there record of any previous 
sowing. For many years prior to 1851 the plan was to manure occasionally with farm¬ 
yard dung, road scrapings, and the like ; and in the later years sometimes with guano, 
or other purchased manures. One crop of hay was removed annually, averaging from 
1^ to If tons per acre. The second crop was always eaten off by sheep. In the 
spring of 1851, and again in 1852, four separate acres of the afterwards selected area 
were appropriated to the consumption by sheep of as many lots of differently-manured 
turnips, 10 tons of the roots being consumed upon each acre. Neither of these four 
acres was manured in any other way, nor was the remainder of the land manured at 
all in those two seasons (1851 and 1852), nor was any of it manured at all in either of 
the three next succeeding seasons—that is, in the three immediately preceding the 
commencement of the experiments in 1856. It may be added that the consumption 
of the different turnips on the land for two consecutive seasons did not in any case 
increase the produce over the five years, 1851-5 inclusive, by more than about 2 cwts. 
of hay per acre per annum. The land is a somewhat heavy loam, with red clay subsoil, 
resting upon chalk, and although it is not artificially, it is thus naturally, well drained. 
Lastly, the area selected is very level, and at the time the experiments were com¬ 
menced the character of the herbage appeared fairly uniform over the whole of it. 
At first, about five-and-a-half acres, divided into 13 plots, most of half, but some of 
a quarter of an acre each, were devoted to the purpose. In 1858 four more plots, 
comprising together two-thirds of an acre, were brought in ; in 1865 one plot of half 
an acre; and in 1872 two plots of an eighth of an acre each; making, in all, about 
seven acres. Thus, the respective plots were commenced as follows :— 
Plots 1-13 in 1856. 
Plots 14-17 in 1858. 
Plot 18 in 1865. 
Plots 19 and 20 in 1872. 
Two of the plots (3 and 12) have been left entirely unmanured from the commence- 
