EXPERIMENTS ON THE MIXED HERBAGE OP PERMANENT MEADOW. 369 
over the eight years of its application, and those of its residue afterwards ; and then 
the difference of effect produced by the use of 200 lbs. of ammonia-salts per acre per 
annum, both during the eight years of the application of the farmyard manure, and 
during the subsequent 12 years of the action of the residue. 
Over the eight years of the application of the farmyard manure, there was an average 
produce of 4804 lbs. of hay, equal to an average annual increase over that without 
manure of 2139 lbs. It is remarkable that, over the first six years after the cessation 
of the application of the manure, the average produce was almost exactly the same as, 
and even rather more than, during the eight years of the application, namely, 4846 lbs ; 
and the average annual increase was also almost identical, being 2147 lbs. This result 
was, indeed, partly due to one or two of the six years being seasons of very high 
productiveness ; but still it is very striking. During the next six years there was one 
season of unusual drought, and others of much less than average productiveness ; and, 
under these circumstances, together with the fact that the then remaining residue 
would doubtless be in a less readily available condition, there was little more than half 
as much average produce, and less than two-fifths as much average increase, as over 
the first six years of the action of the manurial residue. Still, there was an increase of 
between 6 and 7 cwts. of hay, due to the residue, in 1875, the twelfth year after the 
cessation of the application of the manure, and of more in 1876 and 1877. 
The table further shows that very much more nitrogen was removed in the crops 
during the first, than during the second six years, of the action of the residue. But 
the amount was not, as was that of the hay, as much per acre per annum over the first 
six years as it had been over the eight of the application ; and over the second six 
years there was little more than half as much as over the first six, and the average 
annual increase was only about 4-| lbs., against 16 lbs. over the first six years. 
Of mineral matter, again, there was twice as much removed in the first as in the 
second six years of the action of the residue ; and there was of it a greater falling off 
in the first six years compared with the years of the application, than of either the 
hay or the nitrogen. 
The effect of the farmyard manure was to reduce the number of species developed, 
to bring into greater prominence the gramineous and the miscellaneous herbage, but 
to reduce the leguminous. The gramineous herbage became less mixed, a few indi¬ 
vidual species contributing a larger proportion of the hay. Of these, Poa trivialis, 
Bromus mollis, and Arena jlavescens, were the most prominent; whilst, without manure, 
neither of these was in any marked quantity, but Festuca ovina, Agrostis vulgaris, 
Avena pubescens, and IIolcus lanatus were the leading grasses, and Lolium perenne, 
Anthoxanthum odoratnm, and some others, were fairly represented. After the cessa¬ 
tion of the application of farmyard manure, however, the same grasses as without 
manure gradually became the more prominent on plot 2, whilst the Poa trivialis and 
Bromus mollis were, in 1877, represented in very insignificant amounts. Upon the 
whole, indeed, the general character of the herbage on the unmanured, and the 
3 B 
MDCCCLXXX. 
