EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT MEADOW. 337 
disintegration, and consequently greater permeability of the subsoil under its influence, 
the loss of the supplied nitrogen by drainage would be the greater. Lastly, that the 
percentage of nitrogen in the lower layers should be even less in the case of the 
nitrate than of the unmanured plot may perhaps be partly due to more rapid oxi¬ 
dation, and more easy percolation and loss by drainage, of the nitrogen of previous 
accumulations, in the more disintegrated and more porous subsoil. 
The main distinctions in the flora on plot 14 with the nitrate and plot 9 with the 
ammonia-salts are, that with the nitrate there was more, and an increasing amount, of 
Alopecurus, very much more Bromus mollis and Poa trivialis, and more of Lolium 
perenne; but, on the other hand, there was very much less Poa pratensis and Festuca 
ovina, much less Agrostis, and upon the whole less Holcus, with, in all, more total 
Gramineae. 
On neither plot is there, on the average of seasons, anything like 1 per cent, of 
leguminous herbage in the produce; but there is more on the plot with the nitrate 
than on that with the ammonia-salts. 
Of herbage referable to other orders, the ammonia-salts have generally yielded more 
than the nitrate, but latterly not so much. The most prominent of these plants under 
the influence of the ammonia-salts is Pmnex acetosa; next in order comes the Cono¬ 
podium denudatum, and then the Achillea millefolium; others occurring in quite 
immaterial amounts. The chief of those developed on the nitrate-plot are, again, 
Bumex acetosa, and, in somewhat equal and increasing amount, Anthviscus sylvestris, 
the Achillea millefolium and Conopodium denudatum coming next in order, but each 
in less quantity than with the ammonia-salts. All others are in insignificant amount, 
but Taraxicum officinale occurs more plentifully than on plot 9. 
With the striking differences in the amount of produce, in the amount of total 
mineral matter taken up, in the botanical composition of the herbage, in the character 
and distribution of the roots, and in the influence of the vegetation and the manures on 
the mechanical condition, and on the chemical composition, of the subsoil, accordingly 
as the nitrogen is applied as ammonia-salts or as nitrate of soda, it will be of interest 
briefly to call attention to the chief differences in the chemical composition of the produce. 
As shown in Table XII., there was, with much more vegetable matter produced, 
even less nitrogen taken up and retained in the produce grown by the nitrate than in 
that by the ammonia-salts. The result was, a much lower percentage of nitrogen 
in the dry matter of the produce of the nitrate-plot; and, indeed, a much more 
normal percentage for this almost purely gramineous herbage. This lower percentage of 
nitrogen, with at the same time increased crop, implies of course an increased assimi¬ 
lation of carbon—that is to say more activity of growth—in proportion to the nitrogen 
taken up. There was, coincidently, more lime, magnesia, phosphoric acid, and sul¬ 
phuric acid, considerably more silica, and very much more soda, taken up under the 
influence of the nitrate ; but there was, on the other hand, considerably less potass, 
and very much less chlorine, taken up. 
MDCCC'LXXX. 2 X 
