164 
Effects of Manures on Grass-Land. 
with mineral manures ; but it was somewhat less so with the 
nitrate than with the ammonia-sahs. Mineral manure alone, 
containing^ both potass and phosphoric acid, greatly increased 
the growth of the Leguminous plants perennial red clover and 
meadow vetchling. Farmyard-manure like artificial nitrogenous 
manures, also, but in a less degree, much diminished the pro- 
portion of the Leguminous herbage. 
9. Every description of maauie diminished the number of 
species, and the frequency of occurrence, of the Miscellaneous or 
iceedy lierharje ; mineral manures alone less so than any other ; 
nitrogenous ones, especially in combination with mineral con- 
stituents, did so very strikingly, but they at the same time 
greatly increased the luxuriance of a few species, especially 
Rumex acetosa, and frequently Carum Carui and Achillaea^ 
millefolium. Plantago and Ranunculus were generally dis- 
couraged by active manures, excepting farmyard-manure and 
nitrate of soda. The nitrate also favoured Centaurea nigra and 
Taraxacum Dens-leonis. 
10. Considerable increase of produce was only obtained by 
means of farmyard-manure, or artificial manures containing both 
mineral constituents and ammonia-salts or nitrates. The crops 
so obtained were much more Graminaceous, and consisted in 
much greater proportion of but a few species of plants. The 
grasses developed were chiefly of the more bulky and freer 
growing kinds, and the produce Avas generally very stemmy — 
being the more so, and the coarser, the more excessive the 
manuring. 
11. Meadow-land mown for hay should not be manured exclu- 
sively with artificial manures, but should receive a dressing of 
well-rotted farmyard dung every four or five years. 
. 12. Sewage irrigation, like active manures applied to meadow- 
land in the ordinary way, has also a tendency to develop chiefly 
the Graminaceous herbage, excluding the Leguminous, 'and to 
a great extent the Miscellaneous or weedy plants. It also, at 
the expense of the rest, encourages a few free-growing grasses, 
among which, according to locality and other circumstances, Poa 
trivialis, Triticum rcpens, Dactylis glomerata, Holcus lanatus, 
and Lolium perenne have been observed to be A ery prominent. 
The result is an almost exclusively Graminaceous and very 
simple herbage. But, as the produce of sewage-irrigated meadows 
is generally cut in a very young and succulent condition, .the 
tendency wliich the great luxuriance of a few very free-growing 
grasses has to give a coarse and stemmy later growth is less 
objectionable than in the case of meadows left for hay. 
