EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT MEADOW. 311 
figures given on page 309 show that whilst the percentage of nitrogen in the miscel¬ 
laneous herbage is not much higher than that in the gramineous, the percentage in the 
leguminous herbage is very much higher ; in fact, not far from twice as high. The 
result is that, although there is by the mineral manure a greater increase in gramineous 
than in leguminous hay, a larger proportion of the increase of nitrogen is due to the 
leguminous than to the gramineous herbage ; whilst the miscellaneous herbage con¬ 
tributes practically none of the increased yield of nitrogen. Again, whilst in the 
unmanured produce the leguminous herbage has taken up little more than one-fifth as 
much nitrogen as the gramineous, in the mineral manured produce there is nearly two- 
thirds as much in the leguminous as in the gramineous herbage. Or, to put it in 
another way, whilst the average annual amount of nitrogen in the gramineous herbage 
was 20 lbs. without, and 29 - 3 with, the manure, or 9'3 lbs. more with than without it, 
it was in the leguminous herbage only 4‘2 lbs. without, but 1 8 2 lbs. with the manure, 
or 14 - 0 lbs. more with than without it. 
As already said, it is entirely consistent with experience in the growth of individual 
leguminous crops on arable land, that the amount, both of the produce and of the 
nitrogen assimilated, should be considerably increased under the influence of such a 
manure ; and although the source of the increased yield of nitrogen under such circum¬ 
stances is not conclusively proved, the weight of evidence is in favour of the conclusion 
that it is derived from the soil; and, in the case of clover and beans, at any rate, more 
probably from the lower than the upper layers. In the unmanured mixed herbage the 
deeper-rooting Lotus corniculatus and Trifolium rat ease contributed most of the 
leguminous produce; but in the manured herbage it is the comparatively surface¬ 
rooting Lathyrus jpratensis that mainly contributes the leguminous increase. 
Again, although experience in the growth of gramineous crops on arable land did 
not lead us to expect so much increase in the growth of gramineous species in the 
mixed herbage, yet even among the grain crops there is a notable difference in the 
effect of mineral manures, according to the habit of development of the plant, and to the 
circumstances of its growth. Thus, the spring-sown barley, which lias but a short time 
in which to extend its roots, and to gain command of the resources of the soil, throws 
out a large amount of fibre near the surface, and is more benefited by the application 
of direct mineral manures than is the autumn-sown wheat, which has four or five 
months longer for root-distribution, and is less dependent on the stores of the surface 
soil. In accordance with this, the greatly increased yield of gramineous produce in the 
mixed herbage by the purely mineral manure was almost exclusively due to the much 
denser growth, and much greater tendency to form stem and seed, of the creeping, and 
surface-rooting, Festuca ovina, Agrostis vulgaris, and ILolcus lanatus . 
The question still remains—what is the source of the greatly increased yield of 
nitrogen, both in the gramineous and the leguminous herbage, under the influence 
of the purely mineral, that is non-nitrogenous, manure ? 
The annual yield of nitrogen per acre, in the gramineous herbage alone, of the 
