ON THE MIXED HERBAGE OE PERMANENT MEADOW. 
1393 
showed some signs of recovery and increasing tendency to ripen seed, as also did some 
of the Miscellanese. 
From year to year these characters developed, the plot losing all semblance to 
plot 5 and gradually assimilating in character to plot 7 ; the chief difference between 
plots 6 and 7 being that the former did not show so conspicuous a development of 
Leguminosse. 
It will be necessary to make brief reference to the chemical history of the plots, 
and of their produce, in order to attain a clearer conception of the changes of result 
effected by the change of manuring. In the first place, in the first and second crops 
of the last 12 years, there has been about one and a-half time as much dry substance 
grown on plot 6, where mineral manure was substituted for ammonia-salts, as on 
plot 5, where the application of ammonia-salts was continued. Then again, it is found 
that as much nitrogen has been removed in the first crops of the 12 years since the 
change, from plot 6 to which no nitrogen has, during that period, been applied, as 
from plot 5, to which the application has been continued. But in five of the last six 
seasons second crops have also been removed from the land, and in these rather less 
nitrogen has been removed from plot 6 without, than from plot 5 with the continuous 
supply. The reason of this doubtless is that, whilst on plot 5 the first crops were leafy 
and unmatured, those of plot 6 were much more stemmy and ripe, and, therefore, the 
herbage was the more exhausted; to add to which disadvantage, there was also doubt¬ 
less a less available store of nitrogen remaining. The result is, however, that there is 
only an average of between 3 and 4 lbs. less nitrogen yielded per acre per annum 
on plot 6, in the first and second crops taken together, than on plot 5. It is, 
however, remarkable, that even more nitrogen has been taken off in the produce of 
plot 7, to which none has been applied from the commencement (but only a mixed 
mineral manure including potass), than in that of either plot 5, to which more nitrogen 
was annually applied as ammonia-salts than was removed in the crops, or in that of 
plot 6, which had the same amount of ammonia-salts during the first 13 of the 25 years. 
Further, the percentage of nitrogen in the dry substance of the produce is, since 
the change, very much lower in that of plot 6 than in that of plot 5. This indicates 
very much greater maturation, that is, very much more consohdation, or, in other 
words, under the influence of the mineral manure very much more carbon-assimilation 
in proportion to a given amount of nitrogen taken up. The percentage of nitrogen in 
the dry substance of the produce of plot 6 is indeed somewhat lower than in that of 
plot 7, owing to its less proportion of the more highly nitrogenous leguminous herbage. 
In regard to the source of the large amount of nitrogen taken up on plot 7, where 
none has been applied, it was stated (Part I., p. 312) that, after the experiments had 
proceeded 20 years, the soil of plot 7 showed a considerably lower percentage of 
nitrogen than that either of the unmanured plot, or of the ammonia plot 5. 
That of plot 6 also showed a considerable reduction. The obvious inference is that, 
on plot 7 at any rate, nitrogen must, under the influence of the mineral manure, have 
