EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT MEADOW. 291 
80 cwts. Intermediate between the extremes here quoted, very great variation in the 
amount of produce has been exhibited on the other differently manured plots. 
With these great differences in the amounts of produce the botanical character of 
the herbage has varied most strikingly. Thus, starting with perhaps 50 species on the 
unmanured land, any kind of manure—that is, anything that increases the growth of 
any species—induces a struggle, greater or less in degree, causing a greater or less 
diminution, or a disappearance, of some other species, until, on some plots, and in some 
seasons, less than 20 species have been observable; and on some, after a number of 
years, no more than this are ever traceable. 
Even in the first years of the experiments, it was noticed that those manures which 
are the most effective with wheat, barley, or oats, grown on arable land—that is, with 
gramineous species grown separately—were also the most effective in bringing forward 
the grasses proper in the mixed herbage ; and, again, those manures which were the 
most beneficial to beans or clover most developed the leguminous species of the 
mixed herbage, and vice versd. It was further observed, that there was great variation 
in the predominance of individual species among the grasses, and also among the 
representatives of other orders. And even in the second year the differences in the 
flora, so to speak, were so marked that a first attempt at a botanical analysis of care¬ 
fully taken samples of the jmoduce of some of the plots was then made. In the third 
year more detailed separations were made ; and, taking advantage of the experience 
thus gained, pretty complete botanical analyses have since been conducted four times, 
at intervals of five years, during the course of the now 24 years of the experiments ; 
and on several other occasions partial separations have been undertaken. The character 
and tendency of the results so obtained may be very briefly indicated as follows :— 
In the produce grown continuously without manure the average number of species 
found has been 49. Of these, 17 are grasses, 4 belong to the order Leguminosse, and 
28 to other orders. The percentage, by weight, of the grasses has averaged about 68, 
that of the Leguminosse about 9, and that of species of other orders 23. 
In the produce of the plot already referred to as the most heavily manured, and 
yielding the heaviest crops, the average number of species found has been only 19, of 
which 12-13 are grasses, 1 only (or none) leguminous, and 5-6 only represent other 
orders ; whilst the average proportions by weight have been—of grasses about 95 per 
cent., of Leguminosae less than O'Ol per cent., and of species representing other orders 
less than 5 per cent. 
On the other hand, a plot receiving annually manures such as are of little avail for 
gramineous crops grown separately in rotation, but which favour beans or clover so 
grown, has given, on the average, 43 species. Of these, 17 in number are grasses, 4 
Leguminosse, and 22 belong to other orders ; but, by weight, the percentage of grasses 
has averaged only 65-70, that of the Leguminosse nearly 20, and that of species 
belonging to other orders less than 15. 
With such very great variations, not only in the amount, but in the botanical 
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