146 INFLUENCE OF MANURES ON GRASS LAND. 



Rothamsted have rendered classic, and one follows their 
account of “The Battle of the Meadow ” with all the interest 
that a life-and-death struggle can evoke. 
While a knowledge of the botanical composition of 
herbage is most interesting, its practical importance may 
easily be exaggerated. Thus, for instance, while a large 
increase in the percentage of cocksfoot may accompany 
pasture improvement in one district, it does not by any means 
follow that corresponding improvement in another district 
will be associated with an increase in the relative abundance 
ofthis plant. Or, to take the case of another plant—York- 
shire fog—it may safely be asserted that whereas this species 
is generally indicative of unsatisfactory conditions, there are 
circumstances where its presence is a sign of improved 
fertility. In the case of some plants, however— notably 
white clover—an increase in their relative abundance is a 
reliable general index of improvement in the quality of the 
herbage. ? 
The subject, in fact, is one that admits of being looked at 
from many different points of view. Thus,a plant that is 
very abundant in a light crop of hay may be very deficient 
when the yield is large. Then, again, a mere statement of 
the percentage abundance of a plart leaves much that is 
important out of account. Suppose, for instance, that one 
has three plots, one unmanured, one treated with basic siag, 
and the third treated with kainit, and that a botanical 
analysis gives the following figures :— 

Treatment. 
| 3 
; . | Per cent. of Cwt. of 
| Cwt. of Hay. Clover. Classe 



Plot 1 - | No manure 
20 20 4 
Plot 2 - | Basic slag 25 20 5 
Plot 3 - | Kainit 25 16 4 
The percentage of clover is the same in the case of Plots 1 
and 2, but this is no indication of the effectiveness of this 
manure to influence clover, for when the yield is taken into 
account it is seen that Plot 2 has produced 5 cwt. of this plant 
as against 4 cwt.on Plot 1. With the same relative abundance 
we have thus an increase of 25 per cent. in the absolute 
