520 Report of Experiments vnth different Manures 
ripe, the produce, and tliat it was lower in the opposite conditions. 
Combinations of these several conditions (the two latter of which 
are each much influenced both by season and manure) determine 
the actual character of the produce in regard to the point in 
question. 
Percentages of Nitrogen in the Hay. 
Table V. (p. 534) shows the percentages of nitrogen in the 
produce of each plot in each of the four years under considera- 
tion, also the average over the four years, and the average over 
the seven years ; the left hand columns give the proportions in 
the hay as taken from the land, and the right hand ones those 
in the dry substance of the hav. 
It has been already stated — that Leguminous produce, in an 
equal condition of ripeness, gives a higher percentage of nitrogen 
than Graminaceous produce ; that, other things being equal, the 
more leafy or more unripe the crop, the higher will be the per- 
centage of nitrogen in the dry substance ; and that, in succulent 
and unripe produce more especially, the proportion may be 
much increased by a liberal or an excessive supply of nitrogen 
in manure. Keeping in view these few facts, the variations 
exhibited in the Table become intelligible ; and it will be 
observed that they are less directly traceable to the characters 
of the seasons, and much more dependent on variation in ma- 
nuring, than are those of either the dry substance or the mineral 
matter. 
In fact, the general result may be stated to be, that there was 
much less difference from year to year depending upon season, 
than between the produce of different plots in one and the 
same season depending on difference in manuring ; that, other 
things being equal, the more complex and the less Grami- 
naceous the herbage (conditions favoured by mineral manures), 
the more leafy, the less ripe, and the more excessive th6 nitro- 
genous manuring, the higher was the percentage of nitrogen ; 
that the more Graminaceous, the more stemmy, and the more 
ripe (conditions favoured by farmyard -manure, and by artificial 
combinations of both mineral and nitrogenous manure), the 
lower was the percentage of nitrogen. 
It was fully explained in our former paper on this subject, 
that a percentage of nitrogen in meadow-hay much beyond 
that found in the produce grown Avithout manure, or by farm- 
yard-manure, is by no means a sure indication of a propor- 
tionally increased amount of matured and digestible or assimi- 
lable nitrogenous substance. When the increased ])ercentage ol ^ 
nitrogen is due to a large proportion of Leguminous herbage, it 
will probably indicate a large proportion of nutritive nitrogenous- 
