32 
EXPERIMENTS ON THE EFFECT OF 
2) Under the conditions of the Japanese climate, well pre¬ 
pared and finely powdered organic manures (fish manure, 
steamed bone dust) manifest a strikingly rapid action on crops. 
Of the nitrogen contained in them half or more was assimilated 
by the first crop (barley). 
3) Provided that the whole manure be applied in Autumn 
before sowing and the effect on the first crop be only taken into 
account the relative values of the nitrogenous compounds in 
the 4 fertilizers are as follows, assuming the value of ammonium 
sulphate to be 100. 
Ammonium Night- Fish Steamed 
sulphate. soil. manure. bone dust. 
100 103.5 ii 7*3 137-5 
In this case the rate of nitrogen actually consumed from the 
manures was taken as the basis of the calculation. Judging, 
on the other hand, from the increase of the dry matter of the 
crop caused by the nitrogen of the 4 fertilizers, we obtain the 
following scale of values : 
Ammonium Night- Fish Steamed 
sulphate. soil. manure. bone dust. 
100 120.9 117.0 150.5 
It will be noticed that these two scales do not coincide in the 
case of night-soil and steamed bone dust, but that the increase 
of dry matter is comparatively greater than corresponds to the 
rate of nitrogen assimilated. In fact, no close coincidence between 
the two scales could be anticipated, as the periods of growth 
during which the nitrogen of the manures becomes available to, 
and is consumed by, the plants, plays an important part in the 
production of dry matter. If the nitrogen cannot be assimilated 
in the proper period of growth, for example, if it becomes soluble 
too late, the plants may take it up, but it can no more exert any 
effect. On the other side, it is very probable that the time in 
which the manure becomes available, may particularly favour 
the development of the roots at the expense of the stems and 
leaves, wherefore the dry matter produced by the upper organs 
