IO 
MANURING EXPERIMENTS WITH PADDY RICE (SECOND YEAR). 
the assimilable residue left, together with that potash which 
newly became available by decomposition and irrigation, did 
not suffice to yield to the crop as much of this nutrient as 
in the preceding season. A calculation made in the same 
way as in the case of the nitrogen consumption, shows that 
the available residue after the first crop amounted to 4.59 grms. 
per plot, from which the plants could take up only (50 %) 2.30 
grms. As they actually absorbed 3.67 grms., only as much 
as 1.37 grms. were contributed by ingredients newly rendered 
available and by irrigation. The whole increase of available 
potash during the period of one year amounted accordingly 
to only 2.74 grms. per plot = 3.3 kilogrms. per tan, a quantity 
which would not suffice for rice for any successive years unless 
some potash were supplied in the manure. 
An account of the proportion of potash absorbed by the crop 
from the manure is given in the following table : 
In the whole crop. 
In the crop grown without potash . 
Taken up from the manure .. 
Applied in the manure . 
Taken up, per cent of the potash applied 
Potash, grms. 
1889. 1890. 
... 9.25 10.17 
••• 4 - 7 8 4 - 3 2 
... 4.47 5.85 
... 9.18 9.18 
...48.7 63.7 
Thus, in 1890 the crops consumed more potash from the 
manure than in 1889, and this is principally explained by the 
difference of the two seasons. High maturation, such as took 
place in 1890, is generally associated with a high proportion 
of potash in the crop. This fact was also noticed by J. H. 
Gilbert 7 in long continued experiments on the growth of barley 
at Rothamsted ; comparing the contents of nitrogen, phosphoric 
acid, and potash, Gilbert writes: “Whilst in the case of 
potash there is the higher proportion in the better seasons, in 
that of phosphoric acid there are lower amounts in the dry 
7 Results of Experiments at Rothamsted, on the Growth of Barley. Agr. 
Students’ Gazette, vol. Ill, part II. (Reprint p. 19.) 
