The Democratic press. [volume] (Ravenna, O. [Ohio]) 1868-1901, 1871-06-29
THE PRODUCTIVE POWERS OF SOILS
IN RELATION TO THE LOSS OF
PLANT-FOOD By DRAINAGE.

1N 0E4AA11O1N LnE 1SOSS OE
PLANT-FOOD By DRAINAGE.
DIR. Volcker has delivered a lecture
before the Chemical Society, London,
Son the Productive Powers of Soils
in Relation to the Loss of Plant-food
by Drainage The lecturer began by
showing the futility of the belief that
a soiI-analysis could reveal whether a
land was productive or not. To those
who only imperfectly know the teach
ings of modern agricultural science,
it appears very simple to remedy a
deficient soil by finding out, through
analysis, the wanting constituents,
and then to supply them. But this is
not so. Not only is it difficult exactly
to analyze soil, but many other con-
ditions besides the composition of q
land have to be observed. The state
of combination in which the mineral
constituents of land are found, the
physical condition of the soil, the
presence or absence of some matter
injurious to the growth of plants; all
these are SO many important points
upon which soil-analysis throws no
light whatever. The lecturer equally
opposed the views of those who advo-
cate that in a system of rational farm
ing there should be kept up debtor
and creditor account, as regards the
constituents which are removed from
the soil in the crop grown upon it,
and the quantity of fertilizing matter
restored to it in the shape of manure.
The fertility of the soil cannot be
maintained, much less increased, if
only as much fertilizing constituents
would be applied to the land as one
removes from it in the crops. DIR.
Volcker then, discussed the relative
values of various mineral salts as ma.
nures, quoting, in support of his
views, the results of the classical field
experiments of Lawes and Gilbert !;
and this then led the lecturer to speak
of the examination of land drainage
waters. Lawes and Gilbert, through
out long series of experiments on
the growth of wheat, have expert
enced great loss of nitrogen. The
amount of nitrogen supplied in the
manure was greater than that recov-
cred in tho increased produce. 1t ap-
peared to DR.. Volcker that the nitro
gen lost might have passed into the
drains. Careful collection of such
drainage-watersn and their ANALYSIS
proved DR.. Volcker's supposition to
be correct. It became clear that in
whatever form the nitrogen is applied
to the soil, large proportion of it is
carried of, chiefly in the, form of nj
trates. At all times of the year, but
especially during the active period of
growth of Gthe crops, nitrates are
found in the watery liquid which cir
culates in the land, whereas ammonia
salts are never met with in any appre-
ciably large quantities. 1t may there.
fore be assumed that it is chiefly, if
not solely, from the nitrates that the
crops build up their nitrogenous or
ganic constituents. DR.. Volcker's
analysis of drainage-waters further
showed that potash and phosphoric
acid, which certainly are the most i'm
pertant mineral constituents for the
plant, are almost entirely retained in
the soil; while the less important, as
lime, or magnesia, or sulphuric acid,
pass with greater readiness out of the
land.