The Dawson news. (Dawson, Ga.) 1889-current, 1902-06-11
PLANT FOOD ELEMENTS
:. ..oeen and the Way In
Which It Is Absorbed.
CHEMISTS LETTER NO. q

CHEMISTS LETTER NO. 4
Quantities of Plant Food In
What Determines the Crop
0,oduciug Power of the Soil ETC.
,...r.stlna and Instructive Treatise.
,,.rr.Ilv the nitrogen we find in the
~ ANALYSIS next claims our at
pan AS told you in my last let
len'. .hot there are nearly eighty gal
lei of nitrogen in one hundred gal
ON' ~ oir YOU would quite naturally
onI '.;r, that there would be no need
A ether about providing nitrogen for
orons as they ought to be able to
' opt.in all they want from the enor-
w. oceans of it floating all around
M ohout them. Yes, one would natur-
' arl suppose so, but alas, it is not true;
e a, nlant is helpless to feed on the nj
.rogen around it in the air, no mat
tar how thirtsy it may be for it. 1t is
w., ~, tho shipwrecked sailor in the open
noot at sea. though parched and dying
nth thirst, yet he can not Stake his
.hirct though there be nothing but
wafer water, all about him.
Il seems as though there were a GER
.oir malice in Nature in SO constitut-
inc plants that they cannot take the
nit,ooen out of the air directly, yet
norbans it is a good thing they cannot,
bocause if they could, life would be so
oasv that we probably would not exert
Ourselves as much as we should. Nj
+ropon being the most expensive ele-
mont of plant food, if it were provided
4roe of cost like the carbon, hydrogen
and oxygen, we could grow such enor-
mons crops at such small cost, that the
cost of living would be so reduced, that
man would not have the same urgent
ctimulus behind him to work and to
labor that he now has.
The Form in Which Plants Absorb
Nitrogen.
But to return to our subject, the
plant requires nitrogen, but it cannot
take it through it's leaves; it has to
take it up through its. roots, and in Or
der for the roots to take it UP, the nj
trogent must be combined with nitrate.
II must be in the form of nitrate of soda,
or nitrate of lime, or nitrate of mag
nesia, or nitrate of potash, or some
other form of nitrate before the plant
ic matter containing nitrogen into the
soil, either vegetable or animal, as cot
ton seed meal, blood, meat, or even
if we plow under green crops, they will
begin to decay and purify in the soil,
until the nitrogen which they con-
tain in the form of protein (about
which | wrote you SO much last year,
is changed into number of other
forms. being finally converted into a
nitrate otter the decay of the ooriginal
sustance has been fully completed.
As a nitrate it is in a condition
where it dissolves easily in water, and
is then absorbed by the root hairs
and drawn up into the circulation of
the plant Now the vast majority of
plants have to obtain their nitrogen
in the roundabout manner just describ-
ed, but there are few favored plants
which are able to obtain their nitrogen
out of the air through the instrument
tally of certain minute organisms or
microbes in the soil. We will have
more to say Of this later on. When the
organic matters l have described
above. animal or vegetable, as cotton
seed meal, blood meat, manure or
turned under green crops decay in the
SOIL the carbon and hydrogen which
are contained in them are not alb
Sorbed like the nitrogen through the
footS into the plant, the plant does
not get its supply of carbon and n.y.
drogen in that way. They simply re-
main in the soil to form what is known