The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1912-09-13
BEST SOILS FOR ONIONS.

S0seS -" 0tNbNSINOs
O. a. G. Graduate Tells Of Fertilizers
To Be Used On Crop.
Corvallis, Or.-Although onions will
grow on large variety Of soils, they
thrive best in rich, mellow soil with
plenty of moisture. just what fertil-
izers and soil treatment to use is ex-
planned by Jay C. Leedy, of Sher-
wood, one Of this years seniors at
the Oregon Agricultural college, in an
article on Soils and Fertilizers for
Onions in the Oregon Countryman,
published by the students.
For commercial onion growing in
Oregon the beaver meadows are prac-
tically the only ones given considera-
ton" says Mr.. Leedy. "These lands
are located mostly in Washington,
Clackamas and Marion counties.
Theoretically these lands have result
ed from beavers damming streams and
outlets to lakes, hence the name; but
nature has played large part in the
soil formation, in many cases without
the aid of the beavers.
This soil forms type known as
cumulose, composed largely Of organic
matter and humus, and analysis u.s.
ually shows about 2 per cent of nitro
gen. Large portions of this plant
food element are unavailable for the
use of plant life. This type of soil
generally contains moderate amount
of phosphoric acid, and usually very
small amounts of potash, sometimes
as low as 2 per cent. Chemical analy-
sis of the soil is not to be relied upon
in all cases as an Indicator of the
soils power to produce crops, but is
merely an index to the amount of the
various plant foods present in the soil.
It has been found by experiments that
these dam soils will not continue to
produce profitable yields Of onions
without the addition of potassium in
the form of animal manure or COM
mercial fertilizers.
Analysis of yellow Danver onions
showed content of .225 per cent nj
trogen. .88 per cent phosphoric acid
and PIT per cent potash. Taking an
average yield to the acre of 800 sacks,
each weighing 100 pounds, the analy-
sis would remove from the soil 67.5
pounds of nitrogen, 25.8 pounds of
phosphoric acid and 65.1 pounds of
potash. Thus it can be seen that the
onion crop uses comparatively large
amounts Of the three essential fertiliz-
ing elements, and these must be sup
piled to the soil if it does not already
contain them.
"Barnyard manure is almost indis-
pensable in the production of onions in
any except the beaverdam soils, and is
more used than any other fertilizer
even on these soils. Indeed, there is
no fertilizer so well adapted to the
production of onions as a liberal
amount of clean, well composted barn
yard manure. 1t is important that all
stable manure used on onion land be
well rotted before applied to the soil
in order that the weed seeds may lose
their terminating powers, and that
the danger Of diseases attacking the
onions be lessened. A heavy applica-
tion of fresh manure may produce an
overgrowth Of tops at the expense of
the bulbs, and is sure to bring in
large amount of weed seed, increasing
the cost Of wedding. 1t is difficult to
make the soil too rich for onions, pro-
vided the manures are incorporated
with the soil. The usual amounts,
however, are 10 or IL tons to the acre,
applied before ploughing in the fall
and then narrowed with the disc be-
fore planting in the spring.
"Where enough manure is not pro-
duced on the farm, and where it can
not be secured profitably from city
near, commercial fertilizers must be
resorted to. They can supplant
stable manure proftably, especially on
the beaverdam soils, already rich in
organic matter. In some instances
commercial fertilizers are used exclu-
sively with good results. One great
advantage over stable manure is the
| fact Of reducing the weeds to mimi
mum, thus lessening the expensive
production. A higher initial cost
than stable manure tends to Offset the
disadvantages in wedding. As it is
an intensive crop yielding large
amounts of bulbs to the acre, growers
are justified in manuring heavily.
Additional nitrogen increases the
weld. The onion is planted early IN
the spring, before bacterial action be-
gins, and these agents in the soil
which render the nitrogen available
! for plant use do not begin to work
very actively until the soil il
thoroughly warmed and the season
well advanced. An application OF nj
tropen Immediately available early IN
the season is thus beneficial in giving
tie plants an early and vigorous start.
sodium nitrate, containing about -
Der cent nitrogen, is the best form,
/ 100 rounds to the acre as 9 top dress
ing after the onions are planted
ssBone meal containing about g
per cent phosphoric and 4 per cent n'-
tropen is good fertilizer for onions