The Parker post., 1912-10-26
ESSENTIALS OF PLANT
Nitrogen, Phosphorus and Potas-
Sium Are Most important.
Spring Flowing Under of Green Ma
terial in Orchard Interferes Great
ly With First Irrigation-Two
Best Shade Crops.

10y II. ). HERRICK, Colorado Expert
ment station)
There are thirty eight different
chemical elements which are used to
make up the growth of plant The
following nine are very essential for
the proper development of the or
chard plant: Carbon hydrogen, oxy-
gen, nitrogen, sulphur, phosphate, po-
tassium. calcium and iron. The three
most important of these, and which
are sometimes absent in available
form, are nitrogen, phosphorus and
potassium. A certain amount of nitro
gen is required for the vigorous
growth of the plant and Is used
principally in the formation of the
woody part of the plant. Phosphorus
Is not as essential in fruit growing
as it is in the growing of grains, as
it is used to make up a large per
cent. of the seed, but is, however, es-
sential to aid the proper ripening OF
the fruit Potassium aids in the
proper coloring of the fruit and goes
to make up large per cent. of the
ash of both the fruit and of the fruit
wood.
Many of our orchard soils are rich
chemically in nitrogen, phosphorus
and potassium, but oftentimes these
elements are not available for the
plant on account of the poor physi-
cal condition of the soil; We mean
that it lacks humus. By humus we
mean the complete decay of organic
matter which can be obtained by the
blowing under of some green manure
crop, such as alfalfa, clover, vetch,
oats, rye. etc.
In the east where experiments
have been run with clean cultivation
versus sod for orchard soils, the re-
suits were found to be in favor of
the clean cultivation. Clean culti-
vation versus a rotational shade crop
has been tried in Colorado and the
results were in favor of the shade
crop rotation. In the east, cover
crops are used, which means the SOW
ing of the seed in late summer and
the blowing under of the green ma
nure crop the next spring or in the
early summer. Our conditions are
such that this method does not work
we'll, the greatest trouble being that
he spring plowing under of great
mass of green material interferes great
" with the first summer irrigation, as
t sometimes causes the soil to puddle
and thereby causing the leaves to turn
yellow. By shade crops is meant
he sowing of the seed in the spring
IF the year, thus shading the soil du-
ing the summer from the sun,
and the blowing under of the green
crop either the following fall or the
next fall, depending on whether
an annual, biennial or perennial crop
Is grown.
Nearly all of the Colorado orchard
and this is the principal reason why
they are so poor physically. that is,
they are hard to work when it comes
TO irrigation and cultivation Such
soils do not take water readily nor
do they hold it after they have been
irrigated. Humus in the soil will do
away to large extent with these
troubles and can be obtained by the
blowing under of barnyard manure,
but on account of the scarcity of it,
the orchardists will have to rely to a
great extent on the growing and the
blowing under of a shade crop.
Shade crops are divided into two
classes, viz. leguminous and non-legum-
nous. The legumes are plants like al
falfa, clovers, etc.; the non-legumes
are the grains, like oats, rye, barley,
etc. For orchard soils which possess
a hard under soil there is no plant
like alfalfa. This is not hard to
handle if 1t is not allowed to go to
seed and is plowed under in the fall
Of the second year. 1t is well to SOW
oats, about one-half bushel to the
acre, with the alfalfa for nurse crop.
The oats should be cut before they
go to seed and they can be harvested
for feed Alfalfa can be sown later
than clover with good results, but, as
rule, it is better to SOW all shade
crops in the orchard as early in the
spring as possible. Mammoth red clov-
er makes very good orchard shade
crop, but sometimes it is hard to get
the clover to grow well at first un-
less it has the proper amount of mois
ture. This is one reason why clover is
not always success in peach or
chards, as sometimes the clover re-
quires more water than is good for the
peach trees. In growing anything in
the orchard, one must remember that
the trees are the first consideration
and the crop of second Importance.
For this reason do not over-irrigate the
trees in order to get good stand of
clover, etc.