The Kennewick courier-reporter. [volume] (Kennewick, Wash.) 1914-1938, 1921-07-21
- Field and
SGOrchard
Cover Crops in the Orchard
v. l.. Georgeson

v. L. Georgeson
The recent demonstrations of Mr.. E.
G. Wood, the specialist in horticulture
from the Extention Service of the
Washington State College, has but
served to emphasize against the part
cover crop should play in any sys-
tenn of orchard management in the
Yakima Valley.
A cover crop is of value because of
the influence it exerts on soil condi-
tons as regards to humus, moisture,
temperature, soil bacteria and the ele-
ments Of plant food. Fertility is in
proportion to the amount of bacterial
action in the soil; because it is due to
the soil organisms that organic matter
in the soil is broken down, the plant
food in it liberated and the mineral
elements of the soil dissolved by the
acids that are formed in the process of
decomposition. These soil organisms
thrive best at moderate temperatures
where there is moisture, air and ma
terial for them to work on. A cover
crop left to return to the soil brings
this about.
Go into any orchard where a good
cover crop is growing, and you will
find the soil is more mellow ESQ the air
can get through .it) there is moisture
near the surface, and the soil is shaded
so that it does not get burning hot.
But don't cut the cover crop! Where
it has been cut the ground gets burn
ing hot, dry and baked-exactly the
reverse of conditions wanted. The soil
being exposed while the next crop is
growing is losing water by evapora-
ton to a far greater extent than
where the cover crop is standing. The
new growth requires not only extra
water, but is using plant food that
should be going into the trees. The
result of cutting the cover crop is that
Two crops (the cover crop and the
trees) are competing for the same
plant food and moisture, with the re-
suit that the trees receive a sudden
check at the time they are growing
their fruit.
Nitrogen, humus, and moisture
holding capacity are soil essentials
which are increased by leguminus
cover crop. Humus-decompose veg
etable matter-is essential to maintain
the soil in proper moisture-holding
condition. 1t acts somewhat like al
sponge; keeps the soil loose so it will
not bake, allows the water to sub
through it faster and farther, and then
holds on to it longer. 1t increases the
efficiency of the soil as a place for
plants to grow. The humus content
of the orchard soil must be maintained
without manure, cover crops of some
kind must be used and all returned to
the soil or the orchard will not thrive.
Where a legume is used, nitrogen is
also added from the activities of the
nodule forming bacterie on the roots.
Convincing data is available from
orchards in Wenatchee that show the
value of the crops. The work of Mr..
Larsen there points strongly to the
value of alfalfa or vetch. One or the
other will probably suit conditions any
place in Benton Couny. At any rate
the principles involved in the use of
cover crops in an orchard are correct,
although in rare instances the practise
may have to be changed sufficiently to
meet local conditions.
1t is hoped that this fall before ap-
pie picking begins tour to several
orchards in different sections can be
arranged, so that those who make the
tour will be able to see for themselves
what a cover crop, properly handled
be it vetch, alfalfa or something else
can do.