WCN_Dec17WEB

things off to a good start is essential
when considering the investment cost
required to develop a successful orchard.
Soil Evaluation/Preparation
Walnuts are deep rooted trees that
were traditionally grown in river bottom
soils, such as the dark, loamy soils of
Vina and Los Molinos which lie along
the Sacramento River.
However, research has shown walnuts
can be grown on Class III soils when the
right soil evaluation and preparation has
been made. That is why walnut orchards
are now “cropping” up in regions not
adjacent to the Sacramento and other
rivers, in soils once considered uninhabitable
for walnuts.
Krueger said when growers are looking
to plant a walnut orchard, soil survey
maps are well worth the time to peruse.
Soil surveys are available at local
Natural Resources Conservation Service
(NRCS) offices, cooperative extension
offices, and online at websoilsurvey.nrcs.
usda.gov/app.
Soil surveys provide important
information, such as soil types, distribution
and acreage. “It describes each soil
type and provides information about
explore the soil, digging pits five to six
feet deep in strategic locations to allow
first hand examination of the soil. The
soil map can take the guesswork out of
where to dig and on average about six
pits should be dug in a 40-acre field. If
the map shows uniform soil, only one pit
may need to be dug.
Krueger said to look for stratified
soil, compacted zones, hard pans, and
clay pans.
“If soil modification is necessary, it
will be much easier to accomplish before
planting,” he added.
“Modification should be done in the
late summer or fall when the soil is dry
to ensure the most disruption possible
while allowing the winter rains to
settle the soil before planting. Touch up
leveling or smoothing can be done in the
spring before planting.”
However, Krueger explained, leveling
is only necessary when flood irrigating,
and not necessary when drip
or micro-sprinkler irrigation will be
used. Shallow ripping will be needed for
deep uniform soils. Sometimes, but not
always, deep ripping or slip plowing may
be necessary for stratified, hardpan or
claypan. When dealing with claypan, he
reminds growers of special requirements
to avoid reseal of the
soil.
We pride ourselves on
the best trees grown
on virgin ground
With Six Generations of
Farming We Have the
Roots You Can Count On!
Traditional walnut planting design and hedgerow configuration.
At times a shallow,
loam topsoil is underlain
by the heavy
claypan which restricts
drainage of water down
the root profile. Subsoil
tillage in some cases
allows excess water to
drain away from the
root zone and safeguards
against waterlogging.
If roots don’t
have proper drainage, a
whole host of diseases
can occur.
All Walnut
Varieties
drainage, flooding, exchangeable sodium
content, and other details important
to successful orchard establishment,”
Krueger wrote in his studies. “The soil
survey cannot provide every detail that
may be necessary.”
He advised using a backhoe to
One of the ways to deal with less
than prime soil, according to Krueger,
is to plant trees on berms, especially on
heavier soils.
“Ridge berms in the fall for after soil
Continued on Page 10
80 Years of Walnut
Growing Experience
Mark Crow 209-602-8394
Norman Crow 209-988-4570
WWW.ORESTIMBANURSERY.COM
December 2017
www.wcngg.com
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