OSU BLUEBERRY SCHOOL
March 16-17, 2015
held at
Oregon State University, Corvallis, Oregon
This two-day blueberry “school” was organized for new and experienced blueberry growers,
farm managers, crew leaders, advisors, packers/shippers, and consultants. Experts from Oregon
State University, USDA Agricultural Research Service, Washington State University, and the
blueberry industry were asked to address key issues of where the blueberry market is going; how
you might be more successful in tight labor or volume markets; which cultivars are easiest to
grow and are in most demand; how to establish new acreage using cutting-edge methods;
projected costs and the resources available to growers for selecting new planting sites; how to
best manage existing acreage to maximize returns of high-quality fruit; provide basic information
on blueberry plant physiology to help growers minimize environmental stresses and improve
yield potential; nutrient management programs for optimal growth and quality; irrigation and
fertigation practices for higher quality and better efficiency; use of organic amendments and
mulches; planning for and improving machine harvest efficiency; pruning for hand or machine
harvest (where can you cut corners….or not), maximizing pollination for good fruit and seed set;
overviews of the most important blueberry viruses, diseases, insects, weeds, and vertebrate pests;
and tools for good pest management. Information throughout the program addresses the needs of
conventional, transitional, and organic growers. Simultaneous interpretation to Spanish has been
provided. This proceedings book contains information provided on these topics by each speaker
and co-authors. The thumb drive provided in the registration packet for each attendee includes a
copy of each presentation. Thank you for attending. It is our sincere wish that this will be a very
useful meeting and that you find the accompanying materials a valuable reference! –
Bernadine Strik, Professor and Extension Berry Crops Specialist, OSU and the members of the
organizing committee
Organizing Committee
Bernadine Strik, Chair, Oregon State University (OSU)
Wei Yang, OSU. Co-chair (sponsorship coordinator), OSU
Donna Williams, Rachel Williams & team at OSU Conference Services
Dave Bryla, USDA-ARS HCRU
Chad Finn, USDA-ARS HCRU
Vaughn Walton - OSU
Steve Castagnoli - OSU
Steve Renquist - OSU
Bryan Ostlund – Oregon Blueberry Commission
Eric Pond - industry
Jon Umble – industry
Derek Peacock - industry
Steve Erickson - industry
Nancy Jensen - industry
i
Table of Contents
OSU Blueberry School
Title
Authors
Characteristics of production regions in the Pacific
Northwest
Lisa DeVetter, Pat Jones, Bernadine
Strik, Kathie Dello
1
Markets - what's the future for fresh, processed, and
organic markets? Things you MUST think about before
starting or expanding production
Rod Cook, Derek Peacock, Jeff
Malensky, David Granatstein
9
Cultivar choices- Tried and true to brand new
Chad Finn and Bernadine Strik
15
Economics of production – resources
Bernadine Strik and David Granatstein
29
Resources available for selecting a good blueberry site
Wei Q. Yang
37
Site selection and establishment of a blueberry field
Wei Q. Yang and Bernadine Strik
41
Organic soil amendments and mulches for blueberry:
the good, the bad and the ugly
Dan Sullivan (OSU)
47
On-farm irrigation system design and operation
David Bryla
53
Blueberry plant physiology - why it's important to
understand the plant to manage it well
Bernadine Strik
57
Irrigation scheduling: when, where, and how much?
David Bryla
63
Pruning - impact of plant age, cultivar, and harvest
method
Bernadine Strik
69
Harvesting - hand vs. machine
Bernadine Strik (moderator); Paul
Norris (Norris Farms); Frank Brown
(Littau Harvesters (Inc.); Doug
Krahmer (Berries Northwest)
75
Nutrient management of blueberry -- assessing plant
nutrient needs and designing good fertilizer programs
Bernadine Strik and David Bryla
79
Maximizing pollination in blueberry
Ramesh Sagili, Carolyn Breece, John
Borden
95
Blueberry viruses present in the Pacific Northwest and
suggestions for their management
Robert Martin
99
Blueberry bacterial and fungal diseases
Jay Pscheidt and Jerry Weiland
107
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Page
Title
Authors
Page
Weed management for blueberry fields in the Pacific
Northwest
Tim Miller
115
Getting hit high and low: Options for managing bird
and vole damage
Dana Sanchez (OSU
125
Management of arthropods, insect, and plant-parasitic
nematodes in blueberries
Vaughn Walton,Nik Wiman, Inga
Zasada, Joe DeFrancesco, Daniel
Dalton, Amy Dreves, Jana Lee, Lynell
Tanigoshi, Wei Yang
129
iii
Organic soil amendments and mulches for blueberry:
the good, the bad, and the ugly
Dan M. Sullivan, Oregon State University, Corvallis, OR
[email protected]
Collaborators:
Ryan Costello (M.S. graduate, Crop & Soil Science, OSU)
David R. Bryla (USDA-ARS Horticultural Crops Unit, Corvallis, OR)
Bernadine C. Strik (Dept. Horticulture, OSU)
This paper discusses the details of compost analysis and its interpretation. Additional
information is provided in the accompanying PowerPoint presentation on
•
•
composting as a technology for producing high-value soil amendments
research conducted at OSU to determine compost value for blueberry
Compost Analysis
An accurate chemical and physical analysis of compost is essential in choosing compost for
blueberry.
Selecting the right laboratory (lab) to analyze your compost is an important first step. It’s
usually best to use a lab that specializes in compost analysis. Compost testing labs typically
offer several analysis "packages" that are appropriate for different compost uses. When choosing
a lab, ask for a copy of their report form. By looking it over, you can see if the results are
presented in a manner that you can understand, and in units you can relate to. You will also want
to find out how much your desired analysis will cost, how the lab wants the sample handled and
delivered, and on what day the sample should be shipped. Samples that require immediate
attention by the lab should be shipped early in the work week.
Not many agricultural testing labs specialize in compost testing. You can find labs that
specialize in compost testing at the website for the Compost Analysis Proficiency Program
(CAP) sponsored by U.S. Composting Council. Labs participate voluntarily in this program to
improve testing accuracy and precision. These labs use reproducible methods published in a
peer-reviewed manual: Test Methods for Compost & Composting. Only a few labs participate in
CAP in the West. Because compost testing is an art unto itself, using a testing lab that
participates in CAP is recommended. Lab representatives should be able to show you a
proficiency testing report from CAP that reviews the lab's analytical performance.
When you are ordering compost from a vendor, a compost analytical report is sometimes
provided. However, it often unclear whether the analysis provided reflects current compost
quality, and whether the lab conducted tests appropriately. A compost analysis done by an
independent, reputable analytical laboratory will provide you the most reliable information.
A routine compost analysis usually includes analyses of 1) general physical and chemical
properties, 2) organic matter (carbon), and 3) macro- and micronutrients. These analyses are
47
briefly summarized in the next section. An example laboratory analysis of chemical
characteristics is shown in the Table below.
Compost chemical analyses for Douglas-fir sawdust vs. yard debris compost (dry wt. basis).
Organic Systems Trial. OSU North Willamette Research & Extension Center, Aurora, OR.
Analysis
Total N
Organic C
Organic matter
Ash
C:N
NH4-N
NO3-N
EC (1:5 method)
pH (1:5 method)
Total P
Total K
Total Ca
Total Mg
SO4-S
Total Cu
Total Zn
Total Mn
Total B
Units
%
%
%
%
ratio
ppm
ppm
dS/m
%
%
%
%
ppm
ppm
ppm
ppm
ppm
Sawdust Compost
0.1
1.1
49
26
99
50
1
50
494
24
15
12
2
41
0.3
1.4
4.5
7.4
0.02
0.21
0.1
0.6
0.2
0.9
<0.1
0.3
30
7
5
57
11
167
86
585
11
15
Average of compost and sawdust samples collected in 2006 and 2010. Compost analyses using
protocols described in Test Methods for Compost and Composting. Total nutrients determined via
strong acid digestion and ICP determination. Percent and ppm units are w/w. 1 ppm = 1 mg/kg;
1% = 10 g/kg.
General physical and chemical properties:
1. Compost moisture or water content is expressed as a percentage of compost wet weight.
Compost with 40% moisture contains 60% dry matter. Composts with high moisture (above
60%) are usually clumpy and difficult to spread. Composts with low moisture (less than
40%) are dusty. The higher the moisture content, the lower the amount of organic matter you
get per ton of fresh compost.
2. Bulk density. This measurement is expressed in pounds per cubic yard. Laboratories can
perform a bulk density test, or you can perform it in the field. An estimate of compost bulk
density is needed to convert compost nutrient content from your lab report (expressed on a
fresh weight basis) to a volume basis (for compost application in the field). Screened
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composts containing 50% moisture typically have a bulk density of about 1000 lb per cubic
yard. In the field, bulk density can be estimated by packing a bucket of known size with
compost, then measuring the compost weight.
3. Electrical conductivity (EC) is an indicator of soluble salt content. It is usually reported in
units of memos/cm, mS/cm, or dS/m. All of these units are equal numerically and have the
same interpretation. High salt levels may injure blueberry. The interpretation of compost
EC measurements varies depending on the method used. Because compost absorbs water,
most compost testing labs measure pH using a 1:5 compost:water method. Other labs may
use a saturated media extract (SME) method, or a 1:10 compost:water method. The more
water added to the compost sample, the lower the measured EC will be.
4. Compost pH. Most composts have slightly acidic to alkaline pH (6-8.5). The high pH of
most manure-based composts (e.g., chicken and dairy) is unsuitable for acid-loving plants
like blueberry. Compost pH values are not affected by pH measurement method (amount of
water added to the sample before pH is determined). The same compost pH is typically
reported when a compost EC is determined by saturated media extract (SME), 1:5 or 1:10
compost:water methods.
Organic matter (carbon) and nitrogen
1. Total Carbon (C) or organic matter (OM) is expressed as a percentage of the dry weight
of compost. Typical values for compost are 40 to 60% organic matter, and the remaining
material is ash (inorganic). Carbon comprises about half of the organic matter weight (total C
multiplied by 2 equals organic matter). Compost with 50% organic matter, contains about
25% C.
The most valuable component of compost for blueberry is typically organic matter. You can
compare the amount of organic matter supplied per cubic yard of compost based on
measurements of compost organic matter, moisture, and bulk density. Typical composts
contain about 50% organic matter (dry weight) basis, about 50% moisture, and weigh 1000 lb
per cubic yard (fresh "as-is" compost). So, a cubic yard of compost typically supplies about
250 lb of organic matter.
Composts that are low in organic matter are usually not a good value. Often, low organic
matter values in compost are the result of mixing of soil or sand into the compost. This
usually occurs when compost is prepared on bare ground, and the soil or sand is incorporated
when the compost pile is turned. Composts that contain very high levels of organic matter
may not have been thoroughly composted, and may contain a lot of unstable organic matter
that will be lost (as carbon dioxide gas) via rapid decomposition after field application.
2. Total Nitrogen (N) is comprised of organically bound N (not immediately plant-available)
plus inorganic N (ammonium-N plus nitrate-N). Usually, over 90% of total N in compost is
in organic form. Compost organic N is estimated as total N minus inorganic N.
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3. Carbon to nitrogen ratio (C:N) is the ratio of total carbon to total nitrogen. Wellcomposted materials reach a stable C:N ratio of 12 to 15, similar to the C:N ratio found in
soil organic matter. Woody composts typically have higher C:N (above 20). As a
comparison, Douglas-fir sawdust typically has a C:N ratio above 400.
4. Inorganic N sometimes called “plant-available N” is composed of soluble ions (ammonium
and nitrate), and is reported as ammonium-N (NH4-N) and nitrate-N (NO3-N). AmmoniumN and nitrate- N are released from decomposition of organic nitrogen. In most composts,
inorganic N comprises less than 10% of compost total N, with the remainder of total N in
organic form. Finished composts usually contain more nitrate-N than ammonium-N.
The short-term N fertilizer replacement value of compost can be estimated using its inorganic
N content. The organic N in compost decomposes very slowly in soil after application, and
can be ignored in estimating short term N fertilizer replacement value. A compost that
contains 0.1% inorganic N (1000 ppm N) on a dry weight basis, contains 2 lb inorganic N per
dry ton or about 0.5 lb inorganic N per cubic yard of compost (1000 lb/yd3 x 50% dry matter
x 0.1% inorganic N).
Phosphorus, potassium and micronutrients. Composts supply other nutrients that are
important for plant nutrition, such as phosphorus (P), potassium (K), calcium (Ca), magnesium
(Mg), sodium (Na), sulfur (S), and micronutrients. Total nutrient analysis is commonly used to
evaluate compost for field application. The sample is first digested in a strong acid and then
measured for nutrients by ICP. This is the same methodology used to determine total nutrients in
a plant tissue sample.
Other tests can sometimes be helpful in determining the utility of compost for blueberry:
1. Particle size is determined by sieving. Larger particle size is required when using compost
as a mulch. Composts with finer particles are suitable for soil incorporation. As a general
rule, most composts contain particles that are too small for successful use as mulch.
2. Stability is the resistance of compost to further biological decomposition. Stability is usually
determined by measuring carbon dioxide loss during incubation of a compost sample. Very
unstable composts contain organic acids and/or ammonia that can kill or injure plants.
Composts that are stable are slowly decomposed in soil, and can make long-term
contributions to enhancing soil organic matter.
3. Calcium carbonate equivalent (CCE) is the amount of inorganic lime present in a compost.
Lime increases pH (makes soil alkaline). The more lime present, the less suitable the
compost is for blueberry. This test does not give an accurate measurement of the amount of
S that would be required to acidify a compost. It will identify composts that are unsuitable
for blueberry because of lime addition at the composting facility.
4. Microbial testing. Several labs offer analyses designed to evaluate compost biology such as
counts of fungi, bacteria, actinomycetes, and other microbial indicators. These tests may be
50
of interest for specific applications. However, compost biology is extremely variable, and
organisms present in compost are typically short-lived in soil. Therefore, results from these
tests can be interesting, but they typically do not provide reliable information that can be
used to improve soil health.
Field research with yard debris compost
A long-term Organic Systems Trial is ongoing at the OSU North Willamette Research and
Extension Center in Aurora, OR. A yard debris compost was applied at 1 to 2 inch depth at
establishment (2006), and additional compost was applied after three growing seasons. Compost
effects on soil test values included:
• Soil organic matter increased from 3% (no compost control) to 4%.
• Soil pH was maintained in the optimum range for blueberry (5.0 to 5.5).
• Berry yield was increased by 0 to 10% vs. no compost control (weedmat), depending
upon year.
• Soil exchangeable K increased from 250 ppm (no compost control) to 400 ppm, but leaf
K did not increase with compost application.
However, the yard debris compost application did not improve economic return because it
increased weed growth and thereby increased cost for weed control.
Interpretation of compost analyses for blueberry
Blueberry is sensitive to high salt (EC) and high pH. Composts used for blueberry should
maintain pH in an acceptable range, and not injure plants with excess salt. Guidance provided
here is conservative, designed to avoid plant injury when compost is applied at soil amendment
rates (1-2 inches of compost applied as mulch or soil amendment to a blueberry bed).
First, consider the C:N ratio of the compost.
•
Composts derived from manures usually have low C:N (<12) and high total N (>2%), and
will supply too much N for blueberry, even if they do not injure plants by supplying too
much salt or raising soil pH. Low C:N ratios in compost are almost always associated
with other negative characteristics for blueberry, including high salt, high EC and high
potassium (K). Therefore, composts containing more than 2% N (dry weight basis)
produced from poultry manure, dairy manure, or feedlot manure are not recommended
for blueberry. Other high N composts (e.g. peppermint and mushroom compost) are also
unsuitable for blueberry.
•
Composts with C:N of 12 to 25 (1 to 2% N, dry weight basis) may have value for
blueberry, but caution is advised. Some of these composts may be acceptable for
blueberry, while others will have excessive pH, EC and/or potassium (K).
•
Woody composts with C:N above 40 (<1% N, dry weight basis) supply organic matter,
but usually have close to zero value in supplying plant-available nitrogen. Application of
these composts will often increase the need for supplemental N fertilizer application
during the first growing season following application.
51
Target values for other key compost analyses are provided below. Keep in mind that research is
ongoing, and target values may be adjusted as more research is completed.
•
Compost pH. Goal: Maintain optimum soil pH. Target < pH 6, Acceptable pH < 7.5.
•
Compost EC. Goal: Avoid plant injury. Target depends on EC analysis method. Target
EC < 4 dS/m with the saturated media extract (SME) method, < 2 dS/m with the 1:5
method, and < 1 dS/m with the 1:10 method. Units: 1 dS/m = 1 mmhos/cm.
•
Compost K. Goal: Avoid plant accumulation of excess K, and possible K/Mg nutrient
imbalance. Target total K in compost < 0.7% (dry weight basis); acceptable < 1.3%.
Take Home Messages: Compost for blueberry?
•
Compost analyses can provide important information to guide compost selection.
•
Composts are weak liming materials.
•
Yard debris compost is usually an acceptable compost for blueberry. But excess K may
be a long-term problem.
•
Most, if not all manure composts are not suitable for blueberry. They contain too much
salt (including K) and they often raise soil pH above the target range for blueberry (5.0 to
5.5).
•
Most composts will make a weedy mulch, because they are high in nutrients and have
small particle size. Some growers and researchers have suggested that it may be possible
to overcome this problem by placing compost under weedmat.
52