horticultural soils
TRANSCRIPT
It all depends….
HORTICULTURAL SOILS
Kevin Donnelly, CH
Supervisor of Quality Control
Midwest Trading Horticultural Supplies Inc.
MIDWEST TRADING
Its all about Logistics
Its all about Logistics
CENTER FOR HORTICULTURAL SOILS TESTING
AND RESEARCH (CHSTR)
Our capacity
pH/EC
Moisture Content
Bulk Density
Porosity
Weed Seed Bioassay
Top Soil Hydrometer
Solvita Compost Analysis
And much more…
QC Testing
Mixes
Raw components
Data Management and Tracking
Technical service
R&D
TOTAL QUALITY CONFIDENCE
Know everything we can about the products we
produce and components we use
Manage the natural variability in the material
Ask the right questions
to give the answers
value and meaning
HORTICULTURAL SOILS
“Any substrate used in the growth of
horticultural crops or used in horticultural
applications”
General Categories
Container Substrates
Engineered soils
Landscape Soils
Other
tissue culture; floral foam; hydroponic media
ENGINEERED SOILS
A soil or soilless substrate subject to testing and conformance to a specification
Prescribed spec A+B+C= ?
Straight forward, but will it work
Performance spec ?+?+?=A
Asks the right questions,
Both A+B+C=Z
Very challenging when A+B+C=D not Z
GREEN ROOF MEDIA
Storm Water Management***
Heat Island Effect
Air Quality
Energy Efficiency
Longer Roofing Membrane Life
Biodiversity
CHICAGO BOTANICAL GARDEN EXTENSIVE GREEN ROOF
MILLENNIUM PARK INTENSIVE GREEN ROOF
CHICAGO CITY HALL INTENSIVE & EXTENSIVE GREEN ROOF
GREEN ROOF COMPONENTS
STURCTURAL SOILS
STURCTURAL SOILS
RAIN GARDEN, BIOSWALES & LANDSCAPE
CDOT
Rain Garden
Bioswales
Other
RAIN GARDEN
BIOSWALE
BIOSWALE
OTHER
Golf Courses
Athletic Fields
LANDSCAPE/ PRODUCTION SOILS
Manufactured or amended parent soil
Garden/Landscape soil
Field production of horticultural crops
Soil Amendments
LANDSCAPE/PRODUCTION SOILS
Where do
Soils
Come
From?
LANDSCAPE/PRODUCTION SOILS
Large scale
development
that clears land
and sells off soil
Not a lot of
options in this
economy
CONTAINER SUBSTRATES
Substrates used in containers for the
production of horticultural crops
Some Key elements
Container size
Crop length
Limited soil volume
GREEN HOUSE AND PROPAGATION MEDIA
NURSERY AND TREE MEDIA
POTTING SOILS
GROWING MEDIA
Air
Water
Structure
Nutrient Reservoir
THE IDEAL MIX
It all depends….
Fits your growing style
Produces quality plants with limited
management
Consistent/Predictable
Cost effective
PHYSICAL PROPERTIES
Prevention is the only course of action
Only you can
prevent bad
porosity!
MACRO VS. MICROPORES
25% Solids
75% Water
25% Solids
45% Water
30% Air
CAPILLARY ACTION IN MIX
Important when sub irrigating containers
Pores act as a straw and
ZONE OF SATURATION
Amount mix will hold at the bottom
3% 10% 40%
CONTAINER SIZE
Size and Shape of container can effect water
air water relationships
Look at the force of gravity 45% Air
25% Air
10% Air
BULK DENSITY/ COMPACTION
Depending on how it is filled and handled can
impact air water relationships
Compact vs. lightly filed
Structure is not made in the bag
NESTING EFFECT
Air Porosity
20
5
20
20
SHRINK
Settling after watering
Component breakdown
Out the bottom?
Shrink from blending
Fill pots at optimum moisture content
WETTING AGENT
Aids in wetting
up mix
Peat is
hydrophobic
• Helps with even watering,
Not channeling down the sides of the pot
A good idea for postharvest quality
CHEMICAL PROPERTIES
PH
Will effect nutrient availability
Fluctuates over the course of the crop
The plant causes pH changes
Alkalinity of your water is important
May need to acid injection
Buffer capacity of your components
Lime and Iron Sulfate
PH
EC
AKA soluble salts
Measure of salt content in solution
Can be from good salts or bad
Many use EC as indication of fertility
Listed in dS/m or ppm (dS/m X 670)
Dilution method matters!!
OTHER MEASURMENTS
Organic Matter
CEC
C:N
Weed Seed presence
Wettability
Moisture content
TESTING
What do you test for
How Often
How do you test
Internal testing
External lab
What do you do with that
information
SAMPLING
How you sample may add bias to the test
Area of pot
Top 1/3rd
Middle 1/3rd
Bottom 1/3rd
Random sample or targeted sample
RANDOM
TARGETED
TESTING FOR PHYSICAL PROPERTIES
Air Porosity
Field Method
NCSU Porometer
Sieve analysis
Bulk Density
Shrink testing for
optimum moisture
Field Capacity = Flooded container
Container Capacity = Free water drained
TESTING FOR PHYSICAL PROPERTIES
Porosity
When Dividing by the Container Volume
Air Porosity
Dry Weight
Water Holding
Capacity
TESTING CHEMICAL
In house
EC
pH
External Lab
Nutrients
CEC
Etc.
EC
Method maters
1:1
2:1
SME
Pour Thru
Many use it for managing fert
If EC reading falls below X, then fertigate
PH TESTING
Moving Target
Can be adjusted
4
4.5
5
5.5
6
6.5
7
1 2 3 4 5 6 7 8 9
BIG POINT FOR ANY TESTING
Don’t make major changes right after testing
starts to correct issues that may be normal
Need historical values to see what is your norm
Plants don’t read test reports
Think about what the right question is
COMPONENTS
Its all about logistics
NUTRIENTS
Minerals/non coated
dolomite lime
Iron Sulfate
Controlled Release Fertilizers (CRF or SRF)
Encapsulated NPK+
NUTRIENTS
Organic Fertilizers
Kelp Meal
Bone Meal
Worm Castings
Bat Guano
Poultry Litter
AGGREGATES
Perlite
Vermiculite
Sand
Calcined clay
Oildri
LWA
Others
Lava
Glass
Polystyrene
Rockwool
ORGANIC COMPONENTS
Peat
Sphagnum
Reed Sedge
Pine
Rice
Coir
“Composts”
Landscape compost
Manure compost
Biosolids
Worm Casting
Mushroom “Compost”
Spent Mushroom Substrate
NEW PRODUCTS
Why we need them
Price
Availability
Quality
Sustainability
These are not
replacements
Look for local
Cheap
Effective
NEW FRONTIERS
Whole Tree Substrate
Corn Cobs
Miscanthus
Biochar
“Fingerprinted” media
BIOLOGICAL
Mycorrhizae
Benificial bacteria/fungi
These can be incorporated into mix
As well as some pesticides
PEAT MOSS
The Stuff Dreams Are Made Of
WHAT IS PEAT?
•Specifically we are referring
to sphagnum peat derived
from sphagnum moss
•Stable partially
decomposed organic matter
•Degradation slow due to
acidic anaerobic conditions
Like I said, the conditions in a bog inhibit decomposition.
Where some of our peat comes from
This is a smaller bog for Lambert compared to
The Virgil Nursery and the Ottawa facility!!
WHAT HAPPENS AT A BOG
Go from this: To:
SO IS IT SUSTAINABLE??
Clear cut bog
Pull off what may take
generations to grow
Disturb environment
42thousand acres of
280million harvested
Less than 0.02%
Peat biomass generates 60
times faster than harvested
Must restore bogs to
functioning wetland
On bog for 60-80 yrs
NO PEAT IS THE SAME
Differs from:
Bog to bog
Year to year
Company to company
Many different grades of
peat
Retail peat
How to manage that
variability
Blend everything to get
one base product
Have many different
products
NATURAL PRODUCTS WILL VARY
We have to individually tailor quality management
strategies to each product
Products change both Chemically and Physically
while we have them
You can’t tell just by looking at it, it must be tested
Come on the tour to learn more…
QUESTIONS?
THANK YOU
Yourhorticulturist.blogspot.com
We are always looking for a few good question
askers.