2.
Greenhouse mixes
◦ Important variables
◦ Mix components
Greenhouse trials
◦ Observations
◦ Lessons learned
Compost
◦
◦
◦
◦
Important variables
Production methods
Materials used
How to evaluate a good compost
2
6.
Important Factors
pH: 5.5 to 5.8
EC: <1.0 mmhos/cm
Must be low to prevent damage to young seedlings
Structure
Good porosity, excellent drainage
Fine particle sized material
6
7.
Typical materials
◦ Peat
◦ Perlite
◦ Vermiculite
Other possible materials
◦ Worm Castings: <3%
◦ Compost: <5% -> Must have low EC
7
8.
Important Factors
pH: 5.5 to 6.5
EC: Recommended ranges
NB Soil Lab
U of Mass
MOFGA
NBDAAF trials
.75
1.5
1.0
1.9
–
–
–
–
3.0
3.0
2.0
3.9
Structure
Courser material
Porosity & moisture holding capacity balanced
8
9.
Typical materials used
◦
◦
◦
◦
Sphagnum peat, AND/ OR
Coir (the coconut husk)
Perlite
Vermiculite
Other common materials
◦
◦
◦
◦
Compost
Peat Humus (black peat, muck peat)
Aged bark
Worm Casting
9
10. Pro’s
Excellent drainage
Good moisture
holding capacity
(MHC)
Plentiful in NB
Con’s
Considered by some to
be a Non-renewable
resource
Low pH – needs lime
Low EC – needs fertilizer
Hard to wet
Caution
Certified Organic Growers: Make sure no
commercial wetting agent added
10
13. Pro’s
Provides good porosity
Good MHC
Holds nutrients
Good source of
Calcium & Magnesium
Con’s
Costs
Easy to crumble
Caution
Know your source
Some US sources contain 2-3% asbestos
13
14. Pro’s
Con’s
Can rob nutrients from
Renewable resource
plant if C:N is high
Can replace some peat
Attracts fungus gnats
Reduces lime
& shore flies if wood
Source of nutrients
based
Holds nutrients
Reduces porosity
Good MHC
Disease suppression
Caution
qualities
1. Watch % used
2. Keep EC in range
14
15. Pro’s
Renewable resource
Replaces some peat
Con’s
Difficult to re-wet
Can rob nutrients due
to high C:N ratio
Attracts fungus gnats,
shore flies
Caution
1. Keep to <10% of mix
2. Don’t confuse with compost – different product
15
17. Pro’s
Con’s
Renewable resource
Natural slow release
fertilizer
Good nutrient holding
capacity
Good MHC
Reduces porosity
Cost
Caution
1. Keep around 5% of mix
2. Nutrient levels can vary from source to source
17
18.
Lime
◦
◦
◦
◦
Fine grade needed, not agriculture grade
Calcitic lime for Ca (>30 % Ca)
Dolomitic lime for Mg (22% Ca, 13% Mg)
Choose type based on needs
18
19.
Nitrogen sources
◦ Plant based
◦ Seafood based
◦ Animal based
Caution Notes: Can restart composting process, or
release of ammonia at first watering (seek
professional advice)
Phosphorus (P) sources
◦
◦
◦
◦
Bone meal
Fish meal
Calphos
Bat and Seabird guano
19
21. Four Trials Conducted
1. Basil – No supplemental fertilizer
2. Tomatoes, Lettuce, Broccoli – No supplemental
fertilizer
3. Broccoli -With supplemental feed starting 14 days after
transplanting
4. Lettuce – With supplemental liquid fertilizer – starting day
of transplanting
21
22. April 3 – 23
756 (3”) pots, 42 trays – 13 mixes used
22
23. Apr 18 - May 9
Trial 2 - 270 (4”) pots used
Trial 3 – 90 (4”) pots used
8 mixes used
23
24. May 22 – June 7
90 (4”) pots used
Picture taken day 7
8 mixes used
24
25.
8 greenhouse mixes used in all trials
1 control used in all trials
Weekly observations
Grower’s assessment
Computer randomizing utilized
25
27.
Types
1.
2.
3.
4.
5.
Seafood & wood based products (WBP)
Seafood & peat
Animal manures & WBP
Animal manures & peat
Hay, straw, silage
Inclusion rates
◦ 5 to 20% in most trials
◦ 30% in one and 60% in another
27
28. There were a total of 15 different mixes trialed
Component
Sphagnum peat
Used in how many mixes
14
Peat Humus
5
Coir
2
Aged bark
2
Castings
3 - @ 4.5 to 5%
Perlite
Vermiculite
11
5
28
30.
No significant impact on performance from:
◦ Type of compost (with supplemental fertilizer)
◦ Compost inclusion rate
◦ Use of worm castings
◦ Coir vs peat
◦ Interchange of peat humus, compost & castings
◦ pH range (5.2 to 7.0)
◦ Levels - P, Ca, Mg
30
31. 1) Even with a wide range of mix
configurations used and compost inclusion
rates, (5 to 20%), the two items that
consistently made positive impacts were
when:
a. EC levels: 1.9 to 3.9 mmhos/cm
b. K levels: 200 to 250 ppm
2)
All mixes (other than controls) required
liquid supplemental fertilizer. Best results
when started on day of transplanting
31
37.
Used at Strawberry Hill Farm – trial #4
◦ Day 1 & 8 – Rain Grow (4-2-3) chicken compost
based fertilizer @ 1 oz/ gallon
◦ Day 15 – Neptunes Harvest liquid fish with seaweed
blend (2-3-1) @ 2 oz/ gallon
Many other options available – check ACORN
Inputs and Supplier Directories on-line
37
38. Item
Min
Max
Comments
pH
5.5
6.5
5.5 to 5.8 for starter mixes
EC (mmhos/cm)
1.9
3.9
<1.0 for starter mixes
Phosphorus (ppm)
1
20
ppm range in the trial mixes
Potassium (ppm)
200
250
Best performance range – Note: basil
Calcium (ppm)
60
380
ppm range in the trial mixes
Magnesium (ppm)
35
100
Hort grade peat
0%
100%
Coir fiber
did well even at 500 ppm
Ditto
Grower’s choice - Feed & water will
be needed more frequently
Sub for peat
38
39. Item
Min
Max
Comments
Compost
0%
20-25%
The better the compost, the higher
% can be used
Peat Humus
0%
20%
Aged Bark
0%
5-10%
Economics will dictate its use
Castings
0%
5- 7 %
Benefit: Long term crops
30–35%
Compost, humus, castings
Combinations 0%
Perlite
0%
15–20%
Vermiculite
0%
5 – 10%
NOTE:
1) Observations in this presentation are based on the 4
trials conducted between April and June of 2013.
39
40. Important Analysis
1.
2.
3.
pH:
EC:
K:
Fertilizing
1.
2.
- keep in range of 5.5 – 6.5
- 1.9 to 3.9 performed better
- 200 to 250 ppm for veggies,
higher seems OK for basil
Fertilizing
- BEST to start day 1
Mix Fertility - Important to have in the mix, but
don’t rely on it alone
40
41. Mix Components:
1.
2.
3.
4.
5.
6.
Compost
Castings
Peat Humus Combination –
Aged bark
Structure
beneficial to use, keep <20%
long term crops, <5 to 7%
keep <20%
combination of above 3 items
kept<35%, or porosity impacted
-caution, keep<10%, needs feed
- needs balance of porosity &
moisture holding capacity
41
43.
“All composts are not created equal.”
◦ From: Tim Livingstone presentation on Mixes and
Transplants
Remember, just because a little is good,
does not mean more is better.
43
44. This
section will provide some basics on:
◦ Critical elements for good composting
◦ Production methods
◦ Evaluation of a good compost
44
46.
Factors which influence availability of oxygen
Pile size
Turning frequency
Turning method
Porosity
Oxygen availability determines compost type
Aerobic, or
Anaerobic
46
47.
Moisture Range
Acceptable - 40 to 65%
Optimum – 50 to 60%
• Squeeze/ feel test
Rules of Thumb
◦
◦
◦
◦
Higher during active stage
Lower during curing stage
Hot months - add water
Cold months – keep it out
47
48.
Both Carbon (C) and Nitrogen (N) essential
Beginning C:N ratios: 20 & 40:1
Prevent N loss. Add soil (5 to 10%)
48
49. High carbon sources
Wood based products
Cardboard & newspaper
Medium carbon & low nitrogen sources
Hay and straw
Leaf waste
Nitrogen sources
Animal manures
Silage, fresh green materials
Yard waste
Food processing waste
49
50. Heating will occur naturally - IF there is a;
Good C:N ratio, and
Adequate moisture, and
Sufficient porosity
Active heating range: 50 – 65˚C
Turn when temps in this range
CAUTION: Excessive heat destroys beneficial
microbes
50
51.
Turning windrows
Front end loader
Excavator
Straddle windrow turner
Farm manure spreader
Pitchfork
Other methods include:
In-vessel systems
Static aeration with vents
Bins
51
52. Critical Parameter
Range/ Comment
pH
6.5 to 8.0
EC
3.0 to 6.0 mmhos/cm
C:N ratio
15 to 25:1 (when finished)
Smells
Like a good forest soil
Appearance
No original substrates recognizable
Temperature
Will not reheat if moisture is brought to 50 –
55%
NOTE: To be sold, must also meet CCME
Guidelines for Heavy Metals and pathogens
52
53. Need to Know:
Analysis: pH, EC, K levels
Compost type, % used
Percent of non peat ingredients
Structure
Remember: start fertilizing early
Advice on making your own:
Start small, trial, test
Don’t switch until proven
Enjoy!
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