Introduction to root zone management Maarten Coelen Business Support Export Markets
13 June 2018
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Agenda
1
Main reason of developing Root Zone Management
2
Using the Product
3
The Product: higher Substrate
4
Irrigation Strategy
5
Tools
Grodan 13.06.2018 Part of the ROCKWOOL Group
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69,6%
70,0%
65,0%
61,9%
57,3% 69,1% 57,3%
57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Grodan 13.06.2018 Part of the ROCKWOOL Group
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Precision Growing
69,6%
70,0%
65,0%
61,9%
69,1% 57,3%
57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Precision Growing for Everyone
69,6%
70,0%
65,0%
61,9%
69,1% 57,3%
57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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PRODUCT Substrate choice based on
Crop: Tomato – Capsicum – Cucumber
Required Steering Level: Standard – Balanced - Maximum
Grodan 13.06.2018 Part of the ROCKWOOL Group
Substrate management
Using the product
Effect on plant growth
69,6%
70,0%
65,0%
61,9%
69,1% 57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Substrate volume
Amount of stone wool l/m2 Optimum
7,5-9,0 l/m2 steerable in EC, WC, vegetative-generative development
Maximum
12 l/m2
Steerable in WC% and EC whilst managing generative & vegetative growth Grodan ďƒˇ 13.06.2018 ďƒˇ Part of the ROCKWOOL Group
Steering day-to-day and season-to-season Irrigation strategy
Influence on crop development
Decrease WC
=
Generative effect
Increase EC
=
Generative effect
69,6%
70,0%
65,0%
61,9%
Increase WC
=
Vegetative effect
Decrease EC
=
Vegetative effect
69,1% 57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Control possibilities for manipulating substrate WC
Influence on the slab WC Start time
Large
WC DECREASE (Generative) Later
WC INCREASE (Vegetative) Earlier
Stop time
Large
Earlier
Irrigation length
Small
Longer
Shorter
Frequency
Medium
Lower
Higher
69,6%
Later
70,0%
65,0%
61,9%
69,1% 57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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WC & EC steering in relation to light
69,6%
70,0%
65,0%
61,9%
69,1% 57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Trend towards higher substrate Gives a more generative start Quick refreshment with minimum drain
Both WC and EC can be controlled more quickly and more accurately. The higher slab results in more even root development over the total height with more roots in the zones furthest away from the drippers More active roots due to more oxygen in the middle of the slabs
Grodan ďƒˇ 13.06.2018 ďƒˇ Part of the ROCKWOOL Group
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Substrate management
WC & EC behaviour in the substrate
69,6%
70,0%
65,0%
61,9%
69,1% 57,8%
61,8%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Water & EC behaviour in the substrate • 3 distinct periods in 24 hrs
Period 1 • 1st irrigation to 1st drainage • A step wise increase in Slab WC • EC will also increase
Development of substrate WC & EC in 24 hours
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Water & EC behaviour in the substrate • 3 distinct periods in 24 hrs
Period 2 • Drain period • A stable WC • Decreasing EC
Development of substrate WC & EC in 24 hours
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Water & EC behaviour in the substrate • 3 distinct periods in 24 hrs
Period 3 • Time between stopping irrigation day 1 & starting irrigation day 2. • Decreasing WC
• Increasing EC Development of substrate WC & EC in 24 hours
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Especially drain volumes <20%
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Starting irrigation Bright day
• 100-200 W/m2 or 50-100 J/cm2 • Look for 1.5-2.0% decrease WC from sunrise Dark day • Depending plant development irrigation yes or no? • Look for 1.5-2.0% decrease WC from sunrise
Start time optimised in relation to sunrise and increasing plant activity. Protects plant & fruit quality. Grodan 13.06.2018 Part of the ROCKWOOL Group
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Stop time irrigation Bright day
• 80-100 J/cm2 & 250-350 W/m2 outside radiation. • Aim to leave 150-200 J/cm2 to sunset
Dark day • 3-4 hours before sunset
• EC stable? • Decrease WC over night?
Grodan 13.06.2018 Part of the ROCKWOOL Group
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Getting it right with a steerable substrate With changing weather conditions it works well. Stability in the root zone without the need to “chase a certain drain volume or EC value”. • Start on time. • Drain on time • EC lowest radiation highest. • Stop on time. • Stable decrease in substrate WC.
Structure leads to stability in the root zone despite variable outside weather conditions. Grodan 13.06.2018 Part of the ROCKWOOL Group
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TOOLS Substrate management
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Use of GroSens in practice •
GroSens Reader / handheld
•
GroSens Multisensor set
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GroSens makes precision irrigation possible •
Accurate WC, EC & temperature measurement directly in the substrate.
•
Multiple measuring points for better representation of the root zone. GroSens sensors can be moved easily throughout the greenhouse giving greater flexibility.
•
GroSens graphical output of substrate WC, EC & temperature provides information on the result of the watering strategy.
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GroSens Multisensor system
Overview per section
Graph per section
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Qestions?
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Thank you
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