Maarten Coelen - Introduction to root zone management

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

Grodan  13.06.2018  Part of the ROCKWOOL Group

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Use of GroSens in practice •

GroSens Reader / handheld

•

GroSens Multisensor set

Grodan  13.06.2018  Part of the ROCKWOOL Group

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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.

Grodan  13.06.2018  Part of the ROCKWOOL Group

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GroSens Multisensor system

Overview per section

Graph per section

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Qestions?

Grodan  13.06.2018  Part of the ROCKWOOL Group

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Thank you

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