Symposium

Innovative production systems News from hydroponical trials

September 25th 2019Matthijs Blind, researcher Proeftuin Zwaagdijk

(matthijsblind@proeftuinzwaagdijk.nl , +31 (0) 6 30 81 58 11)

Contents:

Deep water culture (DWC) chrysanthemums

Hydroponics various cut flowers

Interreg project Hy4Dense

Deep water culture with high concentrations sodium (and chloride) (Project Achteroever)

Chrysanthemum (cut flower), DWC

o 2015-2017: 13 successful crop cycles (also in summer)

o 2018/2019: start new project in chrysanthemums and other cut flowers with financial support of:o Landelijke gewascommissie

chrysant/ChrIPo Stimuflorio STOWAo LTO Noord Fondsen

Most important results/conclusion up to now:Potential higher yields than in soil

% loss/infections minimal

Several crop cycles on same nutrient solution without disinfection are possible (emission almost 0)

Reuse of nutrient solution seems to be better than new nutrient solution

Roots of chrysanthemums seem to be very sensitive to oxidative substances (disinfection), observed while using van chloride.

Avoid use of PVC (softening agents, stabilizers)

Adding ammonium to nutrient solution positive effect on yield (weight)

Period before start of short day treatment (rooting + long days) strongly determines final result

Production without any substrate is possible

Focus now: Improving rooting and development

during long-day-period, prevention of chlorosis

Up to now mainly variety ‘Bacardi’, later ‘Pina Colada’ to compare with crop at close by traditional grower

Recent variety trial: ‘Pina Colada’ and ‘Bacardi’ (a bit less) are sensitive for chlorosis

Relation with nutrition not (yet) proved

Pythium(?): roots visual healthy, use of fungicides do not prevent chlorosis

Relation with light/radiation (intensity/DLI?), stress? Reducing radiation/light or change to short day period

leaf colour improves rapidly Trial: extra screen leaf colour improves Production system possibly more sensitive as result of

reflection? (better: we again have to learn how to grow)

Soon: Test prototype in float integrated crop

support Further development substrate-less

production Program of requirements design of new floats

Design of required company structure for large scale production

o Screeningo 2020: Selection 2 or 3 most promising cropso DWC/DFT but possibly also other alternative/innovative

growing systemso Tulip hydro trays (promising results former trials)

Other cut flowers

Tests using sowing trays

Tulip hydro trays with inline fertigation

Promising up to now: Matthiola Antirrhinum Delphinium (from seed) Alchemilla Brassica….

Ammi Tanacetum (Matricaria) Lisianthus

Most promising crops: Trial with both a used and a new nutrient solution

Interreg 2 Hy4Dense

• Development of production system (hydroponics) for spinach, lambs lettuce and (wild) rocket

• Start 2019

• Inagro (Belgium)

• Howest (Belgium)

• NIAB (UK)

• University of Essex

• Proeftuin Zwaagdijk

DWC of various crucifers on water with a high sodium

(and chloride) concentrationPart of project Achteroever Wieringermeer (NL)

(use of regions with water storage – fresh/salty water - for food

production).Commissioned by Rijkswaterstaat (Ministry) with financial support of EFRO and the

Province of North-Holland, in close cooperation with Zilt Proefbedrijf/Salt Farm Texel

Analysis Calculated

Surface water composition

parameter unit 25-06-19 after fertilizing

EC mS/cm 6.9

pH 9.5

NH4-N mmol/l <0.1 0

K mmol/l 1,0 8.5

Na mmol/l 47.9 47.9

Ca mmol/l 6.7 8.5

Mg mmol/l 4.2 4.2

NO3-N mmol/l <0.1 9.1

Cl mmol/l 59.8 59.8

S mmol/l 0.9 0.9

P mmol/l <0.04 2

Fe µmol/l <0.2 40

Mn µmol/l <0.1 10

Zn µmol/l <0.1 8

B µmol/l 15 50

Cu µmol/l <0.1 1.5

Mo µmol/l 0.1 1.5

HCO3 mmol/l 0.2 0.2

IJsselmeer

Trial basins

Region with salinization

Indicative trial: White cabbage : 4 varietiesCauliflower : 4 varietiesKohlrabi : 3 varietiesBorecole : 1 varietyBroccoli : 1 varietySwiss Chard : 1 varietyRape kale : 1 varietymarrowstem kale : 1 variety

Planting: June 28th, rape kale July 8th, merrowstem kale 27 July 27th

All types and varieties developed a harvestable product

Remarkable differences in leaf colour (nutritional deficiencies?) between kohlrabi varieties

Current (demonstration) trials DWC

• Greenhouse 34: chrysanthemums (effect pH and float colour on leaf colour, variety trial) (explanation: Matthijs Blind, +31 (0)6-30815811)

• Greenhouse 23: Screening various cut flowers like Lisianthus, Antirrhinum, Brassica, Ammi and Campanula on DWC/DFT (and Lisianthus on Tulip hydro trays) (explanation: Matthijs Blind)

• Demonstration various crops on DWC lettuce in a tunnel (explanation Jan Botman, Botman Hydroponics, +31 (0)6-38900656)

• Lettuce trials outdoor (Interreg Bio4Safe): effects of biostimulants on uptake of nutrients under suboptimal conditions (nutritional stress) (explanation: Matthijs Blind, +31 (0)6-30815811)

Tunnel

Trial Fields

reception

Green-

house 34

Green-

house 23

Lettuce hydroponics (Bio4Safe)

terrac

e

reception

resta

ura

nt

restaurant

ToiletswardrobeToilets

Symposiums

ENTRANCE

Symposiums

Thank you for your attention!