The document summarizes the history and technology transfer of fertigation in Dutch greenhouse horticulture from the 1950s to present. It discusses how (1) developments in fertilizers, irrigation, computers, and soilless systems enabled yield increases and quality improvements through better nutrient control from the 1950s-1980s. (2) Environmental issues in the late 1970s-1980s led to initiatives to reduce pollution and emissions. (3) Research, demonstration projects, and knowledge sharing through various partners helped transfer technologies to reduce nutrient use and leaching over time. (4) Recent legislation since 2013 aims for almost zero discharge of nitrogen and phosphorus by 2027 through standards, obligations for soilless and soil crop discharges, and mandatory

1. Technology transfer of fertigation
The Dutch experience
Wim Voogt, Wageningen University & Research
Greenhouse Horticulture

2. Brief history of fertigation
 Start late ‘50s
 Parallel developments
● Availability of soluble fertilisers, technology for
dosing (venturi , EC meter)
● Soil analysis
● Fertiliser recommendation system
● Small strip sprinkler systems
● Drip irrigation
● Computer
● Soilless systems
● Sensor technology
2
1950
1960
1970
1980
1990
2000
2010
Yield increase
Better quality
More control over
crop growth factors

3. Technology transfer
in general:
In the old days....
 Cooperative system
● Marketing: auctions
● Purchasing Cooperation's
No competition
Open knowledge transfer
 Support Dutch government
● Golden Triangle
3

4. The Golden Triangle
4
Extension
ResearchEducation
 Sharing knowledge and
experience

5. Environmental issues
 From late ‘70s -> ‘80s
 Pollution of surface water
● Eutrophication (N and P )
● PPP’s
 Pollution of groundwater
 Societal demands
5

6. Initiatives
 Governmental pressure
● Policy note ‘89 (“structuurnota landbouw”
“... By 2000 all crops soilless....+ recirculation...”
● Research and demonstrations
 Initiatives from market organisations ( auctions )
 Growers organisations
● GLAMI convenant
● Agreement -> zero emissions in 2027
● Obligation to recirculate ( soilless)
6

7. Meanwhile
 Graduallly transfer from cooperation to competitive
systems
● Auctions -> marketing boards
● Common growers organisations -> closed unions
 Government retreat
● Privatisation extension service
● Research and experimental stations
● Soil testing laboratory
7
Extension
Research
Education

8. Research and development and extension
● Demonstration projects
● Reduction N/P use, reduction leaching
● New technologies
● Soilless: reuse drainage water / water
treatment/ water resources
● Soil: irrigation on demand ( soil moisture,
model based irrigation, lysimeters)
8

9. Technology transfer
9
Knowledge partners
Articles,
Newsletters
Websites, e.g.
Courses
Lectures
Open days
Demonstratons
Thematic days
Supply companies
Computer fims
Consultants
Seed companies
Suppliers of propagation
plants
The Grower
Excursion groups

10. Initiative from government:
System innovation
10

11. Irrigation in
soil grown crops vs. soilless crops
11
WATER
NUTRIENTEN
UITSPOELING
ET
leaching
WATER
NUTRIENTEN
RECIRCULATIE
ET
recirculation

12. <10% soil grown
(2% organic)
>90% soilless cultivation

13. 0
5
10
15
20
25
30
nitrogen(mgN/l)
Amount of nitrogen in Greenhouse areas
Reuse is common practice since 1994
1994: obligatory recirculation
Hoogheemraadschap van Delfland
Greenhouse area
Reference area
Goal

14. However.....
 Concentration PPP’s remain high in concentrated
greenhouse areas
 NO3 and P in surface waters decline too slowly
 Zero emission target 2027 out of reach
 European WFD and ND requires more drastic steps
14

15. Pesticides in surface waters NL
15
> 5x norm
> 2x norm
> norm
not testable
> target value ≤ norm
≤ target value
Westland-Oostland

16. Amount of discharge per year (m3/ha)
gerbera cucumber tomato
337 133 52
925
523
278
2,370
2,077
746
most discharging farmers (20%)
60% of farmers
least discharging farmers (20%)
Source: emissieproject LTO
Norm
2017: 125 kg N /ha 75 kg N /ha 67 kg N / ha
~ 525 m3/ha ~150 m3/ha

17. Wat went wrong ?
17

18. Water is cheap, risk (perception) is high
Fixed costs
(incl soil)
27%
Variable
costs
13%
Labour
29%
Energy
22%
General,
market,
transport
9%
Distribution of costs
Tomato production
Production costs
5% PPP*
2% Fertilizer
1% Water
*PPP = plant protection products (pesticides)

19. Sodium accumulation
Growth inhibition
● Start cultivation or later
● Root exudates, microorganisms, PPPs ...
Unbalanced nutrient composition
Technical failures of equipment
Filter back-flush water
Poor dimensioning
Start and end of cultivation
● First drain of slabs
● First months
● Left-over water
● Cleaning
Reasons for discharging:

20. Eventually.....
 New and more tough regulations
 Soilless :closed system / discharge only with purification
 Soil: “zorgplicht“ (obligation to care )
+ reuse drainage water ( if possible)
20

21. New legislation since 2013
 Agreement between government, water
authorities and grower’s organisation LTO:
● (Almost) Zero discharge of N and P in 2027
● Towards 2027:
● Soil crops: N+P norms for use
● Soilless crops: N-emission standards;
reason for discharge up to grower;
along with N, also P and pesticides will decrease

22. Nitrogen emission standards (soilless crops)
22
0
50
100
150
200
250
300
350
2010
2015
2018
2021
2024
2027
KgNha-1year-1
phalaenopsis, potted orchids
Gerbera, rose, young
vegetable plants
Strawberry, aubergine, sweet
pepper
cucumber, potted plants,
young plants ornamental
tomato, herbs
tulips
Orchid (cymbidium)
Anthurium
other vegetables

23. Additional legislation for PPP (2018)
Obligatory discharge water treatment
 95% removal of plant protection products (PPPs)
 99.5% for imidacloprid
 Approval of installations of suppliers
(not: prove purification efficacy at grower / at each discharge
event)
23

24. Additional legislation for PPP
(2018)
Obligatory discharge water treatment
for all greenhouses
Discharge to sewage and surface water
For soilless & soil-grown cultivations
Soil cultivation:
● Only when drainage is present
● If too much seepage: reuse and purification of
discharge not obliged,
BUT grower should solve seepage problem within
10-15 years!
24

25. Effectuation of obligation
25
Ontsmetting
Optimale
bemesting
100% recirculatie
Natriumarm
gietwater
Precision
growing
Mobile
application
Cooperative applicationIndividual application
Zero Discharge

26. To conclude
 Technology transfer smoothly, easy from ‘50s – ‘90s
● Growers cooperation's, Infrastructure, Golden
triangle
● Increase of productivity ( soilless !), “low hanging
fruit”
 From ‘90s
● No more yield increase, no incentives
● Need persuasion, find added values and benefits
● More emphasis on responsibilities
● Using various means
 In the end, regulatory solutions
26

27. Thank you for
your attention