Advanced water and nutrient management towards efficient nutrient use in greenhouse horticulture

Transcription

1 Advanced water and nutrient management towards efficient nutrient use in greenhouse horticulture Wim Voogt Wageningen UR Greenhouse Horticulture Osnabrücker Kontaktstudientage nov 21 Contents Greenhouse Horticulture in the Netherlands; state of the art The closed growing system Water and nutrient use efficiency Constraints Salt accumulation Growth problems Nutrient problems The way forward 1

2 Intensive horticulture in the Netherlands Netherlands Europe Westland Greenhouse horticulture 12 Overall 8 % soil less culture 1 Area (ha) peat mix soil substrate 2 Greenhouse total area vegetables cutflowers potplants 2

3 Substrate / Soil less culture: Typical Restricted Root Volume 1 15 l m 2 Restricted quantity water and nutrients 2 5 % of total demand present any time Requires adequate water and nutrient supply! Greenhouse crops: high water and fertilizer demand High growth rates, crop nutrient requirements. Over Irrigation necessary: unequal water distribution. prevent salinity Costs of fertilizers insignificant compared to total costs. Initially low water fertilizer use efficiency Heavy environmental pollution 3

4 EU Policy Ground water protection Surface water protection Soil protection European Water Framework Directive Nitrate Directive (groundwater) Dutch context (1998) Soilless growing: Recirculation /reuse of drainage water obligatory Discharge drainage water only if: Na > legal limits (crop specific) Disease outbreak (permission required) Rainwater collection obligatory (5m 3 /ha) 4

5 State of the art (25) Common growers practice: Frequent discharge quite common Significant N, P emissions + Plant Protection Chemic. Causes, motives Disease risks Na, Cl accumulation Nutrient irregularities Growth reduction. Policy / regulations 21 Regardig European Waterframework Directive Agreement growers government: from Emission targets to be reached 227 (almost) zero emission in greenhouse industry Target instead of means regulation N emission? Kg/ha/yr

6 Reuse of drainage / Closed systems Hydroponics Substrate systems Potted plants on tablet ebb flow system Hydroponics Watercultures NFT / DFT 6

7 Substrate systems Substrate systems substrate in throughs / gutters substrate in growth containers, drainage collection in gutters Collection of leachate (drainage water) 7

8 Closed growing systems 7 l/kg High Water 2Use Efficiency possible 1 l/kg Israel / Spain field Spain plastic 199 Israel glass (n.h.) Spain plastic (n.h.) 2 Holland heated glass Holland re use drain Holland semi closed Israel / Spain field Spain plastic 199 Israel glass (n.h.) Spain plastic (n.h.) 2 Holland heated glass Holland re use drain Holland semi closed After Stanghellini 23, Acta Hort 69 High nutrient use efficiency possible T/ha (yield) kg/ha (N) % Recovery Yield N supply N Uptake Soil 198 Rockwool free drainage 198 Rockwool re use drain 1995 rockwool r use drain 21 Data after: Sonneveld (199), de Kreij (1998), Voogt (21) 8

9 Furthermore Closed or semi closed greenhouse Developments in water and nutrient use Completely closed greenhouse no ventilation, mechanical cooling Semi closed greenhouse minimized ventilation + mechanical cooling The new growing concept (low ventilation, dehumidification, mechanical cooling, 9

10 Constraints for closed systems 1 water quality 2 diseases 3 growth inhibitors 4 nutrient irregularities 5 water quantity 1

11 1) Waterquality Na and Cl Residual salts Ca, Mg, SO4, HCO 3 Micro elements Zn, Cu, Mn, B Contaminants Al, F, Pb, Cd Principle I input U uptake root environment Growing system R drainage D No waste water No losses 11

12 Important aspects Input = uptake: I = U I > U I < U More specific: accumulation depletion Input < uptake at max. acceptable concentration R max I max U max Water sources (Na en Cl) Strongly regulated in near future Source remarks EC Na Cl ms/cm mmol/l mmol/l Reversed Osmosis <.1 <.1 <.1 Rainwater Coast.2.5 (>5).5 (>5) Westland area Inland < Tap water Source river Maas Source river Rhine Surface water Westland area Well water Westland area >>2 >> 1 >>1 South-east

13 12 Salinity effects 1 Yield % Treshold value R max 2 Radish Hippeastrum ECss Uptake concentrations 6 6 Na uptake concentration mmol l gerbera carnation rose aster Bouvardia Bouvardia lily Cl uptake concentration mmol l gerbera carnation rose aster Bouvardia Bouvardia lily Na root environment mmol l-1 Cl root environment mmol l-1 13

14 Na uptake concentrations 6 5 Na uptake concentration mmol l Tomato Cucumber Sweet pepper Sweet pepper (fruit load) Na root environment mmol l-1 Uptake mmol l Na in root environment and uptake Treshold value R max root environment mmol l-1 Tomato Cucumber Sweet pepper Sweet pepper generative 14

15 Key to solution Prevention, choice of water source Discharge recirculating nutrient solution partially if Na above threshold levels Developments in water technolgy 2) Root diseases Favorable conditions Rapid development Rapid spreading and infection No biological equilibrium 15

16 Key Hygiene Crop resistance (conditions) Substrate type ( O 2 supply) Adequate water treatment/disinfection Heating UV (Future) surpressiveness of the substrate system 3) Growth inhibition The Recirculation disease Growth reduction, unknown phenomenon Root exudates? Contaminants? Decomposition? Bioassay Organic micro pollutants 16

17 Key Desinfection, combined with advanced oxidation UV treatment + peroxide + active carbon 4 Nutrient irregularities Imbalanced nutrient ratios Rapid depletion / accumulation ph or EC deviation Decomposition (Fe chelate) 17

18 Shift in uptake during growth K, Ca en Mg opnam e bij tomaat mmol/l Tros 2 Tros 4 Tros 6 Tros 8 Tros 12 Tros 1 Trosontwikkeling K CA Mg Week H + mmol/l jan 22-feb 12-apr 1-jun 21-jul 9-sep 29-okt stems /m 2 /week acid supply yield Example: ph fluctuation caused by NH4:NO3 uptake ratio by a rose crop (after Voogt, 24) 18

19 Key: proper Nutrient management Water A B Controlunit EC control ph control Nutrient solution Basic composition Fine tuning Feed back Analysis from root env. Mixing tank disinfestation Drainage collection 5) Water quantity Average year m3 3 m3/ha m3 day-1 Basin level suppletion rainwater Dry year m m3 day Basin level suppletion rainwater 19

20 And. Still discharge problem of residual waste water Emission routes Nutriënts (N en P) en Plant protection chemicals via waterflows Residual drain off Backflush (sand )filters Processwater Ditch Sewage system Groundwater Drainage (soil crops) 2

21 Closed water chain From: Witteveen+Bos, 22 To conclude Greenhouse crops extreme high WUE and NUE possible Hydroponics + closed growing systems The new growing concept Closed or semi closed greenhouse Important constraints: waterquality, diseases, organic micro pollutants, nutrient imbalances. Adequate filtration and disinfestation required Sophisticated management and control 21

22 For those who want to know more. 22