Post on 20-Mar-2018
Irrigation and fertilization in hydroponics
Irrigation control involves the determination of both the timing and quantity of water appliedthe timing and quantity of water applied.
Hydroponics & Soilless media culture
I i i & F ili i F i iIrrigation & Fertilization = Fertigation
Management of water and nutrient supply to avoid excesses or deficiencies
Management for increasing:Fruit yield and fruit quality
and decreasing:Water and fertilizer use Fruit disordersDiseasesPests
Daily water consumption depends on:Transpiration rate
– Crop– Stage of growthStage of growth– Day of the year– Hour of the day
Tomato (fully grown plant) transpires in a summer day:Tomato (fully grown plant) transpires in a summer day:
mm m3/ha Per plant at 3 pl/m2
Northern Europe 3-5 30-50 1-1.7 L/plant
Mediterranean 6-9 60-90 2-3 L/plant
Productivity (kg/m2) of various vegetables in theProductivity (kg/m2) of various vegetables in the greenhouse and in the field
Crop Almería, Spain
The Netherlands FL, greenhouse FL, field
Tomato 10-12 42 8-20 4.0Pepper 6-7 26 7-14 3.3Cucumber 8-9 58 7-28 3.0
Hydroponics, soilless cultureNFT: Nutrient Film Technique
Drip irrigation, roots in substrate orDrip irrigation, roots in substrate or media (no soil)
Mist of nutrient solution roots in air
Floating, roots in aerated
Mist of nutrient solution, roots in air
in aerated nutrient solution
Irrigation system design
Crop water demand
Crop season
Water treatment
Crop season
No. irrigation events/day
Time of irrigation Water treatmentTime of irrigation
Drainage
Required water flow
Irrigation sectors
Water source (quantity and quality)
Capacity of the irrigation equipment: adapted to the transpiration of a fully grown crop on a hot summer day.
Approaches used to estimate irrigation needspp g
• 1) Use of potential ET according to an existing climatic• 1) Use of potential ET according to an existing climatic model,
• 2) Use of one of several sensors to report the amount of water in the substrate,
• 3) Use of one of several plant response parameters,
• 4) Any combinations of the above.
Ad 1995Adams, 1995
Response of the time intervals of irrigation events to different integrated solar radiation set points that started each irrigation event
250 2:09Solar Radiation3 KW i / 2
200
ts/m
2 )
1:26
1:40
1:55
:Min
ute)
3 KW min/ m25 KW min/ m27 KW min/m29 KW min/m211 KW i / 2
100
150
Rad
iatio
n (W
att
0:57
1:12
Inte
rval
(Hou
r:11 KW min/m2
50
100
Sola
r R
0 14
0:28
0:43
Irrig
atio
n I
00:00 2:24 4:48 7:12 9:36 12:00 14:24 16:48 19:12 21:36 0:00
Day Time (Hour:Minute)
0:00
0:14
Day Time (Hour:Minute)
Irrigation schedulingIrrigation scheduling
Savvas and Passam, 2002
Monitoring station
Why surplus of water and fertilizers?
• Uneven deliver of nutrient solution to the plants• Temperature variation within the greenhouse
Why surplus of water and fertilizers?
• Salt accumulation in the substrate• Genetic differences between plants
Savvas and Passam, 2002
Irrigation interval regulated by water content in the slabIrrigation interval regulated by water content in the slab
Cucumber in a rockwool slab.
W i h t ti t ti tWeigh station to estimate moisture in the rockwool slab.
Fertilizer injectors and stock solutions
Fertigation Information
Cucumber crop Spring 2002
transplant harvest 15Element Date 31-Jan 1-Feb 2-Feb 3-Feb 12-Apr 13-AprN 130 130 130 130 156 156P 50 50 50 50 50 50K 148 148 148 148 206 206Ca 158 158 158 158 174 174Mg 48 48 48 48 48 48S 66 66 66 66 66 66Fe 2.8 2.8 2.8 2.8 2.8 2.8Cu 0 2 0 2 0 2 0 2 0 2 0 2Cu 0.2 0.2 0.2 0.2 0.2 0.2Mn 0.8 0.8 0.8 0.8 0.8 0.8Zn 0.3 0.3 0.3 0.3 0.3 0.3
B 0.7 0.7 0.7 0.7 0.7 0.7Mo 0.006 0.006 0.006 0.006 0.006 0.006
EC 2 2 2 2 2.5 2.5pH 6.14 6.14 6.14 6.14 5.9 5.9
irrigation 31-Jan 1-Feb 2-Feb 3-Feb 12-Apr 13-Aprt t (d ti ) 8 00 8 00 8 00 8 00 6 30 6 30starts (day time) 8:00 8:00 8:00 8:00 6:30 6:30
ends (day time) 19:30 19:30 19:30 19:30 19:30 19:30delay (min) 90 90 90 90 20 20event duration (min) 1.17 1.17 1.17 1.17 2.67 2.67
day hs with irrigation 11:30 11:30 11:30 11:30 13:00 13:00y gnumber of events/day 8 8 8 8 30 30ml/event 59 59 59 59 134 134L/day 0.443 0.443 0.443 0.443 4.063 4.063
Slicing cucumberBeit alpha cucumber
Fresh cucumbers crop seasons i th h d fi ldin the greenhouse and field
Beit Alpha SlicingBeit Alpha SlicingUNITS
Crop Period days 105 70Planting date End Jan. Jan.1st Harvest Mid. Mar. Mid. Mar.Time Seeding to 1st harv days 60 40 65Time Seeding to 1st harv. days 60 40-65Last Harvest Mid. May Mar.Plant density plants/ha 30,000 53,820No. harvests no. 27 10-15
Greenhouse FieldBeit Alpha Slicing
Maketable yield kg/ha 270 000 31 197
Cucumber production for fresh consumption. Central FL. Spring crops.
Maketable yield kg/ha 270,000 31,197 no./ha 2,310,000 135,639 g/fruit 115 230
Fruit price $/kg 1.54 0.40
Gross income $/ha 415,800 12,479 Irrigation m3/ha 8,190 1,406Water use efficiency L/kg fruit 30 45
g fruit/L 33 22g fruit/L 33 22 L/no. fruit 4 10 no. fruit/L 0.3 0.1
N applied kg N/ha 1,260 203 N ffi i N/k f it 4 7 6 5N use efficiency g N/kg fruit 4.7 6.5
kg fruit/kg N 214 154 mg N/no. fruit 545 1,495 no. fruit/kg N 1,833 669
K applied kg K/ha 1,620 243K use efficiency g K/kg fruit 6.0 7.8
kg fruit/kg K 167 129 mg K/no fr it 701 1 789mg K/no. fruit 701 1,789no. fruit/kg K 1,426 559
Field K20: 260 lb/a, N: 180 lb/a
Nutrient concentration levels in the solution
Varies with:C iCrop speciesCrop seasonPlant growth developmental stagePlant growth developmental stageGrowing system
Characteristics of the nutrient solutionConcentration of nutrientsRelation of concentration among nutrientspHECEC
N % P %FRUIT
Galia melon
N % P %LEAF
STEM
K % Ca %K % Ca %
Mg %Mg %
Nutrient solution pH: 5 5-6 5Nutrient solution pH: 5.5 6.5
pH correction:
• Phosphoric, nitric, chlorhydric acid.
• Potassium/sodium bi b ibicarbonate, potassium hydroxide.
Nutrients S li d Nutrient Source Nutrient Content
f S (%) Nutrient Source Nutrient Content f S (%)
Nutrients S li dSupplied Nutrient Source of Source (%)
Nitrogen (N) Ammonium nitrate 33.5Calcium nitrate 15.5Calcium nitratez 7Potassium nitrate 13
Nutrient Source of Source (%)Boron (B) Sodium borate 20
Boric acid 17Copper (Cu) Cupric chloride 17
Copper sulfate 25
Supplied
Potassium nitrate 13Nitric acid varies
Phosphorus (P) Monopotassium phosphate 23Phosphoric acid varies
Potassium (K) Potassium chloride 50
Copper sulfate 25Copper nitratez 17
Zinc (Zn) Zinc sulfate 36Zinc nitrate z 17
Iron (Fe) Chelated iron 5-12(EDTA, DTPA)Potassium (K) Potassium chloride 50Potassium nitrate 36.5
18.3Monopotassium phosphate 28Potassium sulfate 43
Potassium magnesium sulfate
Iron (Fe) Chelated iron 5 12Manganese (Mn) Manganese chloride 44
Manganese sulfate 28Manganese nitrate z 15
Molybdenum (Mo) Ammonium molybdate 54
( , )
Calcium (Ca) Calcium nitrate 19Calcium chloride 36Calcium nitrate z 11
Magnesium (Mg) Magnesium sulfate 10
Sodium molybdate 39Chloride (Cl) Potassium chloride 52
Calcium chloride 64z Liquid formulation
22Sulfuric acid variesP t i lf t 18
11Sulfur (S) Magnesium sulfate 14
Potassium magnesium sulfate
Potassium magnesium sulfate
Potassium sulfate 18
Hochmuth, 2001. Florida Greenhouse Vegetable Production Handbook- Volume 3.
Evolution of irrigation equipment used in hydroponics
A & B stock solutions made
from solid fertilizers
Individual liquid fertilizers
O li i l tifertilizers
mixing tank
Online ion selective sensors and EC & pH
adjustment
EC & pH adjustment
Drain to
Disinfection, nutrient and pH adjustment, and reuse of
drained solution
Drain to waste
systems
Waste of water & pollution of ground- and surface water
ith f tiliRecycle into the same greenhouse cropwith fertilizers
Option: Recycle into another (field) crop
greenhouse crop
“Greenhouse horticulture: safe, sustainable, and competitive.”
Fertilizers: A/B dilutor systemyDirect injection
Dilutor A Dilutor BDilutor A Dilutor B
Water
Irrigation l i
C ++
P2O4----
solution
SamplingCa++
NO3-
Fe
SO4--
NO3-
Mg++
K+
EC: 1.5-3 dS m-1
pH: 5.5-6.5
Tank A Tank B
Micro
(Acid)
EC: total salt content
Individual nutrient concentration?
Concentrated solutions
Tank A Tank BNO3- & K+ ion meters
Laboratory samples
Irrigation solution – Pepper cropg pp p
6
7
225
250 ECpH
O
4
5
S cm
-1)
150
175
200
(mg
L-1)
NO3-NK
3
4
or E
C (d
S
100
125
3-N
or K
(
1
2pH
25
50
75
NO
3
0Oct Nov Dec Jan Feb Mar Apr May June
Month
0
Month
N: 40 ppmN: 165 ppm pppp
Cucumber fruit yields in 9 harvests from plants irrigated with high and low N levels in the nutrient solution (N: 165 and 40 ppm, respectively)
Pl t d it 3 3 l t / 2Plant density 3.3 plants/m2
100
High N10
12
High Nm2 )
ber/m
2 )
87
5340
60
80 Low N 10.8
7.06
8
10Low N
ve y
ield
(kg/
m
eld
(frui
t num
b
0
20
40
0
2
4
Cum
mul
ativ
umm
ulat
ive
yie
23-Jul 28-Jul 2-Aug 7-Aug 12-Aug 17-Aug 22-Aug
Harvest date23-Jul 28-Jul 2-Aug 7-Aug 12-Aug 17-Aug 22-Aug
Harvest date
Cu
Nitrate-nitrogen in the petiole sap of melon, cucumber, and pepper plants irrigated with nutrient solution with 165 or 40 ppm of N.
High N Low NIrrig. Solution NO3-N ppm 165 41Melon
Fresh weight g 23.860 14.690Leaf area cm2 374.6 310.1 Dry weight g 2.086 1.915 % D wt 8.7 13.0 Petiole NO3-N ppm 5,050 230 Cucumber Fresh weight g 4.550 2.070 Leaf area cm2 144.5 103.8 Dry weight g 0.532 0.383% D wt 11.7 18.5 Petiole NO3-N ppm 5,650 235 PepperppFresh weight g 3.720 2.130 Leaf area cm2 85.3 72.6 Dry weight g 0.423 0.318 % D wt 11.4 14.9
Petiole NO3-N ppm 14,500 1,700
Closed growing systemNutrients
EC
Supply water
pH
Mixing supply water
DisinfectionDisinfection
StorageStorageDrain collection Storage disinfected water
Storage drain water
Drain collection
Adapted from van Os et al., 2002
Fertimix® system for crops grown in soilless media
PC
soilless media
Weather infoAlarm
SensorsWaterController
Sensors
Mixing tank
PumpPumpValves
& injectors
Fertilizers Acid
Simple element stock solutions
Source: van Os et al., 2002
Frequency of irrigation. 250-day old pepper plants
Mean 9121662 26irrigation events /day
9121662 26
34 L/ t
74
Mean irrig. events/day 1662 26
mL/event
2 m
912
Fruit physiological disorders Fruit physiological disorders that can be related to that can be related to fertigation managementfertigation management
Color spotsColor spots BlossomBlossom end rotend rotColor spotsColor spots BlossomBlossom--end rotend rot
RussetingRusseting Radial crackingRadial cracking
Effects of the irrigation schedule and volume of nutrient solution per irrigation event on the marketable fruit yield, nutrient solution and fertilizer amounts used per unit of marketable fruit yield harvested and percentage of fruits with
russeting and blossom-end radial cracking.