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SmartphoneBasedContentEstimationinGreenhouseCrops

RanjeetaAdhikari02/12/2019

IndianaHort Congress

BackgroundNitrogen• Essential element for crop growth and quality

Nsufficient Ndeficient

ExcessNitrogenfertilizer

Algae growing and fish dying due to water pollution

NO3-

Therefore,maintainingtissueNatoptimumleveliscrucialinfloriculturecrops

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EC based measurement of solution/substrate

- measures EC and pH of the substrate and solution applied

- time consuming

- not accurate measurement of Plant N

Background

EC sensors

Laboratory analysis for tissue nitrogen

- costly ($20-25 per sample)

- time taking to get the results (7-10 days)

Other measurements

- Chlorophyll meters ( ex. SPAD)

- Reflectance based (NDVI, PRI)

Visual based measurements

- Color and size

Background

SPAD meter

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Currently,therearenosimple,quickandaffordable

techniquesformeasuringwholeplantNstatusin

floricultureproduction

Developing easy, quick, accurate and affordable imaging technique based on smartphones to monitor whole plant nitrogen status in floriculture crops

Objective

Plant N = 4.2%Status: optimum

Wechosetodevelopatechnologybasedonsmartphonesorcameras(imageanalysis)asitiseasytouseandlessexpensive,therebycanbereadilyadaptedbygrowersandresearchers

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ImageanalysistechniqueuseReflectancebasedmethodtomonitorplantN

Relative absorption or reflectance of red light by the plants can indicate N content in plants

https://www.picicture-absorption-spectrum-chlorophyll-looks-green-eyes-make-general-statement-abso-q25273835

y = 42.989x + 0.8529R² = 0.7541

0

0.5

1

1.5

2

2.5

3

3.5

0 0.01 0.02 0.03 0.04 0.05

Leaf

Tot

al N

itro

gen

(%)

Total chlorophyll (mg/cm2)

Ghasemi etal.,2011

Camera($25)Raspberry pi ($35) Filters($65)

Hardware was built using cheap and commercially available components

SmartphoneAccessory ($115)

Plant N = 4.2%Status: optimum

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Procedures:Taking images and obtaining reflectance value and Whole plant N content (%) using smartphone accessory

Plant N = 4.2%Status: optimum

Taking images with smartphone Image processing in Computer Output in smartphone

Species: Poinsettia

(EuphorbiapulcherrimaWilld. ex Klotzscha)

Varieties: 4 (Wintersun white, Christmas beauty

marble, Christmas glory white, Christmas Tradition)

Treatments: 5 levels of Electrical conductivity

(EC)

0.75, 1.5, 2.5, 3.5 and 4.5 dS·m-1

(112.5, 225, 375, 525 and 675 ppm N)

Measurements: Image derived ratio

(Reflectance ratio: Far-red/red), laboratory

analysis of tissue N content, dry weight, EC and

pH of the substrate, environmental data Experimental layout

MaterialsandMethods

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Wintersun white Christmas tradition

Christmas glory whiteChristmas beauty marble

Fertilizer EC (dS·m-1)

0 1 2 3 4 5

Who

le p

lant

N c

ont

ent

(m

g·g

-1)

10

20

30

40

50

60

70

y= 17.39+9.45xr2=0.935

Results

Plant tissue N content, based on laboratory analysis, increased linearly with increased concentration of fertilizer

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Results

Fertilizer treatments resulted in optimum and sub-optimal levels

Fertilizer Solution EC (dS·m-1)

0 1 2 3 4 5

Sho

ot d

ry w

eig

ht (gm

)

6

8

10

12

14

16

18

20

22

24

y = 8.6256x + 9.4193R² = 0.686

0

10

20

30

40

50

60

0 1 2 3 4 5 6

Who

le p

lant

N c

onte

nt (

mg·

g¯1 )

Image derived ratio

Wintersun white

y = 7.5396x + 7.7906R² = 0.7711

0

10

20

30

40

50

60

0 2 4 6 8Who

le p

lant

N c

onte

nt (

mg·

g¯1 )

Image derived ratio

Christmas Beauty Marble

y = 8.009x + 5.6471R² = 0.7696

0

10

20

30

40

50

60

70

0 2 4 6 8

Who

le p

lant

N c

onte

nt (

mg·

g¯1 )

Image derived ratio

Christmas Glory white

y = 10.698x + 1.4574R² = 0.6573

0

10

20

30

40

50

60

70

0 1 2 3 4 5 6

Who

le p

lant

N c

onte

nt (

mg·

g¯1 )

Image derived ratio

Christmas Tradition

ResultsLinear relationship was found between whole-plant tissue N content and image-derived ratio for poinsettia varieties

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Results

Relation between Whole plant N content and Image derived ratio for all varieties

y = 0.776x + 0.9064R² = 0.6666

0

1

2

3

4

5

6

7

0 1 2 3 4 5 6 7 8

Who

le p

lant

N c

onte

nt (

mg·

g¯1 )

Image derived ratio

All varieties

Future Work

Raspberrypi

Leaf

LEDs

Camera

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Conclusions

Estimation of Whole plant N content in plants

Timely decision

Improved crop growth and quality

Reduced fertilizer wastage and cost

Easily accessible to growers

Benefits of the development of easy, reliable and affordable smartphone based

imaging technology to measure N content

THANKYOU!

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ImageanalysistechniqueuseReflectancebasedmethodtomonitorplantN

Nitrogen

Chlorophyll Rubisco

PhotosynthesisLight

absorption

Light absorption

Nitrogen

Chlorophyll

Relative absorption or reflectance of red light by the plants can indicate N content in plantshttps://www.picicture-absorption-spectrum-chlorophyll-looks-green-eyes-make-general-statement-abso-q25273835

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Imageprocessing

Red Image Near Infrared image

Image derived ratio= Near Infrared/Red

Step 1: Taking images and sending them to Dropbox

1. Record images 2. Sync Dropbox

Procedures:Taking images and obtaining Image derived ratio and Whole plant N content (%) using smartphone accessory

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Step2:ProcessingimageusingImageprocessingsoftware

Output:ExcelfilewithWholeplantNitrogen(%)andImagederivedratio

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AnnualFertilizercostforBeddingPlant/OrnamentalGreenhouse

$6799 per acre

GreenhouseCOPBenchmarkReportAlberta,2017

GreenhouseCOPBenchmarkReportAlberta,2017

AnnualFertilizercostforBeddingPlant/OrnamentalGreenhouse