AJ FosterSoils 4213

Spring 2011

1AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

OutlineIntroductionDefinition of Precision AgPrecision Ag in Jamaica (Present)Precision Ag in Jamaica (Future)Modern Information and TechnologyExampleConclusions

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“ Mining has virtually maximized its growth, tourism has virtually maximized the availability of beaches which can be developed,

manufacturing has contracted from a contribution of 19 per cent of GDP some 40 years ago to seven per cent today, and

agriculture remains underdeveloped" Former Prime Minister Edward Seaga

“The apple cannot be stuck back on the Tree of Knowledge ; once we begin to see, we are doomed and challenged to seek the strength

to see more, not less.”

Arthur Miller

3AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

Jamaica Population – 2.6 mil. Size – 4200 sq miles

(~1/18 size of Oklahoma)

Climate- tropical/interior temperate

Fastest people per capita

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Precision AgAdjusting and fine-tuning land and crop

management practices to the needs of plants within a heterogeneous environment to maximize use of inputs and productivity by using modern information and technology.

5AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

Precision Ag in Jamaica (Present)

Soil analysis Cost

Ph (H2O, KCl) J$150 (US$ 1.80)

Total N J$250 (US$ 2.95)

CEC J$250 (US$ 2.95)

Ca, Mg, Na, K J$200 (US$ 2.40) ea.

Avail. Phosphate (P2O5)

J$200 (US$ 2.40)

Avail. Potash (K2O) J$200 (US$ 2.40)

Texture (hydrometer & sieve method)

J$300 (US$3.50)

Soil testing by the Laboratory may take 3 to 6 weeks.  This is dependent on the workload as well as the availability of chemicals to do specific analyses.

6AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

Field Efficiency Minimal Tillage

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Precision Ag in Jamaica (Future) Modern information and technology

Guide on-the farm management decision Farmers view on sustainability

What to grow? How much to grow? How much to fertilize? When to apply herbicide, insecticide, tillage etc.

To anticipate behavior in field in advance Predictive models

8AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

Technology For EveryoneGreenseeker

Education Cost (J$350,000-US$4000)

Pocket Sensor Education Cost (J$25,000 –US$300)

Digital camera Education Cost (J$850- US$10)

Mobile Device Education Cost (J$5000 –US$60)

9AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

An example of how modern information and technology could be used in Jamaica to

make N recommendation.

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N rate from Digital Photograph

11AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

What is a Digital Photograph? Matrix of cells (pixels) arranged into

rows and columns.

Each cell contain a value that

represent information.

Three Bands Red Green Blue (RGB)

12AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

Digital Photograph Properties

13AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

Spectral Response to N NDVI=

NIR – Red

NIR + Red

14AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

N rate using a Digital PhotographDigital photographs and

Greenseeker (NDVI from plots with varied NPK lb/ac rate

Process photographs Image J ArcGIS

Compute indices NGRDI VARI

Regression

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Normalized Green-Red Difference Index (NGRDI) NGRDI = (GreenDN-RedDN)/(GreenDN + Red DN)

Ranges from -1 to +1

Mathematically related to other indices E.g. NDVI = (NIR - Red)/(NIR + Red)

Significant positive correlation with N concentration in late stage of corn development (Hunt et al.,2005)

NGRDI linearly related to NDVI for wheat

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Visible Atmospheric Resistant Index (VARI) VARI = (GreenDN-RedDN)/(GreenDN + Red DN -

BlueDN)

Ranges from -1 to +1

Mathematically related to other indices E.g. NDVI = (NIR - Red)/(NIR + Red)

Linearly relationship (r 2 =0.96) with green vegetation fraction in corn ( Vina et al., 2004)

Detect onset of senescence earlier than NDVI (Vina et al.,2004)

VARI linearly related to NDVI for wheat

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ConclusionsDigital photographs may be used to develop indices for making N

recommendations that are similar to that of the greenseeker.

The potential for using digital photograph to predict crop yield and make N recommendation is a feasibly option worth pursuing.

Long-term studies are needed to establish a good relationship between Indices computed from digital photograph and greenseeker NDVI readings for different crops.

Technologies such as greenseeker, pocket sensor, digital camera and mobile devices offer great potential for balancing production with environmental threshold in Jamaica

18AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

QuestionsWhat types of precision ag practice are

currently used in Jamaica?Answer

1. Soil testing 2. Minimal tillage in sugarcane

(True or False) Digital camera as a sensor can never be used for making N recommendation?

AnswerFALSE

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Acknowledgement Dr Brian ArnallDr Bill Raun Dr Gopal Kakani Raghu Veer SripathiNana Thompson

AJ Foster, Department of Plant and Soil Sciences, Oklahoma State University

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          “Don’t be seduced into thinking that that which does not make a profit is without value” – Arthur Miller