Precision Agriculture using

GPS

By

E.LAKSHMI

131867

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Contents :

Introduction

Precision Agriculture

Technological tools

Benefits of PA

PA vs Traditional Agriculture

PA with GPS

Literature review

Methodology

Case study 1

Case study 2

Summary

References

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Precision Agriculture

Precision farming (PA) or satellite farming or site specific crop

management (SSCM) is a farming management concept based on

observing, measuring and responding to inter and intra-field variability

in crops.

Spatial and temporal variability of crop variables are at the heart of

PA.

Spatial - changes across a field.

Temporal - changes from season to season and from year to year.

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Precision agriculture aims to optimize field-level management with

regard to:

Crop science (e.g. fertilizer inputs);

Environmental protection (e.g. limiting leaching of nitrogen)

Economics (e.g. improved management of fertilizer usage and

other inputs)

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Technological tools

1.Remote sensing

2.GPS

3.GIS

4.Yield monitor

5.Variable rate technology

5 Fig 1

Benefits of Precision Agriculture

Increase productivity and net profit;

Provide better decision making ability;

Improve soil productivity;

Improve water quality;

Improve wildlife habitat;

Sustain natural resources for generations to come.

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PA vs Traditional Agriculture

Precision farming

The farm field is broken into

“management zones” based on

soil pH, yield rates, pest

infestation, and other factors that

affect crop production.

Management decisions are based

on the requirements of each zone

and PF tools (e.g. GPS/GIS) are

used to control zone inputs.

Traditional agriculture

Traditional farming methods have

used a “whole field” approach

where the field is treated as a

homogeneous area.

Decisions are based on field

averages and inputs are applied

uniformly across a field in

traditional farming.

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PA with GPS

Farm uses include:

mapping yields (GPS + combine yield monitor),

variable rate planting (GPS + variable rate planting system),

variable rate lime and fertilizer application (GPS + variable rate

controller),

field mapping for records and insurance purposes (GPS + mapping

software), and

parallel swathing (GPS + navigation tool).

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Thomas et al, (2000) explained about the development of Carrier-

Phase Differential GPS (CPDGPS) for automatic tractor control to

track the target lines in the field for plowing, sowing, fertilizing,

pesticide spraying etc.

Hermann (2001) discussed about the environmental challenge in

Precision Farming with use of information technologies in agriculture.

It is identified that precision farming will likely gain in importance

only when viable additional benefits, such as reduced environmental

burdens and increased flow of information, are recognised and

evaluated.

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Literature review

Maheswari et al, (2008) discussed about the adoption of precision

farming technology and productivity of vegetables in Resource poor

environment and also comparing the results with non-precision

farming.

Manuel et al, (2011) discussed about RTK accuracy mapping system

for transplanted plants and could provide substantial savings in agro-

chemicals with associated environmental and economic advantages for

sustainable agricultural production systems.

Rodica et al, (2011) explained the use of GNSS RTK technology in

agriculture which shows the increase in profit. The GPS-GNSS

positioning systems, together with the Geographical Informational

Systems represent the future in all fields of activity, and especially in

that of agriculture. 10

Methodology for PA

Review current data

Obtain additional data

Gather yield data

Examine results

Data Interpretation

Management strategy

11 Fig 2. General methodology

12 Fig 3. PA cycle

Case Study 1

Title: Precision Farming Technology, Adoption Decisions and

Productivity of Vegetables in Resource-Poor Environments

Authors: R. Maheswari, K.R. Ashok and M. Prahadeeswaran

Journal: Agricultural Economics Research Review

Objective: The impact of precision farming on resource-poor regions

and underprivileged farmers. Specifically, the study has looked into

productivity, income, employment, and adoption behaviour of

technology in agriculture.

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Study Area

In Tamil Nadu, precision farming was implemented under the Tamil

Nadu Precision Farming Project (TNPFP) in the Dharmapuri and

Krishnagiri districts on about 400 ha of land with a total budget of 720

lakhs for a period of three years.

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Methodology used

The data on precision and non-precision farmings were collected

through the interview schedule during the year 2007.

The respondents were selected were 35 adopters and 35 non-adopters

of precision farming in each of tomato and brinjal crops, making the

total sample to be of 140 respondents.

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Variable rate application with GPS

Using the field position from a

GPS receiver and a prescription

map of desired rate, the

concentration of input is changed

as the applicator moves through

the field.

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Fig 4. GPS

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Chisel plough

The chisel plough technology ensured better

aeration to root zone and effective drainage

during rainy days.

Further it has helped the plants to develop

root system with characteristical uniformity

in pattern, architecture and in adequate

mass.

The Chisel plough needs to be operated once

in two years.

Drip irrigation

Fig 5. chisel plough

Observation

Adoption of precision farming leads to about 80 per cent increase in

yield in tomato and 34 per cent in brinjal.

Increase in gross margin has been found 165 per cent and 67 per cent

in tomato and brinjal production.

The net return increases by 39 per cent and 28 per cent in tomato and

brinjal cultivation, respectively.

Lack of finance and credit facilities have been identified as the major

constraints for non-adoption of precision farming.

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Case Study 2

Title : Tractor-based Real-time Kinematic-Global Positioning System

(RTK-GPS) guidance system for geospatial mapping of row crop

transplant.

Authors: Manuel Perez-Ruiz , David C. Slaughter , C. Gliever , Shrini K.

Upadhyaya.

Journal: Biosystems Engineering

Objective:

• Develop a real-time, transplant geoposition data-logging system.

• Produce geospatial transplant maps.

• Compare the accuracy of the automatically generated transplant

geoposition map with surveyed transplant locations under

standard and challenging conditions.

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Materials and Methods

Global positioning system

Transplanter design

Data acquisition hardware

Data acquisition software

Field Experiments

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A single Real-time Kinematic-Global

Positioning System (RTK-GPS) system

mounted on the tractor for Global

Positioning System (GPS) location

mapping of planting events occurring on

the tractor-drawn transplanter.

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Fig 6

The mechanical hitch interface

between the tractor and the

transplanter was instrumented

with orientation sensors to

allow computation of the GPS

crop plant location.

Reduce the equipment cost of

the system.

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Fig 7.Hitch position sensor used to determine the

relative heading between the tractor-implement

system.

Fig 8. Automatically generated crop

geoposition map.

After planting, the actual

geospatial location of each

transplant was determined

by RTK-GPS using a

handheld surveying

system interfaced to a

rover RTK-GPS.

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Transplant Map, geo-referenced

to the world coordinate system,

showing the estimated plant

locations automatically generated

from the plant wheel sensor data

and the surveyed plant location.

The performance of the hitch

yaw sensor was quite good and

allowed the estimated plant map

accuracy in the curved sections

of the rows to be comparable to

the straight sections of the trial.

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Fig 9. True track and straight AB

line for the curved planting path

treatment.

Observation

This study demonstrated the feasibility using the GPS signal from an

RTK-GPS auto guidance system mounted on the tractor in the

automatic mapping of crop plants during planting.

Hitch orientation sensor was developed that allowed for accurate real-

time monitoring of the position of the transplanting sled in relationship

to the tractor.

Thus it is possible to use single RTK-GPS system mounted on tractor

for GPS location mapping of planting , reduce the equipment cost.

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Summary

Precision agriculture deals with the Spatial and temporal variability of

crop variables using GPS, RS, GIS.

Precision agriculture also started to adopt in developing countries

especially in India but having some constraints due to small scale

farms.

GPS-based applications in precision farming are being used for farm

planning, field mapping, soil sampling, tractor guidance, crop scouting,

variable rate applications, and yield mapping.

Therefore with the help of GPS it is easy to get the accurate

information of crop variability in precision farming.

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References

Gabriel Badescu, Rodica Badescu, Ovidiu Ştefan Mircea Ortelecan(2011),

“Using GPS-GNSS global positioning systems in Agriculture”, Advances in

Biomedical Engineering Vols. 1-2.

Hermann Auernhammer(2001), “Precision farming - the environmental

Challenge”, Computers and Electronics in Agriculture ,Vol 30 ,31–43

Manuel Perez-Ruiz , David C. Slaughter , C. Gliever , Shrini K.

Upadhyaya(2012),“Tractor-based Real-time Kinematic-Global Positioning

System (RTK-GPS) guidance system for geospatial mapping of row crop

transplant”, biosystems engineering Vol 111 ,64-71.

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Michael O’Connor, Thomas Bell, Gabriel Elkaim, and Dr. Bradford

Parkinson (2000), “Automatic tractor guidance using carrier-phase

differential GPS”, Computers and Electronics in Agriculture Vol 25 ,53–

66.

R. Maheswari, K.R. Ashok and M. Prahadeeswaran(2008), “Precision

Farming Technology, Adoption Decisions and Productivity of Vegetables

in Resource-Poor Environments”, Agricultural Economics Research

Review Vol. 21,415-424.

Pinaki Mondal , Manisha Basu (2009), “Adoption of precision agriculture

technologies in India and in some developing countries: Scope, present

status and strategies”, Progress in Natural Science Vol 19,659–666.

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