Site specific irrigation [Elektronische Ressource] : improvement of application map and a dynamic steering of modified centre pivot irrigation system / by Aboutaleb Hezarjaribi

Informations

• Publié par: justus-liebig-universitat_giessen
• Publié le: 01 janvier 2008
• Nombre de lectures: 14
• Langue: English
• Poids de l'ouvrage: 6 Mo

Extrait

FEDERAL AGRICULTURAL RESEARCH CENTRE (FAL)
INSTITUTE OF PRODUCTION ENGINEERING AND BUILDING RESEARCH
BRAUNSCHWEIG / GERMANY

IN COOPERATION WITH

JUSTUS LIEBIG UNIVERSITY GIESSEN
FACULTY OF AGRICULTURAL SCIENCES, NUTRITIONAL SCIENCES
AND ENVIRONMENTAL MANAGEMENT, INSTITUTE OF AGRONOMY AND PLANT
BREEDING I, PROFESSORSHIP OF AGRONOMY, GERMANY




Site-specific irrigation:
Improvement of application map and a dynamic steering of
modified centre pivot irrigation system



DISSERTATION
Submitted for the degree of Doctor of Agricultural Sciences (Dr. agr.)
by
ABOUTALEB HEZARJARIBI
from IRAN


ADVISOR: PROF. DR. FRANZ-JOSEF BOCKISCH
CO-ADVISOR: PROF. DR. BERND HONERMEIER

Germany 2008



























Thesis disputation date: 17.03.2008



Examining commission

Chairman/person:
Prof. Dr. Ingrid Hoffmann

Supervisor:
1. Advisor: Prof. Dr. Franz-Josef Bockisch
2. Co-Advisors: Prof. Dr. Bernd Honermeier

Examiners:
Prof. Dr. Stefan Gäth
Prof. Dr. Hermann Seufert



Preface

Even in the 21st century, water is still used for irrigation in order to produce food and
feedstuff. Given a share of ca. 70 %, agriculture is the largest water consumer worldwide and will
have to remain it in order to guarantee at least the supply of food. Therefore, it is always necessary
to draw attention to careful and efficient water use in agriculture and to show potential
improvements like in this study.
Based on prior studies on irrigation techniques at the Institute of Production Engineering and
Building Research, the present dissertation discusses the very current topic of site-specific
irrigation. The results gained in this study provide scientifically secured decision criteria, which
allow the homogeneity of the soil as well as its different moisture to be taken into account and
enable an application map for differentiated irrigation depths to be developed based on these
criteria. At the same time, a technical solution is presented which allows precise, site-specific
irrigation with a centre-pivot machine to be realized. The water and energy savings provided by
this technique (while the level of production remains the same or is increased) are evaluated, and
the costs are compared.
The author, who had a scholarship as a doctoral student at the Institute of Production
Engineering and Building Research of the Federal Agricultural Research Centre for Agriculture in
Braunschweig (FAL), made a contribution towards a more objective discussion about the use of
site-specific irrigation and described future-oriented solution approaches.


Braunschweig, March 2008

Prof. Dr. agr. habil. Franz-Josef Bockisch Dr. rer. hort. Heinz Sourell








TABLE OF CONTENT

List of Abbreviations……………………………………………………………………………………….. I
List of Tables……………………………………………………………………………………………... III
List of Figures…………………………………………………………………………………………….. IV
List of Appendixes………………………………………………………………………………………... VI

1. INTRODUCTION…………………………………………………………………... 1

1.1 Background………………………………………………………………………………….. 1
1.2 Problems and objectives………………..4
1.2.1 Problems of our investigation………………………………………………………………… 4
1.2.2 Objectives………………………………………….. 5

2. LITERATURE REVIEW…………………………………………………………... 7

2.1 Precision agriculture………………………………………………………………………... 7
2.1.1 Definition……………………………………………………………………………………...8
2.1.2 Managing variability…………………………………………………………………………. 9
2.1.3 Engineering innovations…………………………………………………………………….. 10

2.2 Precision irrigation………………………………………………………………………… 15
2.2.1 Background…………………………………………………………………………………..16
2.2.2 Irrigation system with special focus on mobile drip irrigation systems……………………. 21
2.2.3 Implementing precision irrigation…………………………………………………………... 26
2.2.3.1 Delineation of irrigation management zones………………………………………………... 26
2.2.3.1.1 ent zone by soil sampling grid………………………..... 26
2.2.3.1.2 ent zone by remote sensing (reflectance measurement)...26
2.2.3.1.3 ent zone by sensor-based ECa measurement……………28
2.2.3.2 Precision irrigation control (PIC)……………………..…………………………………….. 31
2.2.3.2.1 Determination of irrigation depth within irrigation management zones…………………..... 31
2.2.3.2.2 Agricultural communication protocols and wireless sensors……………………………….. 35
2.2.3.2.3 Irrigation controller………………………………………………………………..39
2.2.4 Critical literature analysis for precision irrigation…………………………………………...44

3. MATERIALS AND METHODS…………………………………………………..45

3.1 Delineation of irrigation management zones…………………………………………….. 45
3.1.1 Study field……………………………………………………45
3.1.2 ECa sensors and response curves………………………………………………… 47
3.1.3 How to create a TAWC map………………………………………………………………... 51
3.1.4 Soil sampling………………………………………………………………………………... 51
3.1.5 Determination of the optimum number of irrigation management zones…………………... 52

3.2 Performance and evaluation of remote real-time and site-specific distributed
irrigation control system………………………………………………………………….. 53
3.2.1 Soil moisture monitoring methods………………………………………………………….. 54
3.2.1.1 Wireless EnviroSCAN soil moisture sensor…………………………………………………55
3.2.1.2 AMBAV model……………………………………………………………………………... 59
3.2.2 Irrigation scheduling…………………………………………………………………………60
3.2.3 Field tests related to soil moisture monitoring………………………… 61
3.2.3.1 Evaluation and soil-specific calibration of the EnviroSCAN soil moisture sensor….……... 61 3.2.3.2 The field tests of data transmission and power supply……………………………………… 63
3.2.3.3 Validation of the AMBAV model…………………………………………………………... 63
3.2.4 Irrigation system and its modification…………………………………. 64
3.2.4.1 Programmable logic control……………………………………………………………….. 64
3.2.4.2 Position encoder…………………………………………….. 67
3.2.4.3 Solenoid valves (SV)…..……………………………………………… 67
3.2.4.4 Irrigation segments and drop tubes…………………………..69
3.2.4.5 Calculating of the number of emitters installed on the drop tubes and the length of the
drop tubes…………………………………………………..…………………………….….69
3.2.4.6 Evaluation of emitter performance…………………………………….. 71


4. RESULTS AND DISCUSSION…………………………………………………… 76

4.1 Delineation of irrigation management zones……………………………………….…76
4.1.1 Data collection ……………………………..…………………………………………76
4.1.2 Comparison of the EM38 and VERIS 3100 readings…………………………………… 77
4.1.3 Soil samples and the best sensor-based methods of ECa measurements for the
delineation of TAWC variability……….…………………………………………………… 80
4.1.4 Optimum number of irrigation management zones…………. 83
4.1.5 Features of irrigation management zones…………………………………………………… 84

4.2 Performance and evaluation of a remote real-time and site-specific distributed
irrigation control system…………………………………………………………………... 88
4.2.1 Irrigation scheduling………………………………88
4.2.2 Field tests for soil moisture monitoring…………………………………………………… 91
4.2.2.1 Evaluation and soil-specific calibration of the EnviroSCAN soil moisture sensor………….91
4.2.2.2 The field tests of data transmission and power supply……………………………………… 94
4.2.2.3 Validation of the AMBAV model…………………………………………………………... 96
4.2.3 Evaluation of the modified centre pivot irrigation system….……………………………… 98
4.2.3.1 Field tests for the evaluation of programmable logic control Performance…………..…….. 98
4.2.3.2 Number of emitters installed on the drop tubes and length of drop tube…………...……... 104
4.2.3.3 The laboratory and field tests of drop tubes……………………………………………… 105

4.3 Potential economic implications………………………………………………………… 112
4.3.1 Capital requirement and fixed costs……………………………………………………….. 113
4.3.2 Variable costs……………………………………………………………………………….115
4.3.3 Total irrigation cost…………………………………………………………………………119
4.3.4 Farming benefit……………………………………………………………………………..121

4.4 Other advantages of precision irrigation………………………………………………...124


5. CONCLUSION…………………………………………………………………… 125

5.1 Delineation of irrigation management zones…………………………………………….125
5.2 Performance and evaluation of remote real-time and site-specific distributed
irrigation control system…………………………………………………………………. 126
5.3 Laboratory experiments……………..129
5.4 Potential economic implication………………………..………………………………… 130
5.5 Resume………………………………………………………………..130
6. SUMMARY……………………………………………………………………….. 132

7. ZUSAMMENFASSUNG…………………………………………………………. 135

8. REFERENCES…………………………………………………………………….139

9. LIST OF APPENDIXES……………………………………………………….….167

Acknowledgement…………….……………………………………………………………...…193
Dedication………………………………………....…………………………………….………194
Curriculum vitae……..………………………….………..…………………………….………195
List of Abbrevia