An introduction to drip irrigation systems

243 Pages·2012·9.794 MB·English

by  Singh, Ajay

AN INTRODUCTION
TO
DRIP IRRIGATION SYSTEMS
Ajai Singh
Assistant Professor in Soil and Water Conservation
Uttar Banga Krishi Viswavidyalaya
West Bengal
NEW DELHI PUBLISHERS
New Delhi
Ajai Singh, An Introduction to Drip Irrigation Systems, New Delhi Publishers,
New Delhi
© Publishers
First Edition 2012
ISBN: 978-93-81274 -18-7
All rights reserved. No part of this book may be reproduced
stored in a retrieval system or transmitted, by any means, electronic
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without written permission from the publisher
New Delhi Publishers
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Dedicated to
My Mother-in-Law
LLLLLAAAAATTTTTEEEEE SSSSSMMMMMTTTTT..... SSSSSHHHHHAAAAANNNNNTTTTTIIIII DDDDDEEEEEVVVVVIIIII
1
CHAPTER
Foreword
Water is a natural resource which can not be replenished. As the demand
for water is growing up from all the user groups, lesser water will be
available for agriculture. Efficient water use is necessary for sustainable
crop production and drip irrigation proved to provide efficiently irrigation
water and nutrients to the roots of plants, while maintaining high yield
production. Since not all the soil surface is wetted under irrigation, less
water is required for irrigation. Modern drip irrigation has become the
most valued innovation in agriculture. Higher water application efficiencies
are achieved with drip irrigation due to reduced soil evaporation, less surface
runoff and minimum deep percolation.
The knowledge about drip system and its design principles is essential for
the students of Agricultural Engineering and professionals of Water
Resources Engineering. I am sure that this book, which includes the basics
of drip system and recent published research work on designing of drip
irrigation system, will serve the student community as well as Faculties of
Agricultural Engineering Department to a great extent by providing up to
date information in a clear and concise manner.
I would like to compliment Dr. Ajai Singh for having brought out this
textbook with quite useful and valuable information for the Agricultural
Engineering Under Graduate and Post Graduate students in India.
Prof. (Dr.) Sabita Senapati
Director of Research
Uttar Banga Krishi Viswavidyalaya
Coochbehar, West Bengal, India

Preface
Excessive and improper use of water due to lack of information has become
a common practice to grow more water intensive crops and earn more. The
water resources are being depleted by current practice of farming and we
will be devoid of sufficient irrigation water if the trend continues in the
years to come. Time has come now to focus on judicious and efficient use
of water for agricultural purpose. Adoption of Micro Irrigation System can
be a panacea in irrigation related problems. In this technology, the cropped
field is irrigated in the close vicinity of root zone of crop. It reduces the
water loss occurring through evaporation, conveyance and distribution.
Therefore high water use efficiency can be achieved. The unirrigated rainfed
cropped area can be increased with this technology and potential source of
food production for the benefit of country’s food security could be
augmented. The Government of India has been considering rapid promotion
of use of plastics in agriculture and micro irrigation as a major step in
improving overall horticultural crop yields and water use efficiency. The
micro irrigation has gained considerable growth in the country due to
financial assistance provided by the centrally sponsored subsidy scheme.
This book is designed as a professional reference book with basic and
updated information and its aim is to meet the needs of students of
agricultural engineering under graduate and post graduate degree program.
The practicing engineers, agricultural scientists working in the field of
agricultural water management and officers of Agriculture and Horticulture
Departments of State Government will find this book useful. In this book,
the basics of drip irrigation, types, components, design, installation,
operation and maintenance are presented. Efforts have been made to
incorporate the recent published works in peer reviewed journals at
appropriate place. An additional chapter on automation of micro irrigation
system has also been included. Numerical problems and examples have
(viii)
been added to emphasize the design principles and make the understanding
of the subject matter.
I owe my deepest gratitude to Dr. A. K. Das, Vice–Chancellor, UBKV, Dr.
S. K. Senapati, Director of Research, UBKV, Dr. Goutam Mondal, Incharge,
RRS, Majhian, and all my colleagues and other staff of Regional Research
Station, Majhian, for their best wishes and constant encouragement. The
author is grateful to many individuals and organizations for the assistance
provided at different stages of preparation of manuscript and supply of useful
literature. I sincerely thank Dr. K. N. Tiwari, Professor, Agricultural &
Food Engineering Department, IIT, Kharagpur, under whom I worked in a
Plasticulture Development Centre Project, for his blessings and affection.
I am heartily thankful to Prof. (Dr.) Mohd. Imtiyaz, Prof. (Dr.)
R. K. Isaac, Prof. (Dr.) D. M. Denis, Dr. Arpan Shering, Associate Professor,
Dr. S. K. Srivastava, Assistant Professor of Department of Soil, Land and
Water Engineering and Management, Vaugh School of Agricultural
Engineering & Technology, Sam Higginbottom Institute of Agriculture,
Technology & Sciences, Allahabad for continuous encouragement and
support. I am grateful to Dr. R. P. Singh, Professor, Irrigation and Drainage
Engineering Department, GBPUAT, Pantnagar for his kind blessing and
encouragement. The author is indebted to many people and institution/
organizations for providing the material and issuing the permission under
copyright act for inclusion in this textbook. I wish to acknowledge the support
received from the Food and Agricultural Organisation, Arizona Cooperative
Extension, Arizona State University and Dr. Richard John Stirzaker of
CSIRO, Division of Land and Water, Australia for providing the figures and
technical details. The author has tried to acknowledge the every source of
information, any omission is inadvertent. This can be pointed out and will be
included in the book at appropriate time.
I feel profound privilege in expressing my heartfelt reverence to my parents,
brothers and sister, in-laws for their blessings and moral support to achieve
this goal. Last but not the least I acknowledge with heartfelt indebtness,
the patience and the generous support rendered by my better half, Punam
and daughter Anushka who always allowed me to work continuously with
smile on their face. I offer my regards and blessings to all of those who
supported me in any respect during the completion of this book. Author
would welcome suggestions from readers to improve the text of book.
Dr. Ajai Singh
([email protected])
Contents
Foreword v
Preface vii
1. Introduction 1
2. Drip Irrigation Systems 5
2.1 Types of Micro Irrigation System 6
2.1.1 Drip irrigation 6
2.1.2. Sub-surface system 6
2.1.3. Bubbler 8
2.1.4. Micro-sprinkler 8
2.1.5. Pulse system 10
2.2. Advantages of Drip Irrigation 10
2.3. Problems and Demerits of Drip Irrigation 11
2.4 Suitability of Drip Irrigation 11
2.4.1. Crops 11
2.4.2. Slopes 11
2.4.3. Soils 11
2.4.4. Irrigation Water 12
2.5. Quantitative Approach of Wetting Patterns 12
3. Components of Drip Irrigation Systems 25
3.1. Control Head 25
3.1.1. Pump/Overhead Tank 25
3.1.2. Fertigation 28
3.1.2.1. Advantages 29
3.1.2.2. Limitations and Precautions 29
3.1.2.3. Fertigation methods 30
3.1.2.4. Fertigation Recommendations 33
3.1.2.5. Plant Nutrients 37
3.1.2.6. Sources of Fertilizers 41
3.1.2.7. Nutrient Monitoring 42
3.1.3. Filtration System 43