Sustainable water management in smallholder farming: theory and practice

206 Pages·2016·12.325 MB·English

by  Finley, Sara

S W M S
uStainable ater anageMent in Mallholder
F
arMing
Theory and Practice

S W
uStainable ater
M
anageMent in
S F
Mallholder arMing
Theory and Practice
Sara Finley
Water Management Consultant, Canada
CABI is a trading name of CAB International
CABI CABI
Nosworthy Way 745 Atlantic Avenue
Wallingford 8th Floor
Oxfordshire OX10 8DE Boston, MA 02111
UK USA
Tel: [phone]
Fax: [phone] Tel: [phone]
E-mail: [email protected] E-mail: [email protected]
Website: www.cabi.org
© S. Finley, 2016. All rights reserved. No part of this publication may be reproduced in
any form or by any means, electronically, mechanically, by photocopying, recording
or otherwise, without the prior permission of the copyright owners.
A catalogue record for this book is available from the British Library, London, UK.
Library of Congress Cataloging-in-Publication Data
Names: Finley, Sara, author.
Title: Sustainable water management in smallholder farming : theory and
practice / Sara Finley.
Description: Boston, MA : CAB International, [2016]
Identifiers: LCCN 2016000628 (print) | LCCN 2016002509 (ebook) | ISBN
9781780646862 (hardback : alk. paper) | ISBN 9781780646879 (pbk. : alk.
paper) | ISBN 9781780646886 (pdf) | ISBN 9781780646893 (ePub)
Subjects: LCSH: Water-supply, Agricultural--Management. |
Irrigation--Management.
Classification: LCC S494.5.W3 F56 2016 (print) | LCC S494.5.W3 (ebook) | DDC
631.7--dc23
LC record available at http://lccn.loc.gov/2016000628
ISBN-13: 978 1 78064 686 2 (hbk)
978 1 78064 687 9 (pbk)
Commissioning editor: Nicki Dennis and Ward Cooper
Associate editor: Alexandra Lainsbury
Production editor: James Bishop
Illustrations by George Blott
Typeset by SPi, Pondicherry, India
Printed and bound in the UK by CPI Group (UK) Ltd, Croydon, CR0 4YY
Contents
Part 1: theoretical Foundations oF Water ManageMent in agriculture
Preamble to Part 1 3

1 Key Concepts
7
2 Goals of Agricultural Water Management 17

3 Soil and Water 27

4 Plants and Water 43

5 Climate Outlook 55

Part 2: iMProving Water Productivity in rainFed agriculture
Preamble to Part 2 61

6 Soil-focused Strategies: Reducing Water Loss 68

7 Rainwater Harvesting 85

8 Crop-focused Strategies: Using Available Water Wisely 110

9 Conservation Agriculture 118

Part 3: irrigation
Preamble to Part 3 133

10 Irrigation 137

11 Irrigation Scheduling 153

v
vi Contents
12 Water Sources for Agriculture 166

Summary of Key Points 187

Index 189
Part 1
Theoretical Foundations
of Water Management
in Agriculture
Preamble to Part 1 3
Chapter 1: Key Concepts 7
Chapter 2: Goals of Agricultural Water Management 17
Chapter 3: Soil and Water 27
Chapter 4: Plants and Water 43
Chapter 5: Climate Outlook 55

Preamble to Part 1
The Scope of this Book
This book provides an introduction to the theoretical foundations of
agricultural water management, and presents a range of basic techniques for
promoting efficient water use on farms. Subjects covered include crop water
requirements, soil and water conservation, rainwater harvesting, conservation
agriculture, supplementary irrigation, and more. The book provides a prac-
tical, as opposed to an academic, approach; it is hoped that farmers’ groups,
extension agents, students and non-governmental organizations (NGOs) can
use it as a starting point for continued study. The wide variety of climate and
farm types encountered across agricultural areas means that concepts pre-
sented are necessarily broad; space limitations prohibit detailed discussions
of specific crops, soil types, or climate zones. The information provided here
is intended as a generalized practical guide to a suite of techniques that can
be adapted according to each farm’s objectives, resources, climate, and crop.
The methods presented in this book are most applicable to agricultural
projects that fall into the ‘smallholder’ category – that is, small farms with
little or no mechanization. Though some information about partial irrigation is
provided, the focus is primarily rainfed farms in climate zones characterized
by overall rainfall deficits or frequent dry spells. While water is crucial for all
forms of agricultural activity, this publication addresses only the soil-based
cultivation of field crops.
The Importance of Water
Water is the lifeblood of the earth, and is vital to the health of humans, ani-
mals, plants and soils. Living things depend on water not just for the hydration
© S. Finley 2016. Sustainable Water Management in Smallholder Farming (S. Finley) 3