Environmental impacts of pasture-based farming

297 Pages·2008·2.847 MB·English

by  Richard W McDowell

E I
NVIRONMENTAL MPACTS OF
P - F
ASTURE BASED ARMING
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E I
NVIRONMENTAL MPACTS OF
P - F
ASTURE BASED ARMING
Edited by
Richard W. McDowell
AgResearch
Invermay Agricultural Centre
Mosgiel
New Zealand
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©CAB International 2008. 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
Environmental impacts of pasture-based farming / edited by: R.W. McDowell.
p. cm.
Includes bibliographical references and index.
ISBN 978-1-84593-411-8 (alk. paper)
1. Pastures--Environmental aspects. 2. Grazing--Environmental aspects. I. McDowell,
Richard W. II. Title.
SB199.E58 2009
636.08'45--dc22
2008018126
ISBN-13: 978 1 84593 411 8
Typeset by SPi, Pondicherry, India.
Printed and bound in the UK by Biddles Ltd, Kings Lynn.
Contents
Contributors vii
Foreword ix
Preface xi
Acknowledgements xiii
Part I
1 Greenhouse Gas Emissions 1
C.A.M. de Klein, C. Pinares-Patino and G.C. Waghorn
2 Impacts of Pastoral Grazing on Soil Quality 33
S.P. Cuttle
3 Land–Water Interactions: Impacts on the Aquatic 75
Environment
R.J. Wilcock
4 Socio-economic Issues in Pasture-based Farming 98
D. Bewsell and C. Dake
Part II
5 Impact of Livestock Grazing on Extensively Managed 122
Grazing Lands
W.H. Schacht and P.E. Reece
v
vi Contents
6 Environmental Effects of Sheep Farming 144
J.T. Scott and F.A. Robertson
7 Pressures on Beef Grazing in Mixed Production Farming 187
A.N. Sharpley and C. West
8 The Environmental Impacts of Non-irrigated, Pasture-based 209
Dairy Farming
R.M. Monaghan
9 Impacts of Irrigated Dairying on the Environment 232
D. Nash and K. Barlow
10 The Impact of Hybrid Dairy Systems on Air, Soil and 249
Water Quality: Focus on Nitrogen and Phosphorus Cycling
P.J.A. Kleinman and K. Soder
Index 277
Contributors
Kirsten Barlow, Victorian Department of Primary Industries, Rutherglen, RMB
1145, Chiltern Valley Road, Rutherglen, Victoria 3685, Australia. E-mail: K irsten.
[email protected]
Denise Bewsell,AgResearch Limited, Lincoln Research Centre, Corner Springs Road
and Gerald Street, Private Bag 4749, Christchurch 8140, New Zealand. E-mail:
[email protected]
Steve P. Cuttle,Institute of Grassland and Environmental Research, Plas Gogerddan,
Aberystwyth, Ceredigion SY23 3EB, UK. E-mail: [email protected]
Chris Dake, AgResearch Limited, Grasslands Research Centre, Tennent Drive, Pri-
vate Bag 11008, Palmerston North 4442, New Zealand. E-mail: chris.dake@
agresearch.co.nz
Cecile A.M. de Klein, AgResearch Invermay, Private Bag 50034, Mosgiel, New
Zealand. E-mail: [email protected]
Peter J.A. Kleinman,US Department of Agriculture, Agricultural Research Service,
Pasture Systems and Watershed Management Research Unit, University Park, PA
16802, USA. E-mail: [email protected]
Ross M. Monaghan,AgResearch, Invermay Agricultural Centre, Private Bag 50034,
Mosgiel, New Zealand. E-mail: [email protected]
David Nash, Victorian Department of Primary Industries, Ellinbank, RMB 2460
Hazeldean Road, Ellinbank, Victoria 3821, Australia and eWater CRC, University
of Canberra, GPO Canberra 2601, ACT, Australia. E-mail: [email protected].
govt.au
Cesar Pinares-Patino, AgResearch Grassland, Private Bag 11008, Palmerston
North, New Zealand. E-mail:[email protected]
Patrick E. Reece, University of Nebraska-Lincoln, Department of Agronomy
and Horticulture, Lincoln, NE 68583-0915, USA. E-mail: preece@unlnotes.
unl.edu
vii
viii Contributors
Fiona A. Robertson, Future Farming Systems Research, Department of Pri mary
Industries, Hamilton Centre, Mount Napier Road, Private Bag 105, Hamilton,
Victoria 3300, Australia. E-mail: fi [email protected]
Walter H. Schacht,University of Nebraska-Lincoln, Department of Agronomy and
Horticulture, Lincoln, NE 68583-0915, USA. E-mail: [email protected].
edu
John T. Scott,Landcare Research, Manaaki Whenua, Private Bag 3127, Waikato Mail
Centre, Hamilton 3240, New Zealand. E-mail: [email protected]
Andrew N. Sharpley,Department of Crop, Soil and Environmental Sciences, Univer-
sity of Arkansas, Fayetteville, Arkansas, USA. E-mail: [email protected]
Kathy Soder,US Department of Agriculture, Agricultural Research Service, Pasture
Systems and Watershed Management Research Unit, University Park, PA 16802,
USA. E-mail: [email protected]
Garry C. Waghorn,DairyNZ, Private Bag 3221, Hamilton, New Zealand. E-mail:
[email protected]
Charles West,Department of Crop, Soil and Environmental Sciences, University of
Arkansas, Fayetteville, Arkansas, USA. E-mail: [email protected]
Robert J. Wilcock,National Institute of Water and Atmospheric Research Ltd, PO
Box 11–115, Hamilton, New Zealand. E-mail: [email protected]
Foreword
At the heart of this book reside the tensions that people face when managing
grazed ecosystems throughout the world. Sustaining the natural capital of our
grazed lands is crucial, as these areas represent a very large part of our global
terrestrial ecosystems. This challenge is grounded in the socio-economic expec-
tations of land users and nations.
The biophysical elements that need to be managed will vary, depending
on the ecosystem involved. For rangelands, the maintenance of perennial
vegetations cover is critical from a soil erosion perspective. For more intensive
grasslands, the emission of nutrients and gases is of great concern. But in all
cases, the connections between land, water and air are becoming increasingly
evident.
While work involving singular disciplines of study provides knowledge
of greater depth, we also need a better understanding of the interactions and
emergent properties of our grazed ecosystems. The long-standing principles
of ecology, armed with the analytical power of simulation modelling, have a
major role to play in understanding and designing sustainable systems for the
future.
People must be an integral part of any future system design. They are not
observers and their expectations will shape the way grazed ecosystems will be
managed. While some people seek high-quality food and a pristine environment,
we must recognize that many other communities simply seek a little more food
and economic wealth to survive.
It will be interesting to see whether the desired changes we seek in people will
occur voluntarily, or whether they will require incentives and regulations. Like
most things in life, I expect that a mix will be required to ensure the necessary
knowledge and motivation is in place.
ix
x Foreword
Good science must not take a political position with regard to resolving these
tensions and managing our grazed lands in a better way. Rather, it must inform
the various communities of interests. Herein lies the value of this book. In the
end, wise solutions will be a balance of trade-offs that are based on informed deci-
sions and actions.
Gavin W. Sheath
Chair, International Grasslands Congress