FIELD and LABORATORY INVESTIGATIONS AGROECOLOGY in Second Edition 2846_C000.indd 1 11/8/06 1:37:30 PM 2846_C000.indd 2 11/8/06 1:37:30 PM FIELD and LABORATORY INVESTIGATIONS AGROECOLOGY in Second Edition Stephen R. Gliessman University of California, Santa Cruz Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business 2846_C000.indd 3 11/8/06 1:37:30 PM CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2006 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20131106 International Standard Book Number-13: 978-1-4200-0439-7 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com Author Stephen R. Gliessman. With a B.A. in botany, an M.A. in biology, and a Ph.D. in plant ecology from the University of California, Santa Barbara, Stephen R. Gliessman has accumulated more than 33 years of teaching, research, and production experience in the field of agroecology. His international experiences in tropical and temperate agriculture, small-farm and large-farm systems, traditional and conventional farm management, hands-on and academic activities, nonprofit and for-profit work experience, and organic and synthetic chemical farming approaches have provided a unique combination of materials and perspectives to incorporate into this text. He was the founding director of the University of California, Santa Cruz (UCSC), Agroecology Program, one of the first formal agroecology programs in the world, and is the Alfred and Ruth Heller Professor of Agroecology in the Department of Environmental Studies at UCSC. He is the cofounder of the nonprofit Community Agroecology Network (CAN) and director of the undergraduate residential learning Program in Community and Agroecology (PICA). He also dry farms organic wine grapes and olives with his wife Robbie and son Erin in northern Santa Barbara County, California. 2846_C000.indd 5 11/8/06 1:37:32 PM 2846_C000.indd 6 11/8/06 1:37:32 PM Contents AGROECOLOGICAL INVESTIGATIONS Part I Studies of Environmental Factors 1. Effect of Microclimate on Seed Germination ......................................................................................3 2. Light Transmission and the Vegetative Canopy .................................................................................15 3. Soil Temperature ................................................................................................................................29 4. Soil Moisture Content ........................................................................................................................37 5. Soil Properties Analysis .....................................................................................................................45 6. Canopy Litterfall Analysis .................................................................................................................59 7. Mulch System Comparison ................................................................................................................67 8. Root System Response to Soil Type ...................................................................................................83 Part II Studies of Population Dynamics in Crop Systems 9. Intraspecific Interactions in a Crop Population ..................................................................................95 10. Management History and the Weed Seedbank ................................................................................109 11. Comparison of Arthropod Populations ............................................................................................125 12. Census of Soil-Surface Fauna ..........................................................................................................135 Part III Studies of Interspecific Interactions in Cropping Communities 13. Bioassay for Allelopathic Potential ..................................................................................................147 14. Rhizobium Nodulation in Legumes ..................................................................................................169 15. Effects of Agroecosystem Diversity on Herbivore Activity .............................................................179 16. Herbivore Feeding Preferences ........................................................................................................189 17. Effects of a Weedy Border on Insect Populations ............................................................................199 Part IV Studies of Farm and Field Systems 18. Mapping Agroecosystem Biodiversity .............................................................................................211 19. Overyielding in an Intercrop System................................................................................................217 20. Grazing Intensity and Net Primary Productivity .............................................................................233 21. Effects of Trees in an Agroecosystem ..............................................................................................243 2846_C000.indd 7 11/8/06 1:37:33 PM Part V Food System Studies 22. On-Farm Energy Use .......................................................................................................................259 23. Farmer Interview ..............................................................................................................................267 24. Local Food Market Analysis ............................................................................................................273 INSTRUCTOR’S APPENDIX Appendix A. Planning the Field and Laboratory Course ........................................283 Equipment and Facilities ............................................................................................................................284 Choosing Investigations to Match Your Goals ...........................................................................................284 Choosing Investigations for Your Climate and Season ..............................................................................286 Scheduling the Investigations .....................................................................................................................286 Combining and Coordinating Investigations..............................................................................................289 Modifying Investigations ...........................................................................................................................290 Accumulating Data from Year to Year.......................................................................................................291 Running the Field and Laboratory Course .................................................................................................291 Preparing and Maintaining the Investigation Set-ups ................................................................................291 Working with Teams ..................................................................................................................................292 Using the Datasheets ..................................................................................................................................292 Sharing Data among Teams .......................................................................................................................292 Assigning Work ..........................................................................................................................................293 GENERAL APPENDICES Appendix B. Measurement Equivalents ................................................................297 Appendix C. Material and Equipment Suppliers ....................................................301 2846_C000.indd 8 11/8/06 1:37:33 PM Instructor’s Preface The purpose of this manual is to give students opportunities to gain direct hands-on field and laboratory experience with the concepts that make up the science of agroecology. Since agroecology is defined as the application of ecological concepts and principles to the design and management of sustainable food systems, such an experiential approach to teaching agroecology is essential. This manual is specifically designed to be used for the field and lab component of a lecture-based classroom course in which Agroecology: The Ecology of Sustainable Food Systems serves as the main text. The twenty-four investigations are divided into five sections that roughly parallel the organization of the textbook, with each focusing on a distinct level of ecological complexity. Investigations in the first section, Studies of Environmental Factors, are mainly autecological in nature. They deal with how an individual plant responds to the environment, how environmental factors in specific agroecosystems are measured and characterized, and how particular environmental factors affect individual plants. In the second section, Studies of Population Dynamics in Crop Systems, investigations highlight how populations of organisms act in agroecosystems. They focus on what populations are present in a system, how populations change over time and respond to the environment, and how individuals within a population may interact. The level of the community is the focus of the third section, Studies of Interspecific Interactions in Cropping Communities. Here, investigations explore the between-species interactions of the organisms that make up crop communities. These interactions include herbivory, allelopathy, and mutualisms. Investigations in the fourth section, Studies of Farm and Field Systems, look at the system level of agro- ecology, examining either whole farms or systems within farm boundaries. These investigations touch on the complexity with which the farmer deals in managing agroecosystems. Finally, in the fifth section, Food System Studies, investigations reach out beyond the individual farm to examine components of the food system at a local level, which impact all of the levels of analysis in the first four sections. In addition to this parallel structure, Field and Laboratory Investigations in Agroecology provides the instructor with other tools for correlating the lecture and lab components of a course. Each investigation indicates the chapters in the text to which the investigation relates most directly, and the investigation’s Introduction section generally includes more specific references to textbook content. Further, a table at the end of this Preface provides an overview of chapter–investigation correlation. Not all the text’s chapters are included in this table — Chapters 1 through 3 are general enough to have some connection to most investigations, and some later chapters cover topics (such as fire and genetics) that are not addressed in any investigations. Despite the integration of this manual with Agroecology: The Ecology of Sustainable Food Systems, it can also be used without the text — as the core of a field and laboratory course, for example — or with another textbook in agroecology, agronomy, or ecology (in which case a copy of Agroecology will be handy for consultation). 2846_C000.indd 9 11/8/06 1:37:33 PM