University of Florida Thesis Or Dissertation Formatting
Total Page：16
File Type：pdf, Size：1020Kb
CARBON SEQUESTRATION POTENTIAL OF TROPICAL HOMEGARDENS AND RELATED LAND-USE SYSTEMS IN KERALA, INDIA By SUBHRAJIT KUMAR SAHA A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2008 1 © 2008 Subhrajit Kumar Saha 2 To my wife, parents, and sister 3 ACKNOWLEDGMENTS I express my deep gratitude to my chair Dr. P.K. Ramachandran Nair for his excellent guidance and assistance during the course of my graduate work and my committee Dr. Taylor V. Stein (cochair), Dr. David Sammons, Dr. Vimala D. Nair, Dr. Michael Andreu, and Dr. B. Mohan Kumar for their advice, support, and inspiration. I extend my thanks to Dr. Shibu Jose, Cherie Arias, Sherry Tucker, Cindy Love, Dawnette Lauramore, Winnie Lante, Marie Meldrum, and Willie Wood of the School of Forest Resources and Conservation for their help during my doctoral program. I sincerely appreciate my colleagues Dr. Solomon Haile, Dr. Asako Takimoto, and Wendy Francesconi of the agroforestry research group for their help and support. I thankfully acknowledge the Kerala Government Departments of Agriculture and Forest for data sources, the farmers and landowners of the study villages in Kerala, India, for their cooperation in the study, and the Kerala Agricultural University staff for their help with soil sampling and household survey. I am grateful to Dr. Rajarshi and Mrs. Shampa Majumder, Dr. Subrata and Mrs. Manjari Roy, Dr. Indraneel and Mrs. Anuradha Bhattacharya, Dr. Suchandan and Nadini Guha, and Debapriya Dutta for their affection and friendship. I am deeply indebted to my parents (Mr. Subhrangshu.N. Saha and Mrs. Aloka Saha), my sister (Mrs. Indrani Saha), my brother-in-law (Col. Samit. K. Saha) and my nieces (Sanjana and Nilanjana) for their love and encouragement. I am also thankful to my father-in-law (Mr. Supriya Saha) and mother-in-law (Mrs. Kalyani Saha) and all my relatives in India for their inspiration. Finally, I express my gratefulness and indebtedness to my beloved wife Arpita for her love, patience, support, and motivation. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................4 LIST OF TABLES...........................................................................................................................9 LIST OF FIGURES .......................................................................................................................11 ABSTRACT...................................................................................................................................13 CHAPTER 1 INTRODUCTION ..................................................................................................................15 Background.............................................................................................................................15 Objectives ...............................................................................................................................20 Dissertation Outline................................................................................................................20 2 LITERATURE REVIEW .......................................................................................................21 Carbon Sequestration..............................................................................................................21 Agroforestry and Carbon Sequestration .................................................................................22 Carbon Sequestration and Biodiversity ..................................................................................24 Soil Carbon Sequestration ......................................................................................................27 Land-use and Soil Organic Carbon .................................................................................28 Root Activity and Soil Carbon Sequestration .................................................................30 Soil Carbon Fractions and Stability.................................................................................31 Homegardens ..........................................................................................................................32 Socioeconomic Factors, Farming Practices, and Carbon Sequestration.................................35 Tillage..............................................................................................................................36 Plant Residue...................................................................................................................36 Manure.............................................................................................................................37 Inorganic Fertilizer ..........................................................................................................37 Selection of Species.........................................................................................................38 Synthesis.................................................................................................................................39 3 STUDY AREA AND LAND-USE TYPES ...........................................................................41 Description of the Region.......................................................................................................41 Location...........................................................................................................................41 Soil...................................................................................................................................42 Topography......................................................................................................................42 Climate ............................................................................................................................43 Land-Use and Vegetation ................................................................................................43 Socio-cultural Conditions................................................................................................43 Description of Land-use Systems of Kerala ...........................................................................44 5 Homegarden ....................................................................................................................44 Forest ...............................................................................................................................47 Rubber Plantation ............................................................................................................48 Coconut Grove.................................................................................................................49 Rice-Paddy Fields............................................................................................................50 4 SOIL CARBON STORAGE UNDER TROPICAL HOMEGARDENS AND RELATED LAND-USE SYSTEMS IN KERALA, INDIA ..................................................55 Introduction.............................................................................................................................55 Materials and Methods ...........................................................................................................59 Study Area.......................................................................................................................59 Climate and Soil ..............................................................................................................60 Selected Land-use Types.................................................................................................61 Homegarden .............................................................................................................61 Forest).......................................................................................................................62 Rubber plantation .....................................................................................................62 Coconut grove ..........................................................................................................62 Rice-Paddy field.......................................................................................................63 Land-Use Survey.............................................................................................................63 Soil Sampling ..................................................................................................................63 Soil Preparation and Analysis .........................................................................................64 Statistical Methods ..........................................................................................................65 Results.....................................................................................................................................66 Soil Organic Carbon Storage in Whole Soil....................................................................66 Soil Organic Carbon in Macro-Sized Fraction (250 μm − 2000 μm) .............................67 Soil Organic Carbon in Micro-Sized Fraction (53 μm − 250 μm) ..................................68 Soil Organic Carbon in Silt and Clay-Sized Fraction (<53 μm) .....................................68 Discussion...............................................................................................................................68