IMPACT OF TREE SPECIES ON MAIZE PRODUCTIVITY BY SMALLHOLDER FARMERS IN ...

114 Pages·2013·2.17 MB·English

IMPACT OF TREE SPECIES ON MAIZE PRODUCTIVITY BY
SMALLHOLDER FARMERS IN EASTERN KENYA
ELTON NDLOVU
MASTER OF SCIENCE
(Research Methods)
JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND
TECHNOLOGY
2013
Impact of tree species on maize productivity by smallholder farmers in
Eastern Kenya
Elton Ndlovu
Dissertation submitted to the Faculty of Agriculture in partial fulfillment of
the requirements of MSc in Research Methods degree at Jomo Kenyatta
University of Agriculture and Technology
2013
DECLARATIONBY THE CANDIDATE
This dissertation is my original work and to my knowledge has not been presented for
the award of a degree in anyother University.
Signature……………………… Date…………………………
Ndlovu Elton
DECLATION BY SUPERVISORS
This dissertation has been submitted for examination with our approval as University
and ICRAF supervisors.
Signature………………………….. Date………………………
1. Prof. Kamau Ngamau
JKUAT, Kenya
Signature………………………… Date………………………
2. Prof. Catherine .W. Muthuri
ICRAF, Nairobi
Signature…………………………… Date…………………………
3. Dr. Jonathan Muriuki
ICRAF, Nairobi
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DEDICATION
To all the farmers in Meru and Embu who allowed me to conduct my research work in
their farms.
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ACKNOWLEDGEMENTS
This research work was conducted with financial support from RUFORUM (Regional
Universities Forum) scholarship and ICRAF (World agroforestry Centre). I am so
much grateful to the two institutions. I would like to acknowledge the role played by
the Jomo Kenyatta University of Agriculture and Technology (JKUAT) in facilitating
my studies. I would also like to thank my University supervisor Prof. K. Ngamau,
ICRAF supervisors Prof. C.W. Muthuri and Dr. J. Muriuki for their unwavering support
during the whole research process.
My sincere gratitude also goes to all my friends especially Mcebisi Maphosa, Chester
Kalinda, Noella “Nono” Ekhuya, Verrah Akinyi, Gregory Sikumba, Kevin Kenyuira,
Grace Mwangi and Maureen Njuguna for their encouragement and help in different
ways. Not forgetting my best friend Kaari “Josi” who helped me during data collection
and for her encouragement during hard times. The ICRAF staff and students cannot go
unmentioned, especially Ms Ndanu Angela, Ms Hellen Ochieng, Joan, Mary Mumbua,
Ruth “Wanji,” Vincent “Vinny”, John Nyaga, Lydia, Erick , Peter Gachie and
Valentine Gitonga. To all the training unit and Finance staff, thank you folks for your
support in different ways. Special thanks also go to Dr. Madakadze, R. and her
daughters for hosting me at their home several times. Once again I express my deepest
gratitude to my parents for raising me up and teaching me to be patient, my uncles,
aunties, brothers and sisters for all the encouragement and support. I extend many
thanks to all the farmers in Embu and Meru for their greatest role of allowing me to
conduct the research in their farms. I don’t have enough words to thank my greatest
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Provider, Friend, Supervisor, Parent and Guardian the ALMIGHTY GOD; Forever I
shall praise him.
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TABLE OF CONTENTS
CONTENTS
DECLARATION..................................................................................................................i
DEDICATION.....................................................................................................................ii
ACKNOWLEDGEMENTS...............................................................................................iii
LIST OF TABLES...........................................................................................................viii
LIST OF FIGURES...........................................................................................................ix
LIST OF PLATES...............................................................................................................x
LIST OF ACRONYMS......................................................................................................xi
ABSTRACT......................................................................................................................xiii
CHAPTER ONE..................................................................................................................1
1.0 INTRODUCTION.........................................................................................................1
1.1. Background....................................................................................................................1
1.2. The limitations of the study............................................................................................6
1.3. Statement of the problem...............................................................................................6
1.4. Justification of the study................................................................................................8
1.5. Objectives.......................................................................................................................9
1.5.1. The general objective.......................................................................................................................................9
1.5.2. Specific objectives..............................................................................................................................................9
1.5.3. Research questions.........................................................................................................................................10
CHAPTER TWO...............................................................................................................11
2.0 LITERATURE REVIEW...........................................................................................11
2.1. Challenges faced by smallholder farmers....................................................................11
2.2. Importance of agroforestry in crop production and livelihood of smallholder
farmers.................................................................................................................................12
2.2.1. Benefits of agroforestry................................................................................................................................12
2.2.2. Limitations of agroforestry systems........................................................................................................14
2.3. Importance of Maize in Kenya.....................................................................................15
2.4. Challenges in the research process of on-farm studies in Agroforestry.......................16
2.4.1. Importance of on-farm studies in Agroforestry..................................................................................16
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2.4.2. Setting objectives in an agroforestry research study.......................................................................19
2.4.3. Selection of the study site.............................................................................................................................20
2.4.4. Designing on-farm studies...........................................................................................................................21
2.4.5. Data collection in agroforestry research studies................................................................................23
2.4.6. Handling data analysis...................................................................................................................................23
2.4.7. Sources of variations in on-farm study...................................................................................................24
CHAPTER THREE..........................................................................................................25
3.0 MATERIALS AND METHODS................................................................................25
3.1. Study site description...................................................................................................25
3.2. Sampling procedure......................................................................................................27
3.3. Study design.................................................................................................................29
3.4. Management of plots....................................................................................................32
3.5. Site characterization.....................................................................................................32
3.5.1. Survey on tree species...................................................................................................................................32
3.5.2. Rainfall data collection..................................................................................................................................34
3.6. Soil measurements........................................................................................................35
3.6.1.Soil sampling......................................................................................................................................................35
3.6.2. Walkley and Black titration method for determination of soil organic carbon.....................36
3.6.3. The pH (water) meter method...................................................................................................................37
3.7. Quantitative traits of maize..........................................................................................37
3.7.1. Vegetative growth data on non-destructive measurements (height, diameter)...................37
3.7.2. Chlorophyll content determination in maize.......................................................................................38
3.7.3. Grain yield at maturity...................................................................................................................................39
3.8. Data analysis................................................................................................................40
3.8.1. Tree data..............................................................................................................................................................40
3.8.2. Soil parameters.................................................................................................................................................40
3.8.3. Maize growth and yield.................................................................................................................................40
CHAPTER FOUR.............................................................................................................42
4.0 RESULTS AND DISCUSSIONS...............................................................................42
4.1. The prevalence and distribution of the tree species growing in farms in Eastern
Kenya in the long cropping season of 2012........................................................................42
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4.2. The influence of different tree species on organic soil carbon in farms in the four
study sites at the beginning of the long cropping season of 2012 in Eastern Kenya..........49
4.3. The influence of different tree species on soil pH on farms in the four study sites at
the beginning of the long cropping season of 2012 in Eastern Kenya................................53
4.4. The influence of trees species and distance from the tree on maize height and basal
diameter at different stages of growth in the long cropping season of 2012 in the four
study sites............................................................................................................................56
4.5. Variation of SPAD values with tree species and distance from the tree in maize
plants at 6 WACE in the long cropping season of 2012 in the four study sites..................61
4.6. The variations of maize grain yield at physiological maturity, with tree species
during the long cropping season of 2012 in Kyeni.............................................................66
4.7. Challenges in research process encountered during the study.....................................69
5.0. Conclusions..................................................................................................................72
6.0. Recommendations and way forward............................................................................73
REFERENCES..................................................................................................................75
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LIST OF TABLES

Table 1.Minimum, maximum and mean values for trunk diameter at breast height ....…33
Table 2. Summary of the most prevalent trees used in agroforestry ..................................46
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