La lecture à portée de main
116
pages
English
Documents
2011
Écrit par
Yosef Amha Amde
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116
pages
English
Ebook
2011
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Publié le
01 janvier 2011
Nombre de lectures
68
Langue
English
Poids de l'ouvrage
1 Mo
Publié le
01 janvier 2011
Nombre de lectures
68
Langue
English
Poids de l'ouvrage
1 Mo
Microbial activity and biomass of peats in relation to
the intrinsic organic matter composition, pH,
moisture, and C and N inputs
von der Naturwissenschaftlichen Fakultät
der Gottfried Wilhelm Leibniz Universität Hannover
zur Erlangung des Grades
Doktor der Gartenbauwissenschaften
Dr. rer. hort.
genehmigte Dissertation
von
Yosef Amha Amde (Master of Science)
geboren am 15.02.79 in Holetta, Äthiopien
2011
Referent: Prof. Dr. Heike Bohne
Leibniz Universität Hannover
Institut für Zierpflanzen‐ und Gehölzwissenschaften
Herrenhäuser Straße 2
30419 Hannover
Deutschland
Koreferent: Prof. Beatrix Alsanius
Område Hortikultur, SLU
Box 103, 230 53 Alnarp
Sweden
Tag der Promotion: 25 March 2011
i
Dedicated to my parents and my sister, the late
Elsabet Amha
ii
Acknowledgment
First and foremost, I would like to thank THE ALMIGHTY GOD for giving me the
strength, health and courage to finish this PhD work.
I would like to express my sincere gratitude to my first advisor Prof. Dr. Bohne H. for
her supervision and guidance during my years as a PhD student. I am also wordless in
expressing my appreciation for her devotion, patience and tolerance to me throughout
this period!
I am thankful to Prof. Alsanius B. for her willingness to be my second advisor. The
technical and theoretical skills that I learned from her Microhort Postgraduate School
(Alnarp, Sweden) also helped me to better understand some of the methods described in
this thesis work. My special thank should also go to Dr. Khalil S. for allowing me to
enroll in this post‐graduate program. The school has covered my frequent traveling and
accommodation expenses, for which I am grateful. I am thankful to Prof. Dr. Stützel H.
for accepting my invitation to be the external examiner.
I gratefully acknowledge the Institute of Floriculture and Woody Plant Science for
offering me the position to pursue my Ph.D. study.
I am deeply indebted to Mrs. Buse J. and Mrs. Röhm D. for their untiring support during
data collections. Most of the analyses described in this thesis work were measured in
the Institute of Soil Science. Hence, I thank Dr. Ciglasch H. for his friendly and never‐
ending assistance at that facility. I am thankful to Mr. Schmilewski G., Dr. Picken P. and
Reinikainen O. for their contributions in analyzing the von Post humification degree
and botanical composition of peats. KlasmannDeilmann GmbH (Germany) and Vapo
Oy (Finland) are also acknowledged for their provision of the peat materials for free.
I owe special thanks to my beloved Mrs. Embet M.F. and Mrs. Tikdem G. for giving me
countless help and motivation in my last years of this study. I will never forget their
frequent phone calls to make me lively, joyful and stay on purpose. I am grateful for
times spent with them!
iii
Acknowledgment
I am deeply indebted to my father Mr. Amha A., my mother Mrs. Genet A., and all of my
sisters and brothers for their encouragement and support that constantly inspired me
to better myself and aim higher. I am at a loss for words and s imply I would say
“እግዚአብሄር ይስጥልኝ፦ አመሠግናለሁ!!”
I am thankful to all staffs of the Tree Nursery section for their kind treatments. I am
particularly grateful to the institute’s secretary Mrs. Reinecke S. who helped me in
facilitating some of the administrative tasks needed for this work.
My time in Hannover was made enjoyable and memorable in large part due to the many
Ethiopian friends and the Ethiopian Orthodox Church Community in the city. In line
with this, my special thanks should go to Mr. Abel D., Mrs. Genet A., Mrs. Aster N., Mrs.
Abeba Ts., Mrs. Nigist K., Mrs. Selamawit G., Mrs. Meron B., Mr. Hiwot A., Mrs.
Fasika T., Meseret D., Mrs. Liya M., Mrs. Sara A., Mrs. Genet W. and Mrs. Tigist H. for
their excellent hospitality.
There are also a number of people who have helped me at various stages; and I owe a
great deal of thanks to my sisters Yemeserach A. and Kidist A., my brother Yeshitela
A., Dr. Kindu M., Mr. Hailu R., Dr. Balesh T., Dr. Worku A., Dr. Getnet D., Mr. Dawit
M., Mr. Adane G., Mr. Tesfaye T., Mr. Sisay S., Mr. Mesay H. and Mr. Mekuria M. Of
course, I fail to list all names and apologize to those whom I mistakenly omitted!!
iv
Abstract
Excessive decomposition of organic matter (OM) from the potting media (e.g. peat) is known to
influence plant growth by decreasing the total porosity, altering the chemical properties (pH,
electrical conductivity), and releasing organic compounds that might have phytotoxic or
stimulating effects. When peats are used as constitutes of the potting media, they should, <