Phosphate dynamics in peat-based substrates and P efficiency of ornamental plants [Elektronische Ressource] / von Azizollah Khandan-Mirkohi

Azizollah Khandan-Mirkohi

Informations

• Publié par: gottfried_wilhelm_leibniz_universitat_hannover
• Publié le: 01 janvier 2009
• Nombre de lectures: 27
• Langue: Deutsch
• Poids de l'ouvrage: 1 Mo

Extrait

PHOSPHATE DYNAMICS IN PEAT-BASED SUBSTRATES AND P
EFFICIENCY OF ORNAMENTAL PLANTS



Von der Naturwissenschaftlichen Fakultät
der Gottfried Wilhelm Leibniz Universität Hannover

zur Erlangung des Grades
Doktor der Gartenbauwissenschaften
Dr. rer. hort.

genehmigte Dissertation
von
M.Sc. Azizollah Khandan-Mirkohi
geboren am 30.04.1973 in Sarab-Iran

2009








































Referent: Prof. Dr. Manfred K. Schenk
Korreferent: Dr. Bernd Steingrobe
Tag der Promotion: 24. 04. 2009















Dedicated to my parents and my family

Especially my Father who passed away during my PhD study


























Erklärung zur Dissertation

Hierdurch erkläre ich, dass die Dissertation:

Phosphate Dynamics in Peat-Substrate and P Efficiency of Ornamental Plants

selbstständig verfasst und alle benutzten Hilfsmittel sowie evlt. Zur Hilfeleistung
herangezogene Institutionen vollständig angegeben wurden.

Die Dissetation wurde nicht schon als Diplom- oder ähnliche Prüfungsarbeit
verwendet.

Hannover, den


_____________________________
Unterschrift

Name: Azizollah Khandan-Mirkohi

TABLE OF CONTENTS
ABSTRACT................................................................................................................. 1
KURZFASSUNG......................................................................................................... 2
GENERAL INTRODUCTION ...................................................................................... 3
1. Phosphorus as a nutrient..................................................................................... 3
2. Phosphorus supply to the root ............................................................................. 4
2.1. Mass flow and diffusion................................................................................. 4
2.1.1. Mass flow................................................................................................ 4
2.1.2. Diffusion.................................................................................................. 5
2.2. Impedance factor and buffer power............................................................... 6
3. P efficiency .......................................................................................................... 7
3.1. P uptake efficiency ........................................................................................ 7
3.1.1. Root hairs ............................................................................................... 7
3.1.2. Root/shoot ratio ...................................................................................... 8
3.1.3. Specialized roots .................................................................................... 8
3.1.4. Mycorrhizal symbiosis............................................................................. 9
3.1.5. Rhizosphere chemistry ........................................................................... 9
3.1.6. Physiological uptake kinetics ................................................................ 10
3.1.7. Relationship between relative growth and uptake rates........................ 10
3.2. P utilization efficiency.................................................................................. 11
4. Modeling of plant and substrate parameters...................................................... 12
5. Phosphorus demand for optimum yield.............................................................. 12
6. Representative ornamental plants ..................................................................... 14
7. Significance and scope of the study .................................................................. 15
CHAPTER 1.............................................................................................................. 16
Phosphorus dynamics in peat-based substrates................................................. 16
Abstract.................................................................................................................. 17
I TABLE OF CONTENTS
1. Introduction........................................................................................................ 18
2. Materials and methods....................................................................................... 19
2.1. Impedance factor (f) .................................................................................... 19
2.2. Buffer power (b) .......................................................................................... 21
2.3. Extension of the depletion zone (∆x)........................................................... 22
2.4. Mean half distance between neighboring roots (r ) ..................................... 23 1
2.5. Soil analysis ................................................................................................ 23
2.6. Statistics...................................................................................................... 23
3. Results and discussion ...................................................................................... 24
3.1. Impedance factor......................................................................................... 24
3.2. Buffer power................................................................................................ 27
3.3. Effective diffusion coefficients (D ).............................................................. 31 e
CHAPTER 2.............................................................................................................. 33
Characteristics of phosphorus uptake kinetics of ornamental plants ............... 33
Abstract.................................................................................................................. 34
1. Introduction........................................................................................................ 35
2. Material and methods ........................................................................................ 36
2.1. Propagation and growth .............................................................................. 36
2.2. Treatments .................................................................................................. 37
2.3. Determination of P uptake kinetics.............................................................. 37
2.4. Determination of plant parameters .............................................................. 38
2.5. Estimation of concentration gradient ........................................................... 39
2.6. Statistical analysis....................................................................................... 39
3. Results............................................................................................................... 40
3.1. Plant growth ................................................................................................ 40
3.2. Physiological P uptake parameters ............................................................. 45
4. Discussion ......................................................................................................... 49
4.1. Plant growth parameters ............................................................................. 49
II TABLE OF CONTENTS
4.2. Uptake kinetic parameters........................................................................... 51
5. Conclusions ....................................................................................................... 53
CHAPTER 3.............................................................................................................. 54
Phosphorus efficiency of ornamental plants in peat-substrates........................ 54
Abstract.................................................................................................................. 55
1. Introduction........................................................................................................ 57
2. Material and methods ........................................................................................ 58
2.1. The growing medium................................................................................... 58
2.2. Cultivation and harvesting ........................................................................... 59
2. 3. Analytical procedures................................................................................. 60
2. 3.1. Physical and chemical properties ........................................................ 60
2. 3.2. Root morphological parameters........................................................... 61
2. 3.3. Root physiological parameters............................................................. 63
2. 3.4