Characterisation of natural and synthetic nitrification inhibitors and their potential use in tomato cultivation [Elektronische Ressource] / vorgelegt von Mohammad Kazem Souri
131 pages
English

Characterisation of natural and synthetic nitrification inhibitors and their potential use in tomato cultivation [Elektronische Ressource] / vorgelegt von Mohammad Kazem Souri

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131 pages
English
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Aus dem Institut für Pflanzenernährung, der Universität Hohenheim Prof. Dr. V. Römheld Characterisation of natural and synthetic nitrification inhibitors and their potential use in tomato cultivation Dissertation zur Erlangung des Grades eines Doktors der Agrarwissenschaften Vorgelegt der Fakultät Agrarwissenschaften der Universität Hohenheim Vorgelegt von M. Sc. Mohammad Kazem Souri aus Toyserkan, Iran Stuttgart-Hohenheim 2008 Mohammad Kazem Souri: Characterisation of natural and synthetic nitrification inhibitors and their potential use in tomato cultivation e-mail address: Kazem_sca@yahoo.ca D100 Dissertation University of Hohenheim, Institute of Plant Nutrition, 2008 Dissertation thesis of the University of Hohenheim, Faculty of Agricultural Sciences, for the acquisition of the degree of a”Doktor der Agrarwissenschaften” (Dr. sc. agr.) (Ph. D. in Agricultural Sciences). 1. Supervisor and Review Prof. Dr. V. Römheld 2. Co-reviewer Prof. Dr. W. Claupein 3. Co-reviewer Prof. Dr. R. Blaich 4. Assistant Dean and Head of the Committee Prof. Dr. W. Bessei Date of oral examination: 28. Aug. 2008 ii List of Content Chapter 1: Introduction ................................

Informations

Publié par
Publié le 01 janvier 2009
Nombre de lectures 31
Langue English
Poids de l'ouvrage 1 Mo

Extrait

Aus dem Institut für Pflanzenernährung,
der Universität Hohenheim
Prof. Dr. V. Römheld









Characterisation of natural and synthetic nitrification inhibitors and their
potential use in tomato cultivation








Dissertation
zur Erlangung des Grades eines Doktors
der Agrarwissenschaften
Vorgelegt der Fakultät Agrarwissenschaften
der Universität Hohenheim




Vorgelegt von

M. Sc. Mohammad Kazem Souri
aus Toyserkan, Iran

Stuttgart-Hohenheim

2008






Mohammad Kazem Souri:

Characterisation of natural and synthetic nitrification inhibitors and their potential use
in tomato cultivation

e-mail address: Kazem_sca@yahoo.ca





D100
Dissertation University of Hohenheim, Institute of Plant Nutrition, 2008






Dissertation thesis of the University of Hohenheim, Faculty of Agricultural Sciences,
for the acquisition of the degree of a”Doktor der Agrarwissenschaften” (Dr. sc. agr.)
(Ph. D. in Agricultural Sciences).







1. Supervisor and Review Prof. Dr. V. Römheld
2. Co-reviewer Prof. Dr. W. Claupein
3. Co-reviewer Prof. Dr. R. Blaich
4. Assistant Dean and Head of the Committee Prof. Dr. W. Bessei


Date of oral examination: 28. Aug. 2008












ii
List of Content

Chapter 1: Introduction ........................................................................................................... 1
1.1. Generals on nitrogen ....................................................................................................... 1
1.2. Forms of nitrogen:2
1.3. Nitrogen in the soil .......................................................................................................... 2
1.4. Nitrification ..................................................................................................................... 4
1.5. Nitrification inhibitors ..................................................................................................... 6
1.6. 3,4-Dimethylpyrazole phosphate (DMPP) ...................................................................... 8
1.7. Brachiaria as a source of natural nitrification inhibitor (NNI): ....................................... 9
1.8. Nitrogen uptake by plants ............................................................................................. 11
1.9. Why ammonium? .......................................................................................................... 13
1.10 Objectives of the research ............................................................................................ 15
Chapter 2: General Materials and Methods ........................................................................ 16
2.1 Plant cultivation ........................................................................................................ 16
2.1.1. Cultivation of Brachiaria humidicola .................................................................... 16
2.1.2. Cultivation of tomato plants ................................................................................... 17
2.2. Collection of root exudates: ..................................................................................... 18
2.3. Collection of xylem exudates18
2.4. Plant harvest and determination of growth parameters ............................................ 19
2.5. Plant mineral analysis: ............................................................................................. 19
2.6. Preparation of root exudates and tissue homogenates for characterization of
nitrification inhibiting compounds ........................................................................... 19
2.7. Bioassay for nitrification potentials ......................................................................... 20
2.7.2. Principle ........................................................................................................... 20
2.7.3. Application ....................................................................................................... 20
2.7.4. Chemicals ......................................................................................................... 20
2.7.5. Laboratory equipments ..................................................................................... 21
2.7.6. Procedure .......................................................................................................... 21
2.7.7. Test ................................................................................................................... 21
2.7.8. Spectrophotometric determination of nitrite .................................................... 21
2.7.9. Calculation22
2.8. Statistical analysis .................................................................................................... 22
Chapter 3: Efficiency of DMPP and chloride as microbial nitrification inhibitors in soil
.............................................................................................................................. 23
3. 1 Abstract .................................................................................................................... 23
3.2 Introduction .............................................................................................................. 23
3.3 Materials and Methods ............................................................................................. 25
3.3.1 Analysis ............................................................................................................ 26
3.4 Results ...................................................................................................................... 27
3.5 Discussion ................................................................................................................ 29
3.6 Conclusion35
Chapter 4: Effects of root exudates from Brachiaria humidicola on nitrification ........... 36
4.1. Abstract ......................................................................................................................... 36
4.2. Introduction ................................................................................................................... 36
4.3. Materials and Methods: ................................................................................................. 39
4.3.1. Soil incubation ........................................................................................................ 40
4.4. Results ........................................................................................................................... 40
4.4.1. Effects of DMPP concentrations ............................................................................ 40
4.4.2. Effects of N forms and pH of pre-culture solution ................................................. 41 4.4.3. Effects of plant age ................................................................................................. 42
4.4.4. Effects of collecting period .................................................................................... 42
4.4.5. Effects of N concentrations43
4.4.6. Effects of different light intensity .......................................................................... 44
4.4.7. Effect of freeze drying of root exudates ................................................................. 46
4.4.8. Effect of NH Cl in collection medium ................................................................... 46 4
4.5. Discussion ..................................................................................................................... 47
4.6. Conclusion51
Chpater 5: Effect of shoot and root homogenates and extracts from Brachiaria
humidicola on nitrification ................................................................................. 52
5.1 Abstract .................................................................................................................... 52
5.2 Introduction .............................................................................................................. 52
5.3 Materials and Methods ............................................................................................. 54
5.3.1 Plant culture ...................................................................................................... 54
5.3.2 Plant homogenates ............................................................................................ 54
5.3.3 Sequential extraction of plant material ............................................................. 55
5.3.4 Biotest for NI potential ..................................................................................... 55
5.4 Results ...................................................................................................................... 55
5.4.1 Plant growth and nutritional status ................................................................... 55
5.4.

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