TALE
OF CONTENT
DEDICATION 2
ACKNOWLEDGEMENTS 3
ABSTRACT 5
RESUME 5
TALE OF CONTENT 5
LIST OF FIGURES 6
LIST OF APPENDICES 6
LIST OF TABLES 7
CHAPTER 1.INTRODUCTION 8
1.1. Statement of the problem
8
1.2. Objectives of the study
8
1.3 The hypotheses of the study are
8
CHAPTER 2. LITERATURE REVIEW
9
2.1 Phosphorus in soil 9
2.1.1 Role of phosphorus in plant growth
9
2.1.2 Deficiency symptoms of P
9
2.1.3 Availability of phosphorus in soil
9
2.1.4.1. Total Soil Phosphorus:
9
2.1.4.2. Precipitated Phosphorus Minerals
9
2.1.4.3. Adsorbed Phosphorus
10
2.1.4. 4. Labile Phosphorus
10
2.1.4.5. Organic Phosphorus
10
2.1.6. Factors affecting soil phosphorus
availability in soil 10
2.2. Generality on Andosols
11
2.2.1. Definition 11
2.2.2. Phosphorus Fixation Mechanisms in
Andosols 11
2.2.3. Volcanic soils and agriculture
11
2.3 Lime and organic matter on soil P
availability, crop growth and yield 11
2.3.1 Meaning of soil amendment
11
2.3.2.1 Organic amendments
11
2.3.2.2 Mineral soil amendments: Lime
16
2.3.2.3. Functions of Lime
16
2.3.2.4. Liming materials and their reaction
in soils 16
2.3.2.5. Reaction of liming material with
organic and inorganic acids. 18
2.3.2.6 Rate of reaction of liming material
18
2.3.2.7 Rate of application
19
2.3.2.8. Time of Application
19
2.4. Generality on Carrots 19
2.4.1. Botanical description
19
2.4.2. Ecology 19
2.4.3. Fertilization. 19
2.3.4 .The yield 19
CHAPTER 3. MATERIAL AND METHODS
20
3.1. Experimental site 20
3.2. Materials 20
3.2.1. Test plant 20
3.2.2. Farm yard manure and Lime
20
3.3. Experimental design 21
3.4. Setting up of the experiment
22
3.4.1 Tillage and application of manure and
lime. 22
3.4.2 Sowing 22
3.5. Maintenance of the experiment
22
3.6.4 Harvesting 22
3.7. Data Collection 22
3.7.1 .Soil sampling 22
3.7.2. Crop growth characteristics.
22
3.7.3. Yield measurements
22
3.7.4. Laboratory analysis
23
3.8. Statistical analysis of data.
23
CHAPTER 4. Results and Discussion
24
4.1. Soil chemical properties
24
4.1.1 The soil reaction 24
4.1.2 Organic matter 26
4.1.3 Total Nitrogen 27
4.1.5. Total exchangeable acidity
28
4.1.6. Exchangeable Calcium and Magnesium
29
4.1.4. Available phosphorus
31
4.2 PLANT GROWTH 33
4.2.1 Height of plants at 30 days
33
4.2.2Heights of plants at 60 days after
sowing 34
4.2.3 Plant heights at 90 days after sowing
36
4.3 Yield evaluation 37
4.3.1 Length of tap-root at harvesting time (cm)
37
4.3.2. Tap-root diameter (cm) at harvesting
time 38
4.3.3 Yield of Carrot taproot at harvesting time
39
CHAPTER 5. CONCLUSION AND RECOMANDATIONS
41
5.1 Conclusion 41
5.2. Recommendations 41
REFERENCE
42
LIST OF FIGURES
LIST OF APPENDICES
LIST OF TABLES
CHAPTER 1.INTRODUCTION
1.1.
Statement of the problem
The use of chemicals and organic fertilizers in
developing countries like Rwanda experiences many constraints such as high
cost, their availability on markets, less knowledge about their use, their
harmful effects on environment and more particularly the techniques of
their use to the diversity of soils(Ntahompagaze,2000).
According to American soil classification, the volcanic soil
belongs to Andisols soil order. Volcanic soils have high content of Iron and
Aluminum hydroxyls, which fix tightly the phosphorus. They are essentially
amorphous in nature, crystalline, containing some minerals like allophanes.
These substances have a property of forming the organo- minerals complexes,
highly stable with humic acids (Quantin, 1992).
Also as noted by Donalme (1990), Andisols tend to have large
amount of humus (7-12%) organic carbon content in many soils). The amorphous
allophanes clays have high cation exchange capacities (often 150cmol /kg, which
is high than Montmorillinite).Unfortunately, these soils also rapidly adsorb
and precipitate phosphorus. The efficiency of added phosphorus fertilizer is
often less than 10%, compared to 10-30% in most soils. This phosphorus problem
is caused by high content of soluble Aluminum and Iron.
Thus the productive use of this type of soil may require some
level of manure and lime to possibly overcome some phosphorus adsorption and
precipitation by soluble Aluminum and Iron. This situation therefore
necessitates the present study entitled: `'INFLUENCE OF MANURE AND LIME ON
THE AVAILABILITY OF PHOSPHORUS, THE GROWTH AND YIELD OF CARROTS IN VOLCANIC
SOILS OF BUSOGO''
.
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