ABSTRACT
The
changes in physiochemical properties of soil influenced by bush burning in Ali-ogo
Ekoli in Ebonyi state, Nigeria was studied during the 2012 cropping season.
Soil samples were collected from the unburnt and burnt areas of Ali-ogo Ekoli
at the depth of 0 – 30cm. The soil samples were analyzed in the laboratory
after which data was analyzed using ANOVA and mean differences were separated
using F-LSD (P = 0.05).
Result on particle size distribution showed that
burning increased sand and clay fraction, while silt fraction declined with
burning in the unburnt area of Ali-ogo Ekoli. Result on chemical analyses
indicated that there was reduction in some chemical properties in the unburnt
area while some chemical properties were increased by bush burning in the burnt
area. Also, the result on some selected heavy metals showed that some selected
heavy metals (Bo, Fe, Mo) were increased in unburnt area and decreased in the
burnt area while Zn increased in the
burnt area and decreased in unburnt area. This shows that fire has both
meritorious and deleterious effect in the soil.
TABLE OF CONTENTS
Title page
Certification
Dedication
Acknowledgements
Abstract
List of tables
Table of contents
CHAPTER ONE
1.0 INTRODUCTION
1.1
Main objective
1.2 Specific Objective
CHAPTER TWO
2.0
LITERATURE REVIEW
2.1.0
Effect of bush burning on soil physical
properties
2.1.1
Soil
texture
2.1.2
Soil
colour
2.1.3
Infiltration
rate
2.1.4
Bulk
density
2.1.5
Total
porosity
2.1.6
Moisture
content
2.1.7
Soil
temperature
2.1.8
Soil
aggregate and particle size
2.2.0
Effect
of bush burning on soil chemical properties
2.2.1
Soil pH
2.2.2
Organic matter
2.2.3
Nutrient dynamics
2.2.4
Macro – nutrients
2.2.5
Micro – nutrients
2.2.6
Exchangeable acidity
2.3 Effect of bush burning on heavy metal
accumulation
In
soil
CHAPTER THREE
3.0
MATERIALS AND METHOD
3.1 Study area
3.2 Soil sampling
3.3 Laboratory methods
3.4 Soil chemical properties
3.5 Heavy metal accumulations
3.6 Data
Analysis
CHAPTER FOUR
4.0 RESULT
AND DISCUSSION
4.1.0 The
effect of bush burning on chemical properties of soil
4.1.1 Soil pH
4.1.2 Total nitrogen
4.1.3 Calcium
4.1.4 Available phosphorus
4.1.5 Magnesium
4.1.6 Potassium
4.1.7 Sodium
4.1.8 Exchange abreaction
4.1.9 Effective cation exchange capacity
4.1.10 Exchangeable Sodium percentage
4.1.11 Exchangeable acidity
4.1.12 Base saturation
4.1.13 Organic carbon
4.2.0 The
effect of bush burning on soil selected physical
4.2.1
Bulk density
4.2.2
Total porosity
4.2.3
Hydraulic conductivity
4.2.4
Moisture content
4.2.5
Sand, silt and clay
4.3.0 The
effect of bush burning on soil selected heavy metals
4.3.1 Zinc
4.3.2 Boron
4.3.3 Iron
4.3.4 Molybdenum
CHAPTER FIVE
5.0 SUMMARY,
CONCLUSION AND RECOMMENDATION
5.1 Summary
5.2 Conclusion
5.3 Recommendation
References
LIST OF TABLES
Table 1: Effect of Bush Burning on Soil Chemical Properties
Table 2: Effect of Bush Burning on Soils Selected Properties
Table 3: Effect of Bush Burning on Soil Selected Heavy Metals
1.0 INTRODUCTION
Soil which has over the years been a
basic resources for agricultural production and the most important possession
and asset of farmers, is made up of different features and characteristics that
make it unique, (Brady and Wiels, 1999). Under natural condition, the level or
rate at which soil build up nutrients are anchored on the differences that
exist between the additions and losses of organic matters, physical, chemical
properties and other variables that form soil.
These additions could be from animal
and plant decay while losses are caused by immobilization and to a certain
degree burning. Sometime burning leads to leaching causing soil nutrient loss
beyond the root zone. The soil organic matter is also a characteristics
constituent of the soil ecosystem and it controls the soil physical, biological
and chemical properties (Olayinka, 1990).
Fire is the most fundamental and
effective cultural and land treatment tool in the hands of humans (Goldammer
and Grulzen 1993). Earliest evidence of the use of fire dates back to
1.5million year’s age, when natural fire regimes were successfully altered by
humans (Brain and Sillen, 1988). Large areas of forest formation have been
shaped and maintained by anthropocentric fires, and in most regions of the
world, human caused fires are more important that natural fires. (Goldammer and
Grutzen, 1993). Burning destroys the litter layer and so diminishes the amount
of organic matter returned to the soil. The organisms that inhabit the surface
soil and litter layer are also eliminated. For future decomposition to take
place, energy has to be invested first in rebuilding the microbial community
before plant nutrients can be released. Fallow lands and bush are burned before
cultivation; this provides a rapid supply of phosphorous to stimulate seed
germination. However, the associated losses of nutrients, organic matter and
soil biological activities have long-term consequences. Bush burning is a typical
type of cultivation practiced in Ali-Ogo Ekoli in Ebonyi state, South East
Nigeria. The system involves essentially cutting and burning of the vegetations
before cultivation.
Burning of vegetation in these areas
has a catastrophic effect, affects the ecosystem and physiochemical properties
of the soil (Ketterings and Bigham, 2000). Much attention has not been paid to
the effect of bush burning on physical and chemical properties of the soil in
this area. The effects of the heating processes caused by severe bush fire on
soil are a result of burning severity, which is determined by the peak
temperatures and duration of fire (Certini, 2005). Low to medium fire severity
resulted in darkening of the topsoil while high severity fire (>600oc)
cause pronounced reddening of the topsoil, (Ketterings and Bigham, 2000).
With a review of bush burning on soil
properties, Certini (2005) concluded that low to moderate severity fires result
in a renovation of the dominate vegetation by the elimination of undesired
species and transient increase in pH and available nutrients in the soil, while
severe burning generally lead to a great significant loss of organic matter,
deterioration of both structure and porosity, leaching and erosion, among
others. Burning influences soil temperature, which in turn affects crop physico-chemical
processes such as seed germination, root growth, plant development and bio-microbial
activity based on the fact that there is dearth of information on the effect of
burning on the soils of Ali- ogo (Potter and Neary, 1987)
1.1 Main objective
The main objective of this research was to determine
changes in physico-chemical properties of Ali – ogo soil resulting from bush
fire.
1.2 SPECIFIC
OBJECTIVE
The
specific objectives are to determine the,
i. Changes in physical properties of the
soil
ii. Changes in the chemical properties of
the soil
iii. Effect
of bush burning on heavy metal accumulation in soil
A RESEARCH PROJECT SUBMITTED IN PARTIAL
FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF BACHELOR OF AGRIC (B. Agric)
TO THE DEPARTMENT OF SOIL AND ENVIRONMENT
MANAGEMENT, FACULTY OF AGRICULTURE AND NATURAL RESOURCE MANAGEMENT