Assessment Of Nutrient Contribution And Cassava/Maize Yields In 3 and 4-Year Old Triplochiton scleroxylon (K. Schum.) Based Agroforestry Systems In Abia State, Nigeria
ABSTRACT
Agroforestry
tree species perform differently in terms of nutrient contributions, promotion
of crops yields, carbon sequestration, biodiversity conservation and ecological
services. Trials were conducted on quantity of leaf litter production, rate of
leaf litter decomposition and nutrient content return of T. scleroxylon. Litter trays and litter bags methods
harvested monthly were used to study leaf litter fall and leaf litter decomposition
respectively in a single-factor Randomized Complete Block Design (RCBD) with
three replications within the plantation. The coefficient of determination (R2) and decomposition constant (k) of T.
scleroxylon leaf litter were determined using regression graphs.
A 2x3x2 factorial experiment in a Randomized
Complete Block Design (RCBD) was used to determine the effects of T. scleroxylon leaf litter nutrient contribution to soil fertility and cassava/maize
yields in monocrop and intercrop systems in a 3/4 year old
T. scleroxylon-based
agroforestry in 2019 and 2020 respectively with a 7 year old bushfallow land as
control at the Humid Forest Research Station, Forestry Research Institute of
Nigeria (FRIN), Okwuta-Ibeku, Umuahia, Abia State, Nigeria. Results showed significant
differences (P<0.05) in the monthly means of T.
scleroxylon litter
production of 2019 and 2020 respectively while no significant differences
(P>0.05) occurred between the yearly means litter production of 2019 and
2020. The dry season months of November β March had litter production ranging
from 174.07-724.53 kgha-1 in 2019 and 199.47-1485.10 kgha-1
in 2020 which were higher than the rainy season months of April β October at
the ranges of 35.80 - 174.07 kgha-1 in 2019 and 85.45 - 220.00 kgha-1
in 2020. Total leaf litter decomposition (100%) of T. scleroxylon surface-placement
method was observed at the 8th month (32 weeks) after commencement
of the trials in 1st January 2019 and 2020 respectively. The
coefficient of determination (R2), decomposition constant (k), C:N
ratio, time to 50, 95 and 99% decay for leaf litter of T.
scleroxylon in 2019 and 2020 were 0.76 and 0.80; 2.39 and 1.95; 2.:1
and 2:1; 0.29 and 0.36; 1.25 and 1.54; 1.92 and 2.36 respectively. The results of P, K, Ca and Mg content in the
leaf litters between 2019 and 2020 were significantly different (P<0.05) while
N, OC, OM and pH were not significantly different (P>0.05). The presence of T. scleroxylon litter
in the T. scleroxylon agroforestry system increased cassava tuber yields
over the yields in the bushfallow plot (control) in cassava monocropping and
cassava/maize intercropping systems in the 2019/2020 cropping seasons.
Irrespective of treatments, there were no significant differences (P>0.05)
in the yearly mean yields of maize cobs and maize heights in the T.
scleroxylon agroforestry system and bushfallow plot (control). T.
scleroxylon being rich in organic matter, N, P, K, Mg and Ca minerals
contributes remarkably in soil fertility improvement, and cassava and maize
yields. In conclusion, farmers and stakeholders in agriculture should adopt and
promote T. scleroxylon species respectively in their farming systems and
plantation establishments.
TABLE OF CONTENTS
Cover page
Title
page i
Declaration
ii
Certification iii
Dedication iv
Acknowledgement
v
Table
of contents vi
Abstract
xvii
CHAPTER
1: INTRODUCTION 1
1.1: Background information 1
1.2: Statement of the problem 3
1.3: Objectives of the study 5
1.4 :Justification of the study 5
1.5
:Scope of the study 7
CHAPTER 2: LITERATURE REVIEW 8
2.1: Agroforestry 8
2.1.1: Classification of agroforestry systems and
practices 11
2.1.2:
Roles of agroforestry in forest management 17
2.1.2.1:
Carbon cycle 17
2.1.2.2: Biodiversity conservation 19
2.1.2.3:
Healthy forest ecosystem 20
2.1.2.4: Socio-economic benefits 21
2.1.2.5: Wood and non-timber products
22
2.1.3: Plant
species used in agroforestry ecosystem
23
2.2:
Littterfall and litter production 26
2.2.1: Types and
sources of leaf litter 28
2.2.2: Litter decomposition
29
2.2.3: Rate of litter decomposition
31
2.2.3.1: Some factors influencing litter
decomposition rate 32
2.2.3.1.1:
Climatic condition 32
2.2.3.1.2:
Substrate quality
33
2.2.3.1.3:
Microbial activities
36
2.2.4:
Methods for estimating litter decomposition 37
2.2.4.1: Mass balance
38
2.2.4.2:
Litterbags 38
2.2.4.3:
Tethered Leaves Technique 39
2.2.4.4: Cohort layered screen
40
2.3: Litterfall as part of nutrient cycle
40
2.3.1: Nutrient accretion to soil through litterfall
41
2.4: Benefits of litter production and nutrient
cycling 42
2.4.1: Degraded site restoration/erosion
43
2.4.2: Importance of litterfall on growth and yield
of forest species 44
2.5:
Application of fertilizers on arable crops production in agroforestry ecosystem 45
2.5.1:
Effect of organic fertilizers on arable crop production in agroforestry
ecosystem 46
2.5.2:
Combination of inorganic fertilizers and organic fertilizers/manures 48
2.6: Crops
yields in agroforestry 49
2.7: Soil fertility
conditions in the tropics
50
2.7.1: Influence of trees on soil fertility 52
2.8:
Agroforestry and climate change
55
2.9: Trees and
soil biodiversity 57
2.10:
Description of Triplochiton scleroxylon
58
2.10.1:
Propagation of Triplochiton scleroxylon
59
2.10.2: Roles of Triplochiton scleroxylon 60
2.11:
Origin of maize (Zea mays L.)
60
2.11.1: Ecology
of maize 62
2.11.2:
Utilization of maize 63
2.12:
The Origin, domestication and distribution of Cassava (Manihot
esculenta Crantz) 64
2.12.1:
Classification of cassava 64
2.12.2: Flowering habit of cassava 65
2.12.3:
Importance of cassava
67
CHAPTER
3: MATERIALS AND METHODS 69
3.1:
Study location
69
3.2: Methodology 73
3.2.1:
Stand structure of Triplochiton
scleroxylon plantation
at Okwuta-Ibeku, Umuahia,
Nigeria 73
3.2.2:
Experiment 1: Leaf litter production
of Triplochiton scleroxylon in
2019 and
2020 74
3.2.2.1: Determination of pH level of T. scleroxylon leaflitter 75
3.2.2.2:
Determination of total Nitrogen (N) content of T. scleroxylon leaflitter 75
3.2.2.3:
Determination of Organic Carbon (OC) and organic matter (OM) content of
T.
scleroxylon leaflitter 76
3.2.2.4:
Macro minerals (Ca, Mg, P and K) content of T.
scleroxylon leaflitter 77
3.2.2.5:
Nutrients returns of Triplochyton
scleroxylon leaf litter
77
3.2.3:
Experiment 2: Leaf litter decomposition studies 79
3.2.3.1: Regression equation
of litter decomposition rates 81
3.2.4:
Experiment 3: Determination
of the contribution of T. scleroxylon to
soil fertility in cassava and maize
production system in Okwuta-Ibeku, Umuahia, Abia State
81
3.2.4.1: Soil samples
preparation 82
3.2.4.2:
Determination of soil pH 82
3.2.4.3:
Determination of soil Organic Carbon (OC) and organic matter (OM)
83
3.2.4.4:
Determination of cation exchange capacity of Soil Sample 83
3.2.4.5:
Determination of exchangeable base of sodium and potassium in
soil sample 84
3.2.4.6:
Determination of exchangeable base of ca and mg in soil sample 85
3.2.4.7: Soil particle size
determination 86
3.2.4.8: Heavy metal analysis: 87
3.2.4.9: Determination of total Nitrogen
87
3.2.5:
Experiment 4: Establishment of cassava (var. TMS
05-1636) and maize (var.
Oba super 6) monocrop and intercrop
plots under T. scleroxylon plantation
in 88
Okwuta-Ibeku, Umuahia, Abia State
3.2.5.1:
Cultural practices 88
3.2.5.2: Treatment combinations of factors at the T. scleroxylon agroforestry
89
3.2.5.3:
Treatment combinations of factors at the bush fallow land 89
3.2.6:
Yield parameters of cassava and maize in T. scleroxylon agroforestry system
in Okwuta-Ibeku, Umuahia, Abia State 90
3.3:
Statistical analysis
94
CHAPTER 4: RESULTS AND DISCUSSION 95
4.1:
Results 95
4.1.1: Leaf litterfall of Triplochiton scleroxylon 95
4.1.2:
Leaf litter decomposition rates of Triplochiton scleroxylon 97
4.1.2.1:
Cumulative leaf litter decomposition rates in 2019 and 2020 97
4.1.2.2: Coefficient
of determination (R2), decomposition constants (k), C: N ratio
time to
50, 95, and 99% decay for leaf
litter of Triplochiton scleroxylon in 2019 and
2020 in Umuahia 100
4.1.3: Nutrient composition of leaf litter Of Triplochiton scleroxylon stand in
Okwuta- Ibeku Umuahia, Nigeria 101
4.1.3.1: Nitrogen (N)
(g/kg) contents of the leaf litter of Triplochiton
scleroxylon 101
4.1.3.2:
Phosphorus (P) (g/kg) contents of the leaf litter of Triplochiton
Scleroxylon 103
4.1.3.3:
Potassium (K) (g/kg) contents of the leaf litter of Triplochiton scleroxylon 105
4.1.3.4:
Calcium (Ca) (g/kg) contents of leaf litter of Triplochiton scleroxylon 107
4.1.3.5:
Magnesium (Mg) (g/kg) contents of the leaf litter of T. scleroxylon 109
4.1.3.6: Organic Carbon (OC) (%) contents of the
leaf litter of T. scleroxylon 111
4.1.3.7: Organic Matter (OM) (%) contents of the
leaf litter of T. scleroxylon 113
4.1.3.8: pH levels of
the leaf litter of Triplochiton
scleroxylon 115
4.1.4: Pre- and post harvest soil physico-chemical
properties in Triplochiton
scleroxylon agroforestry and
Bushfallow Plots at Umuahia 117
4.1.4.1:Pre-planting
physico-chemical properties of soil in Triplochiton scleroxylon
Agroforestry and bushfallow plots
at Umuahia 117
4.1.4.2:Post-harvest
physico-chemical properties of soil in Triplochiton scleroxylon
agroforestry and bushfallow plots
at Umuahia
119
4.1.4.2.1:
Post-harvest pH levels of soils
119
4.1.4.2.2 Post-harvest cation exchange
capacity (CEC) of the soils
123
4.1.4.2.3: Post-harvest Organic
Carbon (OC) (%) contents of soils 127
4.1.4.2.4: Post-harvest Organic Matter
(OM) (%) contents of soils 131
4.1.4.2.5: Post-harvest total Nitrogen
(TN) (mg/kg) contents of soils
135
4.1.4.2.6: Post-harvest Phosphorus
(P) (mg/kg) contents of soils
139
4.1.4.2.7: Post-harvest exchangeable
Calcium (Ca2+)(meq/100 g soil) contents of soils 143
4.1.4.2.8: Post-harvest exchangeable
Magnesium (Mg2+) (meq/100 g soil) contents of
soils
147
4.1.4.2.9: Post-harvest exchangeable
Potassium (K+) (meq/100 g soil) contents of soils 151
4.1.4.2.10: Post-harvest exchangeable
Sodium (Na+) ((meq/100 g soil)) contents of
soils
155
4.1.4.2.11:
Post-harvest Iron (Fe) (mg/kg) contents of soils 159
4.1.4.2.1 2: Post-harvest Copper
(Cu) (mg/kg) contents of soils 163
4.1.4.2.1 3: Post-harvest
Manganese (Mn) (mg/kg) contents of the soils 167
4.1.4.2.14: Post-harvest Zinc
(Zn) (mg/kg) contents of soils 171
4.1.5:
Cassava tuber yield in the Triplochiton
scleroxylon agroforestry and bushfallow
plots in 2019 and 2020 cropping
seasons in Umuahia 175
4.1.6:
Maize cob yields in the Triplochiton
scleroxylon agroforestry and bushfallow
plots in 2019 and 2020 in Umuahia 179
4.1.7:
Maize stalk drymatter in the Triplochiton
scleroxylon agroforestry and bushfallow
plots in 2019 and 2020 in Umuahia 182
4.1.8: Maize plants heights (cm) in 2019 and 2020 cropping season in
the
Triplochiton scleroxylon agroforestry and bushfallow
plots in Umuahia 186
4.2: Discussion 190
4.2.1: Leaf litter production of Triplochiton scleroxylon
190
4.2.2: Leaf litter decomposition rates of Triplochiton scleroxylon 192
4.2.3: Nutrient composition of leaf
litter of Triplochiton scleroxylon
in
the
Humid Forest Research Station, Umuahia, Nigeria 195
4.2.3.1:
Nitrogen (N), Phosphorus (P) and Potassium (K) contents of the leaf litter
of
Triplochiton scleroxylon
195
4.2.3.2:
Calcium (Ca) and Magnesium (Mg) contents of the leaf litter of Triplochiton
Scleroxylon
198
4.2.3.3: Organic carbon (OC), organic
matter (OM) and pH levels of the leaf litter of
Triplochiton scleroxylon
199
4.2.4.1:Pre-planting
physico-chemical properties of soil in Triplochiton scleroxylon
agroforestry and bushfallow plots in Umuahia
200
4.2.4.2:
Effect of cassava/maize cropping systems on soil chemical parameters during
and
over 2019 and 2020 cropping seasons in Triplochiton scleroxylon
agroforestry and bushfallow plots at Umuahia 202
4.2.5:Cassava
tuber yield in the Triplochiton
scleroxylon agroforestry and
bush fallow farm ecosystems in 2019 and 2020 at Umuahia 207
4.2.6: Maize cobs mass, stovers and height yields in
the Triplochiton scleroxylon
agroforestry and Bush fallow farm ecosycstems in 2019 and 2020 at Umuahia
208
CHAPTER 5: CONCLUSION
AND RECOMMENDATIONS 210
5.1:
Conclusion
210
5.2: Recommendations
211
References
212
LIST OF TABLES
2.1: Preferred Agroforestry species in Nigeria 25
3.1:
Monthly climatic variables in 2019 and 2020 at the study site in
the
Humid Forest Research Station, Forestry Research Institute of Nigeria (FRIN),
Umuahia, Nigeria 71
4.1:
Monthly mean leaf litter production of Triplochiton scleroxylon plantation
in 2019 and 2020 at Umuahia
96
4.2: Leaf litter decomposition
percentages of Triplochiton
scleroxylon leaf litter
at
the Triplochiton scleroxylon
plantation in 2019 and 2020 at Umuahia
98
4.3:
Coefficient of determination (R2), Decomposition constants (k), C:N
ratio
time to 50, 95,
and 99% decay for leaf litter of Triplochiton scleroxylon in 2019
and
2020 in Umuahia
100
4.4: Nitrogen
(N) (g/kg) contents of the leaf litter of Triplochiton
scleroxylon 102
4.5: Phosphorus (P) (g/kg)
contents of the leaf litter of T. scleroxylon 104
4.6: Potassium
(K) (gkg-1) contents of the leaf litter of Triplochiton scleroxylon 106
4.7: Calcium
(Ca) (g/kg) contents of the leaf litter of Triplochiton
scleroxylon 108
4.8: Magnesium
(Mg) (g/kg) contents of the leaf litter of T.
scleroxylon 110
4.9:
Organic carbon (OC) (%) contents of the leaf litter of Triplochiton
scleroxylon 112
4.10:
Organic matter (OM)(%) contents of the leaf litter of Triplochiton
Scleroxylon
114
4.11:
pH levels of the leaf litter of Triplochiton
scleroxylon in 2019 and 2020 at
Umuahia 116
4.12:
Pre-planting physico-chemical properties of soil in Triplochiton scleroxylon
agroforestry
and bushfallow plots at Umuahia 118
4.13:
Post-harvest pH levels of soil in Triplochiton scleroxylon agroforestry and
bushfallow plot s at Umuahia 122
4.14:
Post-harvest cation exchange
capacity (CEC) of the soils in Triplochiton
scleroxylon
agroforestry and bushfallow plots at Umuahia 126
4.15:
Post-harvest organic carbon (OC) (%)
contents of soils in Triplochiton
scleroxylon
agroforestry and bushfallow plots at Umuahia 130
4.16:
Post-harvest organic matter (OM) (%)
contents of soils in Triplochiton
scleroxylon agroforestry and bushfallow plots in Umuahia 134
4.17:
Post-harvest Total Nitrogen (N)
(mg/kg) contents of soils in Triplochiton
scleroxylon agroforestry and bushfallow plots at Umuahia 138
4.18:
Post-harvest Phosphorus (P) (mg/kg)
contents of soils in Triplochiton
scleroxylon
agroforestry and bushfallow plots at Umuahia 142
4.19:
Post-harvest Exchangeable Calcium
(Ca2+) (meq/100 g soil) contents of soils in
Triplochiton scleroxylon agroforestry and bushfallow plots at
Umuahia 146
4.20:
Post-harvest Exchangeable Magnesium (Mg2+)
(meq/100 g soil) contents of
soils in Triplochiton scleroxylon agroforestry and bushfallow plot at
Umuahia 150
4.21:
Post-harvest Exchangeable Potassium
(K+) (meq/100 g soil) contents of soils in
Triplochiton scleroxylon agroforestry and bushfallow plots at
Umuahia 154
4.22:
Post-harvest Exchangeable Sodium (Na+)
(meq/100 g soil) contents of soils in
Triplochiton scleroxylon agroforestry and bushfallow plots at
Umuahia 158
4.23:
Post-harvest Iron (Fe) (mg/kg)
contents of soils in Triplochiton scleroxylon
agroforestry and bushfallow plots at Umuahia 162
4.24:
Post-harvest Copper (Cu) (mg/kg) contents of soils in T. scleroxylon
agroforestry and bushfallow plots in
Umuahia 166
4.25:
Post-harvest Manganese (Mn) (mg/kg)
contents of soils in Triplochiton
scleroxylon agroforestry and bushfallow plots in Umuahia 170
4.26
:Post-harvest Zinc (Zn) (mg/kg) contents of soils in T. scleroxylon agroforestry
and bushfallow plots in Umuahia 174
4.27:
Cassava tuber yield in the Triplochiton scleroxylon agroforestry and bush
fallow plots in 2019 and 2020 in
Umuahia 177
4.28:
Maize cob yield in the Triplochiton
scleroxylon agroforestry and Bush
fallow plots in 2019 and 2020 at Umuahia 180
4.29:
Maize stalk dry matter (DM) (stover) yield at the Triplochiton scleroxylon
agroforestry and bushfallow plots in 2019 and 2020 in Umuahia 184
4.30: Maize plants heights (cm) in 2019 and 2020 cropping season in the
Triplochiton
scleroxylon agroforestry and bushfallow plots in Umuahia 188
LIST OF FIGURES
3.1:
Location map of the study area in
Umuahia, Abia State, Nigeria 72
4.1: Biomass remaining in the litter
bags at various time (Month) intervals for
Triplochiton scleroxylon leaf litter decomposition experiments in 2019 and
2020
99
4.10: Cassava tuber yield in the Triplochiton scleroxylon agroforestry
and
bushfallow plots in 2019 and 2020 in Umuahia 178
4.11: Maize cob yield in the Triplochiton scleroxylon agroforestry
and Bush fallow
plots in 2019 and 2020 at Umuahia 181
4.12: Maize stalk dry matter yield in
the Triplochiton scleroxylon agroforestry
and Bush Fallow plots in 2019 and 2020 in Umuahia 185
4.13:
Maize plants heights (cm) in 2019 and 2020 cropping season in the T.
scleroxylon
agroforestry and bushfallow plots in Umuahia 189
0.0
ANTHONY, I (2023). Assessment Of Nutrient Contribution And Cassava/Maize Yields In 3 and 4-Year Old Triplochiton scleroxylon (K. Schum.) Based Agroforestry Systems In Abia State, Nigeria. Repository.mouau.edu.ng: Retrieved Apr 28, 2024, from https://repository.mouau.edu.ng/work/view/assessment-of-nutrient-contribution-and-cassavamaize-yields-in-3-and-4-year-old-triplochiton-scleroxylon-k-schum-based-agroforestry-systems-in-abia-state-nigeria-7-2
IKECHUKWU, ANTHONY. "Assessment Of Nutrient Contribution And Cassava/Maize Yields In 3 and 4-Year Old Triplochiton scleroxylon (K. Schum.) Based Agroforestry Systems In Abia State, Nigeria" Repository.mouau.edu.ng. Repository.mouau.edu.ng, 19 Jul. 2023, https://repository.mouau.edu.ng/work/view/assessment-of-nutrient-contribution-and-cassavamaize-yields-in-3-and-4-year-old-triplochiton-scleroxylon-k-schum-based-agroforestry-systems-in-abia-state-nigeria-7-2. Accessed 28 Apr. 2024.
IKECHUKWU, ANTHONY. "Assessment Of Nutrient Contribution And Cassava/Maize Yields In 3 and 4-Year Old Triplochiton scleroxylon (K. Schum.) Based Agroforestry Systems In Abia State, Nigeria". Repository.mouau.edu.ng, Repository.mouau.edu.ng, 19 Jul. 2023. Web. 28 Apr. 2024. < https://repository.mouau.edu.ng/work/view/assessment-of-nutrient-contribution-and-cassavamaize-yields-in-3-and-4-year-old-triplochiton-scleroxylon-k-schum-based-agroforestry-systems-in-abia-state-nigeria-7-2 >.
IKECHUKWU, ANTHONY. "Assessment Of Nutrient Contribution And Cassava/Maize Yields In 3 and 4-Year Old Triplochiton scleroxylon (K. Schum.) Based Agroforestry Systems In Abia State, Nigeria" Repository.mouau.edu.ng (2023). Accessed 28 Apr. 2024. https://repository.mouau.edu.ng/work/view/assessment-of-nutrient-contribution-and-cassavamaize-yields-in-3-and-4-year-old-triplochiton-scleroxylon-k-schum-based-agroforestry-systems-in-abia-state-nigeria-7-2