ISSN: 2224-0616
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
DOI: https://doi.org/10.3329/ijarit.v10i1.48095
Available online at https://ijarit.webs.com
https://www.banglajol.info/index.php/IJARIT
Evaluation of legume shrubs improved fallow for abandoned
agricultural land rehabilitation
B. Lemage1* and M. Tsegaye2
Received 15 April 2020, Revised 27 April 2020, Accepted 20 June 2020, Published online 30 June 2020
ABSTRACT
The experiment was conducted on abandoned agricultural land at Bena-Tsemay District,
Southern Ethiopia. It was designed to evaluate legume shrubs growth performance, and its
potential for soil fertility enhancement through improved fallow practice. The results of the
current study showed that the growth performance of legume species reveals variation in
different growth parameters. The mean height of Sesbania sesban was significantly higher
than the other species except for Senna siamea. Senna siamea recorded the highest mean
stem diameter followed by Sesbania sesban, 3.47 cm, and 2.86 cm, respectively. Legume
shrub species for soil fertility enhancement under improved fallow showed an increase in
soil pH, organic carbon, organic matter, phosphorus level, available potassium, and total
nitrogen during the growth period. Sesbania provides a large amount of nitrogen (2.91 t ha1) within two years fallow period, linked with the carbon to nitrogen ratio (11.22) having
better mineralization potential. The growing of promising legume shrub species as an
improved fallow practice has an important contribution in the restoration process of
abandoned agricultural land and used as an option to grow crops in a rotational cropping
system.
Keywords: Agroforestry, Leafy biomass, Rehabilitation practices, Shrub species.
1&2
Southern Agricultural Research Institute, Jinka Agricultural Research Center, P.O. Box 96 Jinka, Ethiopia.
*Corresponding author’s email: belaynehlemage@gmail.com (B. Lemage)
Cite this article as Lemage, B. and Tsegaye, M. 2020. Evaluation of legume shrubs improved fallow for
abandoned agricultural land rehabilitation. Int. J. Agril. Res. Innov. Tech. 10(1): 64-70.
https://doi.org/10.3329/ijarit.v10i1.48095
Introduction
The rapidly growing population puts considerable
pressure on scarce natural resources, and there is
an urgent need to develop more efficient and
sustainable agricultural production systems to
feed the growing population. However, in SubSaharan Africa (SSA) agricultural productivity has
been stagnant for many decades and the increase
of production due to expanded areas under
cultivation (Conway, 2012). The tradition of
continuous cultivations results in natural
resources degradation and soil fertility loss in
agricultural landscapes. Improving soil fertility
and applying an adequate supply of nutrients in
agricultural land have major implications for
meeting food security.
Legume shrubs species can fix atmospheric
nitrogen by symbiotic bacterial (i.e. rhizobial)
nodulation in their roots. An improved fallow is
the planting of fast-growing legume tree/shrub
species as a substitute to natural fallow to achieve
benefits of the latter in a shorter time (Prinz,
1986; Young, 1997).
Short-duration planted
fallows using a wide range of legume shrub/tree
species such as Sesbania sesban, Gliricidia
sepium, Tephrosia vogelii, and Cajanus cajan
have been found to replenish soil fertility and to
increase subsequent maize yields (Kwesiga et al.,
1999). Legume shrub species are characterized as
fixes nitrogen, vigorous, fast-growing, and deeprooted, tolerant of drought, and they can
accumulate atmospheric nitrogen (Hairiah et al.,
2006).
Nitrogen supply to be larger in improved fallow
than in cropped land because the plants
accumulate nitrogen from the air and deep layers
of the soil, and drop their leaf litter to enrich the
soil and conserve moisture (Styger and
Fernandes, 2006). The off-season cultivation of
fallow
legumes
and
their
subsequent
incorporation as green manure has been own to
enhance soil productivity by adding N and organic
C and by suppressing the problem of weeds.
International Journal of Agricultural Research Innovation & Technology An open access article under
Lemage and Tsegaye (2020)
Evaluation of legume shrubs for agricultural land rehabilitation
Improved fallows, in which leguminous trees and
shrubs are grown in association with crops, have
the potential to mitigate climate change by
sequestering C in soils and biota, protecting
existing natural forests, and conserving soil
productivity (Sileshi et al., 2007; Schoeneberger,
2008).
breast height, and branch number was
determined on five randomly selected plants of
each shrub species. Measurement of the growth
parameters was done within a six-month interval.
All desirable tending and management activities
were conducted throughout the experimentation
period.
In Ethiopia, agricultural production is intensively
monoculture type either on large scale or in
small-scale farmlands. The productivity declines
from time to time due to soil fertility loss and
insufficient supply of plant nutrients. The
tradition of agricultural production in small-scale
farm face a series of challenges from agricultural
input application, specific fertilizer due to its cost
increment and affordability problem. To address
this problem agroforestry practices play a
significant role in sustainable agricultural
production and soil fertility improvement. This
study mainly intended to evaluate the
rehabilitation potential of degraded agricultural
land through the integration of legume shrubs
under improved fallow practice.
Collected data for legume shrubs
Materials and Methods
Study area description
The field experiment was conducted from July
2016 to October 2019 at continually cultivated
land in the Bena-Tsemay district of South Omo
Zone, Southern Ethiopia. It is located between the
lower reaches of the Omo River in the West and
the Woito and Sagan Rivers in the East. The
district receives bimodal rainfall; the first peak,
from mid-March to the end of April, which is
important for crop production and the second
peak, from mid-October to the beginning of
November, which is short and important only for
pasture
establishments.
Biophysically
characterized as elevation ranges from 567−1,800
m above sea level, annual temperature between
16°C to 40°C (Admasu et al., 2010) and the major
soil type of the area is Chromic Cambisols
(Soromessa et al., 2004). The communities are
practicing both types of crop and animal
production systems.
Experimental design
Completely randomized block design (RCBD) was
used in this experiment involving four legume
shrub species with four replications. The
continuously cultivated site was selected, which
encounters a low fertility status. Experimental
plot size of 4 m x 4 m was constructed. Seedlings
were raised on the nursery site by using prepared
pots filled with forest soil, FYM, and sand with
the appropriate percentage (2:1:1 ratio),
respectively. Seedlings of shrub species were
planted onto the permanent plots with 50 cm x 50
cm spacing and their survival was monitored.
Plant height, root collar diameter, diameter at
The treatments assigned for experimentation
were legume species, named as Sesbania sesban
(trt1), Leucaena leucocephala (trt2), Senna
siamea (trt3) and Chamaecytisus palmensis
(trt4). These leguminous plant species have the
potential for restoring soil fertility through N2
fixation. The seedlings were grown in the nursery
and were transplanted to the main trial plots.
Legume shrubs growth parameters like tree
height, root collar diameter (above ground 10
cm), DBH (diameter at breast height 1.3 m),
branch number, leafy biomass (including leaf and
green branches) to be incorporated into the soil,
and wood products were collected from all
experimental plots. These data are important to
evaluate the adaptability of best performing plant
species on continuously cultivated land and their
potential to restore soil fertility.
Sample collection and nutrient analysis
Leaf samples were collected from each studied
legume species for nutrient analysis at a fully
mature stage. The leaves collected from each
treatment were air-dried, grounded, labeled, and
analyzed for N, P, K, C, and dry weight at Debre
Brihan Agricultural Research Center. A composite
soil sample before planting and soil samples after
the experimentation for each treatment was
collected, air-dried, and grounded for laboratory
analysis. The pH of the soil was measured in 1: 2.5
(soil: water ratio). Soil texture was determined by
the hydrometer method (Day, 1965). Organic C
concentration of the soil was determined
following the wet combustion method (Walkley
and Black, 1934). The total N concentration of the
soil was determined by wet-oxidation (wet
digestion) procedure (Kjeldahl, 1883). The
available phosphorus content of the soil was
determined by using the BrayII method (Bray and
Kurtz, 1965). Moreover, available potassium (K)
was determined by using Morgan solution or
sodium acetate extraction depicted in. Conversion
of soil organic carbon (SOC) into soil organic
matter
(SOM)
will
be
percentages=
1.72*percentage SOC.
Data analysis
The means values of the parameters were
compared using the least significant difference
(LSD) at a 5% level of significance using SAS
statistical software (version 9.0) and for data
organization, Microsoft Excel was used.
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
65
Lemage and Tsegaye (2020)
Evaluation of legume shrubs for agricultural land rehabilitation
Results and Discussion
Growth
performance
production
and
biomass
Legume shrub species used in this study showed a
significant difference (p<0.05) in growth
parameters during the experimentation period
(Tables 1, 2, 3, and 4). The heights of Sesbania
sesban and Senna siamea has significantly higher
than the other species (Table 3). Senna siamea
recorded the highest mean stem diameter
followed by Sesbania sesban, 3.47 cm, and 2.86
cm, respectively (Table 3). This result is in line
with findings of Sjögren (2010) who reported that
Sesbania showed a very high growth potential in
terms of mean tree height (4.4 m and 7.9 m) and
diameter (2.8 cm and 5.4 cm) in 6 and 18 months
of improved fallows, respectively in Western
Kenya. The findings also showed some variation
in stem diameter among the shrub species. The
highest mean number of branches was recorded
from Sesbania sesban (49), while Chamaecytisus
palmensis had the lowest (19) number of
branches.
Table 1. The legume shrubs growth parameters data were taken in the first round.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
LSD
CV(%)
RCD (cm)
1.69b
1.17c
2.07a
0.97c
0.315
14.42
Measured parameters
H (m)
1.85a
0.99b
1.13b
1.07b
0.61
33.50
BN
33.00a
9.86b
9.50b
8.00b
5.10
23.27
Source: Own data, 2016- 2019
Means with the same letter are not significantly different within columns(P<0.05). Where: H =height, BN
=branch number, RCD =root collar diameter, LSD( = least significant difference, CV =coefficient of variation.
Table 2. The legume shrubs growth performance parameters data were taken in the second-round.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
LSD
CV(%)
H (m)
4.11a
2.72b
4.57a
2.49b
0.531
10.93
Measured parameters
DBH (cm)
2.810a
1.420b
3.270a
1.185b
0.56
19.53
BN
65.3a
37.5cb
45.5b
29.5c
9.037
14.81
Source: Own data, 2016- 2019
Means with the same letter are not significantly different within columns (P<0.05). Where: H= height, BN
=branch DBH=diameter at breast height
Table 3. The summarized mean of growth performance parameters of legume shrubs.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
LSD
CV%
H (m)
3.59a
2.08b
3.44a
2.10b
0.561
14.32
Measured parameters
DBH (cm)
Branch number
2.86b
49.25a
1.49c
23.75cb
3.47a
28.00b
1.30c
19.00c
0.462
6.14
15.00
14.71
Source: Own data, 2016- 2019
Means with the same letter are not significantly different within columns (P<0.05). Where: H =height, BN
=branch number, DBH =diameter at breast height, LSD =least significant difference, CV =coefficient of
variation
The mean leafy green biomass produced through
the legume species showed significant variation
among the treatments used, for instance about
123.6 t ha-1 obtained from S. sesban followed by S.
siamea (78.75 t ha-1) and the lowest was recorded
on C. palmensis (11.27 t ha-1) are presented in
Table 6 and Fig. 1. This plays a significant role in
the release of important nutrients when
incorporated as green manure during land
preparation for subsequent cropping. From which
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
66
Lemage and Tsegaye (2020)
Evaluation of legume shrubs for agricultural land rehabilitation
S. sesban and S. siamea record the highest value,
this was the contribution of different growth
parameters like branch number, height, and DBH.
According to Torquebiau and Kwesiga (1996)
reported about 18 t ha-1 for a 2-year Sesbania
fallow in eastern Zambia and Ståhl et al. (2002)
reported 31.5 t ha-1 after 22 months from a study
in Eastern Kenya.
Although soil fertility amelioration is the primary
objective of improved fallow practices, they have
the potential to mitigate climate change through
carbon sequestration. Abundantly high green
leafy biomass production was obtained from S.
sesban followed by S. siamea, under the
improved fallow practice of the present study.
This releases important nutrients, and it adheres
with produced biomass amount and legume
species used under improved fallow practice.
Under improved fallows practice, shrub species
could provide biomass resources for fuel wood
production at the end of the fallow phase. The
result showed that there was an implication
referring to the contribution of fuel wood
production, through the use of S. sesban and S.
siamea about 233.3 t ha-1 and 119.7 t ha-1 wood
biomass obtained, respectively (Fig. 1). This in
agreement with the findings of Kwesiga et al.
(2005) who reported 15 and 21 t ha-1 of fuel wood
material was harvested after two- and three-year
fallows, respectively. Kwesiga and Coe (1994) also
reported short rotation of S. sesban provided
wood biomass after 1, 2, and 3 years fallow period
was 8.3, 17.6, and 21.4 t ha−1 and 10.8, 14.5 and
21.2 t ha−1 for both provenances of Kakamega and
Chipata, respectively.
Table 4. Shrubs growth parameters at the end of the experimental period.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
LSD
CV%
H (m)
4.82a
2.53b
4.61a
2.74b
1.09
21.57
Measured parameters
DBH (cm)
2.91b
1.55c
3.65a
1.41c
0.4402
13.44
Leafy BM (kg)
197.75a
78.25bc
126.00ab
18.03c
84.688
64.207
Source: Own data, 2016- 2019
Means with the same letter are not significantly different within columns(P<0.05). Where: H= height, BN
=branch number, DBH = diameter at breast height, LSD =least significant difference, CV= coefficient of
variation
The figure below shows that biomass produced
from each shrub species in terms of total biomass
that was the combination of wood. This was a very
appealing value of improved fallow system
reduces the harvesting of fuel wood from natural
forests and maintains environmental stability.
Source: own data 2016-2019.
Fig. 1. Total biomass (TBM), wood biomass (WBM), and leafy green biomass (GBM) production per
species under improved fallow period (t ha-1).
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
67
Lemage and Tsegaye (2020)
Soil
fertility
improved fallow
improvement
Evaluation of legume shrubs for agricultural land rehabilitation
under
The current study conducted for the rehabilitation
of abandoned agricultural land under improved
fallow practice showed an increase in soil pH,
organic C, phosphorus level, available K and total
N comparing with before planting (P<0.05), as
well as among legume species used in the
experimentation (Table 5 ). The result of this
study in line with findings of Young (1997), who
reported the provision of plant-available N from
decomposing Sesbania biomass, increased soil
organic matter, improved nutrient, water
retention in the soil. Kwesiga et al. (1999) also
reported short-duration planted fallows using
leguminous species have been found to replenish
soil fertility and to increase subsequent maize
yields at Eastern Zambia. Similarly, Rao et al.
(1998) reported fertilizer tree fallows improve soil
physically, chemically, and microbiologically. This
practice has the advantage of soil nutrients
improvement at the study site. Nutrients released
from leaf determined by green biomass produced
from legume species grown on experimentation
site. The leaf analysis results showed that the
amount of nutrient concentration varies from
species to species (Table 6 and 7). The legume
species improve the soil through biological
nitrogen fixation whereby recycled nutrients are
deposited through litter or when biomass is
harvested at the end of the fallow period. Soil
organic matter and organic carbon increased
through legume species under improved fallow
practice in the study site, this in line with the
findings of Donahue et al. (1983) who reported
that SOM was a major source of nutrients such as
nitrogen, and available P and K in unfertilized
soils. Besides, organic carbon is positively
correlated with available N and K nutrients (Maiti
and Ghose, 2005). The biomass produced by
these species has wider importance in the
composition of important soil nutrients and
increased yield in sequential cropping period. The
production of green leaf biomass has an ideal
contribution in the release of important crop
available nutrients through its decomposition and
modifying the agricultural land either it is by
improving physical, biological or chemical
properties (Table 6 and 7). Similarly, BekeleTesemma (2007) who reported in most parts of
SSA, farmers use improved fallows as a strategy
for improving soil fertility within a shorter period.
Table 4. Analyzed soil Physico-chemical properties under each legume shrub species.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
Before planting
LSD
CV%
pH
6.08a
5.90b
5.78c
5.70d
5.58e
0.0275
0.31
%TN
0.096a
0.087c
0.082d
0.091b
0.066e
0.0019
1.44
Soil parameters
%OC
P (ppm)
1.110a
8.8c
1.013d
8.4d
1.096b
10.8b
1.050c
11.2a
0.764e
7.5e
0.0085
0.0357
0.549
0.248
K (ppm)
122.90a
114.04d
118.20b
115.34c
107.03e
0.195
0.1096
Source: Own data, 2016- 2019.
Means with the same letter are not significantly different within columns (P<0.05).
The average compositions of clay, sand, and silt percentages were 51, 30, and 19, respectively. Thus according
to USDA soil textural classification of the experimental area was classified as clay.
Table 5. Analyzed leaf nutrients from legume shrub species.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
Nutrients released
%N
%P
%K
4.71
0.59
4.31
3.00
0.65
4.39
2.33
0.65
3.3
2.84
0.47
3.69
LDW (g)
LGBM t ha-1
96
88.69
90
83.15
123.6
48.91
78.75
11.2
Source: Own data, 2016- 2019.
For nutrient analysis 0.3 g leaf sample for N, and 0.5 g leaf sample for P & K, used, Where BM =biomass, LDW
=leaf dry weight, N =nitrogen, K =potassium, P =phosphorus.
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
68
Lemage and Tsegaye (2020)
Evaluation of legume shrubs for agricultural land rehabilitation
Table 6. Contribution of green biomass for nutrient release.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
GBM
kg plot-1
197.75
78.25
126.00
18.03
N (from GBM) P (from GBM) K (from GBM)
t ha-1
t ha-1
t ha-1
2.91
0.36
2.660
0.73
0.16
1.073
0.92
0.26
1.300
0.16
0.04
0.21
Source: Own data, 2016- 2019.
Where: GBM = green biomass, kg =kilogram, ha =hectare, N =nitrogen, K = potassium, P =phosphorus.
The relation between organic matter and
organic carbon obtained from green
biomass
The present study result showed that the amount
of organic matter depends on legume shrubs used
in improved fallow and biomass produced by
these species. The present study conducted in
legume shrubs improved fallow on abandoned
agricultural land, the shrub species offered with a
better proportion of organic matter, organic
carbon, and C: N ratio at which the mineralization
process determined. For instance, the variation of
C: N value for each species showed (Table 8) that
the amount of carbon and nitrogen nutrients
constituted in the organic biomass of the species.
The C: N value described as 11.22, 17.68, 18.82,
and 22.84 for Sesbania sesban, Leucaena
leucocephala, Senna siamea, and Chamaecytisus
palmensis, respectively. Mineralization of organic
matter depends on this critical parameter at
which the process is undertaken. The result of the
present study in line with previous studies of
Aerts and De Caluwe (1997) and Teklay et al.
(2007) who reported the concentrations of
nitrogen (N), phosphorus (P), and the ratios of
C/N are recognized as the main organic biomass
quality
variables
controlling
rates
of
decomposition. Mineralization process occurs
faster at lower C: N ratio (high nitrogen) at which
the conversion of organic minerals into organic or
mineral form and easily available for crop uptake.
This in agreement with the findings of Baggie et
al. (2000), who reported low C: N ratio and lignin
indicating the high quality of leaves with a fast
decomposition rate.
Table 7. Analyzed value of organic matter, organic carbon, and C: N ratio from shrub species.
Treatments (trees/shrubs species)
Sesbania sesban
Leuceania leucocephala
Senna siamea
Chamaecytisus palmensis
%OM
90.92
90.94
91.91
91.92
%OC
52.86
52.87
53.44
53.44
%N
4.71
2.99
2.34
2.84
C:N ratio
11.22
17.68
22.84
18.82
Source: Own data, 2016- 2019.
Where: OM =Organic Matter, OC =Organic Carbon, N =Nitrogen, And C: N =Carbon to Nitrogen ratio.
Conclusion
The growing of promising legume shrub species
as an improved fallow practice has an important
contribution to the restoration process of
abandoned agricultural land. On-farm evaluation
of legume, shrubs provide desirable variations in
different growth parameters, on soil properties
and amount of leaf nutrient compositions
respecting to the biomass produced by each
species. The result of the present study showed
that improved fallow agroforestry practice plays a
significant role in the rehabilitation of degraded
or continuously cultivated agricultural land
through the incorporation of the green biomass
(leaves, green twigs, and branches). Sesbania
provides a large amount of nitrogen (2.91 t ha-1)
within two years fallow period, used as an option
to grow crops in a rotational cropping system.
Therefore, this solves soil fertility problem and it
provides an opportunity to cultivate crop
production.
Recommendation
Based on the findings of the present study, the
following point is recommended
Crop production largely hindered by soil
fertility problem; it is improved through the
integration of desirable legume tree/shrub
species capable of providing decomposable
biomass, able to fix nitrogen, fast-growing,
and deep root system to access nutrients
beyond the annual crop root zone.
For instance, Sesbania has better adaptation,
good growth performance, provide fuel wood,
huge leafy green biomass adheres with a large
amount of nitrogen nutrient composition in
the study area, it is recommended as an
important legume shrub to rehabilitate
degraded agricultural within a short fallow
period. Thus, this practice is an important
way of improving the production potential of
degraded agricultural land through the
provision of nutrient-rich organic biomass and
biological nitrogen fixation. This species has
an appropriate proportion of carbon to
nitrogen ratio; mineralization processes of
organic compounds were done.
Therefore, further research is important to
evaluate the crop response after the green
biomass incorporation at the end of the
rotational fallow.
Conflict of interest
The authors declare that there is no conflict of
interest regarding the publication of this article.
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
69
Lemage and Tsegaye (2020)
Evaluation of legume shrubs for agricultural land rehabilitation
References
Admasu, T., Abule, E. and Tessema, Z.K. 2010.
Livestock-rangeland management practices
and
community
perceptions
towards
rangeland degradation in the South Omo
zone of Southern Ethiopia. Livestock Res.
Rural Dev. 22(1): 1-17.
Aerts, R. and de Caluwe, H. 1997. Nutritional and
plant‐mediated controls on leaf litter
decomposition of Carex species. Ecol. 78(1):
https://doi.org/10.1890/0012244-260.
9658(1997)078[0244:NAPMCO]2.0.CO;2
Baggie, I., Zapata, F., Sanginga, N. and Danso,
S.K.A. 2000. Ameliorating acid infertile rice
soil with organic residue from nitrogenfixing
trees. Nutr.
Cycling
Agroecosyst. 57(2): 183-190.
https://doi.org/10.1023/A:1009844019424
Bekele-Tesemma,
A.
2007. Profitable
Agroforestry Innovations for Eastern Africa:
Experience from 10 Agroclimatic Zones of
Ethiopia, India, Kenya, Tanzania, and
Uganda.
World
Agroforestry
Centre
(ICRAF), Eastern Africa Region. pp. 1-388.
Bray, R.H. and Kurtz, L.T. 1945. Determination of
total, Organic, and available forms of
Phosphorus in Soils. Soil Sci. 59(1): 39–
46. https://doi.org/10.1097/00010694194501000-00006
Conway, G. 2012. One billion hungry: can we feed
the world? Cornell University Press. pp. 1456.
Day, P.R. 1965. Particle fractionation and
particle-size analysis. In: Black, C.A. et al.
(eds.), Methods of Soil Analysis, Part I.
Agronomy, 9, pp. 545–567, Madison:
American Society of Agronomy, Wis.
https://doi.org/10.2134/agronmonogr9.1.c43
Donahue, R.L., Miller, R.W. and Shickluna, J.C.
1983. Soils: An introduction to soils and
plant growth. 5th Editon, Prentice-Hall, Inc.
667p.
Hairiah, K., Sulistyani, H., Suprayogo, D.,
Purnomosidhi, P., Widodo, R.H. and Van
Noordwijk, M. 2006. Litter layer residence
time in forest and coffee agroforestry
systems
in
Sumberjaya,
West
Lampung. Forest Ecol. Manage. 224(1-2):
45-57.
https://doi.org/10.1016/j.foreco.2005.12.007
Kjeldahl, J. 1883. A new method for the
estimation
of
nitrogen
in
organic
compounds. Z. Anal. Chem. 22(1): 366-382.
improved fallows in eastern Zambia: Their
inception,
development
and
farmer
enthusiasm. Agrofor. Syst. 47(1-3): 49-66.
https://doi.org/10.1023/A:1006256323647
Maiti, S.K. and Ghose, M.K. 2005. Ecological
restoration of acidic coalmine overburden
dumps- an Indian case study. Land Contam.
Reclam. 13(4): 361-369.
https://doi.org/10.2462/09670513.637
Prinz, D. 1986. Increasing the productivity of
smallholder farming systems by introduction
of planted fallows. Plant Res. Dev. 24: 31-56.
Rao, M.R., Nair, P.K.R. and Ong, C.K. 1997.
Biophysical
interactions
in
tropical
agroforestry systems. Agrofor. Syst. 38(1-3):
3-50. https://doi.org/10.1023/A:1005971525590
Schoeneberger, M.M. 2008. Agroforestry:
working trees for sequestering carbon on
agricultural lands. Agrofor. Syst. 75(1): 2737. https://doi.org/10.1007/s10457-008-9123-8
Sileshi, G., Akinnifesi, F.K., Ajayi, O.C.,
Chakeredza, S., Kaonga, M. and Matakala,
P.W. 2007. Contributions of agroforestry to
ecosystem services in the Miombo eco-region
of eastern and southern Africa. African J.
Environ. Sci. Tech. 1(4):68-80.
Sjögren, H. 2010. Agroforestry systems with trees
for biomass production in western Kenya.
PhD Thesis, Faculty of Forest Sciences
Department of Forest Ecology and
Management Umeå, Swedish University of
Agricultural Sciences. 43p.
Soromessa, T., Teketay, D. and Demissew, S.
2004. Ecological study of the vegetation in
Gamo Gofa zone, southern Ethiopia. Trop.
Ecol. 45(2): 209-222.
Ståhl, L., Nyberg, G., Högberg, P. and Buresh,
R.J. 2002. Effects of planted tree fallows on
soil nitrogen dynamics, above-ground and
root biomass, N2-fixation and subsequent
maize crop productivity in Kenya. Plant
Soil. 243(1): 103-117.
https://doi.org/10.1023/A:1019937408919
Styger, E. and Fernandes, E.C. 2006.
Contributions of managed fallows to soil
fertility recovery. Biol. Appr. Sust. Soil Syst.
425-437.
https://doi.org/10.1201/9781420017113.ch29
Teklay, T., Nordgren, A., Nyberg, G. and Malmer,
A. 2007. Carbon mineralization of leaves
from four Ethiopian agroforestry species
under laboratory and field conditions. Appl.
Soil Ecol. 35(1): 193-202.
https://doi.org/10.1016/j.apsoil.2006.04.002
https://doi.org/10.1007/BF01338151
Torquebiau, E.F. and Kwesiga, F. 1996. Root
development in a Sesbania sesban fallowmaize system in Eastern Zambia. Agrofor.
Syst. 34(2): 193-211.
1127(94)90294-1
Walkley, A. and Black, I.A. 1934. An examination
of the Degtjareff method for determining soil
organic matter, and a proposed modification
of the chromic acid titration method. Soil
Sci. 37(1):29-38.
Kwesiga, F. and Coe, R. 1994. The effect of short
rotation Sesbania sesban planted fallows on
maize yield. Forest Ecol. Manage. 64(2-3):
199-208.
https://doi.org/10.1016/0378Kwesiga, F., Franzel, S., Mafongoya, P., Ajayi,
O.C., Phiri, D., Katanga, R., Kuntashula, E.
and Chirwa, T. 2005. Successes in African
agriculture: Case study of improved fallows
in Eastern Zambia. Environment and
Production Technology Division (EPTD)
Discussion Paper, 130. International Food
Policy Research Institute (IEPRI). pp. 1-87.
Kwesiga, F.R., Franzel, S., Place, F., Phiri, D. and
Simwanza, C.P. 1999. Sesbania sesban
https://doi.org/10.1007/BF00148162
https://doi.org/10.1097/00010694-19340100000003
Young,
A.
1997. Agroforestry
for
soil
management (No. Ed. 2). CAB International.
320p.
Int. J. Agril. Res. Innov. Tech. 10(1): 64-70, June 2020
70