International Research Journal of Plant Science (ISSN: 2141-5447) Vol. 2(6) pp. 160-165, June, 2011
Available online http://www.interesjournals.org/IRJPS
Copyright © 2011 International Research Journals
Full length Research Paper
Growth of coffee seedlings as influenced by Arbuscular
mycorrhizal inoculation and phosphate fertilizers in two
soils in Nigeria
Ibiremo, O.S., Daniel, M.A, Oloyede, A.A and Iremiren, G.O.
Cocoa Research Institute of Nigeria, Ibadan, Nigeria.
Accepted 28 June, 2011
A greenhouse study was carried out to evaluate the effect of phosphate fertilizer types and
Arbuscular Mycorrhizal fungi inoculation (AMF) on the growth of coffee seedlings in two soil types
in Nigeria. The trial was a factorial experiment involving two types of P-fertilizers (Single Super
Phosphate and Sokoto Rock Phosphate) and mycorrhizal inoculation. The P-fertilizers were applied
at 10kg P205/ha and a control (no-P fertilizer application) while the AMF was applied at two levels
(with and without inoculation). The six treatments combinations were applied to two-month old
coffee seedlings grown in the two soils (Ibadan and Mambilla). The experiments were laid out in a
CRD with three replications and data on growth of coffee and soil parameters were taken for six
months. In Mambilla soil, the height and stem diameter of coffee seedlings were significantly (P<
0.05) higher as a result of application of SSP and mycorrhizal inoculation compared with SRP and
inoculation or the control. The number of leaves and leaf area were significantly (P< 0.05) improved
due to application of SSP and SRP with or without mycorrhizal inoculation in Mambilla soil while in
Ibadan soil, mycorrhizal inoculation resulted in consistent and significant improvement on the stem
diameter and leaf area of coffee seedlings. Soil pH and Organic Carbon were not significantly
affected by the application of phosphate fertilizer types in both soils. However, the soil available P
was significantly (P< 0.05) enhanced in the two soils due to application of SSP with or without
mycorrhizal inoculation. Similarly, the root colonization of coffee seedlings at 6 MAT was
significantly higher as a result of mycorrhizal inoculation without P-fertilizer application compared
with root colonization under SSP application and mycorrhizal inoculation in Mambilla soil. The
mycorrhizal inoculation with or without Phosphate fertilizer did not significantly affect the
colonization of coffee seedling roots in Ibadan soil. SRP had a comparable effect with SSP on the
growth of coffee seedlings especially under mycorrhizal inoculation; hence, SRP is a promising
substitute for inorganic phosphate sources for coffee seedling production in Nigeria.
Keywords: coffee, phosphate fertilizer, mycorrhizal inoculation, colonization, seedlings
INTRODUCTION
Coffee is one of the agricultural products in international
markets and an important foreign exchange earning crop
in Nigeria (Famaye, 2002). Coffee production in Nigeria is
fast declining due to neglect, abandonment of farms,
inconsistent government policies, soil infertility, poor
*Corresponding Author E-mail: femiibiremo@yahoo.com
pricing, pests and diseases among others. With the
increase in the current world price of the commodity and
global concern for its sustainability, it becomes imperative
to increase the country`s production level. Most soils
upon which coffee is grown are generally poor in
nutrients such as nitrogen and phosphorus. In subsaharan Africa, farmers use just 8Kg/ha of fertilizer a
year, compared with a global annual average of 90
Ibiremo et al. 161
Kg/ha. Phosphorus is a key element in the establishment
of new plantations. However, in tropical countries where
coffee is cultivated, phosphorus is often the limiting
nutrient. In fact, coffee soils contain abundant
phosphorus, but most of it fixed and unavailable to the
plants. International fertilizer Development Centre (IFDC)
revealed in its recent study revealed that 85% of the
continent’s arable land lost an annual average of 30Kg/ha
of nutrients between 2000 and 2004. Therefore, sound
management of soil and other resources plays key role in
productivity. Phosphorus plays a significant role in cell
division and root development (ISMA 1982; Hafner et al
1993; Akande et al, 2008). The wide spread deficiency of
phosphorus in most soils in Nigeria is due to fixation. The
application of inorganic phosphate fertilizers such as
SSP, TSP, NPK etc over a long period of time results in
very grave consequences (Zainol et al 1993). In recent
times, the use of mineral phosphate fertilizers such as
Sokoto rock phosphate as alternative P-fertilizer in the
cultivation of crops is gaining the attention of research
scientists globally (Ibiremo et al 2002., Ibiremo and
Fagbola 2008b., Siquerra et al 1998, Chem and Hammed
1998). The potential of Arbuscular mycorrhizal fungi
(AMF) in enhancing crop production is well recognized
(Siquerra et al 1995; 1998). Arbuscular mycorrhizal fungi
(AMF) readily form association with coffee roots (Jose
1987; Siquerra et al 1995). Coffee soils are blessed with
mycorrhizae which provide a host of benefits to the
surrounding biotic community in the uptake of soil
phosphorus and other nutrients. Recent studies have
demonstrated the importance of AMF symbiosis to coffee
in low-fertility soils (Lopes et al 1983, Sieverding 1991).
Mycorrhizal coffee seedlings grow much faster, exhibit
improved nutrition and gave higher yields than those
without mycorrhizal inoculation at the nursery stage
(Siqueirra et al 1993). Mycorrhizal growth effects are
primarily nutritionally mediated and are inversely related
to improved soil fertility especially available soil P, which
affects mycorrhizal dependency and fungus symbolic
effectiveness (Saggin-junior et al 1994., Hartley and
Smith 1983). Presently, there is paucity of information on
the effect of Arbuscular mycorrhizal inoculation and
phosphate fertilizers on the growth of coffee seedlings in
Nigeria. Hence, this study evaluated the effect of
phosphate fertilizers and Arbuscular Mycorrhizal fungi
inoculation (AMF) on the growth of coffee seedlings and
its implications on the physical and chemical properties of
the soils.
MATERIALS AND METHODS
The study was conducted in the greenhouse of Cocoa
Research Institute of Nigeria, Ibadan between late
2007and 2008. The soil of Ibadan used for the study has
been classified as Ferric Luvisols (FAO, 1990) and
Ibadan series (Smyth and Montgomery, 1962) lying on
122m above sea level while that of Mambilla soil is
classified as Humic Nitrosols (FAO,1990; Pidwirny,
2006). Top soils (0-30cm depth) were collected at the
coffee plantations at Ibadan and Mambilla substation.
The soils were air-dried and sieved using 2mm sieve.
The factorial experiment had three phosphate fertilizer
types and two rates of application viz; no P application
(control), Single superphosphate (SSP) and Sokoto rock
phosphate (SRP) each applied at rate equivalent to 30kg
P2O5/ha. The second factor was inoculation with
Arbuscular mycorrhizal fungi (Glomus clarum Nicolsen
Shenk) at two levels (with or without) in 5 kg polythene
pots filled with 5kg top soil. Seedlings inoculated with
mycorrhiza were done with 20g of the fungus containing
spores, hyphae and roots of the culture plant. It was
applied just below the roots of the seedlings during
transplanting. Watering was done regularly thrice a week.
The experiment was laid out in a complete randomized
block design with four replicates. Agronomic data were
collected on height, stem diameter, number of leaves and
leaf area on monthly basis. At the end of the experiment,
destructive sampling was done and plant materials were
separated into leaf, stem and roots and soil samples
collected from each pot for chemical analysis.
Percentage mycorrhizal infection from root in young
coffee seedlings in the screen house were carefully
collected and washed in running water to remove soil on
the roots, stored in 50% ethanol in McCartney and bottles
and percentage root infection was estimated using gridline intersect according to Giovanetti and Mosse (1980).
Sokoto rock phosphate has 33.7, 44.23, 0.95 and 7.90 %
for P2O5, CaO, MgO and CaCO3 respectively while single
super phosphate (SSP) has 18 .0 and 27.0 % for P2O5
and CaO respectively. Soil samples were collected
randomly at both locations (Ibadan and Mambilla) and
analyzed for both physical and chemical properties using
the methods described in International Institute of
Tropical Agriculture Manual (IITA, 1982). Analysis of
variance was performed on all data to test the treatment
effect on different parameters measured using a SAS
analytical package of 9.20 version. Least Significant
difference (P<0.05) was used to separate the means.
RESULTS AND DISCUSSIONS
The physical properties of the soils indicated that the
sand fraction of Ibadan soil was 78 % higher compared
with Mambilla soil while the clay in Mambilla soil was 106
% higher than Ibadan soil (Table 1). The pH of Mambilla
soil was much lower than the pH of Ibadan soil by 161 %.
162 Int. Res. J. Plant Sci.
Table 1: Some physical and chemical characteristic of soils of Ibadan and Mambilla.
Soil properties
Physical properties
Sand g/kg
Silt g/kg
Clay g/kg
Texture
Chemical properties
pH (H20)
Organic Carbon g/kg
Total N g/kg
Available P mg/kg
Exchangeable cations
K cmol/kg
Ca cmol/kg
Mg cmol/kg
Ibadan value
Mambilla value
892.00
500.00
143.00
160.00
165.00
Sandy clayey loam
340.00
Clayey loam
6.50
5.60
9.80
2.00
20.00
26.0
1.70
2.15
0.50
10.00
2.00
6.60
2.41
0.59
Table 2: Influence of phosphate fertilizers and Arbuscular Mycorrhizal inoculation on the growth of coffee seedlings in Mambilla soil.
Treatments
P1M0
P1M1
2
P M0
P2M1
P0M0
P0M1
SE
CV (%)
Plant Height (cm)
2
4
MAT
9.05
13.30
15.25
17.65
9.90
12.90
10.80
11.35
9.37
10.15
10.20
12.69
2.33
3.05
11.20
9.64
6
18.67
17.25
15.24
10.70
10.70
15.71
3.63
10.23
Stem Diameter (cm)
2
4
6
MAT
0.23
0.32 0.46
0.22
0.33 0.40
0.24
0.27 0.34
0.25
0.28 0.26
0.23
0.22 0.22
0.22
0.25 0.32
0. 05 0.05 0. 06
5.08
1.54 6.45
Number of Leaves
2
4
6
MAT
7.50 10.00 14.50
7.00
9.00 12.00
7.33 10.50 11.95
8.00
9.00 11.00
6.25
6.00
7.50
7.17
8.83 11.75
1.77
2.13
2.47
8.00
9.23
10.83
Leaf Area (cm2)
2
4
6
MAT
8.46
15.07
25.74
5.18
5.94
2.89
9.79
15.03
22.11
6.29
5.48
4.05
5.07
5.63
3.73
8.96
17.84
24.42
1.51
3.22
5.08
11.23 12.98
14.67
M1 = with mycorrhiza inoculation, M0 = without mycorrhiza inoculation, P1=Single super phosphate, P2=Sokoto rock phosphate, P0= no P
application MAT= months after transplanting.
The organic carbon in Mambilla soil was more than two
and a half times higher than that of Ibadan soil. The
higher soil organic carbon in Mambilla soil is attributable
to the low temperature of less than 25oC that is normally
experienced in the Mambilla plateau which reduces the
rate of organic matter mineralization unlike Ibadan where
o
the temperature could reach as much as 34 C. This is
consistent with earlier findings of Jenkinson and Rayner,
(1977) and most recently Crick, (2007). However, the
total N and available P were higher in Ibadan soil than
Mambilla soil (Table 1). The exchangeable cations (K+,
Ca2+ and Mg2+) in Ibadan soil were much greater than
Mambilla soil. Mambilla soil is classified as sandy clayey
loam while that of Ibadan is sandy loam. The pH of the
two soils ranged from 5.9 to 6.5 which falls within the
range required for coffee production. At 2, 4 and 6 MAT,
the height of coffee seedlings was significantly (p < 0.05)
higher due to SSP application with or without mycorrhizal
inoculation compared with coffee seedling height in the
control and SRP application with or without mycorrhizal
inoculation (Table 2). These results are consistent with
the earlier findings of Sequeira et al (1998) and Lovato et
al (2006) in which mycorrhizal inoculation and P fertilizer
enhanced the earlier growth of coffee and wild cherry.
The height of coffee seedlings under SRP application
with or without mycorrhizal inoculation was not superior
to those in the control with or without mycorrhizal
inoculation. Coffee seedling height was not significantly
affected as a result of mycorrhizal inoculation in Mambilla
soil. Similarly, the stem diameter of coffee was not
significantly affected by phosphate fertilizer types and
mycorrhizal inoculation at 2 MAT. However, at 4 and 6
MAT, coffee seedlings treated with SSP with or without
mycorrhizal inoculation had significantly (p<0.05) higher
stem diameter compared to the control (Table 2).
Specifically, the stem diameter of coffee seedlings at 6
MAT in Mambilla soil was 43 % and 59 % higher
(significant) in the SSP application (with or without
mycorrhizal inoculation) than the stem diameter of coffee
seedlings treated with SRP and the control (with or
Ibiremo et al. 163
Table 3: Influence of phosphate fertilizers and Arbuscular Mycorrhizal inoculation on the growth of coffee seedlings in Ibadan soil.
Treatments
P1M0
P1M1
P2M0
P2M1
P0M0
P0M1
SE
CV (%)
Plant Height (cm)
2
4
6
MAT
11.03 12.62 14.07
11.10 11.50 12.50
11.75 12.50 13.50
11.60 12.00 12.50
11.50 12.05 13.05
11.50 13.00 14.00
0.74
0.67
0.67
2.50
4.34
5.28
Stem Diameter (cm)
2
4
6
MAT
0.25
0.25 0.30
0.30
0.30 0.30
0.35
0.35 0.36
0.30
0.31 0.31
0.25
0.25 0.26
0.24
0.30 0.35
0. 05 0.05 0.06
8.54
6.65 5.78
Number of Leaves
2
4
6
MAT
11.00 12.00 12.00
10.00 10.00 12.00
8.00
8.00 12.00
8.00 10.00 10.00
10.00 10.00 13.50
10.00 12.00 13.00
1.07
1.32
1.57
9.87 10.20
7.89
2
Leaf Area (cm )
2
4
6
MAT
4.05
4.54
4.68
4.75
5.40
5.50
6.00
6.44
6.54
6.91
6.09
6.70
4.37
4.74
4.93
10.89 10.69 15.05
1.42
1.15
1.88
12.56 11.67 13.64
M1 = with mycorrhiza inoculation, M0 = without mycorrhiza inoculation, P1=Single super phosphate, P2=Sokoto rock phosphate, P0= no P
application MAT= months after transplanting.
without mycorrhizal inoculation). The stem diameter of
coffee was not significantly affected by mycorrhizal
inoculation in Mambilla soil. Similarly, the number of
leaves of coffee seedlings was not significantly affected
at 2 MAT as a result of phosphate fertilizer types and
mycorrhizal inoculation. On a general note, mycorrhizal
studies have shown variable results on the growth of
crops (Rao, et al 1990; Ikram et al 1991; Dania and
Fagbola, 2007). However, the number of leaves at 4 and
6 MAT was significantly lower (p < 0.05) in the control
(without P and without mycorrhizal inoculation) compared
with other coffee seedlings treated with phosphate
fertilizer types with or without mycorrhizal inoculation.
Mycorrhizal inoculation significantly (p< 0.05) depressed
the leaf area of coffee seedlings by as much as 64.5%
compared with those without mycorrhizal inoculation in
Mambilla soil. The effect of the mycorrhizal inoculation
was not significant on the number of leaves of coffee
seedlings. The number of leaves ranged from 6 to 14
leaves per plant in Mambilla soil.
The lack of a significant response of mycorrhizal
inoculation on coffee seedlings over the non-inoculated
ones may be attributable to high effectiveness,
competitiveness
and
abundance
of
indigenous
mycorrhizal fungi in the soil as there was no effort to
eliminate indigenous mycorrhizal fungi during this
investigation.
Application of SSP increased (not
significantly) the number of leaves of coffee of seedlings
by 38 and 16 % compared with the coffee seedlings
treated with SRP and control (no P application)
respectively (Table 2). Phosphate fertilizer types and
mycorrhizal inoculation significantly (p<0.05) enhanced
the leaf area of coffee seedlings at 2, 4 and 6 MAT
compared to the control. In Ibadan soil, the influence of P
application and mycorrhizal inoculation was not
significant on the height, stem diameter of coffee
seedlings at 2, 4 and 6 MAT (Table 3). The plant height
and stem diameter of coffee seedlings ranged from 12cm
to 14cm, and 0.26 to 0.36cm respectively. The height of
coffee seedlings at 6 MAT was marginally higher (not
significant 2%) under SSP application compared with the
height under SRP application at 6 MAT. Similarly, the
number of leaves of coffee seedlings at 2 and 6 MAT
were not significantly affected as a result of phosphate
fertilizer application and mycorrhizal inoculation.
Conversely, the number of leaves at 4 MAT was
significantly (p<0.05) higher under SSP application
without mycorrhizal inoculation alone without phosphate
fertilizer application. Similarly, the leaf area under AMF
inoculation without P application was significantly (P<
0.05) higher compared with other treatment combinations
at 6 MAT in Ibadan soil (Table 3). The general consensus
is that if adequate P is applied at planting pre-inoculation
of field crops with mycorrhizal fungi enhances early crop
development and productivity of coffee especially in low
fertility soils (Siqueira et al. 1998; Ibiremo and Fagbola
2008a). In this study, however the level of nutrients
especially P was moderate and may be responsible for
such result. Mycorrhizal inoculation without P application
significantly increased the pH of Ibadan soil at 6 MAT.
The pH ranged from 5.70 to 6.70 (Table 4). However, in
Mambilla soil, the effect of mycorrhizal inoculation and
phosphate fertilizer application was not significant across
the six treatment combinations. The pH ranged in
Mambilla soil was 5.80 to 6.50. Similarly, the effect of
mycorrhizal inoculation and phosphate fertilizer was not
significant on the organic carbon of soils of Ibadan and
Mambilla (Table 4). The mean organic carbon values for
Ibadan and Mambilla were 5.44 and 3.80 g/kg
respectively. The cumulative effect of SSP application
(with or without mycorrhizal inoculation) on available P
was significantly (P<0.05) higher compared with SRP and
the control with or without mycorrhizal inoculation in
Ibadan soil. Specifically, the available P was significantly
(P< 0.05) increased as a result of SSP application without
mycorrhizal inoculation compared with SRP application
164 Int. Res. J. Plant Sci.
Table 4: Soil chemical properties and root infection as influenced by phosphate fertilizer application to
AMF inoculated coffee seedlings in Ibadan and Mambilla soils.
Treatments
P1M0
P1M1
2
P M0
P2M1
P0M0
P0M1
SE
CV (%)
pH
Ibadan
5.75
6.00
5.80
5.70
5.85
6.70
0.28
6.24
Mambilla
6.40
5.80
6.50
5.70
6.40
5.90
0.34
5.79
OC (g/Kg)
Ibadan
Mambilla
5.62
2.72
5.50
4.22
5.54
3.17
5.50
4.74
5.15
3.26
5.35
4.66
0.28
0.52
3.09
12.55
Avail P (mg/kg)
Ibadan
Mambilla
6.18
10.80
8.91
1.47
4.36
6.62
5.61
4.98
5.38
6.79
4.36
9.18
0.41
2.76
13.67
14.87
Myco infection (%)
Ibadan
Mambilla
66.95
66.50
70.90
45.00
68.55
66.35
68.50
77.50
45.30
62.55
70.00
89.50
10.08
12.24
10.34
9.89
M1 = with mycorrhiza inoculation, M0 = without mycorrhiza inoculation, P1=Single super phosphate,
P2=Sokoto rock phosphate, P0= no P application MAT= months after transplanting, OC = Organic
Carbon, Avail. P = Available P
and control (perfect) with or without mycorrhizal
inoculation (Table 4). This result is in contrast to the
earlier findings of Pathiraina et al (1990) in which rock
phosphate increased available soil P. However, the
available P under SSP and mycorrhizal inoculation in
Mambilla soil was extremely reduced compared with
other treatment combinations. The root colonization
ranged from 45 to 70 % in Ibadan soil while it ranged
from 45 to 89 % in Mambilla soil. Similarly, the root
colonization of coffee seedlings at 6 MAT was
significantly higher as a result of mycorrhizal inoculation
without P-fertilizer application compared with root
colonization under SSP application and mycorrhizal
inoculation in Mambilla soil. The converse is the case in
which mycorrhizal inoculation with or without phosphate
fertilizer did not significantly affect the colonization of
coffee seedling roots in Ibadan soil.
CONCLUSION
The growth of coffee seedlings was enhanced as a result
of phosphate fertilizer application particularly SRP in
conjunction with mycorrhizal inoculation; hence, SRP is a
promising substitute for inorganic phosphate sources for
coffee seedling production in Nigeria.
ACKNOWLEDGEMENT
The Authors wish to thank the Executive Director for the
support and permission to publish this article and also
want to appreciate the technical assistance of Mr G.
Adewoye, late Mr G.O Ogunjobi and other laboratory and
field staff of Soils and Plant Nutrition Section, Cocoa
Research Institute of Nigeria,Ibadan.
REFERENCES
Akande MO, Adediran JA, Oluwatoyinbo FO, Makinde EA, Adetunji MT
(2008). Suitability of poultry manure amended Sokoto rock
phosphate on the growth, nutrient uptake and yield of chilli pepper
(Capscicum frutescence L). Soil Sc. Soc. of Niger 18: 167-174.
Ayodele OJ, Agboola AA (1981). The relationship between Bray’s P.
modified NaHCO3, New Mehlick and NH4F.HF extractants for P in
Savanna soils of Western Nigeria. Soil
Science Soc. Ame. J.,
45: 462-464.
Crick AP (2007). Effects of the inclusion of certain tropical legumes in
mixtures of soil fertility. Advanced J. Soil Sc., 4: 411-416.
Chen SH, Hammond L (1988). Agronomic evaluation of Partially
Acidulated Phosphate Rocks in the Tropics. IFDC’s Experience.
IFDC 7: 10
Dania SO, Fagbola O (2007). Growth of in a simulated degraded soil
under the influence of organo-mineral fertilizer and saw dust
application: Niger. J. ecol., 8: 1-5.
Famaye AO (2002). Effect of shade regimes on growth of coffee
species in Nigeria. Moor J. Agric. Res., 3 (2): 184-194.
Food and Agricultural Organization (FAO) (1990). Guidelines for soil
rd
profile Description. 3 Edition.
Hafner H, Geor E, Bationo A, Marschner H (1993). Effect of crop
residues on root- growth and phosphorus acquisition of pearl-millet
in an acid sandy soil in Niger Plant and Soil, 150, 1: 117-127
Hartley JL, Smith SE (1983). Mycorrhizal symbiosis, Academic Press,
London.
Haugen L.M and Smith S.E (1993). The effect of inoculation of cashew
with Nutrilink on vesicular arbuscular mycorrhizal infection and plant
growth. Australian J. Agricul. Res., 44: 1211-1220
Ibiremo OS, Fagbola O, Obatolu CR (2002). Effect of water soluble and
water insoluble types of phosphate fertilizers on the growth of coffee
seedlings. The Niger. J. Horticul. Sc., 6 (2): 43-47.
Ibiremo OS, Fagbola O (2008a). Growth of cashew as influenced by
Arbuscular Mychorrhizal inoculation, organic and phosphate
fertilizers in Ibadan and Uhonmora. Appl. Tropical Agricul., 13-47
Ibiremo OS, Fagbola O (2008b). Effect of phosphate fertilizers and
Arbuscular mycorrhizal fungi inoculations on the growth of cashew
seedlings in two soils in Nigeria. Niger. J. Soil Sc. l8: 148- 156.
Ikram A, Mahmud AW, Mohd Noor G, Othman H, Zainol E (1991).
Ibiremo et al. 165
Growth response of Heavea brasiliensis to mycorrhizal inoculation in
different soils. In Pro. Workshop on Research on Multipurpose tree
species in Asia. Los Banos Philipines : H.S Winrock Int., 181-189
International Institute of Tropical Agriculture (IITA) (1982). Selected
methods for soil and plant analysis Manual series no. 7, Ibadan,
Nigeria.
International Superphosphate Manufacturers’ Association Paris (ISMA)
(1982). A hand book on phophate fertilizers. 210.
Jenkinson DS, Rayner JH (1977). Turnover of soil organic matter in
some Rothamsted classical experiments. Soil Science 123: 298305.Pergamon. New York. 544.
Lopes ES, Toledo SV, Hiroce R, Dias R, Oliveira E (1983) Efeitosdo
fungo micorrízico Gigaspora margarita no desenvolvimentoe
aproveitamento do fósforo e do zinco em mudas decafeeiro “Mundo
Novo” em casa de vegetação. In: Congressode Pesquisas
Cafeeiras, IBC/GERCA: 121–122
Lovato PE, Trouvelot V, Gianinazzi Pearson, Gianinazzi S (2006).
Enhanced growth of wild cherry using micro-propagated plants and
mycorrhizal inoculation. .Agron. Sustainable Deve.
Pathiraina LSS, Des .Waidyanatha UP, Peries OS (1990).Utilization of
phosphorus from apatite and growth of plants inoculated with vesicular
Arbuscular mycorrhiza and phosphate dissolving bacteria. J. Rubber
Res. of Sri- Lanka. 70: 35-43.
Pidwirny M (2006).Soil classification fundamentals of physical
nd
nd
geography, 2
Edition. Date
viewed 2
December, 2010.
http://www.physicalgeography.net/fundermentals/10vv.html.
Rao PSK,Tilak KVBR, Arunachalam V (1990). Genetic variation for VA
mycorrhiza formation and root development in medicago. In Smitrh
JH, Russel RS (eds). The soil-root interface Academic Press,
London : 211-219.
Saggin-Júnior OJ, Siqueira JO, Guimarães PTG, Oliveira E (1994).
Interação fungos micorrízicos versus superfosfato eseus efeitos no
crescimento e teores de nutrientes do cafeeiro em solo não
fumigado. Rev Bras Ci Solo 18: (27–366)209-213.
Sieverding E (1991). Vesicular-arbuscular mycorrhiza managementin
tropical
agrosystems.
Deutsche
Gesellschaft
für
TechnischeZusammenarbeit, Eschborn
Siqueira-Jose O, Orvaldo J, Saggin-Junior Waldo W, Flores-Aylas
Paulo TG, Guima Raes (1998). Arbuscular mycorrhizal inoculation
and superphosphate application influence on plant development
and yield of Coffee in Brazil. Mycorrhizal 7: 293-30
Siqueira JO, Saggin-Júnior OJ (1995). The importance of mycorrhizal
association in natural low fertility soils. Machado (eds) International
Symposium on Environmental Stress: Maize in Perspective.
EMBRAPA/CIMMYT, 240–280
Smyth AI, Montgomery RF (1962). Soil and land use in Cental and
Western Nigeria. Government Printer. The government of Western
Nigeria: 256.
Zainol E, Mahmud AW, Sudin M (1993). Effect of intercropping system
in surface processes in an acid Ultisol 2. Changes in soil chemical
properties and their influence on crop production. J. Natural Rubber
Res 8(2): 124-136.