49%/39 1 fFJ4~ 6.G INSTITUT...
49%/39
1
fFJ4~
6.G
INSTITUT SÉNÉGALAIS
DE
RECHERCHES AGRICOLES
EFFECT OF INOCULATION WITH RHIZOBIUM
AN-D RHIZOBIUM PLUS GLOMUS MOSSEAE
ON Nz FIXATION BY BAMBARA GROUNDNUT
Mamadou GUÈYE
MIRCEN-CNRA, B.P. 53, Bambey, Senegal
Paper presented at the 4* AABNF Conference held at Ibadan, Nigeria, 24-29 September, 1990
I
DI;RECTION DES RECHERCHES SUR LES PRODUCTIONS VÉGÉTALES
Effect of inoculation with Rhizobium and Rhizobium plus Glomus
mosseae on N, fixation by bambara groundnut
Mamadou GUEYE
MIRCEN-CNRA, B.P. 53, Bambey, Senegal
Key words : Bambara groundnut, Vigna subterranea, Rhizobium,
Glomus mosseae, N2 fixation, N-15, shoot/root ratio
Summary Dual inoculation of bambara groundnut with Rhizobium
and Rhizobium plus Glomus mosseae increased shoot/root ratio ex-
pressed as total N, and N derived from fixation, from fertihzer and
from soil.
Introduction
Bambara groundnut (Vignu subterranea (L) Verdc.) is a promising
trop plant in Africa because it belongs to the five most important
protein sources for many Africans (Vietmeyer, 1978) and it cari be
cultivated in poor soils and in areas of uncertain rainfall (Hepper,
1963). Although studies have been reported on nodulation (Denarie
et al., 1968 ; Doku, 1969) and on nitrogen fixation (Dennis, 1977),
research on Rhizobium technology for bambara groundnut is needed
(NAS, 1979).
This study evaluates the N2 fixed by bambara groundnut using l5N
isotope dilution technique in order to explore its full nitrogen fixing
potential.
Materials and methods
The O-20 cm layer of a sandy soil was collected from the Institut
Senegalais de Recherches Agricoles (ISRA) experimental station
located at Sinthiou Maleme in the south east of Senegal. This soi1
had a pH(H20) of 5.6, a total C content of 0.332%, a total N content
of 0.023% with 0.0255 atom % 15N and 21 ppm of available P
(Olsen, 1954). The soi1 was sieved (c 1 mm), autoclaved (120°C,
1 h) and placed into pots (0 = 20 cm, 2 Kg/pot). Then, 10 ppm
2
P was added to each pot as a solution of triple superphosphate. Surface
sterilized seeds of bambara groundnut, cv. 83-113 1 were germinated.
When 3-days-old, the seedlings were transplanted in the pots (1 per
pot) and inoculated with a Rhizobium strain and a vesicular arbuscular
mycorrhizal (VAM) fungi. The Rhizobium strain was applied as a liquid
inoculum (lml/seedling) containing 109 cells/ml and the VAM ino-
culum was applied as a suspension of G2omu.s mosseae (Nicol. and
Gerd.) inoculum (Sml/seedling) prepared by blending 100 g of non
nodulated infected cowpea mots (with hyphae and spores) in 1 liter
of sterile distilled water. There were three treatments with five replicates :
treatment 1, no inoculation ; treatment 2, inoculation with Rhizobium
strain MAO 113 (Gueye and Bordeleau, 1988) alone and addition of
1 ml of filtered washings from the mycorrhizal inoculum in order
to ensure that they received contaminating microorganims but not
mycorrhizal fungi ; treatment 3, inoculation with Rhizobium strain
MAO 113 and Glomus mosseae (dual inoculation). Nitrogen fertilizer
was then applied to a11 pots at the rate of 70 mgN/pot as a solution
of (l5NH4)2SO4 with 5.0322 atom % excess. Plants were watered
daily with distilled water and weekly with 100 ml of a nitrogen and
phosphorus free sterile Hewitt solution (Hewitt, 1966).
Fifty days after planting, N2 fixation was estimated using the fol-
lowing equations (Danso, 1990) :
% 15N atom excess (fc)
%N2 fixed = 100 (1 - -
->
% 15N atom excess (nfc)
and
total N2 fïxed = %N fixed
x total N (fc)
100
where fc and nfc are the fïxing and non-fixing reference crops res-
pectively.
Results
Table 1 shows that inoculating Vigna subterranea with Rhizobium
increased the dry weight and total N of leaves, stems and roots.The
treatment did not affect the shoot (stems + leaves)/root ratio expressed
on dry weight basis, but significantly increased this ratio when expres-
sed on total N basis.
3
Dual inoculation with Rhizobium and Glomus mosseae always
significantly increased these parameters and appeared to be more
effective than inoculation with Rhizobium alone.
According to Table 2, Ndfa% in aerial parts was signifïcantly higher
when Vigna subterranea was inoculated with Rhizobium and Glomus
mosseae than when Rhizobium inoculant was used alone.
Both types of inoculation increased the shoot/root ratio expressed
as N derived from N2 fixation, from fertilizer and from soil. This
effect was much more marked when Ndfa was taken into account :
the shoot/root ratio expressed on Ndfa basis was 9.5-9.7 whereas it
was only in the range of 4.5-5.8 when expressed on N derived from
fertiliser or from soil.
Discussion and conclusion
Dual inoculation with Rhizobium and Glomus mosseae was clearly
more effective than inoculation with Rhizobium alone, which cari be
probably explained by the fact that Glomus mosseae improved the
plant nutrition in P, the soi1 content in this element being relatively
low : ca, 31 ppm (21 ppm in the natural soi1 + 10 ppm P added).
This beneficial effect of dual inoculation on N2 fixation is reminiscent
of a field experiment carried out in similar soils with soybean by Ganry
et al., (1985) : N2 fixation was 109 Kg N2 fixed/ha when soybean
was inoculated with Rhizobium alone and it reached 139 Kg N2 fixed/
ha when the plant was dually inoculated with Rhizobium and Glomus
mosseae.
A second interesting result concerns the increase of the’ shoot/root
ratio resulting from inoculation, the most marked effect being obtained
with dual inoculation. A similar increase of the shoot/root ratio
expressed on weight and total N basis following inoculation was already
reported by Sougoufara et al., (1989) in the case of Casuarina equise-
tifoiia inoculated with Frankia. This specific effect of inoculation is
probably frequent. TO explain it, it is suggested that, owing to the
improvement of the plant nutrition in N or N and P resulting from
inoculation, the plant does not have to develop a large system to ex-
plore the soi1 to fïnd the nutrients it requires, and thus probably saves
a part of the energy provided by photosynthesis.
4
Extrapolating the results of the pot experiment reported here to
the field should be done with caution. However, it cari be predicted,
without risk of errer that Vigna subterranea has a high N2-fixing po-
tential since its Ndfa% cari reach 70% provided that a good Rhizobium
strain such as MAO 113 is used and that the plant requirements in
nutrients other than N are met either directly through fertilization or/
and proper (natural or artificial) mycorrhization.
Acknowledgements
This study was supported by UNESCO’s
agreement No.281.172.9. The author is very grateful to Dr H Burris
of Wisconsin (USA) University for Nitrogen- analyses, to 0 Touré
for valuable technical assistance and to Dr Y R Dommergues for
reviewing the manuscript.
References
Danso S K A 1990 Evaluation of biological nitrogen fixation in plants.
In Maximiser la Fixation Biologique de 1’Azote pour la Production
Agricole et Forestière en Afrique. Papiers présentés à la 3ème
conférence AABNF Dakar 7-12 Novembre 1988. Eds. M Gueye,
K Mulongoy et Y Dommergues. Collection Actes de I’ISRA.
Vol. 2, No 2, pp 249-271.
Denarie J, Andtiamanantena S and Ramonjy J 1968 L’inoculation
des légumineuses à Madagascar ; résultats de l’expérimentation de
la campagne 1966-1967. Agron. Trop. (France). 23, 925-966.
Dennis E A 1977 Nodulation and nitrogen fixation in legumes in
Ghana. In Biological Nitrogen Fixation in Farming Systems in The
Tropics. Eds. A Ayanaba and P J Dart, pp 217-232. John Wiley
and Sons, Chichester (UK).
Doku E V 1969 Host specificity among five species in the cowpea
cross inoculation group. Plant and Soi1 30, 126-128.
Ganry F, Wey J, Diem H G and Dommergues Y 1985 Inoculation
with Glomus mosseae improves N2 fixation by field grown soy-
beans. Biol. Fert. Soils 1, 15-23.
Gueye M and Bordeleau L M 1988 Nitrogen fixation in bambara
groundnut, Voandzeia subterranea (L) thouars. Mircen Journal 4,
365-375.
5
Hepper F N 1963 The bambara groundnut (Voandzeia subterranea)
and Kersting’s groundnut (Kerstingiella geocarpa) wild in West
Africa. Kew Bull. 16, 395407.
Hewitt E J 1966 Sand and water culture methods in the study of plant
nutrition. Technical communication No. 22 (2nd ed) 547 pp.
Commonwealth agricultural Bureaux. London.
National Academy of Sciences 1979 Pulses. In Tropical Legumes :
Resources for The Future. National Academy of Sciences, pp 47-
53.Washington D.C.
Olsen S R, Cole L V, Watanabe F S and Dean L A 1954 Estimation
of available phosphate in soils by extraction with sodium bicar-
bonate. Circular of US Department of Agriculture No. 939.
Sougoufara B, Diem H G and Dommergues Y R 1989 Response of
field grown Casuarina equisetifolia with Frankia strain ORS 021001
entrapped in alginate beads. Plant and soi1 118, 133-137.
Vietmeyer N D 1978 Highly promising plants. Chronica Horticulturae
(Netherlands) 18, 41-42.
6
Table 1 Dry matter and nitrogen yields and % 15N atom excess of plant
parts of bambara groundnut (cv. 83-131) cultivated in pots containing 2 Kg
of sterile soil sampled at ISRA Sinthiou Maleme experimental station and
inoculated with Rhizobium alone or Rhizobium plus Glomus mosseae (G.m.).
Dry weight
Tata N
%15N
Plant parts
Treatments
(w@W
(mg/p~O
atom excess
-.
-~
.-~
Leaves
Control
1235 a
10.40 a
0.987 a
Rhizobium
1622 b
27.00 b
0.365 b
Rhizobium + G.m.
1776 b
32.90 c
0.248 b
LSD 0.05
192
3.30
0.250
CV(%)
7.17
8.10
26.88
Stems
Control
564a
7.90 a
0.823 a
Rhizobium
790 b
18.90 b
0.301 b
Rhizobium + G.m.
931 c
21.80 c
0.199 b
LSD 0.05
118
2.10
0.211
CV(%)
8.99
7.40
27.50
Roots
Control
368 a
5.30 a
0.797 a
Rhizobium
422 b
7.30 b
0.420 b
Rhizobium + G.m.
404b
7.10 b
0.309 b
LSD 0.05
51
0.30
0.256
CV( %)
7.32
2.40
29.02
Nodules
Control
0.00 a
Rhizobium
71.00 b
Rhizobium + G.m.
116.50 c
LSD 0.05
24.22
CV( %)
22.40
Shoot/Root
Control
5.OOa
3.48 a
Rhizobium
5.34 ab
6.33 b
Rhizobium + G.m.
6.27 b
7.77 c
LSD 0.05
1.13
0.73
CV(%)
11.76
7.18
For each plant part, values followed by the same letter in each column do not differ signi-
fïcantly at the 0.05 level by Duncan’s multiple range test
7
TabIle 2 Nitrogen derived from fixation (Ndfa), from fertilizer (Ndff) and from
soi1 (Ndfs) of plant parts of bambara groundnut (cv. 83-131) cultivated in
pots containing 2 Kg of sterile soil sampled at ISRA Sinthiou Maleme experi-
mental station.
Plant parts
Treatments
Ndfa%
Ndff%
Ndfs% N d f a
Ndff Ndfs
-
-
-
-
-
-
Ixaves
Control
0.00 a
19.60 a 80.40 a O.OOa 2.07 a 8.38 a
Rhizobium
57.50 b 7.25 b 35.25 b 15.26 b 2.01 a 9.78 a
Rhizobium + G.m.
71.10 c 4.90 b 24.OOb 23.44~ 1.63 a 7.84 a
LSD 0.05
12.05
4.92
13.91
1.70 0.7
3.90
CV(%)
16.25
26.87
17.28
7.80
22.06 26.43
Stems
Control
0.00 a 16.40 a 83.6Oa
O.OOa
1.29 a 6.67 a
Rhizobium
59.90 b 6.00 b 34.10 b 11.261) 1.16 a 6.55 a
Rhizobium + G.m.
73.50 c 4.00 b 22.50 b 16.07 c 0.86 a 4.91 a
LSD 0.05
11.32
4.18
13.69
1.90 0.60
3.20
CV(%)
14.78
27.61
16.86
12.06 29.28 30.93
Rools
Control
0.00 a 15.80 a 84.20 a 0.00 a
0.82 a 4.49 a
Rhizobium
43.20 b 8.30 b 48.50 b 3.22 b 0.60 ab 3.51 ab
Rhizobium + G.m.
58.10 b 6.10 b 35.80 b 4.11 b
0.43 b 2.52 b
LSD 0.05
15.81
5.07
17.70
1.20
0.24
1.13
Shoot/Root
CV(%)
27.07
29.04
18.23
29.41 21.99 20.82
Control
O.OOa 4.08 a 3.39a
Rhizobium
9.53 b 5.15 ab 4.49 ab
Rhizobium + G.m.
9.70b
5.83 b 5.09 b
LSD 0.05
3.83
1.32
1.12
CV(%)
34.52 15.20 14.94
FOI each plant part, values followed by the same do not differ significantly at the 0.05 level
by Duncan’s multiple range test.
1
fFJ4~
6.G
INSTITUT SÉNÉGALAIS
DE
RECHERCHES AGRICOLES
EFFECT OF INOCULATION WITH RHIZOBIUM
AN-D RHIZOBIUM PLUS GLOMUS MOSSEAE
ON Nz FIXATION BY BAMBARA GROUNDNUT
Mamadou GUÈYE
MIRCEN-CNRA, B.P. 53, Bambey, Senegal
Paper presented at the 4* AABNF Conference held at Ibadan, Nigeria, 24-29 September, 1990
I
DI;RECTION DES RECHERCHES SUR LES PRODUCTIONS VÉGÉTALES
Effect of inoculation with Rhizobium and Rhizobium plus Glomus
mosseae on N, fixation by bambara groundnut
Mamadou GUEYE
MIRCEN-CNRA, B.P. 53, Bambey, Senegal
Key words : Bambara groundnut, Vigna subterranea, Rhizobium,
Glomus mosseae, N2 fixation, N-15, shoot/root ratio
Summary Dual inoculation of bambara groundnut with Rhizobium
and Rhizobium plus Glomus mosseae increased shoot/root ratio ex-
pressed as total N, and N derived from fixation, from fertihzer and
from soil.
Introduction
Bambara groundnut (Vignu subterranea (L) Verdc.) is a promising
trop plant in Africa because it belongs to the five most important
protein sources for many Africans (Vietmeyer, 1978) and it cari be
cultivated in poor soils and in areas of uncertain rainfall (Hepper,
1963). Although studies have been reported on nodulation (Denarie
et al., 1968 ; Doku, 1969) and on nitrogen fixation (Dennis, 1977),
research on Rhizobium technology for bambara groundnut is needed
(NAS, 1979).
This study evaluates the N2 fixed by bambara groundnut using l5N
isotope dilution technique in order to explore its full nitrogen fixing
potential.
Materials and methods
The O-20 cm layer of a sandy soil was collected from the Institut
Senegalais de Recherches Agricoles (ISRA) experimental station
located at Sinthiou Maleme in the south east of Senegal. This soi1
had a pH(H20) of 5.6, a total C content of 0.332%, a total N content
of 0.023% with 0.0255 atom % 15N and 21 ppm of available P
(Olsen, 1954). The soi1 was sieved (c 1 mm), autoclaved (120°C,
1 h) and placed into pots (0 = 20 cm, 2 Kg/pot). Then, 10 ppm
2
P was added to each pot as a solution of triple superphosphate. Surface
sterilized seeds of bambara groundnut, cv. 83-113 1 were germinated.
When 3-days-old, the seedlings were transplanted in the pots (1 per
pot) and inoculated with a Rhizobium strain and a vesicular arbuscular
mycorrhizal (VAM) fungi. The Rhizobium strain was applied as a liquid
inoculum (lml/seedling) containing 109 cells/ml and the VAM ino-
culum was applied as a suspension of G2omu.s mosseae (Nicol. and
Gerd.) inoculum (Sml/seedling) prepared by blending 100 g of non
nodulated infected cowpea mots (with hyphae and spores) in 1 liter
of sterile distilled water. There were three treatments with five replicates :
treatment 1, no inoculation ; treatment 2, inoculation with Rhizobium
strain MAO 113 (Gueye and Bordeleau, 1988) alone and addition of
1 ml of filtered washings from the mycorrhizal inoculum in order
to ensure that they received contaminating microorganims but not
mycorrhizal fungi ; treatment 3, inoculation with Rhizobium strain
MAO 113 and Glomus mosseae (dual inoculation). Nitrogen fertilizer
was then applied to a11 pots at the rate of 70 mgN/pot as a solution
of (l5NH4)2SO4 with 5.0322 atom % excess. Plants were watered
daily with distilled water and weekly with 100 ml of a nitrogen and
phosphorus free sterile Hewitt solution (Hewitt, 1966).
Fifty days after planting, N2 fixation was estimated using the fol-
lowing equations (Danso, 1990) :
% 15N atom excess (fc)
%N2 fixed = 100 (1 - -
->
% 15N atom excess (nfc)
and
total N2 fïxed = %N fixed
x total N (fc)
100
where fc and nfc are the fïxing and non-fixing reference crops res-
pectively.
Results
Table 1 shows that inoculating Vigna subterranea with Rhizobium
increased the dry weight and total N of leaves, stems and roots.The
treatment did not affect the shoot (stems + leaves)/root ratio expressed
on dry weight basis, but significantly increased this ratio when expres-
sed on total N basis.
3
Dual inoculation with Rhizobium and Glomus mosseae always
significantly increased these parameters and appeared to be more
effective than inoculation with Rhizobium alone.
According to Table 2, Ndfa% in aerial parts was signifïcantly higher
when Vigna subterranea was inoculated with Rhizobium and Glomus
mosseae than when Rhizobium inoculant was used alone.
Both types of inoculation increased the shoot/root ratio expressed
as N derived from N2 fixation, from fertilizer and from soil. This
effect was much more marked when Ndfa was taken into account :
the shoot/root ratio expressed on Ndfa basis was 9.5-9.7 whereas it
was only in the range of 4.5-5.8 when expressed on N derived from
fertiliser or from soil.
Discussion and conclusion
Dual inoculation with Rhizobium and Glomus mosseae was clearly
more effective than inoculation with Rhizobium alone, which cari be
probably explained by the fact that Glomus mosseae improved the
plant nutrition in P, the soi1 content in this element being relatively
low : ca, 31 ppm (21 ppm in the natural soi1 + 10 ppm P added).
This beneficial effect of dual inoculation on N2 fixation is reminiscent
of a field experiment carried out in similar soils with soybean by Ganry
et al., (1985) : N2 fixation was 109 Kg N2 fixed/ha when soybean
was inoculated with Rhizobium alone and it reached 139 Kg N2 fixed/
ha when the plant was dually inoculated with Rhizobium and Glomus
mosseae.
A second interesting result concerns the increase of the’ shoot/root
ratio resulting from inoculation, the most marked effect being obtained
with dual inoculation. A similar increase of the shoot/root ratio
expressed on weight and total N basis following inoculation was already
reported by Sougoufara et al., (1989) in the case of Casuarina equise-
tifoiia inoculated with Frankia. This specific effect of inoculation is
probably frequent. TO explain it, it is suggested that, owing to the
improvement of the plant nutrition in N or N and P resulting from
inoculation, the plant does not have to develop a large system to ex-
plore the soi1 to fïnd the nutrients it requires, and thus probably saves
a part of the energy provided by photosynthesis.
4
Extrapolating the results of the pot experiment reported here to
the field should be done with caution. However, it cari be predicted,
without risk of errer that Vigna subterranea has a high N2-fixing po-
tential since its Ndfa% cari reach 70% provided that a good Rhizobium
strain such as MAO 113 is used and that the plant requirements in
nutrients other than N are met either directly through fertilization or/
and proper (natural or artificial) mycorrhization.
Acknowledgements
This study was supported by UNESCO’s
agreement No.281.172.9. The author is very grateful to Dr H Burris
of Wisconsin (USA) University for Nitrogen- analyses, to 0 Touré
for valuable technical assistance and to Dr Y R Dommergues for
reviewing the manuscript.
References
Danso S K A 1990 Evaluation of biological nitrogen fixation in plants.
In Maximiser la Fixation Biologique de 1’Azote pour la Production
Agricole et Forestière en Afrique. Papiers présentés à la 3ème
conférence AABNF Dakar 7-12 Novembre 1988. Eds. M Gueye,
K Mulongoy et Y Dommergues. Collection Actes de I’ISRA.
Vol. 2, No 2, pp 249-271.
Denarie J, Andtiamanantena S and Ramonjy J 1968 L’inoculation
des légumineuses à Madagascar ; résultats de l’expérimentation de
la campagne 1966-1967. Agron. Trop. (France). 23, 925-966.
Dennis E A 1977 Nodulation and nitrogen fixation in legumes in
Ghana. In Biological Nitrogen Fixation in Farming Systems in The
Tropics. Eds. A Ayanaba and P J Dart, pp 217-232. John Wiley
and Sons, Chichester (UK).
Doku E V 1969 Host specificity among five species in the cowpea
cross inoculation group. Plant and Soi1 30, 126-128.
Ganry F, Wey J, Diem H G and Dommergues Y 1985 Inoculation
with Glomus mosseae improves N2 fixation by field grown soy-
beans. Biol. Fert. Soils 1, 15-23.
Gueye M and Bordeleau L M 1988 Nitrogen fixation in bambara
groundnut, Voandzeia subterranea (L) thouars. Mircen Journal 4,
365-375.
5
Hepper F N 1963 The bambara groundnut (Voandzeia subterranea)
and Kersting’s groundnut (Kerstingiella geocarpa) wild in West
Africa. Kew Bull. 16, 395407.
Hewitt E J 1966 Sand and water culture methods in the study of plant
nutrition. Technical communication No. 22 (2nd ed) 547 pp.
Commonwealth agricultural Bureaux. London.
National Academy of Sciences 1979 Pulses. In Tropical Legumes :
Resources for The Future. National Academy of Sciences, pp 47-
53.Washington D.C.
Olsen S R, Cole L V, Watanabe F S and Dean L A 1954 Estimation
of available phosphate in soils by extraction with sodium bicar-
bonate. Circular of US Department of Agriculture No. 939.
Sougoufara B, Diem H G and Dommergues Y R 1989 Response of
field grown Casuarina equisetifolia with Frankia strain ORS 021001
entrapped in alginate beads. Plant and soi1 118, 133-137.
Vietmeyer N D 1978 Highly promising plants. Chronica Horticulturae
(Netherlands) 18, 41-42.
6
Table 1 Dry matter and nitrogen yields and % 15N atom excess of plant
parts of bambara groundnut (cv. 83-131) cultivated in pots containing 2 Kg
of sterile soil sampled at ISRA Sinthiou Maleme experimental station and
inoculated with Rhizobium alone or Rhizobium plus Glomus mosseae (G.m.).
Dry weight
Tata N
%15N
Plant parts
Treatments
(w@W
(mg/p~O
atom excess
-.
-~
.-~
Leaves
Control
1235 a
10.40 a
0.987 a
Rhizobium
1622 b
27.00 b
0.365 b
Rhizobium + G.m.
1776 b
32.90 c
0.248 b
LSD 0.05
192
3.30
0.250
CV(%)
7.17
8.10
26.88
Stems
Control
564a
7.90 a
0.823 a
Rhizobium
790 b
18.90 b
0.301 b
Rhizobium + G.m.
931 c
21.80 c
0.199 b
LSD 0.05
118
2.10
0.211
CV(%)
8.99
7.40
27.50
Roots
Control
368 a
5.30 a
0.797 a
Rhizobium
422 b
7.30 b
0.420 b
Rhizobium + G.m.
404b
7.10 b
0.309 b
LSD 0.05
51
0.30
0.256
CV( %)
7.32
2.40
29.02
Nodules
Control
0.00 a
Rhizobium
71.00 b
Rhizobium + G.m.
116.50 c
LSD 0.05
24.22
CV( %)
22.40
Shoot/Root
Control
5.OOa
3.48 a
Rhizobium
5.34 ab
6.33 b
Rhizobium + G.m.
6.27 b
7.77 c
LSD 0.05
1.13
0.73
CV(%)
11.76
7.18
For each plant part, values followed by the same letter in each column do not differ signi-
fïcantly at the 0.05 level by Duncan’s multiple range test
7
TabIle 2 Nitrogen derived from fixation (Ndfa), from fertilizer (Ndff) and from
soi1 (Ndfs) of plant parts of bambara groundnut (cv. 83-131) cultivated in
pots containing 2 Kg of sterile soil sampled at ISRA Sinthiou Maleme experi-
mental station.
Plant parts
Treatments
Ndfa%
Ndff%
Ndfs% N d f a
Ndff Ndfs
-
-
-
-
-
-
Ixaves
Control
0.00 a
19.60 a 80.40 a O.OOa 2.07 a 8.38 a
Rhizobium
57.50 b 7.25 b 35.25 b 15.26 b 2.01 a 9.78 a
Rhizobium + G.m.
71.10 c 4.90 b 24.OOb 23.44~ 1.63 a 7.84 a
LSD 0.05
12.05
4.92
13.91
1.70 0.7
3.90
CV(%)
16.25
26.87
17.28
7.80
22.06 26.43
Stems
Control
0.00 a 16.40 a 83.6Oa
O.OOa
1.29 a 6.67 a
Rhizobium
59.90 b 6.00 b 34.10 b 11.261) 1.16 a 6.55 a
Rhizobium + G.m.
73.50 c 4.00 b 22.50 b 16.07 c 0.86 a 4.91 a
LSD 0.05
11.32
4.18
13.69
1.90 0.60
3.20
CV(%)
14.78
27.61
16.86
12.06 29.28 30.93
Rools
Control
0.00 a 15.80 a 84.20 a 0.00 a
0.82 a 4.49 a
Rhizobium
43.20 b 8.30 b 48.50 b 3.22 b 0.60 ab 3.51 ab
Rhizobium + G.m.
58.10 b 6.10 b 35.80 b 4.11 b
0.43 b 2.52 b
LSD 0.05
15.81
5.07
17.70
1.20
0.24
1.13
Shoot/Root
CV(%)
27.07
29.04
18.23
29.41 21.99 20.82
Control
O.OOa 4.08 a 3.39a
Rhizobium
9.53 b 5.15 ab 4.49 ab
Rhizobium + G.m.
9.70b
5.83 b 5.09 b
LSD 0.05
3.83
1.32
1.12
CV(%)
34.52 15.20 14.94
FOI each plant part, values followed by the same do not differ significantly at the 0.05 level
by Duncan’s multiple range test.