Ie. Okon et al., VESICULAR-ARBUSCULAR MYCORRHIZA EFFECTS ON GLIRICIDIA-SEPIUM AND SENNA-SIAMEA IN A FALLOWED ALLEY CROPPING SYSTEM, Agroforestry systems, 33(2), 1996, pp. 165-175
Nitrogen fixing and non-N-2 fixing legumes such as Gliricidia speium a
nd Senna siamea have been used in alley cropping systems for soil impr
ovement and source of N for food crops. However their establishments c
ould be limited by P and moisture deficiencies in degraded soils. Vesi
cular-arbuscular mycorrhizal fungi can help to overcome these deficien
cies. We examined the effects of a vesicular-arbuscular mycorrhizal (V
AM) fungus, Glomus deserticola, on the performance of sole hedgerow tr
ees of Gliricidia sepium and Senna siamea and their mixtures (interpla
nted) in a fallowed alley cropping experiment on a degraded Alfisol in
southwestern Nigeria. Percentage root infection by VAM fungi was high
er in inoculated plants than in uninoculated ones irrespective of whet
her they were interplanted or non-interplanted. Inoculation with G. de
serticola increased dry matter accumulation and nutrient uptake (N. P,
Mg and K) but there was no significant interaction between mycorrhiza
l inoculation and interplanting for growth and nutrient uptake except
for the uptake of P, Mg and K in G. sepium. Inoculation with G. desert
icola reduced leaf shedding of G. sepium by 50% but did not have the s
ame effect for S. siamea. For both tree species inoculated plants extr
acted more water from 0-30 cm depth than the uninoculated ones.