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1.
Summary The effects of vesicular-arbuscular mycorrhiza (VAM) and of mulching on growth of barley were investigated in a factorial experiment. Plants were grown in cylinders buried in a field in soil with moderate amounts of available phosphate. VAM infection, dry weight and P uptake were determined at harvest after 10 and 161/2 weeks growth.VAM infection was reduced in the upper soil layer by straw mulch, possibly through a reduction in temperature. By the second harvest VAM increased growth by 56% in the non-mulched plots through increased P uptake but VAM did not increase growth in the mulched plots. Mulch increased growth by 85% in the non-mycorrhizal plots, and 28% in the mycorrhizal plots. 相似文献
2.
Effect of tillage and farming system upon VAM fungus populations and mycorrhizas and nutrient uptake of maize 总被引:1,自引:1,他引:0
Low-input agricultural systems that do not rely on fertilizers may be more dependent on vesicular-arbuscular mycorrhizal [VAM] fungi than conventionally managed systems. We studied populations of spores of VAM fungi, mycorrhiza formation and nutrient utilization of maize (Zea mays L.) grown in moldboard plowed, chisel-disked or no-tilled soil under conventional and low-input agricultural systems. Maize shoots and roots were collected at four growth stages. Soils under low-input management had higher VAM fungus spore populations than soils under conventional management. Spore populations and colonization of maize roots by VAM fungi were higher in no-tilled than in moldboard plowed or chisel-disked soil. The inoculum potential of soil collected in the autumn was greater for no-till and chisel-disked soils than for moldboard plowed soils and greater for low-input than conventionally farmed soil. The effects of tillage and farming system on N uptake and utilization varied with growth stage of the maize plants. The effect of farming system on P use efficiency was significant at the vegetative stages only, with higher efficiencies in plants under low-input management. The effect of tillage was consistent through all growth stages, with higher P use efficiencies in plants under moldboard plow and chisel-disk than under no-till. Plants grown in no-tilled soils had the highest shoot P concentrations throughout the experiment. This benefit of enhanced VAM fungus colonization, particularly in the low-input system in the absence of effective weed control and with likely lower soil temperatures, did not translate into enhanced growth and yield. 相似文献
3.
Development of two endomycorrhizal symbioses on soybean and comparison with phosphorus fertilization
Summary Soybean (Glycine max L. Merr. cv. Amsoy 71) plants were grown in a greenhouse in a soil very low in plant-available P, and plants were harvested
5 times over a 21-week growth period. Soybeans were inoculated with one of two species of VAM fungi or received daily one
of three nutrient solutions of different P concentrations (0.0, 0.2, or 1.0mMP). Until week 9, the dry weights, leaf areas and developmental stage of soybeans inoculated withG. fasciculatum orG. mosseae were similar to the 1.0 or 0.2mMP-treated plants, respectively. Phosphorus concentrations were significantly lower in VAM plants at weeks 6 and 9 as compared
to non-VAM soybeans given 1.0mMP, suggesting P input in VAM plants was immediately used for new growth. Total P input for VAM plants was linear over 21 weeks,
and the average rate of P uptake for these plants was 0.19mg P d−1. Estimated specific P uptake rates (SPUR) for the mycorrhizae (VAM roots) were twice that of the control (0.0mMP) roots. The calculated SPURs forG. fasciculatum andG. mosseae hyphae were 95 and 120μg P g−1 VAM d−1 respectively, a 4 to 5 fold increase over non-inoculated roots, indicating more attention must be paid to P assimilation
by VAM fungi in P-fixing substrates.
Contribution from the Western Regional Research Center, USDA-ARS (CRIS No. 5325-20580-003). 相似文献
4.
The level of vesicular-arbuscular mycorrhizal (VAM) infection in the roots of Leucaena grown in a sand-soil mixture in the
greenhouse increased rapidly with time and reached a peak value of 84% at 30 days from planting. The pattern of immobile nutrient
uptake and accumulation closely paralleled that of the development of infection, particularly during the first 10–30 days
after planting. Significant changes in dry matter yield were also observed only after a significant portion of the root length
was colonized byGlomus aggregatum. The development of VAM infection was not accompanied by growth depression at any of the sampling periods. However, VAM roots
had very high levels of Cu which was not translocated to shoots. It is hypothesized that such a diversion of Cu by the endophyte
from the host could cause growth depression under conditions where the soil volume is supplied with sub-optimal levels of
Cu.
Contribution from the Hawaii Institute of Tropical Agriculture and Human Resources Series No. 3186. 相似文献
5.
We hypothesized that the grazing of vesicular-arbuscular mycorrhizal (VAM) hyphae by soil animals could be responsible for the lack of a direct relationship between mycorrhizal infection intensity and nutrient uptake under field conditions. To test this hypothesis, we determined the effect of a range of densities of the collembola, Folsomia candida, on growth, VAM infection, and P uptake in Geranium robertianum, a common forest herb, under greenhouse conditions. Total and aboveground growth were greater at low collembola density than either at higher collembola density or without collembola. These differences were greater when the plants were grown in a high organic content soil mix than when grown in sand. Root mass was not affected by collembola density. In the soil mix, root length decreased with increasing collembola density, but not in the sand. The percent of root length infected with VAM was lower at any collembola density than when collembola were absent. Total infected root length decreased linearly with increasing collembola density. Few significant differences in P uptake or tissue concentration were found. Thus, plant growth (but not P uptake) may be stimulated at low collembola density and inhibited at high. We discuss mechanisms which may be responsible for this non-linear response, and the implications of the pattern of response to studies of plant competition, nutrient turnover, and revegetation. 相似文献
6.
Growth and nutrient status of citrus plants as influenced by mycorrhiza and phosphorus application 总被引:1,自引:0,他引:1
To test the hypothesis that high levels of soluble phosphate applied in combination with VAM fungi, to citrus plants, can
cause growth depression even in the absence of other limiting factors, and also to test if rock phosphate, under these conditions,
may be a satisfactory P source, a greenhouse experiment was conducted using sterilized soil with four levels of phosphate
(0, 50, 100 and 200 ppm P) supplied either as soluble P or as rock phosphate. Citrus seedlings were either inoculated with
the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus etunicatum or left uninoculated. Six months after the start of the experiment, the plants were harvested and shoot dry weight, P and
K uptake, root colonization and the number of spores in 50 cm3 of soil were determined. Significant increases were found in dry matter yields and in P and K contents, due to VAM fungus
inoculation, at the zero and 50 ppm soluble P levels and at all rock phosphate levels. At 100 ppm soluble P, the development
of VAM plants was equilvalent to that of non-VAM plants, and at 200 ppm, growth was significantly less than that of non-VAM
plants. Root colonization and sporulation were reduced at higher P levels. The absolute growth depression of VAM plants at
the higher P level was likely due to P toxicity. In addition, high leaf P and K concentrations may have interfered with carbohydrate
distribution and utilization in these symbioses. Rock phosphate may be used with VAM citrus to substitute for medium amounts
of soluble phosphate. 相似文献
7.
The growth response of Hevea brasiliensis to vesicular-arbuscular mycorrhizal (VAM) fungi inoculation was assessed in two field nursery sites containing indigenous
mycorrhizal fungi (IMF). Seedling rootstocks were inoculated with mixed VAM-fungal species in a factorial combination with
phosphorus (P) fertilizer application, and planted in randomised blocks on sandy (site 1) and clayey (site 2) soils. Plants
were harvested after 26 weeks for measurements of shoot dry weight (DW), stem diameter, height, mycorrhizal root colonization
and leaf nutrient contents. At site 1, VAM increased shoot DW, stem diameter and plant height only in treatments without P
applied. Increases in shoot DW due to VAM were 70% greater than the uninoculated controls although this was reduced to 5%
when P was applied. At site 2, VAM inoculation also increased shoot DW and stem diameter but the magnitude of the increases
was smaller. Shoot DW response due to VAM was only 29%. At this second site, applying phosphate to uninoculated plants did
not increase shoot yields further. Leaf concentrations of all nutrients were unaffected by VAM at both sites, except for copper
(Cu) which was increased by VAM in treatments where P was not applied. However, leaf contents of P, potassium (K), magnesium
(Mg) and Cu were increased by VAM at site 1, and of leaf nitrogen (N) and K at site 2. These experiments demonstrate that
VAM-fungi could be introduced into field nursery sites to improve growth and P uptake by H. brasiliensis. The relevance of VAM-fungi to H. brasiliensis seedling rootstock development and the influence of IMF in determining field responses is discussed. 相似文献
8.
Anni Jensen 《Plant and Soil》1983,70(2):155-163
Summary To investigate the effect of indigenous VAM fungi and of increasing the amount of natural inoculum barley was grown in containers
buried in the field with uninoculated and inoculated irradiated soil and with uninoculated and inoculated untreated soil from
two locations, one low and one high in available P. The experiment was set up with 3 P fertilizer applications (0, 15, 30
kg P/ha). Growth and uptake of P was measured. The inocula were prepared from natural VAM populations.
VAM fungal infection was established in the irradiated soil at a lower level than in the untreated soil. VAM fungal infection
was decreased by increasing P fertilizer application. In the soil low in available P VAM increased concentration of P and
total uptake of P. VAM did not cause an increased growth. The reason for this may be the low establishment of VAM in the irradiated
soil and/or because the indigenous VAM species were not efficient. It is also possible that a pronounced growth increase due
to irradiation the soil may have masked a smaller effect of the indigenous VAM fungi. Increasing the amount of natural inoculum
in the untreated soil influenced neither VAM frequency nor growth. 相似文献
9.
The effect of vesicular-arbuscular mycorrhizal fungi (VAM) on field bean and spring wheat dry matter production and on phosphorus,
zinc, copper, iron and manganese uptake was determined under greenhouse conditions. Nutrient availability was varied by using
different sizes of pots and by diluting the soil with sand. VAM increased plant dry matter production under all sets of growth
conditions. VAM were found to directly increase the uptake of P, Zn, Cu and Fe by field beans and of P and Zn for wheat in
both experiments. Increased uptake of the other nutrients measured was attributed to increased dry matter production or other
factors. The effect of VAM decreased as the pot size holding the host plants decreased, but was not affected by the ratio
of soil to sand if the pot size was kept constant. Nutrient uptake by beans as a proportion of total amount of nutrient present
increased as the amount of nutrient decreased. Increase in root-soil contact and altered chemical equilibria are probable
reasons for increased efficiency of nutrient uptake by beans as the level of available nutrient decreased. For wheat, which
has a relatively fibrous root system, decreasing the nutrient availability had minimal effects on nutrient uptake in these
experiments. Increases in total uptake of a particular nutrient resulting from inoculation with VAM are not necesarily indicative
of a direct uptake of that nutrient by the VAM. 相似文献
10.
Fred T. Davies Jr. 《Plant and Soil》1987,104(1):31-35
Rooted cuttings ofRosa multiflora ‘Brooks 56’ were grown in a medium of 1 mineral soil: 1 sand (v/v) or bark: 1 sand (v/v) inoculated with the VA-mycorrhizal
(VAM) fungiGlomus mosseae (Nicol. and Gerd.) Gerd. and Trappe andG. fasciculatum (Thaxt. sensu Gerd.) Gerd. and Trappe or left as noninoculated controls. The slow release fertilizer osmocote was applied
at rates of either 0, 1.2, or 4.2 kg/m3 (18N-6P-12K) and incorporated into the container medium. After 180 days plants were evaluated for growth, development and
chemical leaf analysis. Greatest growth responses occurred after the highest fertilizer application of 4.2 kg/m3, and the poorest one after 0 kg/m3. Combination bark: sand medium was superior to mineral soil: sand medium for growth of mycorrhizal plants. At 0 kg/m3, mycorrhizal plants in bark: sand medium had longer shoots than other treatments. At 1.2 kg/m3, VAM plants compared to nonmycorrhizal plants in park:sand medium had greater effect on growth parameters. At the highest
fertilizer application of 4.2 kg/m3, greatest growth responses occurred with VAM plants in bark:sand medium. Mycorrhizal plants compared to nonmycorrhizal plants
in bark:sand medium had greater K and Zn uptake at 0 kg/m3, and greater K, Ca, S, Mn and Zn uptake at 1.2 kg/m3.
Texas Agr. Expt. Sta. Journal Series No. TA-22264. 相似文献
11.
Maize (Zea mays L. cv. Alize) plants were grown in a calcareous soil in pots divided by 30-m nylon nets into three compartments, the central one for root growth and the outer ones for hyphal growth. Sterle soil was inoculated with either (1) rhizosphere microorganisms other than vesicular-arbuscular mycorrhizal (VAM) fungi, (2) rhizosphere microorganisms together with a VAM fungus [Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappel], or (3) with a gamma-irradiated inoculum as control. Plants were grown under controlled-climate conditions and harvested after 3 or 6 weeks. VAM plants had higher shootroot ratios than non-VAM plants. After 6 weeks, the concentrations of P, Zn and Cu in roots and shoots had significantly increased with VAM colonization, whereas Mn concentrations had significantly decreased. Root exudates were collected on agar sheets placed on the interface between root and hyphal compartments. Six-week-old VAM and non-VAM plants had similar root exudate compositions of 72–73% reducing sugars, 17–18% phenolics, 7% organic acids and 3% amino acids. In another experiment in which root exudates were collected on agar sheets with or without antibiotics, the amounts of amino acids and carbohydrates recovered were similar in VAM and non-VAM plants. However, threeto sixfold higher amounts of carbohydrates, amino acids and phenolics were recovered when antibiotics were added to the agar sheets. Thus, the high microbial activity in the rhizosphere and on the rhizoplane limits the exudates recovered from roots. 相似文献
12.
A pot culture experiment and a field experiment were carried out separately to study heavy metal (HM) uptake from soil contaminated
with Cu, Zn, Pb and Cd by Elsholtzia splendens Nakai ex F. Maekawa inoculated with arbuscular mycorrhizal (AM) fungi and the potential for phytoremediation. The HM-contaminated
soil in the pot experiment was collected from the field experiment site. Two AM fungal inocula, MI containing only one AM
fungal strain, Glomus caledonium 90036, and M II consisting of Gigaspora margarita ZJ37, Gigaspora decipens ZJ38, Scutellospora gilmori ZJ39, Acaulospora spp. andGlomus spp., were applied to the soil under unsterilized conditions. In the pot experiment, the plants were harvested after 24 weeks
of growth. Mycorrhizal colonization rate, plant dry weight (DW) and P, Cu, Zn, Pb, Cd concentrations were determined. MI-treated
plants had higher mycorrhizal colonization rates than MII-treated plants. Both MI and MII increased shoot and root DW, and
MII was more effective than MI. In shoots, the highest P, Cu, Zn and Pb concentrations were all observed in the plants treated
with MII, while MI decreased Zn and Pb concentrations and increased P but did not alter Cu, and Cd concentrations were not
affected by either of two inocula. In roots, MII increased P, Zn, Pb concentrations but did not alter Cu and Cd, and MI did
not affect P, Cu, Zn, Pb, Cd concentrations. Cu, Zn, Pb, Cd uptake into shoots and roots all increased in MII-treated plants,
while in MI-treated plants, Cu and Zn uptake into shoots and Cu, Zn, Pb, Cd into roots increased but Pb and Cd uptake into
shoots decreased. In general, MII was more effective than MI in promoting plant growth and HM uptake. The field experiment
following the pot experiment was carried out to investigate the effects of MII under field conditions. The 45-day-old nonmycorrhizal
and MII-colonized seedlings of E. splendens were transplanted to HM-contaminated plots and harvested after 5 months. MII-inoculation increased shoot DW and shoot P,
Cu, Zn, Pb concentrations significantly but did not alter shoot Cd concentrations, which led to higher uptake of Cu, Zn, Pb,
Cd by E. splendens shoots. These results indicate that the AM fungal consortium represented by MII can benefit phytoextraction of HMs and therefore
play a role in phytoremediation of HM-contaminated soils. 相似文献
13.
Mycorrhizal infection,phosphorus uptake,and phenology in Ranunculus adoneus: implications for the functioning of mycorrhizae in alpine systems 总被引:3,自引:0,他引:3
Phosphorus levels, phenology of roots and shoots, and development of vesicular arbuscular mycorrhizal (VAM) fungi were monitored for two years in natural populations of the perennial alpine herb, Ranunculus adoneus. The purpose of this study was to understand how phosphorus uptake relates to the phenology of R. adoneus and to ascertain whether arbusculus, fungal structures used for nutrient transfer, were present when maximum phosphorus accumulation was occurring. Arbuscules were only present for a few weeks during the growing season of R. adoneus and their presence corresponded with increased phosphorus accumulation in both the roots and shoots of R. adoneus. In addition, phosphorus accumulation and peaks in mycorrhizal development occurred well after plant reproduction and most plant growth had occurred. The late season accumulation of phosphorus by mycorrhizal roots of R. adoneus is stored for use during early season growth and flowering the following spring. In this way R. adoneus can flower before soils thaw and root or mycorrhizal nutrient uptake can occur. 相似文献
14.
Response ofLeucaena leucocephala (Lam) de Wit to rock phosphate application and inoculation with the vesicular-arbuscular mycorrhizal (VAM) fungusGlomus aggregatum (Schenck and Smith emend Koske) was evaluated in a pot experiment. VAM colonization increased as rock phosphate application increased. Using phosphorus concentration in pinnules as an indicator of VAM activity, significant VAM activity occurred at 25 days after planting at the lower levels of rock phosphate application (0, 0.34 and 0.68 g P kg–1). The time required for significant VAM activity was shortened by 5 days at the higher P levels (1.36, 2.72 and 5.44 g P kg–1). The highest VAM activity was associated with the highest rate of rock phosphate application.Inoculation withG. aggregatum significantly increased the uptake of Cu, P and Zn and dry-matter yield at all levels of rock phosphate applied. Copper concentrations in roots of mycorrhizal Leucaena were significantly higher than that of shoots. The results indicated that Leucaena in symbiotic association with VAM fungi effectively utilized P from rock phosphate. However, high rates of rock phosphate are required to attain growth comparable to that obtained with the application of water-soluble phosphate.Contribution from Hawaii Institute of Tropical Agriculture and Human Resources, Journal Series No. 3243. 相似文献
15.
Growth and nutrient uptake of sorghum cultivated with vesicular-arbuscular mycorrhiza isolates at varying pH 总被引:2,自引:1,他引:1
This study was conducted to determine the effects of different pH regimes on root colonization with four vesicular-arbuscular mycorrhiza (VAM) isolates, and VAM effects on host plant growth and nutrient uptake. Sorghum [Sorghum bicolor (L.) Moench] was grown at pH 4.0, 5.0, 6.0 and 7.0 (±0.1) in hydroponic sand culture with the VAM isolates Glomus etunicatum UT316 (isolate E), G. intraradices UT143 (isolate I), G. intraradices UT126 (isolate B), and an unknown Glomus isolate with no INVAM number (isolate A). Colonization of roots with the different VAM isolates varied differentially with pH. As pH increased, root colonization increased with isolates B and E, remained unchanged with isolate I, and was low at pH 4.0 and high at pH 5.0, 6.0, and 7.0 with isolate A. Isolates E and I were more effective than isolates A and B in promoting plant growth irrespective of pH. Root colonization with VAM appeared to be independent of dry matter yields or dry matter yield responsiveness (dry matter produced by VAM compared to nonmycorrhizal plants). Dry matter yield responsiveness values were higher in plants whose roots were colonized with isolates E and I than with isolates A and B. Shoot P concentrations were lower in plants colonized with isolates E and I than with isolates A and B or nonmycorrhizal plants. This was probably due to the dilution effect of the higher dry matter yields. Neither the VAM isolate nor pH had an effect on shoot Ca, Mg, Zn, Cu, and Mn concentrations, while the VAM isolate affected not only P but also S, K, and Fe concentrations. The pH x VAM interaction was significant for shoot K, Mg, and Cu concentrations. 相似文献
16.
A greenhouse experiment was carried out to determine whether the decline of Arnica montana L. in heathland vegetation in the Netherlands could be caused by a detrimental effect of soil acidification on vesicular-arbuscular mycorrhiza of this species. Arnica montana and two non-declining species from the same habitat, Hieracium pilosella L. and Deschampsia flexuosa (L.) Trin., were grown with and without the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thaxter sensu Gerdemann) Gerd. and Trappe in pots with an extremely nutrient-poor, sandy soil. They were percolated weekly with nutrient solution with different pH values, viz. 5.5, 4.5, 3.5 and 2.5. At intervals of three weeks and up to 12 weeks, measurements were made on growth, nutrient uptake and VAM infection.In the most acid treatments growth and nutrient uptake were reduced in all species. VAM infection decreased only slightly with decreasing pH of the treatments. Without VAM, Arnica montana died and Hieracium pilosella hardly grew at the most acid treatments. Therefore it is concluded that VAM decreased the stress caused by the most acid treatments. Leachate from the most acid treatment had a pH of approximately 4, and contained considerable amounts of aluminium, dissolved from the solid phase of the soil. This might have played a role in the detrimental effects on the plants in the case of the most acid treatment. No evidence was found in this experiment that the decline of Arnica montana was due to detrimental effects of soil acidification on VAM of this species. 相似文献
17.
Summary Six mycorrhizal fungi were tested as inoculants for pearl millet (Pennisetum americanum Leeke) grown in pots maintained in a greenhouse. VAM fungi varied in their ability to stimulate plant growth and phosphorus uptake. Inoculation withGigaspora margarita, G. calospora andGlomus fasciculatum increased shoot drymatter 1.3 fold over uninoculated control. In another pot trial, inoculation withGigaspora calospora andGlomus fasciculatum resulted in dry matter and phosphorus uptake equivalent to that produced by adding phosphorus at 8 kg/ha.The influence of inoculatingGigaspora calospora on pearl millet at different levels of phosphorus fertilizer (0 to 60 kg P/ha) as triple superphosphate in sterile and unsterile alfisol soil was also studied. In sterile soil, mycorrhizal inoculation increased dry matter and phosphorus uptake at levels less than 20 kg/ha. At higher P levels the mycorrhizal effect was decreased. These studies performed in sterilized soil suggest that inoculation of pearl millet with efficient VAM fungi could be extremely useful in P deficient soils. However, its practical utility depends on screening and isolation of fungal strains which perform efficiently in natural (unsterilized) field conditions. 相似文献
18.
In a pot experiment, wheat was grown for 50 days in two heat-sterilized low-phosphorus (P) soils supplied with organic P as Na-phytate. Seed inoculation with the phosphatase-producing fungus (PPF) Aspergillus fumigatus or soil inoculation with the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus mosseae increased shoot and root dry weight and root length, phosphatase activity in the rhizosphere and shoot concentrations of P and to a lesser extent of K and Mg. As a rule, the greatest effects on those parameters were most in the combined inoculation treatment (PPF + VAM). Shoot concentrations of Cu and Zn were only enhanced by VAM, not by PPF. At harvest, depletion of organic P in the rhizosphere soil increased in the order of: sterilized soil < PPF < VAM < PPF + VAM which corresponded with the enhanced P concentrations in the plants. The results demonstrate that organic P in form of Na-Phytate is efficiently used by VAM and that use of organic P can be increased by simultaneous inoculation with phosphatase-producing fungi. 相似文献
19.
Micronutrient uptake and distribution in mycorrhizal or phosphorus-fertilized soybeans 总被引:8,自引:0,他引:8
R. S. Pacovsky 《Plant and Soil》1986,95(3):379-388
Summary Soybean plants were grown in a soil very low in available P. Seedlings were inoculated with two vesicular-arbuscular mycorrhizal
(VAM) fungi or were left non-inoculated and fertilized with P. Assimilation and allocation of micronutrients (Fe, Mn, Zn,
and Cu) were determined during host development, and the uptake of trace elements in VAM plants was compared to P-fertilized,
non-VAM plants of similar weight, growth stage, and P status. Copper and zinc concentrations were always higher in VAM plants,
while iron and manganese concentrations were lower than in the equivalent P-fertilized soybeans. Differences in the micronutrient
content of fully-mature soybean pods reflected differences in the leaves and roots. Thus, for trace elements, seed quality
can be altered by VAM colonization in a fashion not duplicated by P fertilizer.
Contribution from the Western Regional Research Center, USDA-ARS (CRIS No. 5325-20580-003). 相似文献
20.
A factorial design 23 × 4 with two levels of Mussorie rockphosphate (RP) with or without vesicular-arbuscular mycorrhizal (VAM) fungi and Bradyrhizobium japonicum, and four treatments of phosphate-solubilizing microbes (PSM) Pseudomonas striata, Bacillus polymyxa, Aspergillus awamori was employed using Patharchatta sandy loam soil (Typic Hapludoll). The observations included mycorrhization, nodulation, grain and straw yield, N and P uptake, available soil P and the PSM population in the soil after crop harvest. Inoculation with endophytes alone caused about 70% root colonization. Addition of rockphosphate or inoculation with PSM, except B. polymyxa, stimulated root infection of native as well as introduced VAM endophytes. Application of RP or inoculation with Bradyrhizobium japonicum, mycorrhizal fungi or phosphate-solubilizing microorganisms significantly increased nodulation, N uptake, available soil P and the PSM population in the soil after the crop harvest. The grain and straw yields did not increase following RP addition or mycorrhizal inoculation but increased significantly after inoculation wit Bradyrhizobium or PSM. In general, the application of RP, Bradyrhizobium, VAM and PSM in combinations of any two or three resulted in significant increases in nodulation, plant growth, grain yield and uptake of N and P. Among the four factor interactions, rockphosphate, Bradyrhizobium and P. striata in the absence of VAM resulted in maximal nodulation, grain and straw yields and N uptake by soybean. The highest P uptake by soybean grain was recorded with Bradyrhizobium and A. awamori in the absence of rockphosphate and VAM. Generally, available soil P and PSM population after crop harvest were not significantly increased by the treatment combinations giving the maximal uptake of nutrients. However, they increased significantly in response to PSM, which produced no significant increase in total uptake of nutrients.Research paper no. 7498 相似文献