THE SYNERGISTIC EFFECT OF ORGANIC FERTILIZER FROM AGRICULTURAL-ANIMAL HUSBANDRY WASTE AND ARBUSCULAR MYCORRHAZAL FUNGI ON SOIL FERTILITY AND PERFORMANCE OF UPLAND RICE (Oryza sativa L) IN ULTISOL SOIL

Effect of fertiliser type and mycorrhizal inoculation on growth and development of sunflower (Helianthus annuus L.)

Nitrogen deposition has been proven to facilitate the establishment of alien plants. Previous studies have certified that nitrogen deposition enhances the resource availability of habitats and promotes the growth of alien invaders. Arbuscular mycorrhizal fungi (AMF) symbiose with vascular plants and assist plants in nutrient acquisition. AMF colonization has been proven to be another driving factor of plant invasion. However, few studies have integrated nitrogen deposition and AMF inoculation into the exploration on invasion mechanism. Based on a trait approach, the present study subjected the alien invader, Rhus typhina L., and its co-occurring native species, Acer truncatum Bunge, to nitrogen deposition and AMF inoculation and compared the phenotypic variation in aboveground and belowground traits in an inter-specific competition experiment. Through the effects of different nitrogen deposition and AMF infection on the functional traits of R. typhina and A. truncatum, the effects of mycorrhizal symbiosis between R. typhina and A. truncatum on abiotic factors and interspecific relationships were analyzed. We found that inter-specific competition stimulated the colonization of AMF in R. typhina, however, decreased the colonization rate of AMF in A. truncatum. Correspondingly, inter-specific competition significantly reduced the plant growth of A. truncatum as the aboveground morphological traits including plant height and crown area, and belowground traits including root length, root surface area, root volume, number of root tips, number of root tip branches and number of root cross decreased for A. truncatum. Nitrogen deposition promoted the shoot growth of R. typhina rather than that of A. truncatum. AMF inoculation significantly affected the belowground traits of A. truncatum as the root length and root surface area significantly decreased after AMF inoculation in the mixture planting of the two species. The chlorophyll content of A. truncatum decreased without AMF inoculation, while nitrogen deposition enhanced the net photosynthetic rate of R. typhina. The alien invader R. typhina outperforms its native competitor in the simulated scenario of resource fluctuation and facilitates its establishment. We speculate that AMF colonization promotes the extension of R. typhina rhizosphere and, thus, accelerates the growth and invasion of R. typhina.

Whether arbuscular mycorrhizal fungi (AMF) inoculation promotes soil C sequestration is largely unknown. Here, meta-analysis and logistic regression were applied to study the ecological effects of AMF inoculation on soil organic C (SOC) turnover and plant growth under different inoculation manipulations, plant traits, and soil conditions. Results showed that AMF inoculation generally increased SOC stock and plant biomass accumulation. Soil sterilization, unsterilized inoculum wash (a filtrate of mycorrhizal inoculum excluding AMF) addition in non-mycorrhizal treatments, experimental type, and inoculated AMF species influenced soil microbial biomass C (MBC) but had no impact on SOC turnover. Plant root system, initial SOC content, and soil pH were the key factors that influenced the AMF-mediated SOC turnover. AMF inoculation in fertile or acidic soils might deplete SOC. The symbiosis between tap-rooted plants and AMF was more likely to sequestrate C into the soil compared to fibrous-rooted plants. Moreover, plant total dry biomass largely relied on its own photosynthetic pathway although AMF was introduced. Collectively, our results suggest that AMF inoculation is a promising approach for soil C sequestration.

Tomato (Lycopersicon esculentum Mill.) yields are known to decrease for plants grown in saline soils. This study was conducted to determine the effects of arbuscular mycorrhizal fungi (AMF) inoculation on fruit yield and mineral content of salt-tolerant and salt-sensitive tomato cultivars grown with varied levels of salt. NaCl and CaCl2were added to soil in the irrigation water in equal molar ratios to give ECe values of 1.4 (nonstressed) and 4.9 dS m−1 (salt stressed). Plants were grown in a greenhouse using unsterilized, low phosphorus (P) (silty clay) soil-sand mix. Mycorrhizal root colonization occurred whether cultivars were salt stressed or nonstressed, but the extent of AMF root colonization was higher in AMF inoculated than uninoculated plants. The salt tolerant cultivar ‘Pello’ generally had higher AMF root colonization than the salt sensitive cultivar ‘Marriha’. Shoot dry matter (DM) yield, fruit fresh yield, and AMF colonization were higher for plants grown under nonstressed than for plants grown under salt stressed conditions. Shoot DM and fruit fresh yields were higher in AMF inoculated than uninoculated plants grown with or without salt stress. Pello generally had higher fruit fresh yield per plant and fruit weight than Marriha, but these differences were only significant for fruit weight in unioculated plants grown under salt stressed conditions. The enhancement in fruit fresh yield due to AMF inoculation was 26 and 23% under nonstressed and 28 and 46% under salt stressed treatments for Pello and Marriha, respectively. For both cultivars, fruit contents of P, potassium (K), zinc (Zn), copper (Cu), and iron (Fe) were higher in AMF inoculated compared with uninoculated plants grown under nonstressed and salt stressed conditions. Fruit Na concentrations were lower in AMF inoculated than uninoculated plants grown under salt stressed conditions. The enhancement in P, K, Zn, Cu, and Fe acquisition due to AMF inoculation was more pronounced in Marriha than in Pello cultivar under salt stressed conditions. The results of this study indicated that AMF inoculated plants had greater tolerance to salt stress than unioculated plants.

Abstract. Ishaq L, Adu Tae ASJ, Airthur MA, Bako PO. 2021. Effect of single and mixed inoculation of arbuscular mycorrhizal fungi and phosphorus fertilizer application on corn growth in calcareous soil. Biodiversitas 22: 1920-1926. Low availability of soil phosphorus (P) in calcareous soil in West Timor has become a constraint in improving plant productivity. A field experiment was carried out in the calcareous soil to investigate the effect of single and mixed indigenous arbuscular mycorrhizal fungi (AMF) inoculation and P fertilizer application on growth and yield of corn in Kupang District, East Nusa Tenggara Timur Province, Indonesia. The experiment was laid out in a split-plot design consisting of indigenous AMF inoculation as the main plots and inorganic P fertilizer rates as the sub-plot treatments. The main plot treatments were: without AMF inoculation (M0), inoculated with single AMF inoculum (M1) and inoculated with mixed AMF inocula (M2). Sub-plots consisted of four P rates namely 25% (P1), 50% (P2), 75% (P3) and 100% (P4) of the recommended inorganic superphosphate dose of 200 kg SP36 ha-1. The results showed that there were significant interactions between AMF inoculation and P fertilizer dose on AMF spore density, AMF colonization and soil available P. Results indicated a strong correlation between AMF colonization and soil available P. Inoculation of both M1 and M2 significantly increased soil available P, plant growth and yield compared to the uninoculated plant. Spore production in the two AM responded differently to P fertilizer. Low doses of inorganic P fertilizer favored spore production in M1, whereas P fertilizer sporulation in M2 was adversely affected. The percentage of AMF root colonization of M1 and M2 decreased with an increase in P fertilizer applied. Further studies need to be conducted to evaluate the effectiveness of indigenous AMF in improving plant yield at low level of inorganic fertilizer application to achieve more sustainable agricultural practice in the region.

We established a 13‐week greenhouse experiment based on replicated microcosms to test whether the effects of defoliation on grassland plants and soil organisms depend on plant species composition and the presence of arbuscular mycorrhizal (AM) fungi. The experiment constituted of three treatment factors – plant species composition, inoculation of an AM fungus and defoliation – in a fully factorial design. Plant species composition had three levels: (1) Trifolium repens monoculture (T), (2) Phleum pratense monoculture (P) and (3) mixture of T. repens and P. pratense (T+P), while the AM inoculation and the defoliation treatment had two levels: (1) no inoculation of AM fungi and (2) inoculation of the AM fungus Glomus claroideum BEG31, and (1) no trimming, and (2) trimming of all plant material to 6 cm above the soil surface three times during the experiment, respectively. At the final harvest, AM colonization rate of plant roots differed between the plant species compositions, being on average 45% in T, 33% in T+P and 4% in P. Defoliation did not affect the colonization rate in T but raised the rate from 1% to 7% in P and from 20% to 45% in T+P. Shoot production and standing shoot and root biomass were 48%, 85% and 68% lower, respectively, in defoliated than in non‐defoliated systems, while the AM fungus did not affect shoot production and root mass but reduced harvested shoot mass by 8% in non‐defoliated systems. Of the plant quality attributes, defoliation enhanced the N concentration of harvested shoot biomass by 129% and 96% in P and T+P, respectively, but had no effect in T, while the C concentration of shoot biomass was on average 2.7% lower in defoliated than in non‐defoliated systems. Moreover, defoliation reduced shoot C yield (the combined C content of defoliated and harvested shoot biomass) on average by 47% across all plant species compositions and shoot N yield by 37% in T only. In contrast to defoliation, the AM fungus did not affect shoot N and C concentrations or shoot N yield, but induced 10% lower C yield in non‐defoliated systems and 17% higher C yield in defoliated T. In roots, defoliation led to 56% and 21% higher N concentration in P and T+P, respectively, and 28% higher C concentration in P, while the mycorrhizal fungus lowered root N concentration by 9.7% in defoliated systems and had no effect on root C concentrations. In the soil, the nematode community was dominated by bacterivores and the other trophic groups were found in a few microcosms only. Bacterivores were 45% more abundant in defoliated than in non‐defoliated systems, but were not affected by plant species composition or the AM fungus. Soil inorganic N concentration was significantly increased by defoliation in T+P, while the mycorrhizal fungus reduced NH 4 –N concentration by 40% in T. The results show that defoliation had widespread effects in our experimental systems, and while the effects on plant growth were invariably negative and those on bacterivorous nematodes invariably positive, most effects on plant C and N content and soil inorganic N concentration varied depending on the plant species present. In contrast, the effects of defoliation did not depend on the presence of the AM fungus, which suggests that while the relative abundance of legumes and grasses is likely to have a significant role in the response of legume–grass communities to defoliation, the role of AM fungi may be less important. In line with this, the AM fungus had only a few significant effects on plant and soil attributes in our systems and each of them was modified by defoliation and/or plant species composition. This suggests that the effects of AM fungi in legume–grass communities may largely depend on the plant species present and whether the plants are grazed or not.

In potato production, relatively low phosphorus use efficiency (PUE) leads to excessive phosphorus (P) fertilizer application in many regions, resulting in increasingly environmental risks. Consequently, an increasing number of researchers have started to explore the ways to improve the PUE. The symbiosis between arbuscular mycorrhizal fungi (AMF) and crop roots enhances P uptake. However, the effectiveness of AMF inoculation under field conditions depends on the environment and agronomic managements. In Inner Mongolia, China, few field experiments have been conducted on AMF inoculation in potato production. This is mainly due to low estimates of AMF colonization attributed to fungicide use in seed tuber treatments and soil mechanical disturbance caused by ridging. This study aimed to test whether inoculation with AMF after ridging at the seedling stage could improve AMF colonization in potatoes, thereby enhancing P uptake and tuber yield. Field experiments were conducted in Inner Mongolia to compare the effects of AMF inoculation after ridging at seedling stage versus inoculating seed potato with AMF during sowing, and to investigate the potential of reducing the P application rate through inoculation with AMF in potato production. The AMF colonization rate, soil hyphal density, P uptake, plant growth and tuber yield of potatoes under different treatments were measured. The results showed that compared with AMF inoculation at sowing, inoculation after ridging at the seedling stage significantly increased AMF colonization by 8 percentage points. This led to a significant improvement in P uptake and potato growth, ultimately resulting in a yield increase of approximately 6%. Further findings showed that reducing P application by 25% from the conventional rate (160 kg P2O5 ha−1) led to significant yield loss. Whereas with AMF inoculation at the seedling stage, yield levels were maintained and the partial factor productivity of P fertilizer (PFP) was increased by an average of 39%. In conclusion, this study reveals that AMF inoculation after ridging can mitigate the negative impacts of fungicides in seed tuber treatment and ridging-caused soil disturbance on AMF colonization. It highlights importance of inoculation timing for achieving higher AMF population density. Moreover, the study demonstrates that the developed AMF inoculation enables a reduction of P fertilizer application in potato production. This provides a viable approach to enhance PUE and promote sustainable potato production in areas such as Inner Mongolia. It carries significant agronomic and environmental implications.

High concentrations of soil Al3+ in acid soil severely influence the growth of Medicago sativa (alfalfa). The objective of the current study was to analyze whether Arbuscular Mycorrhizal Fungi (AMF) inoculation could improve alfalfa growth in acid soils. A two-way completely randomized factorial design was employed for M. sativa and M. lupulina (black medick) with two inoculations (rhizobia and AMF) and three Al3+ levels, and replicated four times. The soil Al3+ levels were adjusted to 900 mg/kg, 1000 mg/kg and 1100 mg/kg. Spores of AMF were isolated directly from rhizosphere soils of black medick. The rhizobia were isolated from root nodules in fields separately from two plant species. At each Al3+ level, there were four inoculations, non-inoculation, AMF solely, rhizobia solely and dual-inoculation with AMF and rhizobia. Soil Al3+ concentration significantly limited above- and below-ground growth of both alfalfa and black medick, reducing plant height, branching number, shoot and root weight, and root length, surface area and volume. Compared to rhizobia, AMF showed a higher tolerance to soil Al3+. AMF inoculation increased the shoot and root weight of both plant species under most circumstances. Overall, AMF colonization had a trend in increasing the contents of phosphorus in both plant species at all Al3+ concentrations but not nitrogen and potassium. Dual inoculation significantly increased nodulation ability, enabling both plant species to form nodules at 900 and 1000 mg/kg Al3+. Though the soil Al3+ concentration influenced the efficiency of AMF inoculation, AMF inoculation improved nodulation, increased plant growth and nutrient uptake, suggesting that it was an alternative way in improving alfalfa growth in acid soils.

Associative effects of activated carbon biochar and arbuscular mycorrhizal fungi on wheat for reducing nickel food chain bioavailability

ABSTRACTThe influence of dual inoculation of arbuscular mycorrhizal fungi (AMF) and Rhizobium was assessed on garden pea productivity, root morphology and soil fertility during 2011–2012 at Palampur, India, in a medium phosphorus (P) acid Alfisol. Field experimentation comprised 13 treatments involving Rhizobium, AMF and inorganic fertilizers in (RBD) replicated thrice. The dual inoculation of Rhizobium and AMF exhibited nominal effect on pea pod length, pod girth and number of seeds per pod. However, average pod weight (APW) and productivity increased by 14.1 and 20% following dual inoculation, respectively, over generalized recommended nitrogen, phosphorus and potassium (NPK) dose general recommended dose (GRD). Dual inoculation of pea seed with both symbionts sharply increased the root volume (RV), root dry weight (RDW), root weight density (RWD) and root nodules per plant by 34.5, 13.3, 13 and 44%, respectively. Similarly, the highest AMF root colonization was registered under dual-inoculated plots compared to sole application of Rhizobium or AMF. Different treatments including dual-inoculated ones did not alter the soil organic carbon (SOC), available N, K and diethylenetriaminepentaacetic acid (DTPA)-extractable micronutrients iron, zinc, copper and manganese (Fe, Zn, Cu and Mn) status significantly; however, a nominal buildup in the above-mentioned parameters was registered under dual inoculation. Available P status increased to the tune of 6.7 and 8.7% following dual inoculation with Rhizobium and AMF over their respective sole inoculations. Overall, the current study suggests that Glomus–Rhizobium symbiosis has great potential in enhancing productivity through better proliferation of the root system and improved soil fertility status. Furthermore, dual inoculation of AMF and Rhizobium can save up to 25% fertilizer N and P in garden pea in acid Alfisol of the northwestern Himalayas (NWH).

A pot experiment was conducted to investigate the effects of drought stress and arbuscular mycorrhizal fungi (AMF) inoculation on C:N:P stoichiometry and non-structural carbohydrate (NSC) contents in two-year-old Heptacodium miconioides seedlings. There were four treatments, including control (CK), drought stress (D), AMF inoculation (AMF), and combined drought stress and AMF inoculation (D+AMF). The results showed that drought stress significantly reduced AMF colonization rate, whereas plant height and leaf number of inoculated treatment were significantly higher than the non-inoculated treatment. Inoculation with AMF significantly increased soluble sugar and NSC content in root and leaf, as well as starch content in stem and leaf. The inoculation significantly decreased the stem and leaf soluble sugar to starch ratio under drought stress. Drought stress caused a significant increase in C content in roots and leaves, and a significant decrease in P content in stems. Compared with no inoculation drought stress, P content in roots, stems, leaves, and C content in leaves of mycorrhizal seedlings were significantly increased by inoculation under drought stress, whereas root C and N content and stem C content were significantly reduced. Under drought stress, AMF inoculation significantly decreased C:N, C:P, and N:P ratios in roots and stems, and N:P ratios in leaves of H. miconioides. P content in roots and leaves were significantly positively correlated with soluble sugar and NSC content. Stem P content was significantly positively correlated with starch and NSC content. N:P ratios in each organ was significantly negatively correlated with NSC content. In all, inoculation with AMF can improve the drought tolerance of H. miconioides seedling by increasing soluble sugar content in roots and leaves and the soluble sugar/starch ratio in roots, improving starch content in above-ground organs, promoting the P absorption, and reducing N:P ratios in each organ. Therefore, AMF colonization could improve the survival rate of H. miconioides seedling in dry environments.

Inoculation of arbuscular mycorrhizal (AM) fungi in soil can promote the uptake of nutrients and xenobiotics by plants. In this study, the effects of arbuscular mycorrhizal fungi (including Glomus intraradices and Glomus mossea) on the growth of maize, the uptake of carbosulfan and the control efficacy on Spodoptera frugiperda were investigated through maize seed coating. Results from the pot experiment showed that carbofuran reduced the mycorrhizal colonization of AM fungi in the early stage of the experiment. The inhibiting effect disappeared in 21-49 DAP, whereas the mycorrhizal colonization rate under the G.intraradices treatment was maintained at ≈90%. Compared with noninoculated treatment, the fresh weights of roots in G.intraradices and G.mosseae treatments increased by 20-41% and 10-23%, respectively. Mycorrhizal treatment could significantly increase the transmission rates (root/soil and leaf/stem) and the carbosulfan accumulation in maize. During the harvest period, the control efficacy against S.frugiperda in mycorrhizal treatment was significantly higher than that in noninoculated treatments (P < 0.05) in both Guangzhou and Nanning. Inoculation with AM could accelerate the degradation process of carbofuran in soil and the propagation of carbofuran from soil to plants. Glomus intraradices showed more pronounced effects than G.mosseae on both plant growth and carbosulfan content in plants and soil. The experimental results showed that inoculation of AM fungi increased the accumulation of carbofuran in plants, improved the effective utilization rate and enhanced the control efficacy against S.frugiperda. © 2021 Society of Chemical Industry.

Plant cultivation can influence the immobilization of heavy metals in soil. However, the roles of soil amendments and microorganisms in crop-based phytoremediation require further exploration. In this study, we evaluated the impact of Zea mays L. cultivation, biochar application, and arbuscular mycorrhizal fungi (AMF) inoculation on soil lead (Pb) immobilization. Our results indicated that biochar addition resulted in a significant, 42.00%, reduction in AMF colonization. Plant cultivation, AMF inoculation, and biochar addition all contributed to enhanced Pb immobilization, as evidenced by decreased levels of diethylenetriaminepentaacetic acid- and CaCl2-extractable Pb in the soil. Furthermore, soil subjected to plant cultivation with AMF and biochar displayed reduced concentrations of bioavailable Pb. Biochar addition altered the distribution of Pb fractions in the soil, transforming the acid-soluble form into the relatively inert reducible and oxidizable forms. Additionally, biochar, AMF, and their combined use promoted maize growth parameters, including height, stem diameter, shoot and root biomass, and phosphorus uptake, while simultaneously reducing the shoot Pb concentration. These findings suggest a synergistic effect in Pb phytostabilization. In summary, despite the adverse impact of biochar on mycorrhizal growth, cultivating maize with the concurrent use of biochar and AMF emerges as a recommended and effective strategy for Pb phytoremediation.IMPORTANCEHeavy metal contamination in soil is a pressing environmental issue, and phytoremediation has emerged as a sustainable approach for mitigating this problem. This study sheds light on the potential of maize cultivation, biochar application, and arbuscular mycorrhizal fungi (AMF) inoculation to enhance the immobilization of Pb in contaminated soil. The findings demonstrate that the combined use of biochar and AMF during maize cultivation can significantly improve Pb immobilization and simultaneously enhance maize growth, offering a promising strategy for sustainable and effective Pb phytoremediation practices. This research contributes valuable insights into the field of phytoremediation and its potential to address heavy metal pollution in agricultural soils.

The objective of this study was to investigate the effects of arbuscular mycorrhizal fungus (AMF) inoculation on plant growth and drought tolerance in seedlings of a promising oilseed crop, Sacha Inchi (Plukenetia volubilis L.), under well-watered or drought conditions. AMF inoculation was applied in four treatments: without AMF inoculation, Glomus versiforme, Paraglomus occultum, or combination of both microorganism inoculations. The results showed that AMF colonization significantly enhanced the growth of Sacha Inchi seedlings regardless of soil water conditions, and the greatest development was reached in plants dually inoculated under well-watered conditions. G. versiforme was more efficient than P. occultum. Plants inoculated with both symbionts had significantly greater specific leaf area, leaf area ratio and root volume when compared with the uninoculated control, G. versiforme, and P. occultum treatments alone, indicating a synergistic effect in the two AMF inoculation. Photosynthetic rate and water-use efficiency were stimulated by AMF, but not stomatal conductance. Inoculation with AM fungus increased antioxidant enzymes activities including guaiacol peroxidase and catalase, thus lowering hydrogen peroxide accumulation and oxidative damage, especially under drought stress conditions. However, proline content showed little change during drought stress and AMF colonization conditions, which suggested that proline accumulation might not serve as the main compound for osmotic adjustment of the studied species. These results indicate that AMF inoculation stimulated growth and enhanced drought tolerance of Sacha Inchi seedlings, through alterations in morphological, physiological and biochemical traits. This microbial symbiosis might be an effective cultivation practice in improving the performance and development for Sacha Inchi plants.

Cotton (Gossypium hirsutum L.) is a promising candidate for an Arsenic (As)-tolerant plant due to its low As accumulation in fibers. The individual arbuscular mycorrhizal fungi (AMF) inoculation or exogenous calcium (Ca2+) application is known to enhance heavy metal tolerance in higher plants; however, their synergistic mechanisms in alleviating As stress in cotton remain poorly understood. A three-factor pot experiment was conducted, including two levels of AMF (Funneliformis mosseae C.Walker &amp; A.Schüßler) inoculation (non-inoculated/inoculated), As stress (0/100 mgAs5+·kg−1soil), and exogenous Ca2+ (CaCl2) application (0/20 mmol·L−1 CaCl2). AMF inoculation and Ca2+ application were investigated for their effects on cotton growth, root morphology, photosynthetic characteristics, osmotic regulators, antioxidant enzyme activities, and ion homeostasis under As stress. Results showed As stress significantly disrupted cotton growth (decreased plant height, shoot and root dry weight) and root morphology (reduced total root length, root area, and root fork number), photosynthetic capacity (reduced Pn, Ci, Fv/Fm, and ΦPSII), osmotic adjustment (decreased proline, soluble sugar and protein), antioxidant defense (inhibited SOD, POD, CAT activities), and K+/Ca2+ homeostasis (reduced concentration of K+ and Ca2+, and K+/Ca2+ ratio). Both AMF inoculation and Ca2+ application independently alleviated these adverse effects of As stress. At the same time, AMF symbiosis combined with exogenous Ca2+ was better than AMF inoculation or Ca2+ application alone in optimizing root architecture, improving stomatal function and photosynthetic efficiency, enhancing osmotic regulator accumulation and antioxidant enzyme activities, and restoring ion balance under As stress. Three-way ANOVA confirmed significant As×AMF×Ca2+ interactions on key parameters such as Pn and ΦPSII. In summary, both AMF inoculation and Ca2+ application synergistically enhanced cotton As tolerance through regulating growth, root morphology, photosynthetic characteristics, osmotic regulators, antioxidant enzyme activities, and ion homeostasis, demonstrating its potential for sustainable cotton cultivation in As-contaminated soils.