Revegetation in an iron ore mine - Nutrient requirements for plant growth and the potential role of vesicular arbuscular (VA) mycorrhizal fungi

Soil Research ◽  
1988 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
DA Jasper ◽  
AD Robson ◽  
LK Abbott

Revegetation after iron-ore mining in the Pilbara region of Australia is difficult because of the harsh climate and because the material to be revegetated is likely to have poor fertility and low microbial activity. In this work we defined the infectivity of VA mycorrhizal fungi in local soils and mine materials, and then the nutrient requirements for adequate plant growth in low-grade ore. Finally, we tested the hypothesis that addition of phosphorus to low-grade ore, and inoculation with VA mycorrhizal fungi, increases the growth of Acacia pyrijolia. The VA mycorrhizas were formed only in soil collected from sites dominated by Triodia pungens. A. pyrifolia nodulated only in soil from sites dominated by A. aneura. In low-grade ore, phosphorus deficiency was the major limitation to plant growth. Inoculation with a Glomus sp. resulted in up to 70% increases in dry matter production at low rates of phosphorus. The response to phosphorus or inoculation with VA mycorrhizal fungi was limited by nitrogen deficiency.

1999 ◽  
Vol 34 (6) ◽  
pp. 1018-1024 ◽  
Author(s):  
Elizabeth Ying Chu

With the objective of verifying the response of Euterpe oleracea seedlings to seven arbuscular mycorrhizal fungi species, an experimental trial was carried out under greenhouse conditions. Seeds of E. oleracea were sown in carbonized rice husk. Germinating seeds were initially transferred to plastic cups, containing fumigated Reddish Yellow Quartz Sand and inoculated with arbuscular mycorrhizal fungi. Two months later, seedlings were transferred to 2 kg black plastic bags, containing the same soil without fumigation. Plant growth and mineral nutrients were evaluated nine months after mycorrhizal inoculation. Differential effects were observed among the species tested, with Scutellispora gilmorei being the most effective ones in promoting growth and nutrient content of E. oleracea seedlings. The increment resulted from inoculation with S. gilmorei were 92% in total plant height, 116% in stem diameter, 361% in dry matter production, 191% in N, 664% in P, 46% in K, 562% in Ca, 363% in Mg and 350% in Zn contents, comparing to uninoculated controls. Infected root length was positively correlated to nutrient content and plant growth. It was concluded that growth and nutrient uptake of E. oleracea seedlings could be significantly improved by inoculation of effective arbuscular mycorrhizal fungi.


1989 ◽  
Vol 37 (1) ◽  
pp. 33 ◽  
Author(s):  
DA Jasper ◽  
LK Abbott ◽  
AD Robson

We used plant bioassays to monitor the decline in infectivity of VA mycorrhizal fungi in topsoil during bauxite mining. In a second experiment, we investigated the seasonal changes in the infectivity of VA mycorrhizal fungi in jarrah (Eucalyptus marginata Donn ex Smith) forest soil. Finally, we tested the hypothesis that Acacia pulchella growing in soil disturbed during bauxite mining would respond to phosphorus and to inoculation with VA mycorrhizal fungi. During bauxite mining in the Western Australian jarrah forest, the infectivity of propagules of VA mycorrhizal fungi in topsoil was destroyed, even when the soil was stripped and respread promptly without stockpiling. Most infectivity was lost within 3 weeks of clearing the vegetation, before the soil was disturbed. The rapid loss of infectivity may be associated with the absence of spores in the soil. In a revegetated, respread soil, the infectivity of VA rnycorrhizal fungi was substantially greater than that of freshly disturbed soil, but less than levels recorded in similar undisturbed forest soil. There were no clear seasonal changes in VA mycorrhizal infectivity, indicating that the loss of infectivity during mining was not a seasonal response. Dry matter production by Acacia pulchella, in a glasshouse experiment, was at least doubled if soil from experiment 1 was inoculated with effective VA mycorrhizal fungi.


2021 ◽  
Vol 5 ◽  
Author(s):  
Pratikhya Mohanty ◽  
Puneet Kumar Singh ◽  
Debosmita Chakraborty ◽  
Snehasish Mishra ◽  
Ritesh Pattnaik

A multitude of roles is played by microbes in food and agriculture that include nutrient cycling and management, organic matter decomposition and fermentation. Plant growth promoting rhizobacteria (PGPR), representing microbial groups and with ability of colonizing plant roots, influence plant growth through various indirect and direct modes in order to promote its growth and/or protect it from diseases or damage due to insect attack. Thus, PGPR research has received renewed interest worldwide. Increasing number of crop-specific PGPR are being commercialized these days. Approaches like seed-inoculation and soil application either alone or in combination with bacterial culture/product for increased nutrient availability through phosphate solubilisation, potassium solubilisation, sulfur oxidation, nitrogen fixation, iron, and copper chelation are gaining popularity. Arbuscular mycorrhizal fungi (AMF) are root fungal symbiont that improve management of abiotic stress such as phosphorus deficiency. PGPR involves roles like production of indole acetic acid (IAA), ammonia (NH3), hydrogen cyanide (HCN), catalase, etc. PGPR also improve nutrient uptake by altering the level of plant hormone that enhances root surface area by increasing its girth and shape, thereby helping in absorbing more nutrients. PGPR facilitate seed germination, seedling growth and crop yield. An array of microbes including Pseudomonas, Azospirillum, Azotobacter, Klebsiella, Enterobacter, Alcaligenes, Arthrobacter, Burkholderia, Bacillus, and Serratia enhance plant growth. Various Pseudomonas sp. have demonstrated significant increase in germination, seedling growth and yield in different agricultural crops, including wheat. Hence, developing a successful crop-specific PGPR formulation, the candidate should possess characteristics like high rhizosphere competence, extensive competitive saprophytic ability, growth enhancing ability, ease of mass production, broad-spectrum action, safety toward the environment and compatibility with other partnering organisms.


1982 ◽  
Vol 33 (2) ◽  
pp. 389 ◽  
Author(s):  
LK Abbott ◽  
AD Robson

Vesicular arbuscular (VA) mycorrhizas are roots infected with particular soil fungi which form symbiotic associations. It is often assumed that VA mycorrhizal fungi could be used to increase the efficiency of phosphate fertilizers in agriculture. Our principal concern is the question: 'Can the symbiosis be exploited on a large scale?'. VA mycorrhizas increase nutrient uptake, and hence plant growth, by shortening the distance that nutrients must diffuse through soil to the root. Mycorrhizal roots do not appear to have a lower threshold concentration of nutrients for absorption from solution than do non-mycorrhizal roots. Most soils contain VA mycorrhizas. Hence, for plant growth to respond to inoculation with VA mycorrhizal fungi, agricultural soils must have either a low incidence of indigenous VA mycorrhizal fungi or alternatively, species which are less effective than the inoculant fungi in their ability to stimulate nutrient uptake by plants. The distribution of species of VA mycorrhizal fungi varies with climatic and edaphic environment, as well as with land use. However, the factors which control their distribution are poorly understood. Differences among VA mycorrhizal fungi in their ability to increase nutrient uptake appear to be due to differences in their ability to form mycorrhizas rapidly and extensively. The importance of other differences among the fungi, such as in the absorption of nutrients from solution or in the distribution and amount of external mycelium, has yet to be clearly demonstrated. Inoculant VA mycorrhizal fungi must be capable of persisting in soils at a high inoculum potential, as well as being able to increase nutrient uptake. Until now, little attention has been paid to characteristics which enable the fungi to persist after inoculation. We are critical of many of the methods employed in experiments aimed at selecting 'efficient' VA mycorrhizal fungi. For practical purposes, selection can only be achieved by means of comparisons performed in untreated field soils, with phosphorus supply limiting plant growth. Because the form of inoculum can affect the relative abilities of VA mycorrhizal fungi to infect and improve plant growth, appropriate inocula are needed for each agricultural situation. The survival of many species of fungi in various types of inocula requires further study so that procedures can be developed for introducing particular fungi into agricultural soils. This review emphasizes many gaps in our knowledge. For example, we need more information on how and to what extent species or strains of VA mycorrhizal fungi differ in their ability to increase plant growth. We know even less about their beneficial effects in years following that of field inoculation. The ecology of indigenous VA mycorrhizal fungi in field soils has also been largely neglected. These and other deficiencies preclude any immediate recommendations for large-scale inoculation with selected VA mycorrhizal fungi.


2019 ◽  
Author(s):  
Mohanraj G. T. ◽  
Krishneindu P. ◽  
R. P. Choudhary ◽  
Sher Singh Meena ◽  
S. M. Yusuf ◽  
...  
Keyword(s):  
Iron Ore ◽  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdolrahim Foroutan ◽  
Majid Abbas Zadeh Haji Abadi ◽  
Yaser Kianinia ◽  
Mahdi Ghadiri

AbstractCollector type and pulp pH play an important role in the lead–zinc ore flotation process. In the current study, the effect of pulp pH and the collector type parameters on the galena and sphalerite flotation from a complex lead–zinc–iron ore was investigated. The ethyl xanthate and Aero 3418 collectors were used for lead flotation and Aero 3477 and amyl xanthate for zinc flotation. It was found that maximum lead grade could be achieved by using Aero 3418 as collector at pH 8. Also, iron and zinc recoveries and grades were increased in the lead concentrate at lower pH which caused zinc recovery reduction in the zinc concentrate and decrease the lead grade concentrate. Furthermore, the results showed that the maximum zinc grade and recovery of 42.9% and 76.7% were achieved at pH 6 in the presence of Aero 3477 as collector. For both collectors at pH 5, Zinc recovery was increased around 2–3%; however, the iron recovery was also increased at this pH which reduced the zinc concentrate quality. Finally, pH 8 and pH 6 were selected as optimum pH values for lead and zinc flotation circuits, respectively.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1531
Author(s):  
Narcisa Urgiles-Gómez ◽  
María Eugenia Avila-Salem ◽  
Paúl Loján ◽  
Max Encalada ◽  
Leslye Hurtado ◽  
...  

Coffee is an important, high-value crop because its roasted beans are used to produce popular beverages that are consumed worldwide. Coffee plantations exist in over 70 countries and constitute the main economic activity of approximately 125 million people. Currently, there is global concern regarding the excessive use of agrochemicals and pesticides in agriculture, including coffee crops. This situation has motivated researchers, administrators, and farmers to seek ecologically friendly alternatives to decrease the use of synthetic fertilizers and pesticides. In the last decades, multiple studies of the rhizosphere, at the chemical, physical and biological levels, have improved our understanding of the importance of beneficial microorganisms to plant health and growth. This review aims to summarize the state of the use of plant growth-promoting microorganisms (PGPM) in coffee production, where the most extensively studied microorganisms are beneficial plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF). This review also contains information on PGPM, in regard to plantations at different latitudes, isolation techniques, mass multiplication, formulation methods, and the application of PGPM in nurseries, monoculture, and coffee agroforestry systems. Finally, this review focuses on relevant research performed during the last decade that can help us improve sustainable coffee production.


2021 ◽  
Vol 7 (7) ◽  
pp. 571
Author(s):  
Dilfuza Jabborova ◽  
Kannepalli Annapurna ◽  
Sangeeta Paul ◽  
Sudhir Kumar ◽  
Hosam A. Saad ◽  
...  

Biochar and arbuscular mycorrhizal fungi (AMF) can promote plant growth, improve soil properties, and maintain microbial activity. The effects of biochar and AMF on plant growth, root morphological traits, physiological properties, and soil enzymatic activities were studied in spinach (Spinacia oleracea L.). A pot experiment was conducted to evaluate the effect of biochar and AMF on the growth of spinach. Four treatments, a T1 control (soil without biochar), T2 biochar alone, T3 AMF alone, and T4 biochar and AMF together, were arranged in a randomized complete block design with five replications. The biochar alone had a positive effect on the growth of spinach, root morphological traits, physiological properties, and soil enzymatic activities. It significantly increased the plant growth parameters, such as the shoot length, leaf number, leaf length, leaf width, shoot fresh weight, and shoot dry weight. The root morphological traits, plant physiological attributes, and soil enzymatic activities were significantly enhanced with the biochar alone compared with the control. However, the combination of biochar and AMF had a greater impact on the increase in plant growth, root morphological traits, physiological properties, and soil enzymatic activities compared with the other treatments. The results suggested that the combined biochar and AMF led to the highest levels of spinach plant growth, microbial biomass, and soil enzymatic activity.


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