Mineral Sand Mining Research Articles

Equivalent mating system parameters in post‐mining and undisturbed native plant populations confirms restitution of bird‐pollinator function

Abstract The restoration of diverse self‐sustaining ecosystems requires re‐establishment of functional interactions among species. For plant communities, pollinators are usually essential for pollination, seed set and seed quality. A common assumption in ecological restoration for plants pollinated by animals is one of ‘build it and they will come’, which is rarely tested. Beyond seed set, there may be negative genetic consequences for seed quality if pollinators and their behaviour do not reflect those in reference populations. Here, we conduct an ecological genetic assessment of seed quality via mating system parameters in Lambertia multiflora (Proteaceae), a species dependent on nectar‐feeding birds for pollination. Four populations of L. multiflora in disturbed sites that were rehabilitated following mineral sands mining were compared with four native reference populations, near Eneabba, Western Australia. In each population, approximately 10 offspring from each of 10 maternal plants were genotyped with 11 highly polymorphic microsatellite markers. From these data, genetic diversity and mating system parameters were assessed, and found to be equivalent across all populations. Mean allelic diversity and heterozygosity across loci were very high. All populations were completely outcrossing with no bi‐parental inbreeding. Mean correlated paternity, sibship and effective population size estimates for restored and natural populations were not significantly different and reflected uniformly high paternal diversity and wide outcrossing. Equivalent genetic results for restored and natural reference populations indicate successful restitution of bird‐pollinator services for L. multiflora in these post‐mining rehabilitation sites. Synthesis and applications. Reviewing our results with other published studies to date suggests a resilience of bird‐pollinator services in restored plant communities. These findings provide some reassurance to restoration practitioners working in these global south systems where bird pollination is a feature, at least for similar landscape scenarios. Our study also highlights the global contribution of ecological genetics to the objective assessment of functional species interactions in ecological restoration, an increasingly important goal of land managers and regulators seeking to improve restoration standards.

Assessment of Heavy Metal Pollution in Soil and Associated Risks in the Environs Adjacent to a Heavy Mineral Sand Mine on the South Coast of Kenya

Assessment of Heavy Metal Pollution in Soil and Associated Risks in the Environs Adjacent to a Heavy Mineral Sand Mine on the South Coast of Kenya

Availability of Residual and/or Applied Inorganic Phosphorus for Sugarcane Uptake and Growth in a Post-Mined Reconstituted Soil

Mineral sands mining is worldwide an environmental issue and also at the Hillendale mine in KwaZulu-Natal, South Africa. The post-mined soil is to be rehabilitated to sugarcane cropping. One of the concerns with the post-mined soil which is reconstituted with a 70:30 mixture of sand: slimes (silt-plus-clay fraction), is its low phosphorus (P) status, which could be limiting for optimum sugarcane production. A field experiment was conducted on a reconstituted soil at Hillendale to establish the availability of either residual or applied inorganic P to the plant and first ratoon sugarcane crop. Four treatments were evaluated including those where P fertilizer was omitted, applied at half the recommended rate or introduced equal to the recommended rate according to chemical analysis of the soil. In the fourth treatment, no fertilizer was applied at all, whereas nitrogen (N) and potassium (K) were added at recommended rates in the first three treatments. Phosphorus application had a significant effect on sugarcane fractional light interception and aboveground biomass yield of the plant and first ratoon crops, and stalk length and diameter of the first ratoon crop. Pol, brix, purity and fibre content and tiller number were not affected by P application. The application of P increased the foliar N, P, K, calcium (Ca), magnesium (Mg) and sulphur (S) contents of both crops. However, foliar N, P and K were deficient in the first ratoon crop even in the case where fertilizer was applied at the recommended rates, which could have been because of waterlogging. The possible effect of waterlogging on P uptake needs to be addressed in future studies in this reconstituted soil.

The anticipatory politics of dispossession in a Senegalese mining negotiation

The concept of accumulation by dispossession is often mobilized in political ecological and geographical literature, to explain the ways that capitalist accumulation depends on the violent and extra-economic seizure of land and resources. Yet dispossession is also mobilized as a fear about the future, as a way of articulating historical and non-capitalist motivations for land expropriation, and as an avenue for political action. Amid negotiations for a heavy mineral sands mine in the Casamance region of Senegal, narratives of dispossession circulated frequently, even though no mining had yet taken place. Drawing on ethnographic fieldwork and qualitative interviews, this article examines the contentious politics around the proposed mine, which mobilize multiple timescales. In this context, activists and village residents have engaged in an anticipatory politics that is influenced by past and present processes of land occupancy, environmental change, and state disinvestment, and is aimed at contesting potential dispossessions to come, making claims to resources, and securing a place in the imagined future. At the same time, state and corporate actors have engaged in their own anticipatory actions, through environmental impact assessments and other technologies of prediction that minimize, invalidate, or circumvent anti-dispossession movements. This article argues that experiences of and resistances to dispossession are mediated by the folding together of temporal frames and diverse displacements. In particular, it attends to anticipation as a key temporal mechanism through which dispossession is both enacted and contested. As such, it contributes to political ecology by combining materialist conceptions of dispossession and displacement with theorizations of anticipation and the future. Keywords : accumulation by dispossession, anticipatory politics, mining, Senegal

Witnessing four decades of change in coastal park management: Interview with Mike Dodkin

Mike Dodkin’s career as an officer with the NSW National Park and Wildlife Service spanned four decades. His work involved ecological surveys of potential new conservation reserves, overseeing rehabilitation works after mineral sand mining, supporting innovative restoration projects in rainforest and coastal dunes, and pioneering work in marine mammal rescue. In this interview, Mike reflects on those activities and the changes he has witnessed over time.

Changes over time and changes yet to come

Change over time is of primary interest for ecologists and managers. Change can be positive and is often part of nature's flux, but it can also be negative if arising from impacts that push ecosystems beyond net sustainability. Researchers work long and hard to develop methodologies to gain insight into how much change is part of acceptable flux and how much is unacceptable impact; and monitoring change is also essential to identify levels of recovery over time after restorative management interventions and, in many cases, to fully test hypotheses. This issue's interview with Mike Dodkin, retired naturalist ranger and pest species officer, touches on all these themes as he recollects projects over a 40-year period. Mike was there during the period of social change that saw mineral sand mining on Australia's east coast sites destined for dedication as national parks post-mining. His role not only included finding ways to reduce mining impacts and attain recovery, but also involved starting up new restoration projects to overcome damage that occurred many decades previously – all such projects which will take many decades hence to be fully realized. In a similar vein in this issue, Brad Farmilio and colleagues report about changes in plant composition after 10 years of monitoring in grazed native pastures in south-eastern Australia after an incentive scheme to reduce impacts on grassland remnants; Richard van Dongen and colleagues observe changes in native vegetation on Dirk Hartog Island, Western Australia many years after removal of non-native herbivores; and, Andrew Carter and Laura Ruykys document a gradual eradication of introduced predators in a fenced reserve in South Australia The passage of time is also important to fully test new hypotheses. Hannah Franklin and colleagues in New Zealand tested the capacity of a range of native riparian plants to take up nitrogen and propose a framework for selecting species that can best buffer farm runoff into streams. Longer term study of riparian plantings based on this model will provide valuable insights, as will application of the value-based arguments for seascape repair put forward by Vishnu Prahalad and colleagues in this issue's second feature and Linda Luck and colleagues’ longer term testing of residual herbicides to reduce Gamba Grass populations in northern Australia. Indeed, all our interventions to improve the functionality of impaired ecosystems could be considered tests of hypotheses, including the core hypothesis that interventions can make a positive difference. Ian McLeod and colleagues acted on an informed hunch in North Queensland that relocation of coral colonies displaced by a cyclone would result in recovery, and all the indicators are pointing to success in this case and many others. In this and many cases involving lower-to-establish species or processes, only time and ongoing monitoring will tell. For example, longer time frames have proven to be useful in the detection by Tai White-Tony and colleagues of long-term patterns of establishment of tree species after mine site restoration in the Jarrah Forest in Western Australia – as well as to allow Kimberly McCallum and colleagues to assess the relationship between the configuration of planted species and their effective pollination in South Australian revegetation sites, many years after plant establishment. With the passage of time also comes change in personnel, such that longitudinal studies and ongoing nurturing of long-term recovery require commitments by institutions that persist beyond the working lives of individuals. It is hard to overstate the need for future managers and researchers to recognize the amount of past work that has gone into many studies and into securing the current condition of many sites. We need to firmly but gently remind current and future generations that long-term effort in these areas is a multi-generational compact.

Microbial biobanking – cyanobacteria-rich topsoil facilitates mine rehabilitation

Abstract. Restoration of soils post-mining requires key solutions to complex issues through which the disturbance of topsoil incorporating soil microbial communities can result in a modification to ecosystem function. This research was in collaboration with Iluka Resources at the Jacinth–Ambrosia (J–A) mineral sand mine located in a semi-arid chenopod shrubland in southern Australia. At J–A, assemblages of microorganisms and microflora inhabit at least half of the soil surfaces and are collectively known as biocrusts. This research encompassed a polyphasic approach to soil microbial community profiling focused on “biobanking” viable cyanobacteria in topsoil stockpiles to facilitate rehabilitation. We found that cyanobacterial communities were compositionally diverse topsoil microbiomes. There was no significant difference in cyanobacterial community structure across soil types. As hypothesised, cyanobacteria were central to soil microprocesses, strongly supported by species richness and diversity. Cyanobacteria were a significant component of all three successional stages with 21 species identified from 10 sites. Known nitrogen-fixing cyanobacteria Symploca, Scytonema, Porphyrosiphon, Brasilonema, Nostoc, and Gloeocapsa comprised more than 50 % of the species richness at each site and 61 % of the total community richness. In the first study of its kind, we have described the response of cyanobacteria to topsoil stockpiling at various depths and ages. Cyanobacteria are moderately resilient to stockpiling at depth and over time, with average species richness greatest in the top 10 cm of the stockpiles of all ages and more viable within the first 6 weeks, indicating potential for biocrust re-establishment. In general, the resilience of cyanobacteria to burial in topsoil stockpiles in both the short and long term was significant; however, in an arid environment recolonisation and community diversity could be impeded by drought. Biocrust re-establishment during mine rehabilitation relies on the role of cyanobacteria as a means of early soil stabilisation. At J–A mine operations do not threaten the survival of any of the organisms we studied. Increased cyanobacterial biomass is likely to be a good indicator and reliable metric for the re-establishment of soil microprocesses.

Assessing the success of experimental rehabilitation on a coastal mineral sands mine in Namaqualand, South Africa

The success of different rehabilitation treatments following surface mining on the arid west coast of South Africa was assessed. Treatments consisting of one or a combination of topsoil addition, plant translocation and seeding were applied to experimental rehabilitation sites in 2001, while the treatment of another site in 2008 combined all three techniques. Vegetation and species cover, species richness, diversity and evenness, and grazing capacity of rehabilitation sites were sampled during winter 2009 and summer 2010, and compared with a reference site. All rehabilitated sites achieved the objective to attain a minimum grazing capacity of 20 ha per small stock unit. Rehabilitation trials were successful in establishing a vegetation cover, but were unable to return species richness and diversity to reference levels and did not resemble the reference site in species composition. Common species in reference sites were absent or only occurred in low numbers. No treatment outperformed the others and further experimentation is needed to determine the most suitable combination. It is recommended that rehabilitation should be done in multiple stages in future to improve seedling survival and to return species that are unable to establish in the adverse conditions present at the onset of rehabilitation.

The effect of community consultation on perceptions of a proposed mine: A case study from southeast Australia

Consultation is the predominant method of community engagement in infrastructure development. Therefore, understanding stakeholder interactions within consultation is critical to acquiring a social licence to operate. While previous research has focused on the factors which contribute to this social licence, little work has been conducted on how mining company consultation strategies influence perception formation. We explore how stakeholder expectations and experience of consultation impact perceptions of proposed mining projects. We undertook a case study of a proposed, large-scale, mineral sands mine in rural Australia using an open and closed-question questionnaire (n =32) and semi-structured interviews (n =20). We find that there are multiple, diverging understandings of the purpose of consultation both within and between stakeholder groups. The community experience of consultation drove negative perceptions of the proposed mine due to procedural and personal factors. We find several overlaps with the renewable energy (RE) literature, including: calls for two-way communication, (mis)trust of professional stakeholders, and the need for consistent and well-timed consultation. Other factors are not as common in the RE literature, and may be more specific to mining, such as stakeholder disenfranchisement misunderstood as apathy, calls for community involvement in agenda setting, the need for careful selection of company representatives, and the importance of meeting stakeholder expectations of consultation.

The expected impacts of mining: Stakeholder perceptions of a proposed mineral sands mine in rural Australia

The form and evolution of stakeholder perceptions toward renewable energy (RE) developments continue to be investigated, but there has been little similar research regarding mines. Responses of community members and other stakeholders cannot be expected to evolve the same way between different resource and infrastructure projects. We ask what the various expectations of planned mines are among community members, and what factors impact these expectations. We perform a case study of a planned, large-scale, mineral sands mine in rural Victoria, Australia (2013–2015). Using a closed-question questionnaire (n=32) and semi-structured interviews (n=25), individual and community experiences of the planning process were examined. We explore stakeholder perceptions of the mining company and development process to date, as well as future expectations. Despite the recognition of mining as a normalised part of modern Australian economy and culture, the results revealed a community with low-trust in the mining company, and accompanying negative perceptions of their own involvement thus far. These perceptions translated into negative future expectations. Many factors influential in the formation of RE opinions were also significant here, these include: background factors; visual and environmental impacts; and, the actions of the company to date. Other factors are not so prevalent in RE literature and may be specific to mines, these include issues surrounding the rehabilitation of the land and the history of the mining company.

Spinifex–mallee revegetation: implications for restoration after mineral-sands mining in the Murray–Darling Basin

Mineral-sands mining in the semiarid and arid zone of south-eastern Australia is now a widespread disturbance that may adversely affect large areas of remnant vegetation, including mallee (Eucalyptus spp.) with hummock grass or spinifex (Triodia scariosa) understorey. No broad-scale restoration projects have been undertaken to revegetate mallee Eucalyptus species with spinifex. We report on the survivorship and relative importance (spatial coverage) of hand-planted tubestock 10 years after establishment in 2001, which included mallee Eucalyptus, Triodia scariosa, Acacia spp. and Hakea spp. These taxa are the dominant plants in a semiarid dune–swale system on a former mineral-sands mine licence area in semiarid, north-western Victoria. Mean survivorship of tubestock was 0.58 ± 0.04. Spinifex (Triodia scariosa), needlewood (Hakea) and several mallee species (Eucalyptus spp.) survived substantially better than the average of all tubestock-planted species, although Acacia spp. had low survivorships. Although the plantings were undertaken in the early stages of the most severe drought in the instrumental record (the ‘Millennium drought’), several taxa survived well and species such as spinifex established and developed ground coverage greater than the benchmark values for the ecological vegetation class of the location. We conclude that hand-planting of tubestock can achieve restoration objectives for this component of spinifex–mallee vegetation, even under extremely arduous conditions associated with long-term drought. We also herald the importance of taking a long-term view to the assessment of revegetation success, in this case 10 years.

LITHOSTRATIGRAPHY OF THE GRAAUW DUINEN FORMATION (CENOZOIC WEST COAST GROUP), SOUTH AFRICA

The Graauw Duinen Formation forms part of the Cenozoic West Coast Group and was named after the farm Graauw Duinen 152 south of the Olifants River, where it is well exposed in mining faces of a heavy mineral sand mine. However, these exposures are ephemeral and more enduring natural sections at Cliff Point on the farm Geelwal Karoo 262 were chosen as the type area. The formation was previously regarded as a ‘Member’ of the Alexander Bay Formation, but along with other former subdivisions of this unit, has been elevated to ‘Formation’ status because of their broad significance on regional and even global scales. The formation essentially comprises late Neogene coastal calcareous aeolianites, widely distributed along the Namaqualand coast from north of Elands Bay to the Gariep (Orange) River. Fossils, stratigraphic context and correlation with the marine isotope record indicate that the age of the formation ranges from early to late Pliocene.

Estimation of radon and thoron caused dose at exraction and processing sites of mineral sand mining area in Vietnam (HA TINH province)

Mineral sands are mined in several countries to supply to the titanium and zircon producing industries. Coastal black mineral sands usually contain, besides ilmenite (FeTiO3) and rutile (TiO2), radioactive minerals such as zircon (ZrSiO4) and monazite (RePO4). Radon and thoron activity concentration originated from natural radioactive contents of the black mineral sand was monitored at the extraction and processing for black minerals in the coastal areas of Ha Tinh Province, one of the around 40 coastal mineral sand deposits in Vietnam. The survey was carried out with the Raduet chambers made by Radosys Ltd—Hungary. The obtained results for 25 investigated points show that the measured values are not high in the residential houses and in case of the sand extraction site as well. At the titanium processing plant the measured values were higher than outside the facility (Radon: 18–55 Bq/m3 with average of 34 Bq/3 and Thoron 33–118 Bq/m3 with average of 58 Bq/m3) but still comparable to the average concentration of the world published by UNSCEAR. The typical outdoor levels of radon and thoron gas are each of the order of 10 Bq/m3. Although the radon concentrations were low in the zircon and titanium processing plants, the thoron concentrations in the houses for separating rutile and zircon were very high. At zircon processing factory, the thoron concentration could reach 2,931 Bq/m3 and the estimated annual effective dose would be 21.4 mSv/a. Intervention has to be taken in order to reduce the thoron level in this factory since the level of thoron and its progenies corresponding to an annual occupational effective dose is beyond the action level of 6 mSv/a.

Parallel radon and thoron measurements in mineral sand mining area of Ha Tinh province

In this study, we have tested the possibility of parallel measurement of radon (222Rn) and thoron (220Rn or Tn) by alpha track detectors at the extraction and processing of black sands that contains high content of Zircon and Monazite minerals in a coastal area of the Ha Tinh province. A pair of cylindrical cups RADUET, designed to separately measure Rn and Tn with CR-39 detectors (Radosys Company Ltd – Hungary), were used for the test. The results showed that concentrations of indoor Rn and Tn in the black sand extraction area are not high (28 ± 6 Bq/m3 for Rn, 14 ± 5 Bq/m3 for Tn). The Rn and Tn concentrations in the indoor air of the titanium processing plant are 34 ± 6 Bq/m3 for Rn, 58 ± 11 Bq/m3 for Tn, and are higher than those concentrations in the residential houses outside the plant (20 ± 4 Bq/m3 for Rn, 16 ± 8 Bq/m3 for Tn) but still comparable to the average concentrations of indoor Rn and Tn reported by the UNSCEAR 2006. At Zircon processing plant, indoor Rn concentrations are similar to those in the titanium processing plant but Tn concentrations in the houses for separating Rutile and Zircon are very high. Indoor Tn concentration is especially high in the house for separating Zircon where it could reach 2931 Bq/m3, hundred times higher than that in the surrounding residential houses and that of the world average published by UNSCEAR 2006.

Organic matter accumulation post‐mineral sands mining

AbstractSoil development and organic matter (OM) accumulation are vital for sustainability in reclaimed prime farmlands following mineral sands mining. Additionally, the effectiveness of soil reconstruction techniques on soil development greatly influences crop productivity. Soil development and management effects following mineral sands mining were evaluated in years 1 (2005), 4 (2009) and 6 (2011) at the Carraway‐Winn Reclamation Research Farm, VA, USA. Treatments for this full scale agricultural experiment are as follows: biosolids applied at a rate of 78 Mg/ha managed with conventional tillage (BIO‐CT) and no‐till (BIO‐NT), a 15‐cm topsoil cap (TS), and a lime + fertilized control. Crop yields were determined annually, and soils were collected and analysed for aggregate size distributions and OM pools (available, aggregate‐protected and mineral‐bound). Crop yields (Corn‐Zea mays and wheat/soybean‐Triticum aestivum/Glycine max) were generally larger in the biosolids treatments from 2005 to 2008, with no difference among treatments from 2009 to 2011. Whole soil carbon (C) and nitrogen (N) rapidly increased between 2005 and 2009, mainly in the large macroaggregate (2000–8000 μm) size fraction. Carbon accumulation rates in the whole soils ranged from 2.85 to 3.58 Mg C/ha in the first 4 yr of soil development (similar trends were observed for N). There were no differences for soil aggregate parameters among treatments until year 6, where biosolids treatments contained more microaggregate (53–250 μm) and mineral‐bound C and N relative to other treatments. Short‐term increases in crop yields and long‐term increases in stable soil C and N make biosolids applications a viable alternative to traditional TS replacement strategies for this mining land use scenario.

Sorption of pesticides by a mineral sand mining by-product, neutralised used acid (NUA)

This study investigated the sorption–desorption behaviour of four pesticides by a by-product from mineral sand mining, commonly referred to as neutralised used acid (NUA). In batch studies the average amount of pesticide removed after 6h was 69% for atrazine, 89% for diuron, 61% for 2,4-D and 83% for chlorpyrifos. The lower sorption of 2,4-D to NUA compared with the other pesticides studied is most likely to be due to the high pH of the solutions (7.8 to 8.8) which would have resulted in 2,4-D being predominantly in an anionic form. The presence of other pesticides only significantly decreased the amount of 2,4-D sorbed from 59% to 34% when present in a mixture. Little (2 to 17%) diuron, chlorpyrifos, atrazine or 2,4-D were found to desorb from the NUA. The presence of nitrate or phosphate had minimal effect on the amount of diuron or atrazine sorbed to the NUA. However, all phosphate and nitrate treatments significantly (P<0.05) decreased the amount of 2,4-D sorbed (<50%) compared with when 2,4-D was present alone (65%). This study has shown that NUA has potential to be used as a sorbent for pesticides.

English

Significant areas of prime farmland in the upper Coastal Plain of Virginia have been disturbed by heavy mineral sands (Ti/Zr-bearing ilmenite, rutile, zircon) mining over the past 15 years. Mine soils created by the deposition of tailings and slimes in dewatering pits exhibit physical and chemical properties that limit agricultural use due to abrupt textural changes, heavy compaction from grading and the inherently low pH and available P of the processed subsoils. In 2004, the Carraway-Winn Reclamation Research Farm (CWRRF) was developed with Iluka Resources Inc. in Dinwiddie County to evaluate reconstruction strategies for returning mined land to agricultural production. In 2004, row crop plots were established in a randomized complete block design with 4 replications of 4 treatments: 1) LBS-CT - lime-stabilized biosolids (78 dry Mg ha -1 ) with conventional tillage, 2) LBS-NT - lime-stabilized biosolids (78 dry Mg ha -1 ) with no tillage, 3) TS - 15 cm of topsoil replacement with lime+NPK, and 4) C - control (tailings+lime+NPK). All treatments were deep ripped to 90 cm following grading and limed and fertilized annually to optimal levels. Two additional study sites, managed similarly to the treatment plots, included a compacted (no ripping) area (COMP) and a nearby unmined prime farmland (Orangeburg series) field (UM). Between 2005 and 2008, the plots were managed with a corn-wheat/double crop soybean rotation. In 2009, the plots were managed with cotton and in 2010 with wheat/double crop soybeans. During the initial four year corn-wheat/double crop soybean rotation, the two LBS treatments produced significantly higher yields than the TS or C treatments. No significant differences were observed among treatments for the 2009 cotton yield; however, erratically distributed settlement depressions adversely affected crop growth and harvest and led to high variability within each treatment. Similarly, no significant differences were observed for the 2010 wheat and soybean yields in a low rainfall year. Overall, yields from all four treatments typically exceeded 5-year local county averages, but were 25 to 40% lower than yields from the local prime farmland soil under identical management. Relatively low COMP yields illustrated the need for initial deep ripping and periodic tillage to improve physical conditions of these mine soils.

Evaluating the success of mineral sand mine rehabilitation on North Stradbroke Island, Queensland: Comparisons with reference eucalypt communities

Evaluating the success of mineral sand mine rehabilitation on North Stradbroke Island, Queensland: Comparisons with reference eucalypt communities

Transformations of Nitrogen and Carbon in Entrenched Biosolids at a Reclaimed Mineral Sands Mining Site

Biosolids deep-row incorporation (DRI) provides high levels of nutrients to the reclamation sites; however, additions of N in excess of the vegetation requirements can potentially impair water quality. The effects of anaerobically digested (AD) and lime stabilized (LS) DRI biosolids and inorganic N fertilizer were compared on C and N transformations and transport at a reclaimed mineral sands mining site. Biosolids were applied at 213 and 426 Mg AD biosolids ha(-1) and 328 and 656 Mg LS biosolids ha)(-1) (dry mass), and inorganic N fertilizer was applied at 0 (control) and 504 kg N ha-(-1) yr(-1). Zero tension lysimeters were installed to collect leachate for determination of vertical N transport, and the biosolids seams were analyzed for N and C transformations after 28 mo aging. The leachijng masses from the DRI biosolids treatments were 139 to 291 kg ha(-1) NO3-N, 61 to 243 kg ha(-1) NH4-N, and 61 to 269 kg ha(-1) organic N, while the fertilizer treatment did not differ from the control. Aged biosolids analysis showed that total N lost over the course of 2 yr was 15.2 Mg ha(-1) and 10.9 Mg ha(-1) for LS and AD biosolids, respectively, which was roughly 50% of the N applied. Organic C losses were 81 Mg ha(-1) and 33 Mg ha(-1) for LS and AD biosolids, respectively. Our results indicated that entrenchment of biosolids in coarse-textured media should not be used as a mined land reclamation technique because the anaerobic conditions required to limit mineralization and nitrification cannot be maintained in such permeable soils.

Development and assessment of rehabilitation criteria for high dune mineral sands mining on North Stradbroke island

Development and assessment of rehabilitation criteria for high dune mineral sands mining on North Stradbroke island