Environmental consequences from the use of sewage sludge in soil restoration related to microbiological pollution
TL;DR: In this article, the survival of Escherichia coli, total coliforms, and Salmonella spp. was determined in a soil amended with different doses of four different urban sewage sludge.
Abstract: This article analyzed the survival of Escherichia coli, total coliforms, and Salmonella spp. in a soil amended with urban sewage sludge due to its potential use in soil rehabilitation and to the risk of microbial pollution. The survival of E. coli, total coliforms, and Salmonella spp. was determined in a soil amended with different doses of four different urban sewage sludge based on equivalent nitrogen fertilization of 0, 85, 170, and 340 kg N/ha. After the topsoil/sludge mixtures were made, they were wet to 18% moisture and analyzed for 2 months to determine the presence of bacteria, and then again after 1 year. The results indicate that the presence of microorganisms was strongly conditioned by the type of biosolid and the dose applied. Soil moisture diminished as the experiment progressed and seemed to play a role in controlling the presence of the bacteria. The initial concentrations of bacteria depend on the sewage sludge treatment. The evolution of E. coli had a similar trend as total coliforms, and Salmonella spp. was absent after 8 weeks although a positive presence was detected in some soils after a year. As a conclusion, long periods of time reduce the risk from the presence of pathogens in soils, and the persistence may be closely related to the treatment of sewage sludge and the initial amount of microorganisms in the sewage sludge.
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TL;DR: Risks of Ascaris spp infection was very high for farmers applying this sludge on their farms in both Durban and Dakar, and further treatment of the sludge either through composting or drying for longer periods of time is recommended from a public health perspective.
28 citations
TL;DR: It is demonstrated that soil chemical properties and soil bacterial communities significantly changed with organic amendments in calcareous Mediterranean soils degraded by mining.
27 citations
TL;DR: In this article, the long-term effects of partial substitution of mineral N by organic fertilizers on diazotroph abundance and composition in double rice cropping systems were investigated through high-throughput sequencing, network analysis, and 15N2 labelling methods.
Abstract: Free-living nitrogen fixation (FLNF) by diazotrophs is a ubiquitous renewable resource and may constitute an attractive viable solution to the problem of environmental degradation caused by nitrogen over-fertilization. However, the biotic and abiotic control mechanisms of free-living nitrogen fixation are poorly understood. Moreover, there is rare information to link the composition and functions of diazotrophic communities; additionally, there are insufficient or inadequate predictors of the potential N fixation rate (PNFR) to help improve fertilization strategies. Here, through high-throughput sequencing, network analysis, and 15N2 labelling methods, we investigated the long-term effects of partial substitution of mineral N by organic fertilizers on diazotroph abundance and composition in double rice cropping systems. The field trial was conducted for 34 years and included five treatments: control without fertilizer (CK); only mineral NPK fertilizer (NPK); 70% inorganic N + 30% organic N + PK (NPKM1); 50% inorganic N + 50% organic N + PK (NPKM2); 30% inorganic N + 70% organic N + PK (NPKM3). Our results revealed that at the same nutrient input level, increasing the percentage of organic N substitution reduced diazotrophic abundance. Compared with the CK and NPK treatments, the organic substitution regimes reduced the fluctuation range of the PNFR between the early and late rice growing seasons. NH4+-N was the primary factor that negatively correlated (p
27 citations
25 citations
TL;DR: The available evidence supports the idea that plant mycorrhizal niche space (PMNS) is independent of place of origin (invasive status), and understanding the drivers of the PMNS of both native and alien plant species may help to predict the potential invasiveness of plants and the invasibility of a habitat.
Abstract: Invasive plant species pose a global threat because they alter ecosystem functioning and biodiversity. The majority of plants form mutualistic mycorrhizal associations with mycorrhizal fungi, which contribute to the nutrient and water supply as well as diversity, competitive ability, and ecosystem productivity. In addition, the role of mycorrhizal interactions in plant invasiveness and the susceptibility or resistance of a habitat to invasion is increasingly recognized. However, the mechanisms by which mycorrhizae contribute to invasion remain unresolved. Here, we provide an overview of the empirical evidence and discuss the prospects for mycorrhizaemediated plant invasion. Overall, mycorrhizal fungi appear to have impacts on plant invasion that depend on the similarities between the mycorrhizal associations of the alien and native plants. We introduce plant mycorrhizal niche space (PMNS) as a plant’s ability to exploit and shape the mycorrhizal fungi pool of a habitat based on its dependency on mycorrhizal fungi, traits and priority effects. Collectively, the available evidence supports the idea that PMNS is independent of place of origin (invasive status). Understanding the drivers of the PMNS of both native and alien plant species may help to predict the potential invasiveness of plants and the invasibility of a habitat, to elucidate the role of the mycorrhizal fungal community in plant invasion and the impact of plant invasion on the structure of the mycorrhizal fungal community in new habitats (i.e., neighbour effect) and to improve restoration planning. In this regard, we highlight a number of knowledge gaps and discuss future research directions.
21 citations
References
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14,888 citations
"Environmental consequences from the..." refers methods in this paper
...5 and 1:5 m/V, respectively); the N-Kjeldahl content (Bremmer and Mulvaney 1982), available P by the Burriel-Hernando method (Díez 1982), and oxidizable organic matter (Nelson and Sommers 1982) were relatively low (0....
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...…conductivity 125 μS/cm (pH and electrical conductivity measured in deionized water, 1:2.5 and 1:5 m/V, respectively); the N-Kjeldahl content (Bremmer and Mulvaney 1982), available P by the Burriel-Hernando method (Díez 1982), and oxidizable organic matter (Nelson and Sommers 1982)…...
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TL;DR: In this article, the authors describe methods of particle-size analysis for soils, including a variety of classification schemes and standard methods for size distributions using pipet and hydrometer techniques.
Abstract: Book Chapter describing methods of particle-size analysis for soils. Includes a variety of classification schemes. Standard methods for size distributions using pipet and hydrometer techniques are described. New laser-light scattering and related techniques are discussed. Complete with updated references.
8,997 citations
01 Jan 1982
5,659 citations
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01 Jan 1996
449 citations
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...This longtime cultivated Anthrosol (IUSS Working Group 2006) had a sandy-clay-loam texture based on the Bouyoucos method (Gee and Bauder 1986)....
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