Soil Nitrogen Transformations as Affected by Salinity

McClung, Gwendolyn; Frankenberger, W. T.

doi:10.1097/00010694-198505000-00005

Cited by 82 publications

(45 citation statements)

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“…Tratamento (1) ( (Patriquin et al, 1993). A condutividade elétrica também pode afetar, indiretamente, a mineralização da matéria orgânica (McClung & Frankenberger, 1985). O pH diminuiu no tratamento testemunha após a incubação (Figura 3), resultado também observado por Silva et al (1999) em incubações com sete solos brasileiros.…”

Section: Resultsunclassified

Mineralização de nitrogênio em solo tropical tratado com lodos de esgoto

Boeira

Ligo

Dynia

2002

Pesq. agropec. bras.

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Resumo -A mineralização do N orgânico é um dos principais fatores que determinam as quantidades de lodos de esgoto (LE) a aplicar em solos. O objetivo deste trabalho foi quantificar, em laboratório, o potencial de mineralização de N orgânico num Latossolo Vermelho distroférrico, tratado com dois LE anaeróbios, um de origem estritamente urbana (Franca, SP) e outro com presença de despejos industriais (Barueri, SP). Os LE foram aplicados ao solo em doses de 1,5, 3, 6 e 12 g kg -1 (Franca) Termos para indexação: Latossolo, acidificação, pH, condutividade elétrica. Nitrogen mineralization in a tropical soil amended with sewage sludgesAbstract -Mineralization of organic N contained in sewage sludges is a key factor in determining the rates of these materials to be applied to agricultural soils. This work aimed at quantifying the potential of mineralization of the organic N in an Oxisol treated with two anaerobically-digested sewage sludges (one derived from strictly urban sewage -Franca, São Paulo State, Brazil -, and the other from a mixture of urban and industrial sewages -Barueri, São Paulo State). The sludges were applied at four rates: 1.5, 3, 6 and 12 g kg -1 (Franca), and 4, 8, 16 and 32 g kg -1 (Barueri), and the incubation period, was 15 weeks. Net inorganic N accumulation in the soil measured at the end of the incubation period was proportional to the rate of organic N applied as sludges. The potential of mineralization estimated by the single exponential model for the soil without sludge was 24 mg kg -1 of N, and ranged from 44 to 265 mg kg -1 of N, for the sludge-treated soil. The fraction of potential mineralization of the organic N contained in the sludges was estimated in 31%. N mineralization was slower in the soil treated with the two higher rates of the Barueri sludge. Sewage sludges caused soil acidification; Franca sludge was more effective in this way than Barueri sludge.Index terms: Latosol, acidification, pH, electrical conductivity.(1) Aceito para publicação em 9 de julho de 2002.(2) Embrapa-Centro Nacional de Pesquisa de Monitoramento e Avaliação de Impacto Ambiental, Caixa Postal 69, CEP 13820-000 Jaguariúna, SP. E-mail:rcboeira@cnpma.embrapa.br, ligo@cnpma.embrapa.br, dynia@cnpma.embrapa.br IntroduçãoEm virtude da poluição provocada por lançamen-to de esgotos in natura em cursos d'água, estações de tratamento de esgoto vêm sendo implementadas nas principais cidades brasileiras, obtendo-se, geralmente, considerável redução da carga orgânica dos efluentes. No entanto, as estações de tratamento de esgoto defrontam-se com novo problema: a destinação a ser dada ao lodo de esgoto, resíduo que permanece após o tratamento dos esgotos. Diversas alternativas têm sido buscadas, entre elas a utilização de solos como meio de descarte para o lodo, situação em que há risco de poluição ambiental, com possibilidade de contaminação da cadeia alimentar com diversas substâncias e elementos nocivos.Utilizado com fins agrícolas, o lodo pode atuar como condicionador de solo, por sua elevada carga orgânica (40% a...

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Section: Resultsunclassified

Mineralização de nitrogênio em solo tropical tratado com lodos de esgoto

Boeira

Ligo

Dynia

2002

Pesq. agropec. bras.

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“…In addition, not all salts associated with soil salinization have the same effect on the microbial community. Differences in toxicity have been found between, e.g., SO 4 2Ϫ and Cl Ϫ salts (25)(26)(27)(28)(29)(30) as well as K ϩ and Na ϩ salts (28). However, few studies have been designed to explicitly compare the toxicity of different salts using a range of processes.…”

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confidence: 99%

Comparative Toxicities of Salts on Microbial Processes in Soil

Rath

Maheshwari

Bengtson

et al. 2016

Appl Environ Microbiol

154

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Soil salinization is a growing threat to global agriculture and carbon sequestration, but to date it remains unclear how microbial processes will respond. We studied the acute response to salt exposure of a range of anabolic and catabolic microbial processes, including bacterial (leucine incorporation) and fungal (acetate incorporation into ergosterol) growth rates, respiration, and gross N mineralization and nitrification rates. To distinguish effects of specific ions from those of overall ionic strength, we compared the addition of four salts frequently associated with soil salinization (NaCl, KCl, Na 2 SO 4 , and K 2 SO 4 ) to a nonsaline soil. To compare the tolerance of different microbial processes to salt and to interrelate the toxicity of different salts, concentrationresponse relationships were established. Growth-based measurements revealed that fungi were more resistant to salt exposure than bacteria. Effects by salt on C and N mineralization were indistinguishable, and in contrast to previous studies, nitrification was not found to be more sensitive to salt exposure than other microbial processes. The ion-specific toxicity of certain salts could be observed only for respiration, which was less inhibited by salts containing SO 4 2؊ than Cl ؊ salts, in contrast to the microbial growth assessments. This suggested that the inhibition of microbial growth was explained solely by total ionic strength, while ion-specific toxicity also should be considered for effects on microbial decomposition. This difference resulted in an apparent reduction of microbial growth efficiency in response to exposure to SO 4 2؊ salts but not to Cl ؊ salts; no evidence was found to distinguish K ؉ and Na ؉ salts. Soil salinization affects a large area of land globally and has become a major threat to agricultural productivity and food security (1). Due to the wide distribution of salt-affected soils around the world (2, 3), it is important to understand the influence of salinity on the soil microbial community. The soil microbial decomposer community plays an essential role in the decomposition and stabilization of soil organic matter (SOM), as well as the cycling of nutrients vital for plant growth. How substrate during decomposition is allocated to either microbial biomass production or respiration determines the microbial growth efficiency (MGE), which is an important parameter for the C sequestration potential of a soil (4). The potential for soil C storage could be compromised by disturbances or unfavorable environmental conditions that reduce microbial growth efficiencies due to the metabolic burden they place on microbial cells (5).It is generally held that fungus-dominated communities have a higher MGE than communities dominated by bacteria (4). Thus, changes in the relative contribution of bacteria and fungi to the soil microbial community are thought to reflect changes in ecosystem processes, such as decomposition, C sequestration potential, and nutrient cycling (6, 7). It is unclear whether fungi and bacteria are affe...

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“…The analysis of nitrogen speciation in our study indicated a NO − 3 -N dominance in the surface and interstitial water, which suggest that the nitrification and coupled denitrification may have been the dominant processes in the sediment N transformation, but according to McClung and Frankenberger (1985) the anoxic conditions, high pH and salinity inhibit nitrification. In marine sediments the anoxic denitrification has been observed by Mortimer et al (2004) and the coupled anoxic nitrification-manganese reduction processes by Freitag and Posser (2003).…”

Section: Nutrientsmentioning

confidence: 57%