scholarly journals Rock-Sourced Nitrogen in Semi-Arid, Shale-Derived California Soils

2021 ◽  
Vol 4 ◽  
Author(s):  
Nina L. Bingham ◽  
Eric W. Slessarev ◽  
Peter M. Homyak ◽  
Oliver A. Chadwick
Keyword(s):  
Mass Balance ◽  
Chemical Weathering ◽  
Field Studies ◽  
N Deposition ◽  
Mixing Model ◽  
N Fixation ◽  
Atmospheric N Deposition ◽  
Geochemical Mass Balance ◽  
Semi Arid ◽  
N Flux

Models suggest that rock-derived nitrogen (N) inputs are of global importance to ecosystem N budgets; however, field studies demonstrating the significance of rock N inputs are rare. We examined rock-derived N fluxes in soils derived from sedimentary rocks along a catena formed under a semi-arid climate. Our measurements demonstrate that there are distinct and traceable pools of N in the soil and bedrock and that the fraction of rock-derived N declines downslope along the catena. We used geochemical mass balance weathering flux measurements to estimate a rock-derived N flux of 0.145 to 0.896 kg ha–1 yr–1 at the ridgecrest. We also developed independent N flux estimates using a 15N-based isotope mixing model. While geochemical mass-balance-based estimates fell within the 95% confidence range derived from the isotope mixing model (−1.1 to 44.3 kg ha–1 yr–1), this range was large due to uncertainty in values for atmospheric 15N deposition. Along the catena, N isotopes suggest a diminishing effect of rock-derived N downslope. Overall, we found that despite relatively large N pools within the saprolite and bedrock, slow chemical weathering and landscape denudation limit the influence of rock-derived N, letting atmospheric N deposition (7.1 kg ha–1 yr–1) and N fixation (0.9–3.1 kg ha–1 yr–1) dominate N inputs to this grassland ecosystem.

Rare earth elements geochemistry of groundwater from Shanmuganadhi, Tamilnadu, India: Chemical weathering implications using geochemical mass-balance calculations

Geochemistry ◽  
2020 ◽  
Vol 80 (4) ◽  
pp. 125668
Author(s):  
F. Vinnarasi ◽  
K. Srinivasamoorthy ◽  
K. Saravanan ◽  
S. Gopinath ◽  
R. Prakash ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mass Balance ◽  
Chemical Weathering ◽  
Geochemical Mass Balance

scholarly journals Geochemical Mass Balance and Elemental Transport during the Weathering of the Black Shale of Shuijingtuo Formation in Northeast Chongqing, China

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Sixiang Ling ◽  
Xiyong Wu ◽  
Siyuan Zhao ◽  
Xin Liao ◽  
Yong Ren ◽  
...  
Keyword(s):  
Mass Balance ◽  
Black Shale ◽  
Chemical Weathering ◽  
Principal Component ◽  
Major Elements ◽  
Mass Transportation ◽  
Weathering Profile ◽  
Ph Values ◽  
Mass Fluxes ◽  
Geochemical Mass Balance

An understanding of the processes that control the behavior of major elements with respect to weathering profile is essential to calculate the mobility, redistribution, and mass fluxes of elements. Hence, this study aims to determine the geochemical mass balance, strain, elemental correlation, and transport in weathering profiles. We constructed three weathering profiles for the black shale of Shujingtuo formation. As per the principal component analysis of major elements, density, and pH values, the first component represents the “elemental factor” and the second denotes the “external factor.” The “depletion” pattern is a mass transportation pattern, and Na, K, and Mg are depleted along transect relative to the composition of fresh rock. Fe is redeposited at the bottom half of the saprock zone, whereas Al is accumulated at the regolith zone. The Fe and Al patterns are attributed to the “depletion–addition” and “addition” patterns, respectively. The strain in profiles A and B demonstrates the expansion at the regolith zone and part of the saprock zone. In profile C, however, these zones collapsed at all depths. In chemical weathering, Na, K, Ca, Mg, and Si are depleted in the following order: valley (C) > near mountaintop (B) > ridge (A).

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

Rainfall-associated chronic N deposition induces higher soil N2O emissions than acute N inputs in a semi-arid grassland

2021 ◽  
Vol 304-305 ◽  
pp. 108434
Author(s):  
Yujie Shi ◽  
Junfeng Wang ◽  
Ya'nan Li ◽  
Jinwei Zhang ◽  
Yunna Ao ◽  
...  
Keyword(s):  
N Deposition ◽  
N2o Emissions ◽  
Semi Arid

scholarly journals The influence of water–rock interactions on household well water in an area of high prevalence chronic kidney disease of unknown aetiology (CKDu)

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Liza K. McDonough ◽  
Karina T. Meredith ◽  
Chandima Nikagolla ◽  
Richard B. Banati
Keyword(s):  
Water Quality ◽  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Water Chemistry ◽  
Mass Balance ◽  
Stable Carbon Isotopes ◽  
Environmental Isotopes ◽  
Well Water ◽  
High Prevalence ◽  
Geochemical Mass Balance

AbstractPoor drinking water quality in household wells is hypothesised as being a potential contributor to the high prevalence of chronic kidney disease of uncertain aetiology (CKDu) among the farming communities of the Medawachchiya area, Anuradhapura, Sri Lanka. One of the natural processes that can affect water quality is the dissolution of minerals contained within an aquifer by water–rock interactions (WRIs). Here we present a comprehensive assessment of WRIs and their influence on the water chemistry in household wells and spring waters in the Medawachchiya area by combining measurements of environmental isotopes, such as strontium, lithium and stable carbon isotopes and inorganic chemistry parameters, and modelling geochemical mass balance reactions between rainfall and groundwater samples. Our results reveal the presence of strontium, dissolved from both silicate and carbonate minerals, with high isotopic (87Sr/86Sr) ratios of up to 0.7316. Geochemical mass balance modelling and prior 87Sr/86Sr studies on the Wanni Complex bedrock suggest these strontium values may be the result of biotite dissolution. We also identify lithium and uranium contributed from the dissolution of silicates, albeit at concentrations too low to constitute a known health risk. In contrast, the levels of magnesium and calcium in our samples are high and demonstrate that, despite the felsic bedrock, well water chemistry in the Medawachchiya area is dominated by carbonate dissolution.

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