Water Movement and Finger Flow Characterization in Homogeneous Water‐Repellent Soils

Wang, Yichen; Wang, Xiaofang; Chau, Henry Wai; Cheng, Bing; Yao, Ning; Li, Yang

doi:10.2136/vzj2018.01.0021

Cited by 28 publications

(11 citation statements)

References 43 publications

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“…The lysimeter experiment was run continuously for more than 165 days in 2018, in which the lower boundary was controlled either with a constant positive pressure head using a Mariotte's bottle to induce a water table, or by applying a negative pressure using a hose pump to induce drainage flow (see Wang et al [23], for more details of the setup). During periods of water saturation, soil pore water was sampled using the suction cups installed at the five different depths and analyzed for NO The entire study consisted of four different experimental phases (see also Table 1): First a period without fertilization (called Experiment 1, from March 21 to June 1).…”

Section: Methodsmentioning

confidence: 99%

“…Before the soil was filled into the column, the soil was air-dried until the gravimetric water content of the soil was about 7%. An overview of the main characteristics of the soil can be found in [23].…”

Section: Soil Materialsmentioning

confidence: 99%

“…The gas flux rates were determined using a simple linear regression for the five concentration points as described by Parkin and Venterea [36]. Flux values were accepted if the coefficient of determination (R 2 ) was larger than 0.8, or assumed to be zero when the deviation of the concentration values of the five different time points from the mean of the five samples was below two standard deviations [23]. In all other cases, calculated flux rates were discarded.…”

Section: N 2 O Flux Measurementsmentioning

confidence: 99%

“…For instance, aerobic microorganism populations thrive under oxic conditions, whereas the activity of anaerobic microorganisms is suppressed [18,19]. Therefore, the redox potential (Eh) is often used as an indicator for the activity of specific microbial populations that control N 2 O emission [20][21][22][23]. For instance, Yu and Patrick [24] found that the highest N 2 O emission occurred during intermediate redox conditions in which Eh ranged between +200 and +400 mV.…”

Section: Introductionmentioning

confidence: 99%

“…Recent sensor developments open the possibility for combined long-term monitoring of field-scale soil water content and soil Eh changes to increase the understanding of the N 2 O emission originated. In a recent study, Wang et al [23] conducted laboratory lysimeter experiments to investigate how changes in Eh induced by the changes in the water level affect N 2 O emissions from agricultural soil. They found that soil Eh proved to be an important indicator for N 2 O flux rates, as well as the availability of NO 3 − and NH 4 + in the soil.…”

Section: Introductionmentioning

confidence: 99%

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Stable-Isotope-Aided Investigation of the Effect of Redox Potential on Nitrous Oxide Emissions as Affected by Water Status and N Fertilization

Wang¹,

Bogena²,

Vereecken³

et al. 2020

Water

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Soils are the dominant source of atmospheric nitrous oxide (N2O), especially agricultural soils that experience both waterlogging and intensive nitrogen fertilization. However, soil heterogeneity and the irregular occurrence of hydrological events hamper the prediction of the temporal and spatial dynamics of N2O production and transport in soils. Because soil moisture influences soil redox potential, and as soil N cycling processes are redox-sensitive, redox potential measurements could help us to better understand and predict soil N cycling and N2O emissions. Despite its importance, only a few studies have investigated the control of redox potential on N2Oemission from soils in detail. This study aimed to partition the different microbial processes involved in N2O production (nitrification and denitrification) by using redox measurements combined with isotope analysis at natural abundance and 15N-enriched. To this end, we performed long-term laboratory lysimeter experiments to mimic common agricultural irrigation and fertilization procedures. In addition, we used isotope analysis to characterize the distribution and partitioning of N2O sources and explored the 15N-N2O site preference to further constrain N2O microbial processes. We found that irrigation, saturation, and drainage induced changes in soil redox potential, which were closely related to changes in N2O emission from the soil as well as to changes in the vertical concentration profiles of dissolved N2O, nitrate (NO3−) and ammonium (NH4+). The results showed that the redox potential could be used as an indicator for NH4+, NO3−, and N2O production and consumption processes along the soil profile. For example, after a longer saturation period of unfertilized soil, the NO3− concentration was linearly correlated with the average redox values at the different depths (R2 = 0.81). During the transition from saturation to drainage, but before fertilization, the soil showed an increase in N2O emissions, which originated mainly from nitrification as indicated by the isotopic signatures of N2O (δ15N bulk, δ18O and 15N-N2O site preference). After fertilization, N2O still mainly originated from nitrification at the beginning, also indicated by high redox potential and the increase of dissolved NO3−. Denitrification mainly occurred during the last saturation period, deduced from the simultaneous 15N isotope analysis of NO3− and N2O. Our findings suggest that redox potential measurements provide suitable information for improving the prediction of soil N2O emissions and the distribution of mineral N species along the soil profile under different hydrological and fertilization regimes.

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Section: Methodsmentioning

confidence: 99%

Section: Soil Materialsmentioning

confidence: 99%

Section: N 2 O Flux Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stable-Isotope-Aided Investigation of the Effect of Redox Potential on Nitrous Oxide Emissions as Affected by Water Status and N Fertilization

Wang¹,

Bogena²,

Vereecken³

et al. 2020

Water

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On the controls of preferential flow in soils of different hillslope position and lithological origin

Tang

Duncan

Guo

et al. 2020

Hydrological Processes

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Soils derived from different lithologies and their controls on preferential flow remain underexplored in forested landscapes. In the same lithology, the propensity for preferential flow occurrence at different hillslope positions also remains largely elusive. By utilizing a soil moisture response time method, we compared preferential flow occurrence between a shale site (Shale Hills, silt loam soils) and a sandstone site (Garner Run, sandy loam soils) at four hillslope positions: ridge-top, North-and South-facing mid-slopes and toe slope, for over 2 years. The catchments are neighbouring and covered by temperate forest. For the four hillslope positions, Shale Hills had higher preferential flow frequencies compared to Garner Run. Between these two catchments, the South-facing mid-slope sites showed the highest contrasts in preferential flow frequency (33.5% of events at Shale Hills vs. 8.8% at Garner Run)

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Carbon and water fluxes and their coupling in an alpine meadow ecosystem on the northeastern Tibetan Plateau

Wang

et al. 2020

Theor Appl Climatol

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Water Movement and Finger Flow Characterization in Homogeneous Water‐Repellent Soils

Abstract: 2018. Water movement and finger flow characterization in homogenous water-repellent soils. Vadose Zone J.

Cited by 28 publications

References 43 publications

Stable-Isotope-Aided Investigation of the Effect of Redox Potential on Nitrous Oxide Emissions as Affected by Water Status and N Fertilization

Stable-Isotope-Aided Investigation of the Effect of Redox Potential on Nitrous Oxide Emissions as Affected by Water Status and N Fertilization

On the controls of preferential flow in soils of different hillslope position and lithological origin

Carbon and water fluxes and their coupling in an alpine meadow ecosystem on the northeastern Tibetan Plateau

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