Phosphorus release from shoots of Phleum pretense L. after repeated freeze-thaw cycles and harvests

Kieta, Kristen; Owens, Philip N.

doi:10.1016/j.ecoleng.2018.11.024

Cited by 9 publications

(4 citation statements)

References 26 publications

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“…This different effect of the FTCs on the N loss route in the loamy sand versus the silt loam was consistent with the lower water retention capacity and higher hydraulic conductivity of the loamy sand. In the loamy sand, warming pulses increased soil temperatures, which led to higher water and solute transport rates relative to the with snow cover scenario, where soil was insulated from air temperature, which is consistent with the results of Kieta and Owens (2019). NO 3 − is particularly prone to leaching due to charge repulsion between its intrinsic negative charge and the prevalence of negatively charged soil particles (Di and Cameron, 2002).…”

Section: Snow Removal Had Contrasting Impact On N Loss Route In Silt ...supporting

confidence: 82%

Effects of winter pulsed warming and snowmelt on soil nitrogen cycling in agricultural soils: A lysimeter study

Green

Rezanezhad

Jordan

et al. 2022

Front. Environ. Sci.

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In cold regions, climate change is expected to result in warmer winter temperatures and increased temperature variability. Coupled with changing precipitation regimes, these changes can decrease soil insulation by reducing snow cover, exposing soils to colder temperatures and more frequent and extensive soil freezing and thawing. Freeze-thaw events can exert an important control over winter soil processes and the cycling of nitrogen (N), with consequences for soil health, nitrous oxide (N2O) emissions, and nearby water quality. These impacts are especially important for agricultural soils and practices in cold regions. We conducted a lysimeter experiment to assess the effects of winter pulsed warming, soil texture, and snow cover on N cycling in agricultural soils. We monitored the subsurface soil temperature, moisture, and porewater geochemistry together with air temperature, precipitation, and N2O fluxes in four agricultural field-controlled lysimeter systems (surface area of 1 m2 and depth of 1.5 m) at the University of Guelph’s Elora Research Station over one winter (December 2020 to April 2021). The lysimeters featured two soil types (loamy sand and silt loam) which were managed under a corn-soybean-wheat rotation with cover crops. Additionally, ceramic infrared heaters located above two of the lysimeters were turned on after each snowfall event to melt the snow and then turned off to mimic snow-free winter conditions with increased soil freezing. Porewater samples collected from five depths in the lysimeters were analyzed for total dissolved nitrogen (TDN), nitrate (NO3−), nitrite (NO2−), and ammonium (NH4+). N2O fluxes were measured using automated soil gas chambers installed on each lysimeter. The results from the snow removed lysimeters were compared to those of lysimeters without heaters (with snow). As expected, the removal of the insulating snow cover resulted in more intense soil freeze-thaw events, causing increased dissolved N loss from the lysimeter systems as N2O (from the silt loam system) and via NO3− leaching (from the loamy sand system). In the silt loam lysimeter, we attribute the freeze thaw-enhanced N2O fluxes to de novo processes rather than gas build up and release. In the loamy sand lysimeter, we attribute the increased NO3− leaching to the larger pore size and therefore lower water retention capacity of this soil type. Overall, our study illustrates the important role of winter snow cover dynamics and soil freezing in modulating the coupled responses of soil moisture, temperature, and N cycling.

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Section: Snow Removal Had Contrasting Impact On N Loss Route In Silt ...supporting

confidence: 82%

Effects of winter pulsed warming and snowmelt on soil nitrogen cycling in agricultural soils: A lysimeter study

Green

Rezanezhad

Jordan

et al. 2022

Front. Environ. Sci.

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“…However, this study was limited in the amount of natural runoff events that occurred outside the growing season, especially in the fall. This may be a critical period for future study as the fall is when the vegetation and plant residue amounts are considerably higher in the VFS than the annual crop strips and P is highly susceptible to release from the senescing and decaying plant material (Sharpley, 1981; Rekolainen et al, 1997; Bechmann et al, 2005; Kröger et al, 2007; Roberson et al, 2007; Øgaard, 2015; Lozier et al, 2017; Kieta and Owens, 2019). Although this study benefited from the artificially induced runoff that created additional events and enabled more samples to be collected and for different time periods, it is clear that these events were not typical of runoff for this agricultural region.…”

Section: Discussionmentioning

confidence: 99%

Seasonal Efficacy of Vegetated Filter Strips for Phosphorus Reduction in Surface Runoff

et al. 2019

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A vegetated filter strip (VFS) is a measure commonly implemented in agricultural landscapes for the purpose of improving water quality. However, much of the evidence to support their effectiveness comes from warm regions dominated by rainfall driven runoff. This study assessed the performance of VFS plots and compared them with annual crop strips to reduce phosphorus (P) levels in runoff in the cold climate of the Canadian Prairies. Analysis of water samples from 22 events during the study indicated no significant difference in the inflow and outflow concentrations of total dissolved P (TDP) or total P (TP) for either the VFS or the annual crop strips. Although the VFS plots had little effect on TDP or TP during the spring, they performed better during the growing season, reducing mean TP concentrations in five out of seven, or 71%, of these events. The VFS plots did not perform as well during the fall events, with the overall mean TP concentration in runoff increasing after flowing through the filters during this time period.

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“…As a result, conversion of annual cropland to perennial forage can result in no net change, or an increase in total nutrient transport, despite decreased erosion (Christensen and Kieta 2014;Liu et al 2014b). The release of nutrients from vegetation is greatest during snowmelt because nutrients released due to cell rupture on freezing are retained in the snowpack and contribute to the dissolved nutrient load in snowmelt runoff (Elliott 2013;Kieta and Owens 2019). In an eight-year paired watershed study in southern Manitoba where annual cropland was converted to alfalfa forage for three years (replicated in two pairings), total runoff losses of P in snowmelt from alfalfa forage land were 160% greater than those from annual crop land, due in large part to a 221% increase in losses of dissolved P (Liu et al 2014b).…”

Section: Dissolved Nutrientsmentioning

confidence: 99%

Soil and water management: opportunities to mitigate nutrient losses to surface waters in the Northern Great Plains

et al. 2019

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The Northern Great Plains is a key region to global food production. It is also a region of water stress that includes poor water quality associated with high concentrations of nutrients. Agricultural nitrogen and phosphorus loads to surface waters need to be reduced, yet the unique characteristics of this environment create challenges. The biophysical reality of the Northern Great Plains is one where snowmelt is the major period of nutrient transport, and where nutrients are exported predominantly in dissolved form. This limits the efficacy of many beneficial management practices (BMPs) commonly used in other regions and necessitates place-based solutions. We discuss soil and water management BMPs through a regional lens—first understanding key aspects of hydrology and hydrochemistry affecting BMP efficacy, then discussing the merits of different BMPs for nutrient control. We recommend continued efforts to “keep water on the land” via wetlands and reservoirs. Adoption and expansion of reduced tillage and perennial forage may have contributed to current nutrient problems, but both practices have other environmental and agronomic benefits. The expansion of tile and surface drainage in the Northern Great Plains raises urgent questions about effects on nutrient export and options to mitigate drainage effects. Riparian vegetation is unlikely to significantly aid in nutrient retention, but when viewed against an alternative of extending cultivation and fertilization to the waters’ edge, the continued support of buffer strip management and refinement of best practices (e.g., harvesting vegetation) is merited. While the hydrology of the Northern Great Plains creates many challenges for mitigating nutrient losses, it also creates unique opportunities. For example, relocating winter bale-grazing to areas with low hydrologic connectivity should reduce loadings. Managing nutrient applications must be at the center of efforts to mitigate eutrophication. In this region, ensuring nutrients are not applied during hydrologically sensitive periods such as late autumn, on snow, or when soils are frozen will yield benefits. Working to ensure nutrient inputs are balanced with crop demands is crucial in all landscapes. Ultimately, a targeted approach to BMP implementation is required, and this must consider the agronomic and economic context but also the biophysical reality.

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Phosphorus release from shoots of Phleum pretense L. after repeated freeze-thaw cycles and harvests

Cited by 9 publications

References 26 publications

Effects of winter pulsed warming and snowmelt on soil nitrogen cycling in agricultural soils: A lysimeter study

Effects of winter pulsed warming and snowmelt on soil nitrogen cycling in agricultural soils: A lysimeter study

Seasonal Efficacy of Vegetated Filter Strips for Phosphorus Reduction in Surface Runoff

Soil and water management: opportunities to mitigate nutrient losses to surface waters in the Northern Great Plains

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