Patterns of nitrogen export from a seasonal freezing agricultural watershed during the thawing period

Zhao, Qiang; Chang, Dan; Wang, Kang; Huang, Jiesheng

doi:10.1016/j.scitotenv.2017.04.174

Cited by 18 publications

(11 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Spring 2014 was lacking a large snowmelt event and the smaller freshet storms (71-77) mainly diluted NO 3 -N concentration. The NO 3 -N concentration experienced only a moderate increase after the ice clearance in March 2014 and did not rise as high as during the spring thaw in 2010-2013, which might have been influenced by the deeper than the average soil frost depth during February 2014 (Table S1) (Zhao et al, 2017). The results are inconsistent compared to those reported by Fitzhugh et al (2001) who found that soil freezing accelerated NO 3 -N leaching from forests.…”

Section: Implications Of Warmer Winters On Concentrations and Loadsmentioning

confidence: 77%

“…10). The C-Q response suggests flushing of a finite source of NO 3 -N from soil and snowpack into the river (Ohte et al, 2004;Pellerin et al, 2012;Zhao et al, 2017) and that unfrozen soil NO 3 -N pools have gradually increased under the snowpack. The result does not support the suggestion by Brooks et al (1998) that microbial biomass developed in snowcovered soil acted as a significant buffer limiting NO3-N flushing from soils into surface waters during early snowmelt.…”

Section: Response Of Turbidity No 3 -N and Cod To Snowmeltmentioning

confidence: 99%

See 1 more Smart Citation

High-frequency monitoring reveals seasonal and event-scale water quality variation in a temporally frozen river

Kämäri

Tattari

Lotsari

et al. 2018

Journal of Hydrology

View full text Add to dashboard Cite

Potential influences of climate change on water quality, riverine suspended sediments, nitrogen and organic matter loads in temporally frozen rivers, which have ice-covered flow and snow-affected basins, are poorly understood. However, before being able to understand potential future changes, the impact of ice and snow needs to be investigated more thoroughly for years which were hydrologically different. We investigated seasonal and event scale concentration-discharge (C-Q) dynamics of total suspended solids/turbidity, nitrate-N (NO 3-N) and chemical oxygen demand (COD), which is indicative of the amount of organic matter in river water. In particular, the influence of ice cover, contrasting spring thaw, and soil frost conditions on intra-annual fluxes and the C-Q response of the three solutes are detected based on over four years of hourly data. Seasonally flow-weighted suspended solids and NO 3-N concentrations were at their highest in either the autumn or spring thaw, but COD concentrations were the highest each year in autumn. NO 3-N and COD levels typically decreased during winter. The ice-covered river water was less turbid compared to open-channel water at an equivalent river discharge likely due to in-stream factors. Storms during the freshet period introduced flushing of organic matter and suspended solids. The ratio of organic matter yield to water yield was similar each freshet and was independent of the amount of precipitation as snow or soil frost status. The freshet NO 3-N yield per water yield was higher during the years with a thick snowpack and the consequent thawed soil compared to a year with soil frost and minor snowpack. 91 storm events studied revealed differences and similarities in storm 2 dynamics in between the three variables. Anticlockwise hysteresis was most common for the variables, with turbidity peaking faster than the COD or NO 3-N concentration in most of the storms. Snowmelt storms showed highly variable C-Q responses inbetween the variables. However, spring thaw-related COD concentration peaks abated more slowly compared to turbidity or NO 3-N. NO 3-N showed a strong dilution pattern during several autumn storms during an extremely wet year, indicating limited N sources for flushing from the catchment. As a result, the flow-weighted mean NO 3-N concentration was not the largest during the year of largest water yield instead which was true for suspended solids and COD. We found no evidence that warmer winters with precipitation as rain instead of snow would increase suspended sediment, organic matter and NO 3-N load at entire winter-spring season or annual timescales.

show abstract

Section: Implications Of Warmer Winters On Concentrations and Loadsmentioning

confidence: 77%

Section: Response Of Turbidity No 3 -N and Cod To Snowmeltmentioning

confidence: 99%

High-frequency monitoring reveals seasonal and event-scale water quality variation in a temporally frozen river

Kämäri

Tattari

Lotsari

et al. 2018

Journal of Hydrology

View full text Add to dashboard Cite

show abstract

“…Nitrogen is the key element for maize yield (Evenson and Gollin, 2003;Rubin et al, 2016;Abera et al, 2017;Ning et al, 2018). To achieve high yield in China and other countries, farmers frequently apply N fertilizers in excess of crop requirements (Richter and Roelcke, 2000;Peng et al, 2010;Chen et al, 2011;Zhang et al, 2013;Zhang et al, 2015), which reduces N use efficiency (NUE; Noor, 2017;Chen et al, 2018;Yong et al, 2018) and contributes to N losses and environmental pollution Zhao et al, 2017;Zhang et al, 2017;Chen et al, 2017). Previous studies have shown that increased plant density is among the major factors associated with increases in maize yield (Tollenaar and Lee, 2002;Tokatlidis and Koutroubas, 2004;Long et al, 2006;Meng et al, 2013) and NUE (Cheng et al, 2015;Ren et al, 2017;Wei et al, 2017).…”

Section: Researchmentioning

confidence: 99%

Nitrogen Uptake and Response to Radiation Distribution in the Canopy of High‐Yield Maize

et al. 2019

View full text Add to dashboard Cite

Nitrogen is an essential element for maize (Zea mays L.). Farmers in developed countries most often apply more N fertilizer than necessary, which reduces N use efficiency (NUE). Improving radiation and N distribution, and thus the NUE of modern maize production systems with high plant density, is of great significance. In this study, field experiments were conducted in 2014 and 2015 in Xinjiang, China, using hybrid maize cultivar DH618 with high density. In addition, a synthesis analysis was conducted using data from 95 publications to observe N characteristics under different yield levels and compare the experimental results with existing studies. The relationship between radiation and N distribution in the canopy of high‐yield maize was also assessed. Nitrogen uptake was significantly correlated with grain yield. However, N uptake per unit grain yield and grain N concentration at maturity decreased as grain yield increased. The positive correlations between radiation and leaf and stalk N concentrations at silking showed that N concentration at silking increased as the height of the canopy layer increased because of increased radiation in the canopy. These results indicate that maize hybrids with erect upper leaves and high post‐silking N uptake can coordinate and optimize the distribution of radiation and N in different canopy layers and thus improve NUE and yield under high‐density production.

show abstract

“…Additional evidence is shown with the positive relationship between Ca 2+ + Mg 2+ and HCO 3 − with pCO 2 (Figure 8c,d), denoting that a higher pCO 2 level in water promotes higher carbonate dissolution rates. Figure 8f also shows a net pCO 2 decrease from end-of-summer to winter, probably due to the increase in water flow level and to the decrease of temperature [136,137]. But outside the dilution effect during the high flow period, the lower content of bicarbonate could be attributed to the consumption of DIC by secondary formation of CaCO 3 and also to losses by CO 2 degassing into the atmosphere (inverse reaction of Equation (4)).…”

Section: Role Of Discharge Temperature and Vegetation On Stream Watementioning

confidence: 94%

A Forty-Year Karstic Critical Zone Survey (Baget Catchment, Pyrenees-France): Lithologic and Hydroclimatic Controls on Seasonal and Inter-Annual Variations of Stream Water Chemical Composition, pCO2, and Carbonate Equilibrium

Ulloa-Cedamanos

Probst

Binet

et al. 2020

Water

View full text Add to dashboard Cite

The long-term trends and seasonal patterns of stream water chemical composition in a small remote forested karst catchment, were investigated from 1978 to 2018. Calcium, magnesium, and bicarbonates, the dominant ions, increased over the period together with temperature, while sulfates decreased. Carbonate and sulfate mineral dissolution was the main source of these elements. These trends and the seasonal opposite patterns of discharge vs. temperature, calcite saturation index vs. pCO2 and bicarbonate vs. sulfates, suggested the influence of discharge, of reduced long-range atmospheric pollution, and of increasing air temperature on biological activity and carbonate dissolution. Furthermore, the hydrological regime controlled the seasonal stream water chemical composition and fluxes by: (i) a dilution during the high discharge period, (ii) a change in the contribution rate of the waters draining different lithological areas in the catchment, e.g., the increased sulfates to bicarbonates ratio during summer low flows, with a maximum alkalinity decrease of 24%, and (iii) a “piston” and a “flushing” effects of dissolved elements stored in soils and epikarst with the first autumn heavy rains. Long-term stream water hydrochemical surveys of karst system have proved to be powerful indicators of biogeochemical processes, water sources and pathways under variable natural and anthropogenic environmental pressure conditions.

show abstract

Patterns of nitrogen export from a seasonal freezing agricultural watershed during the thawing period

Cited by 18 publications

References 70 publications

High-frequency monitoring reveals seasonal and event-scale water quality variation in a temporally frozen river

High-frequency monitoring reveals seasonal and event-scale water quality variation in a temporally frozen river

Nitrogen Uptake and Response to Radiation Distribution in the Canopy of High‐Yield Maize

A Forty-Year Karstic Critical Zone Survey (Baget Catchment, Pyrenees-France): Lithologic and Hydroclimatic Controls on Seasonal and Inter-Annual Variations of Stream Water Chemical Composition, pCO2, and Carbonate Equilibrium

Contact Info

Product

Resources

About