Stream phosphorus and nitrogen export from agricultural and forested watersheds on the Boreal Plain

1998 ◽  
Vol 55 (10) ◽  
pp. 2292-2299 ◽  
Author(s):  
Sandra E Cooke ◽  
Ellie E Prepas
Keyword(s):  
Inorganic Nitrogen ◽  
Agricultural Watershed ◽  
Particulate Phosphorus ◽  
Agricultural Activity ◽  
Agricultural Watersheds ◽  
Forested Watersheds ◽  
Dissolved Phosphorus ◽  
Agricultural Streams ◽  
Dissolved Reactive Phosphorus ◽  
Reactive Phosphorus

We evaluated phosphorus (P) and inorganic nitrogen (IN) export from two agricultural and two forested watersheds on the nutrient-rich but relief-poor Boreal Plain. One agricultural stream was in a watershed that contained cropland, while the second consisted of mixed agricultural activities. Over the 2-year study, total dissolved phosphorus (TDP) concentrations were proportionately high, particularly in the agricultural streams. Flow-weighted TDP averaged 82% of the total phosphorus (TP) in the agricultural streams and 43% in the forested streams. In all watersheds, TDP was almost exclusively dissolved reactive phosphorus and most of the annual P export was in summer. The type of agricultural activity in the watershed influenced IN speciation; in the mixed agricultural watershed, 94% of IN export was ammonium, whereas 98% of IN load was nitrate from the cropland watershed. Disproportionately high TDP to TP export from agricultural watersheds suggests that, in areas of low relief and relatively high soil water P content, land clearing may influence dissolved more than particulate phosphorus export.

scholarly journals Nutrient criteria to achieve New Zealand’s riverine macroinvertebrate targets

2021 ◽  
Author(s):  
Adam D Canning ◽  
Michael Joy ◽  
Russell G Death
Keyword(s):  
New Zealand ◽  
Inorganic Nitrogen ◽  
Intensive Agriculture ◽  
Dissolved Inorganic Nitrogen ◽  
Nutrient Criteria ◽  
Global Trend ◽  
Dissolved Reactive Phosphorus ◽  
Nitrogen Concentrations ◽  
Reactive Phosphorus ◽  
Environmental Goals

Waterways worldwide are experiencing nutrient enrichment from population growth and intensive agriculture, and New Zealand is part of this global trend. Increasing fertilizer in New Zealand and intensive agriculture have driven substantial water quality declines over recent decades. A recent national directive has set environmental managers a range of riverine ecological targets, including three macroinvertebrate indicators, and requires nutrient criteria be set to support their achievement. To support these national aspirations, we use the minimization-of-mismatch analysis to derive potential nutrient criteria. Given that nutrient and macroinvertebrate monitoring often does not occur at the same sites, we compared nutrient criteria derived at sites where macroinvertebrates and nutrients are monitored concurrently with nutrient criteria derived at all macroinvertebrate monitoring sites and using modelled nutrients. To support all three macroinvertebrate targets, we suggest that suitable nutrient criteria would set median dissolved inorganic nitrogen concentrations at ~0.6 mg/L and median dissolved reactive phosphorus concentrations at ~0.02 mg/L. We recognize that deriving site-specific nutrient criteria requires the balancing of multiple values and consideration of multiple targets, and anticipate that criteria derived here will help and support these environmental goals.

Assessing Bioavailability of Typical Lakes and Reservoirs in Northeast China Based on Phosphorus Fractions

2021 ◽  
pp. 1-11
Author(s):  
Junqiu Wu ◽  
Yue Zhao ◽  
Ran Zhao ◽  
Liming Jia ◽  
Zimin Wei
Keyword(s):  
Microbial Biomass ◽  
Organic Phosphorus ◽  
Mineralization Rate ◽  
Dissolved Phosphorus ◽  
Positive Effects ◽  
Algae Blooms ◽  
Dissolved Reactive Phosphorus ◽  
Lakes And Reservoirs ◽  
Concentration Changes ◽  
Reactive Phosphorus

To explore the eutrophication degree in the typical lakes and reservoirs of the northeast region of China, the bioavailability of dissolved organic phosphorus (DOP) of the lakes has been examined in this study. The laboratory incubation was carried out at 20 °C for 55 days and the concentrations of total dissolved phosphorus (TDP), dissolved reactive phosphorus (DRP), DOP and the microbial biomass have been detected. Results showed that, during the process of incubation, the concentrations of TDP and DRP were increased, whereas the DOP was decreased, which leads to the decreased mineralization rate. In addition, the changes of microbial biomass were fluctuant, but they had significantly positive effects on the concentration changes and mineralization rate of DOP (p < 0.05). The correlation analysis among the phosphate fractions showed that the TDP significantly promoted the DRP concentration, mineralization rate of DOP and the cumulative mineralization of DOP. The kinetics model was conducted to predict the further mineralization of DOP and to analyze the pollution degree of the eight lakes and reservoirs. Accordingly, the lakes with high DRP and TDP had worse water quality and are prone to algae blooms.

Surface and subsurface flows of nutrients in natural and human impacted lake catchments on Broknes, Larsemann Hills, Antarctica

2002 ◽  
Vol 14 (4) ◽  
pp. 343-352 ◽  
Author(s):  
ENN KAUP ◽  
JAMES S. BURGESS
Keyword(s):  
Active Layer ◽  
Inorganic Nitrogen ◽  
Nutrient Levels ◽  
Subsurface Flows ◽  
Subsurface Waters ◽  
Dissolved Reactive Phosphorus ◽  
Natural Transformations ◽  
Lake Inflows ◽  
Reactive Phosphorus ◽  
Lake Waters

This study aimed to use nutrients in lake inflows as proxies for assessing human impact and separating this from natural transformations of material in the soil active layer. Nutrients, conductivity and δ18O were monitored in surface and subsurface (using ceramic tipped piezometers) lake inflows during summer in near natural and human impacted catchments. The nutrient levels were highly variable but generally higher during the last weeks of the flow, in both subsurface waters and in human impacted catchments. Up to 2000 μgN l−1 subsurface dissolved inorganic nitrogen (DIN) was measured in human impacted catchments but only 315 μg N l−1 in natural catchments. Subsurface levels of dissolved reactive phosphorus (DRP) were up to 310 μgP l−1 in natural catchments and up to 108 μgP l-1 in human impacted catchments. The maximum levels of both DIN and DRP in surface inflows were much higher in human impacted than in natural catchments. Conductivity and δ18O data showed general enrichment of snowbank meltwater presumably through evaporation from the active layer. This combined with fluctuating nutrient levels in catchment waters indicated that soil brines and decaying organic matter of natural and human origin were possible sources for nutrients and other salts. Marked salinization and substantially increased DIN levels near the research stations indicated that lake waters were receiving nutrients generated by humans.

scholarly journals Nutrient criteria to achieve New Zealand’s riverine macroinvertebrate targets

2021 ◽  
Author(s):  
Adam D Canning ◽  
Michael Joy ◽  
Russell G Death
Keyword(s):  
New Zealand ◽  
Inorganic Nitrogen ◽  
Intensive Agriculture ◽  
Dissolved Inorganic Nitrogen ◽  
Nutrient Criteria ◽  
Global Trend ◽  
Dissolved Reactive Phosphorus ◽  
Nitrogen Concentrations ◽  
Reactive Phosphorus ◽  
Environmental Goals

Waterways worldwide are experiencing nutrient enrichment from population growth and intensive agriculture, and New Zealand is part of this global trend. Increasing fertilizer in New Zealand and intensive agriculture have driven substantial water quality declines over recent decades. A recent national directive has set environmental managers a range of riverine ecological targets, including three macroinvertebrate indicators, and requires nutrient criteria be set to support their achievement. To support these national aspirations, we use the minimization-of-mismatch analysis to derive potential nutrient criteria. Given that nutrient and macroinvertebrate monitoring often does not occur at the same sites, we compared nutrient criteria derived at sites where macroinvertebrates and nutrients are monitored concurrently with nutrient criteria derived at all macroinvertebrate monitoring sites and using modelled nutrients. To support all three macroinvertebrate targets, we suggest that suitable nutrient criteria would set median dissolved inorganic nitrogen concentrations at ~0.6 mg/L and median dissolved reactive phosphorus concentrations at ~0.02 mg/L. We recognize that deriving site-specific nutrient criteria requires the balancing of multiple values and consideration of multiple targets, and anticipate that criteria derived here will help and support these environmental goals.

Phosphorus speciation, transformation and retention in the Three Gorges Reservoir, China

2016 ◽  
Vol 67 (2) ◽  
pp. 173 ◽  
Author(s):  
Xiang-bin Ran ◽  
Hong-tao Chen ◽  
Jun-feng Wei ◽  
Qing-zhen Yao ◽  
Tie-zhu Mi ◽  
...  
Keyword(s):  
Three Gorges Reservoir ◽  
Coarse Fraction ◽  
Particulate Phosphorus ◽  
Minor Role ◽  
Three Gorges ◽  
Dissolved Phosphorus ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Reactive Phosphorus ◽  
A Minor

Damming of river systems allowing the transformation of former rivers into artificial lakes will increase the transformation and retention of dissolved and sediment-associated phosphorus (P). The reservoir is therefore a ‘filter’ or ‘converter’, reducing and delaying the transport of nutrients to marine systems. Our study of the Three Gorges Reservoir (TGR) found that no stratification of phosphorus occurred, and the high particulate phosphorus (PP) concentrations upstream decreased gradually in the reservoir. Detrital P was found in greater concentrations in the surface sediment, accounting for 39% of PP; exchangeable P was rare and contributed very little to the total P budget. P forms and their concentrations in the suspended particulate matter varied throughout the TGR, with a significant increase of bioavailable P in the <8-μm particle fraction from 27% of PP in Fuling to 60% in Yichang, and decreasing detrital P and authigenic P in each grain size class. The TGR acted as a ‘converter’ for the dissolved reactive phosphorus, and it therefore plays a minor role in trapping incoming total dissolved phosphorus; whereas the TGR behaved as a ‘filter’ for the PP, especially for the coarse fraction, which resulted in the retention of 70% of the non-bioavailable PP. The controlling mechanism of P species and retention in the reservoir is particulate settling and its associated effects.

Water chemistry gradient in a degraded bog area

2006 ◽  
Vol 53 (2) ◽  
pp. 63-71 ◽  
Author(s):  
R. Iqbal ◽  
S. Akimoto ◽  
K. Tokutake ◽  
T. Inoue ◽  
H. Tachibana
Keyword(s):  
Water Chemistry ◽  
Ground Water ◽  
Sampling Point ◽  
Natural Area ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Major Cations ◽  
Dissolved Reactive Phosphorus ◽  
Reactive Phosphorus ◽  
Representative Points

Surface and ground water was sampled in a degraded bog area 36 times during 1993–2003 at Five representative points: point E (natural area with Sphagnum as the main vegetal cover), point W (boundary between the natural and degraded areas), point W' (area installed with vinyl sheeting), point WW (area where Sasa thrives), and point NC (area with naturally formed ditches). Analysis of variance (ANOVA) was conducted for parameters measured in surface water and ground water at 0.5, 1.0, 1.5, and 2.0 m depths. “Sampling point” (i.e. locations along the degradation gradient) accounted for most of the variation in surface and ground water chemistry. It accounted for 30–80% of the total variation in pH, electrical conductivity, ammonia, dissolved nitrogen, major cations (Na+, K+, Ca2+ , Mg2+ ), alkalinity and dissolved organic carbon. “Year” accounted for more variation in nitrate, nitrite, chloride, and sulfate than the sampling point did, but the variation in dissolved reactive phosphorus and dissolved phosphorus concentrations was not based on any of the calculated variables.

scholarly journals Spatial Variations in the Abundance and Chemical Speciation of Phosphorus across the River–Sea Interface in the Northern Beibu Gulf

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1103 ◽  
Author(s):  
Bin Yang ◽  
Zhen-Jun Kang ◽  
Dong-Liang Lu ◽  
Solomon Dan ◽  
Zhi-Ming Ning ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Coastal Waters ◽  
Organic Phosphorus ◽  
Inorganic Nitrogen ◽  
Inorganic Phosphorus ◽  
Particulate Phosphorus ◽  
Beibu Gulf ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Dissolved Inorganic Phosphorus

Water samples were collected to measure dissolved and particulate phosphorus species in order to examine the dynamics of phosphorus in the water column across the river–sea interface from the lower Dafengjiang River to the open Beibu Gulf. Dissolved inorganic phosphorus concentrations were as high as 0.90 ± 0.42 μM in river water but decreased dramatically to as low as 0.02 ± 0.01 μM in open coastal waters. Total dissolved phosphorus was largely measured in the form of dissolved inorganic phosphorus in river waters (58% ± 18%), whereas dissolved organic phosphorus became the predominant species (>90% on average) in open coastal waters. Total dissolved phosphorus was the dominant species, comprising 76% ± 16% of the total phosphorus, while total particulate phosphorus only comprised 24% ± 16% of the total phosphorus pool. Riverine inputs, physical and biological processes, and particulate phosphorus regeneration were the dominant factors responsible for the dynamic variations of phosphorus species in the study area. Based on a two-end-member mixing model, the biological uptake resulted in a dissolved inorganic phosphorus depletion of 0.12 ± 0.08 μM in the coastal surface water, whereas the replenishment of dissolved inorganic phosphorus in the lower river from particle P regeneration and release resulted in an increase (0.19 ± 0.22 μM) of dissolved inorganic phosphorus in the estuarine mixing region. The molar ratios of dissolved inorganic nitrogen to dissolved inorganic phosphorus and dissolved silicate to dissolved inorganic phosphorus in the open surface waters were >22, suggesting that, although the lower Dafengjiang River contained elevated concentrations of dissolved inorganic phosphorus, the northern Beibu Gulf was an overall P-limited coastal ecosystem.

Relationships Between Soluble and Sediment Nutrient Losses, Land Use and Types of Soil in Agricultural Watersheds

1977 ◽  
Vol 12 (1) ◽  
pp. 121-134 ◽  
Author(s):  
G.H. Neilsen ◽  
A.F. Mackenzie
Keyword(s):  
Land Use ◽  
Inorganic Nitrogen ◽  
High Surface ◽  
Sediment Concentration ◽  
Chemical Oxidation ◽  
Nutrient Loss ◽  
Potassium Sulfate ◽  
Agricultural Watersheds ◽  
Nutrient Losses ◽  
Calcium Magnesium

Abstract Seven agricultural watersheds in southwestern Quebec and southeastern Ontario, ranging in area from 2,000 to 20,000 hectares, were monitored systematically during 1973–75 for soluble inorganic nitrogen, total soluble phosphorus, calcium, magnesium, potassium, sulfate-sulfur, chemical oxidation demand, discharge, suspended sediment concentration, sediment Kjeldahl nitrogen, Bray extractable phosphorus, and ammonium acetate extractable calcium, magnesium and potassium. For 1974–75, annual Kg/ha, loss rates were calculated for the soluble and sediment associated nutrients. Losses varied with nutrient and watershed, with volume of runoff being an important control of nutrient loss variation. Significant amounts of SO4−S in precipitation were suggested by an average watershed soluble N:P:S loss ratio of 10:1:92. Sediment nutrient losses were especially important for N and P, comprising over 40% of their total loss. The importance of spring snow-melt runoff was demonstrated by the high proportion of all nutrients lost at this time. Correlations of nutrient loss, land use and soils suggested that certain land uses resulted in increased stream nutrient losses while increased watershed area of soils with a high surface runoff potential was particularly conducive to increased soluble nutrient and sediment losses.

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