Classification of Mini-catchment typologies for analyzing dominant controls of nutrient dynamic in three Nordic countries

Selection of non-point nutrient pollution management and mitigation options in catchments requires in-depth understanding of both spatial and temporal controlling aspects on nutrient dynamics for covering a diversity of factors controlling nutrient transfer to surface waters. Such an understanding can be obtained by analyzing the hysteresis behaviors and export regime in concentration-discharge (c-Q) relationships from the monitoring stations in smaller streams.&#160; A classification scheme developed by Pohle et al. (2019), including nine different c-Q relationships classes were defined as a combination of export behavior (dilution, neutral, enrichment) and rotational pattern of the hysteresis (clock-wise, no rotation, anti-clockwise). To perform this, the export behavior was assessed based on the theoretical c-Q relationships by checking whether concentrations decrease, increase or do not change with discharge (Mann-Kendall test). The rotational pattern was also determined by comparing concentrations at the rising and the falling limb of the hydrograph (Kruskal-Wallis test). The classification has been applied to a 8 years record (2010-2017) of daily discharge and discrete nutrient concentration &#160;data from 88 small streams including forms such as - Nitrate, Organic N, Dissolved Reactive Phosphorus and Particulate P &#160;from Denmark, Sweden and Finland. The streams drains catchments with a size ranging from 0.1 km&#178; &#8211; 65 km&#178;. Additionally similarity in types of c-Q relationships were investigated by multivariate analysis for N and P forms &#160;considering effects of land use, climate, soil type and the size of the catchments &#160;.&#160; The dilution behavior of the catchments might dominantly be related to arable catchments with low groundwater inputs and with a good direct contact from root zone to the stream (e.g. through tile drains for N) and macropore or surface runoff for P. The constant behavior of the catchments might dominantly be related to dominance of groundwater fed streams in arable or natural catchments and the enrichment behavior might dominantly be found in catchments influenced by point source discharges of nutrients. This kind of catchments classification can be used for planning of optimal sampling frequencies in monitoring programs, cost-optimal dosing of mitigation options in catchments and inform about expected inertias in catchment responses to management.&#160;

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Conceptual Mini-Catchment Typologies for Testing Dominant Controls of Nutrient Dynamics in Three Nordic Countries

Water ◽

10.3390/w12061776 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1776 ◽

Cited By ~ 1

Author(s):

Fatemeh Hashemi ◽

Ina Pohle ◽

Johannes W.M. Pullens ◽

Henrik Tornbjerg ◽

Katarina Kyllmar ◽

...

Keyword(s):

Land Use ◽

Nutrient Dynamics ◽

Pollution Monitoring ◽

Organic N ◽

Particulate Phosphorus ◽

Nutrient Concentrations ◽

Data Series ◽

Nutrient Export ◽

Small Streams ◽

Export Behaviour

Optimal nutrient pollution monitoring and management in catchments requires an in-depth understanding of spatial and temporal factors controlling nutrient dynamics. Such an understanding can potentially be obtained by analysing stream concentration–discharge (C-Q) relationships for hysteresis behaviours and export regimes. Here, a classification scheme including nine different C-Q types was applied to a total of 87 Nordic streams draining mini-catchments (0.1–65 km2). The classification applied is based on a combination of stream export behaviour (dilution, constant, enrichment) and hysteresis rotational pattern (clock-wise, no rotation, anti-clockwise). The scheme has been applied to an 8-year data series (2010–2017) from small streams in Denmark, Sweden, and Finland on daily discharge and discrete nutrient concentrations, including nitrate (NO3−), total organic N (TON), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP). The dominant nutrient export regimes were enrichment for NO3− and constant for TON, DRP, and PP. Nutrient hysteresis patterns were primarily clockwise or no hysteresis. Similarities in types of C-Q relationships were investigated using Principal Component Analysis (PCA) considering effects of catchment size, land use, climate, and dominant soil type. The PCA analysis revealed that land use and air temperature were the dominant factors controlling nutrient C-Q types. Therefore, the nutrient export behaviour in streams draining Nordic mini-catchments seems to be dominantly controlled by their land use characteristics and, to a lesser extent, their climate.

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Limnological properties of Antarctic ponds during winter freezing

Antarctic Science ◽

10.1017/s0954102091000482 ◽

1991 ◽

Vol 3 (4) ◽

pp. 379-388 ◽

Cited By ~ 41

Author(s):

S. Schmidt ◽

W. Moskal ◽

S. J. De Mora ◽

C. Howard-Williams ◽

W. F. Vincent

Keyword(s):

Respiratory Activity ◽

Sodium Sulphate ◽

Organic N ◽

Nitrogen Species ◽

Dissolved Reactive Phosphorus ◽

Bottom Waters ◽

Shallow Ponds ◽

Reactive Phosphorus ◽

Chemical Conditions ◽

Physical And Chemical

Two shallow ponds at Cape Evans, Ross Island, were sampled at 1–2 week intervals, during winter freezing throughout the winter and during the subsequent melt period, to examine the physical and chemical conditions imposed on the biota during the year. Liquid water was first detected at the base of the ponds in late December. During the main summer melt period conductivities were less than 10 mS cm−1 with maximum daily temperatures around 5°C. The bottom waters became increasingly saline during freezing and water temperatures decreased below 0°C; by June the remaining water overlying the sediments had conductivities >150 mS cm−1 and temperatures of −13°C. Calcium carbonate, then sodium sulphate precipitated out of solution during early freezing. The dominant nitrogen species was dissolved organic-N which reached 12 g m−3 in Pond 1 just prior to final freeze up. The organic and inorganic forms of nitrogen and dissolved reactive phosphorus increased with increasing conductivity in the ponds. The behaviour of particulate-N and particulate-P mirrored that of chlorophyll a with a peak in March-April and a second higher peak just before final freeze-up. This study provides clear evidence that organisms which persist throughout the year in Antarctic coastal ponds must be capable of surviving much more severe osmotic, pH, temperature and redox conditions than those measured during the summer melt. Deoxygenation, pH decline and H2S production, however, point to continued respiratory activity well into the dark winter months.

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High-Resolution Profiles of Dissolved Reactive Phosphorus in the Porewaters of Lake Sediments Assessed by DGT Technique

Journal of Environmental Protection ◽

10.4236/jep.2014.58070 ◽

2014 ◽

Vol 05 (08) ◽

pp. 694-702

Author(s):

Jian Wang ◽

Jingtian Zhang ◽

Qiong Xie ◽

Fengyu Zan ◽

Shengpeng Zuo ◽

...

Keyword(s):

High Resolution ◽

Lake Sediments ◽

Dissolved Reactive Phosphorus ◽

Reactive Phosphorus

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Poultry Litter Ash Rate and Placement Affect Phosphorus Dissolution in a Horticultural Substrate1

Journal of Environmental Horticulture ◽

10.24266/0738-2898-35.3.117 ◽

2017 ◽

Vol 35 (3) ◽

pp. 117-127

Author(s):

Daniel E. Wells ◽

Jeffrey S. Beasley ◽

Edward W. Bush ◽

Lewis. A. Gaston

Keyword(s):

Crop Production ◽

Poultry Litter ◽

Lantana Camara ◽

Shoot Biomass ◽

Horticultural Crops ◽

P Loss ◽

P Rate ◽

Dissolved Reactive Phosphorus ◽

Reactive Phosphorus ◽

Poultry Litter Ash

Abstract Poultry litter ash (PLA) is a byproduct of bioenergy production and an effective P source for horticultural crops since it reduces P losses from container production due to its low P solubility. Experiments were conducted to determine effects of rate and placement of PLA on P loss from greenhouse crop production and growth and quality of two commonly-grown greenhouse crops, Verbena canadensis Britton ‘Homestead Purple' and Lantana camara L. ‘New Gold', by comparing two rates (140 and 280 g·m−3 P or 0.4 and 0.8 lb·yd−3) and two application methods (post-plant topdressed and pre-plant incorporated). Leachate-dissolved reactive phosphorus (DRP) concentrations were reduced by an average of 24% as P rate was reduced from 280 to 140 g·m−3, but were 134% less on average when PLA was topdressed instead of incorporated. Foliar P concentrations were less 33% and 44% for verbena and lantana, respectively when plants were topdressed compared to incorporated. Shoot biomass of verbena and lantana was 9% and 24% greater, respectively, when incorporating instead of topdressing PLA. As a P source, PLA should be pre-plant incorporated within the substrate at a total P rate between 140 g·m−3 (0.4 lb·yd−3) and 280 g·m−3 (0.8 lb·yd−3). Index words: phosphorus, poultry litter ash, Verbena canadensis Britton ‘Homestead Purple', Lantana camara L. ‘New Gold', dissolved reactive phosphorus. Species used in this study: ‘Homestead Purple' verbena (Verbena canadensis Britton); ‘New Gold' lantana (Lantana camara L.).

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The Response of Water and Nutrient Dynamics and of Crop Yield to Conservation Agriculture in the Ethiopian Highlands

Sustainability ◽

10.3390/su12155989 ◽

2020 ◽

Vol 12 (15) ◽

pp. 5989 ◽

Cited By ~ 1

Author(s):

Sisay A. Belay ◽

Tewodros T. Assefa ◽

P. V. Vara Prasad ◽

Petra Schmitter ◽

Abeyou W. Worqlul ◽

...

Keyword(s):

Water Use ◽

Crop Yield ◽

Irrigation Water ◽

Nutrient Dynamics ◽

Root Zone ◽

Conservation Agriculture ◽

Soil Disturbance ◽

Green Pepper ◽

Irrigation Water Use ◽

Supplementary Irrigation

Smallholder agriculture constitutes the main source of livelihood for the Ethiopian rural community. However, soil degradation and uneven distribution of rainfall have threatened agriculture at present. This study is aimed at investigating the impacts of conservation agriculture on irrigation water use, nutrient availability in the root zone, and crop yield under supplementary irrigation. In this study, conservation agriculture (CA), which includes minimum soil disturbance, grass mulch cover, and crop rotation, was practiced and compared with conventional tillage (CT). We used two years’ (2018 and 2019) experimental data under paired-t design in the production of a local variety green pepper (Capsicum annuum L.). The results showed that CA practices significantly (α = 0.05) reduced irrigation water use (13% to 29%) and runoff (29% to 51%) while it increased percolated water in the root zone (27% to 50%) when compared with CT practices under the supplementary irrigation phase. In addition, CA significantly decreased NO3-N in the leachate (14% to 44%) and in the runoff (about 100%), while PO4-P significantly decreased in the leachate (33% to 50%) and in the runoff (16%) when compared with CT. Similarly, CA decreased the NO3-N load in the leachate and in the runoff, while the PO4-P load increased in the leachate but decreased in the runoff. The yield return that was achieved under CA treatment was 30% higher in 2018 and 10% higher in 2019 when compared with the CT. This research improves our understanding of water and nutrient dynamics in green pepper grown under CA and CT. Use of CA provides opportunities to optimize water use by decreasing irrigation water requirements and optimize nutrient use by decreasing nutrient losses through the runoff and leaching.

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