Trends in dissolved phosphorus in Gray Luvisol soil profiles after forest harvest

2005 ◽  
Vol 85 (1) ◽  
pp. 89-101 ◽  
Author(s):  
I. R. Whitson ◽  
S. Abboud ◽  
E. E. Prepas ◽  
D. S. Chanasyk
Keyword(s):  
Forest Floor ◽  
Soil Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Water Soluble ◽  
Phosphorus Concentration ◽  
Negative Consequences ◽  
Forest Harvest ◽  
Dissolved Phosphorus ◽  
P Concentration ◽  
Gray Luvisol

Forest disturbances that increase P export from hillslopes will have negative consequences for site productivity and regional water quality. We studied P behavior in Gray Luvisols to understand the soil profile’s influence on P export from typical hillslopes of the Boreal Plain ecozone. We hypothesized that (1) P concentration is highest in upper horizons, (2) solution P is primarily in the dissolved and organic form, and (3) forest harvest will increase solution P concentration. We analyzed the soil solution, with emphasis on P, and determined P sorption properties of key soil horizons. Mean soluble reactive phosphorus concentration decreased with depth, ranging from 64 mg L-1 in the forest floor to 0.01 mg L-1 in the groundwater zone; solution P was mostly orthophosphate. Water soluble phosphorus decreased from 74 ± 9 to 41 ± 9 mg L-1 and extractable phosphorus was reduced in the forest floor only on two of four sampling occasions after harvest. Dissolved organic carbon may indirectly promote orthophosphate dominance in solution by complexing metal cations that would otherwise precipitate metal-P from solution. Gray Luvisols probably export P to soils lower on the hillslope catena, such as those of the Gleysolic and Organic Orders, both commonly associated with wetlands. Key words: Forest soil, phosphorus, orthophosphate, Gray Luvisol, biogeochemistry, sorption

scholarly journals Uncertainty assessment of a dominant-process catchment model of dissolved phosphorus transfer

2016 ◽  
Vol 20 (12) ◽  
pp. 4819-4835 ◽  
Author(s):  
Rémi Dupas ◽  
Jordy Salmon-Monviola ◽  
Keith J. Beven ◽  
Patrick Durand ◽  
Philip M. Haygarth ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Uncertainty Assessment ◽  
Hydrologic Model ◽  
Calibration Data ◽  
Soil Biogeochemistry ◽  
Dissolved Phosphorus ◽  
Propagation Of Uncertainty ◽  
Generalized Likelihood Uncertainty Estimation

Abstract. We developed a parsimonious topography-based hydrologic model coupled with a soil biogeochemistry sub-model in order to improve understanding and prediction of soluble reactive phosphorus (SRP) transfer in agricultural headwater catchments. The model structure aims to capture the dominant hydrological and biogeochemical processes identified from multiscale observations in a research catchment (Kervidy–Naizin, 5 km2). Groundwater fluctuations, responsible for the connection of soil SRP production zones to the stream, were simulated with a fully distributed hydrologic model at 20 m resolution. The spatial variability of the soil phosphorus content and the temporal variability of soil moisture and temperature, which had previously been identified as key controlling factors of SRP solubilization in soils, were included as part of an empirical soil biogeochemistry sub-model. The modelling approach included an analysis of the information contained in the calibration data and propagation of uncertainty in model predictions using a generalized likelihood uncertainty estimation (GLUE) "limits of acceptability" framework. Overall, the model appeared to perform well given the uncertainty in the observational data, with a Nash–Sutcliffe efficiency on daily SRP loads between 0.1 and 0.8 for acceptable models. The role of hydrological connectivity via groundwater fluctuation and the role of increased SRP solubilization following dry/hot periods were captured well. We conclude that in the absence of near-continuous monitoring, the amount of information contained in the data is limited; hence, parsimonious models are more relevant than highly parameterized models. An analysis of uncertainty in the data is recommended for model calibration in order to provide reliable predictions.

scholarly journals Uncertainty assessment of a dominant-process catchment model of dissolved phosphorus transfer

2016 ◽  
Author(s):  
R. Dupas ◽  
J. Salmon-Monviola ◽  
K. Beven ◽  
P. Durand ◽  
P. M. Haygarth ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Uncertainty Assessment ◽  
Hydrologic Model ◽  
Calibration Data ◽  
Soil Biogeochemistry ◽  
Dissolved Phosphorus ◽  
Propagation Of Uncertainty ◽  
Reactive Phosphorus

Abstract. We developed a parsimonious topography-based hydrologic model coupled with a soil biogeochemistry sub-model in order to improve understanding and prediction of Soluble Reactive Phosphorus (SRP) transfer in agricultural headwater catchments. The model structure aims to capture the dominant hydrological and biogeochemical processes identified from multiscale observations in a research catchment (Kervidy-Naizin, 5 km2). Groundwater fluctuations, responsible for the connection of soil SRP production zones to the stream, were simulated with a fully-distributed hydrologic model at 20 m resolution. The spatial variability of the soil phosphorus status and the temporal variability of soil moisture and temperature, which had previously been identified as key controlling factor of SRP solubilisation in soils, were included as part of an empirical soil biogeochemistry sub-model. The modelling approach included an analysis of the information contained in the calibration data and propagation of uncertainty in model predictions using a GLUE "limits of acceptability" framework. Overall, the model appeared to perform well given the uncertainty in the observational data, with a Nash–Sutcliffe efficiency on daily SRP loads between 0.1 and 0.8 for acceptable models. The role of hydrological connectivity via groundwater fluctuation, and the role of increased SRP solubilisation following dry/hot periods were captured well. We conclude that in the absence of near continuous monitoring, the amount of information contained in the data is limited hence parsimonious models are more relevant than highly parameterised models. An analysis of uncertainty in the data is recommended for model calibration in order to provide reliable predictions.

Long-Term (15 Years) Results of NPS Controls in an Agricultural Watershed upon a Receiving Lake's Water Quality

1993 ◽  
Vol 28 (3-5) ◽  
pp. 441-449 ◽  
Author(s):  
Paul J. Garrison ◽  
Timothy R. Asplund
Keyword(s):  
Water Quality ◽  
Structural Changes ◽  
Soil Phosphorus ◽  
Water Clarity ◽  
Management Control ◽  
Agricultural Watershed ◽  
Control Measures ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
White Clay

Nonpoint source controls were installed in a 1215 ha agricultural watershed in northeastern Wisconsin in the late 1970. Changes were made in handling of animal wastes and cropping practices to reduce runoff of sediment and nutrients. Modelling results predicted a reduction in phosphorus runoff of 30 percent. The water quality of White Clay Lake has worsened since the installation of NPS controls. The lake's phosphorus concentration has increased from a mean of 29 µg L−1 in the late 1970s to 44 µg L−1 in recent years. Water clarity has declined from 2.7 to 2.1 m and the mean summer chlorophyll levels have increased from 9 to 13 µg L−1 with peak values exceeding 40 µg L−1. Increased phosphorus loading is not the result of elevated precipitation but instead the failure of the control measures to sufficiently reduce P loading. Most of the effort was placed on structural changes while most of the P loading comes from cropland runoff. Further, soil phosphorus concentrations have increased because of artificial fertilizers and manure spreading. The White Clay Lake experience is discouraging since the majority of the polluters in this watershed utilized some NPS control practices, including 76 percent of the farms which installed waste management control facilities.

scholarly journals Genetic variation of seed phosphorus concentration in winter oilseed rape and development of a NIRS calibration

Euphytica ◽  
2021 ◽  
Vol 217 (4) ◽  
Author(s):  
Jakob Eifler ◽  
Jürgen Enno Wick ◽  
Bernd Steingrobe ◽  
Christian Möllers
Keyword(s):  
Genetic Variation ◽  
Field Experiments ◽  
Seed Quality ◽  
Rapeseed Meal ◽  
Quality Analysis ◽  
Phosphorus Concentration ◽  
Genotypic Differences ◽  
Organic P ◽  
P Concentration ◽  
Total P

AbstractPhytic acid is the major organic phosphorus storage compound in rapeseed. Following oil extraction, the defatted meal is used in feed mixtures for livestock. However, monogastric pigs and chickens can only poorly metabolize phytate. Hence, their excrements are rich in phosphorus (P), which when applied as manure may lead to eutrophication of surface waters. The aim of the present study was to analyze the genetic variation for total and organic P concentration (i.e. mainly phytate) in rapeseed and to compare the results with soybean. Two sets of rapeseed material were tested in field experiments in different environments with varying soil P levels and harvested seeds were used for seed quality analysis. Results revealed significant genotypic differences in total seed P concentration, which ranged from 0.47 to 0.94%. Depending on the experiment, the heritability for total P concentration ranged from 52 to 93%. The organic P portion of total P concentration was above 90% for current rapeseed hybrids. In both sets, there was a significant positive correlation between seed protein and P concentration. A NIRS calibration for total P concentration in intact seeds showed in cross validation a standard error of 0.05% and a coefficient of determination of R2 = 0.83. Total P concentration of soybean seeds and meal was between 0.55 and 0.65%, and around 1.1% for rapeseed meal. Rapeseed meal had a twofold higher ratio of total P to nitrogen concentration as compared to soybean which could be considered adverse when the meal is used for feeding livestock.

scholarly journals Seasonal Variations of Phosphorus Species in the Overlying and Pore Waters of the Tuohe River, China

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Qing Xu ◽  
Xiaoping Yu ◽  
Yafei Guo ◽  
Tianlong Deng ◽  
Yu-Wei Chen ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Yangtze River ◽  
Algal Bloom ◽  
Soluble Reactive Phosphorus ◽  
Pore Waters ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Vertical Distributions ◽  
Reactive Phosphorus ◽  
Main Factor

Overlying sediment and pore waters were collected in summer and winter at upstream (Jintang) and downstream (Neijiang) sites of the Tuohe River, which is one of the five largest tributaries of the Yangtze River in China. Phosphorus species, including soluble reactive phosphorus (SRP), soluble unreactive phosphorus (SUP), and total dissolved phosphorus (TDP), and some diagenetic constituents including dissolved Fe(II), Mn(II), and sulfide in overlying and pore waters, were measured systematically. The seasonal variations and vertical distributions of phosphorus species in overlying and pore waters at both sampling sites were obtained to elucidate some aspects of the transport and transformations of phosphorus. Based on the profiles of pore and overlying waters as well as the TDN/TDP data during an algal bloom in 2007, it was clearly demonstrated that phosphorus was the main factor limiting the phytoplankton growth in the Tuohe River.

Naturally rainfall-induced changes in runoff-associated nitrogen and phosphorus losses in purple soil area: roles of land disturbance and plot length

2021 ◽  
Author(s):  
Ke Liang ◽  
Binghui He
Keyword(s):  
Rainfall Intensity ◽  
Purple Soil ◽  
Rainfall Events ◽  
Dissolved Phosphorus ◽  
Land Disturbance ◽  
P Concentration ◽  
Long Duration ◽  
Artificial Disturbance ◽  
Runoff Rate ◽  
Sloping Land

<p>Severe soil erosion occurs in southwestern China owing to the large expanses of human disturbance and sloping land. This field monitoring study was conducted during the rainy season to record the rainfall events, runoff, sediment yield, nitrogen, and phosphorous loss in 20-, 40-, and 60-m plots under conditions of artificial disturbance or natural restoration on a 15° slope in the purple soil area of southwestern China. The concentrations and loss amounts of total nitrogen (TN), total dissolved nitrogen (TDN), ammonium-nitrogen (NH4-N) and nitrate-nitrogen (NO<sub>3</sub>-N), total phosphorus (TP), total dissolved phosphorus (TDP) and orthophosphate (PO<sub>4</sub>-P) were comparatively determined. The highest N concentration was observed in long duration and soft rainfall events across all plots. The highest P concentration in artificial disturbed plots was found in long duration and intensive rainfall events while it was recordeds for measured variables were dominantly recorded under the long duration and lowest soft rainfall events in naturally restored plots intensity., while The the highest loss amounts for N and P in different forms for these variablesalmostmostly appeared under high rainfall intensity. Land disturbances differed orthophosphate PO<sub>4</sub>-P concentration in 20--m plot and and loss amounts of of measured variables N and P with different forms across in all plots. Plot lengths differed total dissolved phosphorus TDP concentration in natural restored plot and loss amounts of total dissolved nitrogenTDN and orthophosphate PO<sub>4</sub>-P in artificially disturbed plots. Naturally restoration reduced loss amounts of total nitrogen and total phosphorus by 69.4%62.14-79.05% and 79.28-83.43% TN, 68.8% TDN, 71.2% NH<sub>4</sub>-N, 74.3% NO<sub>3</sub>-N, 81.5% TP, 71.9% TDP and 70.0% PO<sub>4</sub>-P loss amounts comparedrelative to artificial disturbance, respectively. There were significant interrelationships among N and P concentrations in different forms in two land disturbance plots, while nitrate-NO<sub>3</sub>-nitrogenN concentration hadwas significantly negatively negative correlatedion with rainfall intensity and runoff rate in artificialally disturbanceed plots. Rainfall intensity was logarithmically correlated with TN, NO<sub>3</sub>-N concentrations in artificially disturbed plots and with NO<sub>3</sub>-N concentration in naturally restored plots. Runoff rate was logarithmically correlated with TN, TDN and NO<sub>3</sub>-N concentrations in artificially disturbed plots. Our results highlight the effects of land disturbance and plot length on nutrient losses in sloping land.</p>

Fast Determination of Phosphorus Concentration in Phosphogypsum Waste Using Calibration-Free LIBS in Air and Helium

2021 ◽  
Author(s):  
Khaled Elsayed ◽  
Walid Tawfik ◽  
Ashraf E M Khater ◽  
Tarek S Kayed ◽  
Mohamed Fikry
Keyword(s):  
Complete Analysis ◽  
Phosphorus Concentration ◽  
Stark Broadening ◽  
Breakdown Spectroscopy ◽  
P Concentration ◽  
Characteristic Lines ◽  
Laser Induced Breakdown ◽  
Novel Method ◽  
Calibration Free

Abstract This work represents a novel method to determine phosphorus (P) concentration in phosphogypsum (PG) waste samples using calibration-free laser-induced breakdown spectroscopy (LIBS). A 50 mJ Q-switched Nd: YAG laser has generated the PG LIBS spectrum. Spectroscopic analysis of plasma evolution has been characterized by electron density Ne and electron temperature Te using the emission intensity and stark broadening for P I characteristic lines 213.61, 214.91, and 215.40 nm under non-purged (air) and purged (helium) conditions. It was found that both Te and Ne have significant changes linearly with P concentrations 4195, 5288, 6293, and 6905 ppm. The values of plasma Te and Ne increased from about 6900 to 10000 K and 1.1×1017 to 3.4×1017 cm− 3, respectively, for the non-purged PG. On the other hand, Te and Ne ranged from 8200 to 11000 K and 1.4×1017 to 3.5×1017 cm− 3, respectively, for the PG purged with helium. It is concluded that Te and Ne values represent a fingerprint plasma characterization for a given P concentration in PG samples, which can be used to identify P concentration without a PG's complete analysis. These results demonstrate a new achievement in the field of spectrochemical analysis of environmental applications.

scholarly journals Phosphorus dynamics in the water of tropical semiarid reservoirs in a prolonged drought period

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Herika Cavalcante ◽  
Fabiana Araújo ◽  
Vanessa Becker
Keyword(s):  
Water Column ◽  
Organic Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Particulate Phosphorus ◽  
Semiarid Region ◽  
Drought Period ◽  
Chl A ◽  
Dissolved Phosphorus ◽  
Phosphorus Dynamics ◽  
Prolonged Drought

Abstract Aim To verify the vertical distribution of phosphorus in the water and to identify the predominant forms of P in the water column for understand the phosphorus dynamics in tropical semiarid reservoirs during a prolonged drought period. Methods Two reservoirs from the semiarid region of Rio Grande do Norte were analysed during the period from May 2015 to June 2016. Were analysed: Suspended solids (SS), chlorophyll a (Chl-a), dissolved oxygen (OD) and temperature. Vertical profiles were plotted for total phosphorus (PT), total dissolved phosphorus (PTD), particulate phosphorus (PP), dissolved organic phosphorus (POD) and soluble reactive phosphorus (FRS). Results The phosphorus values distributed in the water column were high for both reservoirs, presenting the highest values during the periods with lower depth. Gargalheiras presented greater predominance of PT and PP, while Cruzeta had the highest values of FRS. Chl-a and SS values were also consistent with phosphorus values: Chl-a was higher in Gargalheiras, while SS, mainly inorganic, were higher in Cruzeta. Gargalheiras presented anoxic conditions close to the sediment from May 2015 to December 2015, which may induce the release of phosphorus from the sediment to the water column. Values that are too high during the shallower months, especially in Cruzeta, may have been influenced by the release of P from sediment through wind resuspension. Conclusions The amounts and predominant types of phosphorus in the water column are of great importance to understand the phosphorus dynamics and will support restoration plans for the studied environments. In this study it was possible to verify that the reservoirs are susceptible to the release of P from the sediment due to the environmental conditions, mainly low depths, resuspension of the wind and anoxia in the hypolimnion.

scholarly journals Antagonism of Bacillus thuringiensis to phytopathogenic micromicetes as pathogens of apple trees

2021 ◽  
Author(s):  
О. Sherstoboeva ◽  
А. Krzyhanivsky ◽  
А. Bunas
Keyword(s):  
Bacillus Thuringiensis ◽  
Nutrient Medium ◽  
Leaf Surface ◽  
Water Soluble ◽  
Ecological Niches ◽  
Negative Consequences ◽  
Apple Trees ◽  
Produce Water ◽  
Antagonistic Microorganisms

Antagonistic microorganisms, producing bactericidal and fungicidal substances, spread in space and occupy various ecological niches. Antagonistic action of microorganisms can be combined with a number of other properties that can be used by humans for their own purposes. Microorganisms — agents of biological products often have a multifunctional effect on the components of the agroecosystem, which under the influence of various environmental factors could have positive and negative consequences. The aim of the study was to study the effect of new highly active entomopathogenic strains of Bacillus thuringiensis on non-target objects — components of the biocenosis of the apple orchard. When developing technologies for biocontrol of the number of apple trees pests using B. thuringiensis revealed an additional positive protective effect — reducing the number of pathogens of fungal diseases on the leaf surface. Treatment of apple leaves with a liquid culture of strain B. thuringiensis 0376 after 72 hours of application reduced the number of scab of Fusicladium dendriticum by 7 times, and the pathogen of monolisis of Monilia fructigena — 9 times. Strain B. thuringiensis 0371 showed the highest level of antagonism, because in vitro completely inhibited the growth and development of micromycetes on the surface of the nutrient medium. On the leaf surface, the application of culture strain 0371 reduced the number of Fusicladium dendriticum by 92%, and Monilia fructigena — by 86% after 72 hours of treatment. In a field experiment when treating apple trees with a culture of this strain, scab development decreased by 7.1%. Strain B. thuringiensis 787 did not show antagonism against phytopathogenicmicromycetes during co-cultivation on nutrient medium, which may be explained by its inability to produce water-soluble exotoxin, in contrast to strains of B. thuringiensis, which are antagonists of scab and apple monolisis. Strain B. thuringiensis 0371 requires further research and development of its formulations, because it is promising for the creation of a complex biological product with insect-fungicidal properties for use in ecological and agriculture friendly technologies.

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