Phosphorus, Iron, and Aluminum Losses in Runoff from a Rotationally Grazed Pasture in Georgia

2017 ◽  
Vol 60 (3) ◽  
pp. 861-875
Author(s):  
Dinku M. Endale ◽  
Harry H. Schomberg ◽  
Dwight S. Fisher ◽  
Lloyd B. Owens ◽  
Michael B. Jenkins ◽  
...  
Keyword(s):  
Transport Processes ◽  
Total Load ◽  
P Loss ◽  
Grazed Pasture ◽  
Dissolved Reactive Phosphorus ◽  
The Difference ◽  
Reactive Phosphorus ◽  
Runoff Events ◽  
Total P

Abstract. Well-managed grazing systems can provide valuable ecosystem services, such as reducing sediment and phosphorus (P) loading to nearby waterways. However, the available long-term data to fully support this hypothesis are limited. In this article, we describe flow-weighted concentrations (FWCs) and loads for dissolved reactive P (DRP), total P (TP), iron (Fe), and aluminum (Al) over 11 years (1999-2009) from a 7.8 ha rotationally grazed pasture (W1) near Watkinsville, Georgia. The region is characterized by Fe and Al rich and acidic Ultisols. Cattle numbering 21 to 224 (mean 91) grazed W1 on 69 occasions for 1 to 71 d (mean 19.2). Of 74 runoff events, 20 occurred when the monthly rainfall was below the long-term average (deficit period) and 54 occurred during non-deficit periods. Samples were collected from 43 of 74 runoff events for nutrient analyses. Event FWC (mg L-1) ranged from 0.38 to 7.07 for DRP (mean 1.91), from 0.36 to 7.60 for TP (mean 2.43), from 0.03 to 0.55 for Fe (mean 0.23), and from 0.43 to 553 µg L-1 for Al (mean 65 µg L-1). Event load (kg ha-1) ranged from 0.00 to 0.45 for DRP (mean 0.10), from 0.00 to 0.55 for TP (mean 0.12), from 0.00 to 0.11 for Fe (mean 0.02), and from 0.00 to 0.10 for Al (mean 0.01). The total load (kg ha-1) was 4.12 for DRP, 5.12 for TP, 0.71 for Fe, and 0.25 for Al. DRP accounted for 80% of the TP FWC and load. Cattle presence increased sediment load, but the difference was not statistically significant. There was high correlation between Fe and DRP loads (r = 0.87), a likely indicator of erosion-induced losses due to cattle treading. Cattle presence increased FWCs but not loads for DRP and TP. The FWCs for DRP and TP were not different between deficit and non-deficit periods, but mean loads were 3-fold to 4-fold greater during non-deficit periods. Means from the six largest P loss events were 3-fold greater for FWC and 7-fold greater for load than the remaining 37 events. These six large events accounted for 53% of the total P load. Less than 1% of the inorganic P applied and redeposited through manure was lost in runoff. The study demonstrated that hydrologic transport processes were the dominant drivers of pollutant fluxes and highlighted the possible mitigation of pollutant fluxes through grazing management that includes maintenance of good grass cover, effective rotational grazing, and limited fertilization. Keywords: Calving, Cattle, Dissolved reactive phosphorus, Drought, Eutrophication, Manure, Runoff, Total phosphorus, Water quality.

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

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.).

Effect of Leaching on Loss of Soil Phosphorus in Different Types of Sand Dune in Horqin Sandy Land, China

2013 ◽  
Vol 726-731 ◽  
pp. 3818-3827 ◽  
Author(s):  
Quan Lai Zhou ◽  
De Ming Jiang ◽  
Zhi Min Liu ◽  
Alamusa ◽  
Xue Hua Li
Keyword(s):  
Soil Phosphorus ◽  
Available Phosphorus ◽  
Horqin Sandy Land ◽  
Sandy Land ◽  
Soil P ◽  
P Loss ◽  
Different Types ◽  
The Difference ◽  
P Leaching ◽  
Total P

We simulated P leaching on active dune (AD), semi-stabilized dune (SSD) and stabilized dune (SD) under 140, 700 and 1400 mm of rainfall in Horqin Sandy Land Inner Mongolia, China. The results showed that the available phosphorus (AP) pool decreased by 5–50% in topsoil (0–10 cm), and increased by -5–220% in subsoil (10–20 cm) in AD, SSD, and SD soil. The total P (TP) pool in topsoil (0–10 cm) decreased by 1.8–5.0%, and increased by -5–4.6% in subsoil (10–20 cm) in AD, SSD, and SD soil. The P loss in the soils (0-20 cm) was 0.5–4.5% in AD, SSD, and SD soil. These data indicated that significant downward movement of P occurred during soil leaching. And, the movement of soil P by leaching can cause P loss and changes in vertical distribution of P. Moreover, the difference in P concentration, drawn up by plant roots, between topsoil and subsoil can buffer the P loss at the start of leaching. Therefore, vegetation restoration is essential to reduce P loss in sandy lands.

Removing filterable reactive phosphorus from highly coloured stormwater using constructed wetlands

2001 ◽  
Vol 44 (11-12) ◽  
pp. 85-92 ◽  
Author(s):  
M.A. Lund ◽  
P.S. Lavery ◽  
R.F. Froend
Keyword(s):  
Constructed Wetlands ◽  
Plant Biomass ◽  
Central Zone ◽  
Benthic Flux ◽  
Removal Capacity ◽  
Removal Processes ◽  
Reactive Phosphorus ◽  
Total P ◽  
P Removal

A constructed wetland design, consisting of 16 repeating cells was proposed for Henley Brook (Perth, Western Australia) to optimise the removal of FRP from urban stormwater. Three replicate experimental ponds (15×5 m), were constructed to represent at a 1:1 scale a single cell from this design. Three 5 m zones of each pond were sampled: shallow (0.3 m) vegetated (Schoenoplectus validus) inflow and outflow zones and a deeper (1 m), V-shaped central zone. In 1998/99, inflows and outflow waters were intensively sampled and analysed for FRP and Total P. In addition, all major pools of P (plants, sediment) within the ponds, and important P removal processes (benthic flux, uptake by biofilm and S. validus) were quantified. A removal efficiency of 5% (1998) and 10% (1999) was obtained for FRP. Initial uptake was mainly in plant biomass, although the sediment became an increasingly important sink. Benthic flux experiments showed that anoxia did not cause release of P from sediments, indicating that most of the P was bound as apatite rather than associated with Fe or Mn. The highly coloured waters were believed responsible for the very low biofilm biomass recorded (<1 g.m-2). We have demonstrated that constructed wetlands can be effective for removing FRP immediately after construction, although their long-term removal capacity needs further research.

A Problem of Long - Term Digital Preservation: Difference in Humanities and Natural Sciences

2014 ◽  
Vol 3 ◽  
pp. 183-195
Author(s):  
Elena Macevičiūtė
Keyword(s):  
Social Sciences ◽  
Digital Preservation ◽  
Dynamic Activity ◽  
Private Companies ◽  
Time Line ◽  
Digital Documents ◽  
Whole Process ◽  
The Difference ◽  
Technological Science

The article deals with the requirements and needs for long-term digital preservation in different areas of scholarly work. The concept of long-term digital preservation is introduced by comparing it to digitization and archiving concepts and defined with the emphasis on dynamic activity within a certain time line. The structure of digital preservation is presented with regard to the elements of the activity as understood in Activity Theory. The life-cycle of digitization processes forms the basis of the main processing of preserved data in preservation archival system.The author draws on the differences between humanities and social sciences on one hand and natural and technological science on the other. The empirical data characterizing the needs for digital preservation within different areas of scholarship are presented and show the difference in approaches to long-term digital preservation, as well as differences in selecting the items and implementing the projects of digital preservation. Institutions and organizations can also develop different understanding of preservation requirements for digital documents and other objects.The final part of the paper is devoted to some general problems pertaining to the longterm digital preservation with the emphasis of the responsibility for the whole process of safe-guarding the cultural and scholarly heritage for the re-use of the posterior generations. It is suggested that the longevity of the libraries in comparison with much shorter life-span of private companies strengthens the claim of memory institutions to playing the central role in the long-term digital preservation.

CSO Modelling Considering Moving Storms and Tipping Bucket Gauge Failures

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
M. Hochedlinger ◽  
W. Sprung ◽  
H. Kainz ◽  
K. König
Keyword(s):  
Hydrological Models ◽  
Rain Intensity ◽  
Hydrodynamic Models ◽  
Data Intensive ◽  
Storm Flow ◽  
Cell Velocity ◽  
Combined Sewer ◽  
Moving Direction ◽  
The Difference

The simulation of combined sewer overflow volumes and loads is important for the assessment of the overflow and overflow load to the receiving water to predict the hydraulic or the pollution impact. Hydrodynamic models are very data-intensive and time-consuming for long-term quality modelling. Hence, for long-term modelling, hydrological models are used to predict the storm flow in a fast way. However, in most cases, a constant rain intensity is used as load for the simulation, but in practice even for small catchments rain occurs in rain cells, which are not constant over the whole catchment area. This paper presents the results of quality modelling considering moving storms depending on the rain cell velocity and its moving direction. Additionally, tipping bucket gauge failures and different corrections are also taken into account. The results evidence the importance of these considerations for precipitation due the effects on overflow load and show the difference up to 28% of corrected and uncorrected data and of moving rain cells instead of constant raining intensities.

scholarly journals Soil erosion by snow gliding – a first quantification attempt in a subalpine area in Switzerland

2014 ◽  
Vol 18 (9) ◽  
pp. 3763-3775 ◽  
Author(s):  
K. Meusburger ◽  
G. Leitinger ◽  
L. Mabit ◽  
M. H. Mueller ◽  
A. Walter ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Land Cover ◽  
Sediment Yield ◽  
Soil Loss ◽  
Water Erosion ◽  
Erosion Rates ◽  
The Difference ◽  
Snow Gliding

Abstract. Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959–2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha−1 yr−1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha−1 yr−1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2 = 0.64; p < 0.005) and to the snow deposition sediment yields (R2 = 0.39; p = 0.13). The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based on these results, we conclude that snow gliding appears to be a crucial and non-negligible process impacting soil erosion patterns and magnitude in subalpine areas with similar topographic and climatic conditions.

scholarly journals Malpigmentation of Common Sole (Solea solea) during Metamorphosis Is Associated with Differential Synaptic-Related Gene Expression

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2273
Author(s):  
Menelaos Kavouras ◽  
Emmanouil E. Malandrakis ◽  
Ewout Blom ◽  
Kyriaki Tsilika ◽  
Theodoros Danis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nervous System ◽  
De Novo ◽  
Close Association ◽  
Ionic Channels ◽  
Long Term Potentiation ◽  
General Term ◽  
The Difference ◽  
Common Sole

In farmed flatfish, such as common sole, color disturbances are common. Dyschromia is a general term that includes the color defects on the blind and ocular sides of the fish. The purpose was to examine the difference in gene expression between normal pigmented and juveniles who present ambicoloration. The analysis was carried out with next-generation sequencing techniques and de novo assembly of the transcriptome. Transcripts that showed significant differences (FDR < 0.05) in the expression between the two groups, were related to those of zebrafish (Danio rerio), functionally identified, and classified into categories of the gene ontology. The results revealed that ambicolorated juveniles exhibit a divergent function, mainly of the central nervous system at the synaptic level, as well as the ionic channels. The close association of chromophore cells with the growth of nerve cells and the nervous system was recorded. The pathway, glutamate binding–activation of AMPA and NMDA receptors–long-term stimulation of postsynaptic potential–LTP (long term potentiation)–plasticity of synapses, appears to be affected. In addition, the development of synapses also seems to be affected by the interaction of the LGI (leucine-rich glioma inactivated) protein family with the ADAM (a disintegrin and metalloprotease) ones.

scholarly journals Long-term risks after kidney donation: how do we inform potential donors? A survey from DESCARTES and EKITA transplantation working groups

2021 ◽  
Author(s):  
Geir Mjøen ◽  
Umberto Maggiore ◽  
Nicos Kessaris ◽  
Diederik Kimenai ◽  
Bruno Watschinger ◽  
...  
Keyword(s):  
Evaluation Process ◽  
Kidney Donation ◽  
Kidney Donors ◽  
Living Kidney Donors ◽  
Relative Risks ◽  
Written Information ◽  
The Difference ◽  
Stage Renal Disease ◽  
End Stage

Abstract Background Publications from the last decade have increased knowledge regarding long-term risks after kidney donation. We wanted to perform a survey to assess how transplant professionals in Europe inform potential kidney donors regarding long-term risks. The objectives of the survey were to determine how they inform donors and to what extent, and to evaluate the degree of variation. Methods All transplant professionals involved in the evaluation process were considered eligible, regardless of the type of profession. The survey was dispatched as a link to a web-based survey. The subjects included questions on demographics, the information policy of the respondent and the use of risk calculators, including the difference of relative and absolute risks and how the respondents themselves understood these risks. Results The main finding was a large variation in how often different long-term risks were discussed with the potential donors, i.e. from always to never. Eighty percent of respondents stated that they always discuss the risk of end-stage renal disease, while 56% of respondents stated that they always discuss the risk of preeclampsia. Twenty percent of respondents answered correctly regarding the relationship between absolute and relative risks for rare outcomes. Conclusions The use of written information and checklists should be encouraged. This may improve standardization regarding the information provided to potential living kidney donors in Europe. There is a need for information and education among European transplant professionals regarding long-term risks after kidney donation and how to interpret and present these risks.

scholarly journals Tooth loss in complying and non-complying periodontitis patients with different periodontal risk levels during supportive periodontal care

2021 ◽  
Author(s):  
Roberto Farina ◽  
Anna Simonelli ◽  
Andrea Baraldi ◽  
Mattia Pramstraller ◽  
Luigi Minenna ◽  
...  
Keyword(s):  
Active Treatment ◽  
Clinical Relevance ◽  
Tooth Loss ◽  
Loss Rate ◽  
Risk Levels ◽  
Recall Interval ◽  
Level 3 ◽  
The Difference ◽  
Periodontal Risk

Abstract Objectives To evaluate yearly tooth loss rate (TLR) in periodontitis patients with different periodontal risk levels who had complied or not complied with supportive periodontal care (SPC). Materials and methods Data from 168 periodontitis patients enrolled in a SPC program based on a 3-month suggested recall interval for at least 3.5 years were analyzed. For patients with a mean recall interval within 2–4 months (“compliers”) or > 4 months (“non-compliers”) with different PerioRisk levels (Trombelli et al. 2009), TLR (irrespective of the cause for tooth loss) was calculated. TLR values were considered in relation to meaningful TLR benchmarks from the literature for periodontitis patients either under SPC (0.15 teeth/year; positive benchmark) or irregularly complying with SPC (0.36 teeth/year; negative benchmark). Results In both compliers and non-compliers, TLR was significantly below or similar to the positive benchmark in PerioRisk level 3 (0.08 and 0.03 teeth/year, respectively) and PerioRisk level 4 (0.12 and 0.18 teeth/year, respectively). Although marked and clinically relevant in non-compliers, the difference between TLR of compliers (0.32 teeth/year) and non-compliers (0.52 teeth/year) with PerioRisk level 5 and the negative benchmark was not significant. Conclusion A SPC protocol based on a 3- to 6-month recall interval may effectively limit long-term tooth loss in periodontitis patients with PerioRisk levels 3 and 4. A fully complied 3-month SPC protocol seems ineffective when applied to PerioRisk level 5 patients. Clinical relevance PerioRisk seems to represent a valid tool to inform the SPC recall interval as well as the intensity of active treatment prior to SPC enrollment.

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