Water Quality Sampling, Analysis and Annual Load Determinations for TSS, Nitrogen and Phosphorus at the Washington County Road 76 Bridge on Ballard Creek

The Illinois River Basin has experienced water quality impairment from non-point source pollution for many years. This fact was well documented in the State of Arkansas\u27 Water Quality Assessment report, the Soil Conservation Service River Basin Study, and several University of Arkansas studies. Thirty-seven sub-watersheds have been identified by the SCS in the Arkansas portion of the Illinois River basin. In the Arkansas portion of the Basin, the Illinois River, Evansville Creek, Baron Fork, Cincinnati Creek, Muddy Fork, Moores Creek, Clear Creek, Osage Creek and Flint Creek were all classified as not supporting their designated use as primary contact recreation streams. The identified causes of the impairment were: sediment, bacteria and nutrients. In 1997, the University of Arkansas completed a project that estimated the phosphorus loading from each of the thirty-seven sub-watersheds. This project also prioritized watersheds for implementation work based on phosphorus loads, nitrogen loads and total suspended solids loads per unit area. The thirty-seven sub-watersheds were grouped into Low (16), Medium (10) and High (11) categories based on phosphorus loadings. If all the sub-watersheds above the median value for on phosphorus loading in the Illinois River basin were brought down to the current median value for phosphorus loading, this reduction would result in the agreed to 40% reduction of phosphorus at the state line. The selection of a sub-watershed for targeted intensive voluntary BMP implementation was based on the following criteria: a) the sub-watershed had to be above the current median value for phosphorus loading, b) there would be no sewage treatment plant in the sub-watershed, and c) land user interest. The Upper Ballard Creek watershed met all these requirements. The watershed covers 6700 hectares. The creek is listed in the High category with a unit area loading of 1.75 kg. per hectare per year. The median value for the thirty-seven watersheds is 0.73 kg. per hectare per year

Dynamically optimal phosphorus management and agricultural water protection

This paper puts forward a model of the role of phosphorus in crop production, soil phosphorus dynamics and phosphorus loading that integrates the salient economic and ecological features of agricultural phosphorus management. The model accounts for the links between phosphorus fertilization, crop yield, accumulation of soil phosphorus reserves, and phosphorus loading. It can be used to guide precision phosphorus management and erosion control as means to mitigate agricultural loading. Using a parameterization for cereal production in southern Finland, the model is solved numerically to analyze the intertemporally optimal combination of fertilization and erosion and the associated soil phosphorus development. The optimal fertilizer application rate changes markedly over time in response to changes in the soil phosphorus level. When, for instance, soil phosphorus is initially above the socially optimal steady state level, annually matching phosphorus application to the prevailing soil phosphorus stock produces significantly higher social welfare than using a fixed fertilizer application rate. Erosion control was found to increase welfare only on land that is highly susceptible to erosion

Dynamically Optimal Phosphorus Management and Agricultural Water Protection

This paper puts forward a model of the role of phosphorus in crop production, soil phosphorus dynamics and phosphorus loading that integrates the salient economic and ecological features of agricultural phosphorus management. The model accounts for the links between phosphorus fertilization, crop yield, accumulation of soil phosphorus reserves, and phosphorus loading. It can be used to guide precision phosphorus management and erosion control as means to mitigate agricultural loading. Using a parameterization for cereal production in southern Finland, the model is solved numerically to analyze the intertemporally optimal combination of fertilization and erosion control and the associated soil phosphorus development. The optimal fertilizer application rate changes markedly over time in response to changes in the soil phosphorus level. When, for instance, soil phosphorus is initially above the socially optimal steady state level, annually matching phosphorus application to the prevailing soil phosphorus stock produces significantly higher social welfare than using a fixed fertilizer application rate. Erosion control was found to increase welfare only on land that is highly susceptible to erosion.precision nutrient management, agricultural phosphorus loading, cereal production, soil phosphorus reserves, agricultural water pollution, dynamic programming, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy,

Economic Analysis of Management Practices to Reduce Phosphorus Load to Lake Eucha and Spavinaw

Changes in management practices are often proposed to reduce phosphorus loading from a watershed due to over application of poultry litter. This study determines the choice, location, and level of each best management practice in the watershed to meet a Total Maximum Daily Load and margins of safety at least cost.best management practice, phosphorus runoff, poultry litter, Target MOTAD, Environmental Economics and Policy,

Changes of water quality and sediment phosphorus of a small productive lake following decreased phosphorus loading

Esthwaite Water is the most productive or eutrophic lake in the English Lake District. Since 1945 its water quality has been determined from weekly or biweekly measurements of temperature, oxygen, plant nutrients and phytoplankton abundance. The lake receives phosphorus from its largely lowland-pasture catchment, sewage effluent from the villages of Hawkshead and Near Sawrey, and from a cage-culture fish farm. From 1986 phosphorus has been removed from the sewage effluent of Hawkshead which was considered to contribute between 47% and 67% of the total phosphorus loading to the lake. At the commencement of phosphorus removal regular measurements of phosphorus in the superficial 0-4 cm layer of lake sediment were made from cores collected at random sites. Since 1986 the mean annual concentration of alkali-extractable sediment phosphorus has decreased by 23%. This change is not significant at the 5% level but nearly so. There has been no marked change in water quality over this period. Summer dominance of blue-green algae which arose in the early 1980s after decline of the previous summer forms, Ceratium spp., has been maintained. Improvement in water quality is unlikely to be achieved at the present phosphorus loading

Nitrogen, Phosphorus, and Suspended Solids Concentrations in Tributaries to the Great Bay Estuary Watershed in 2011

Nitrogen, phosphorus, and sediment loads to the Great Bay Estuary are a growing concern. The Piscataqua Region Estuaries Partnership (PREP) calculates the nitrogen load from tributaries to the Great Bay Estuary for its State of the Estuaries reports. Therefore, the purpose of this study was to collect representative data on nitrogen, phosphorus, and suspended sediment concentrations in tributaries to the Great Bay Estuary in 2011. The study design followed the tributary sampling design which was implemented by the New Hampshire Department of Environmental Services between 2001 and 2007 and by the University of New Hampshire in 2008 and 2010, so as to provide comparable data to the previous loading estimates

Nitrogen, Phosphorus, and Suspended Solids Concentrations in Tributaries to the Great Bay Estuary Watershed in 2013

Nitrogen, phosphorus, and sediment loads to the Great Bay Estuary are a growing concern. The Piscataqua Region Estuaries Partnership (PREP) calculates the nitrogen load from tributaries to the Great Bay Estuary for its State of Our Estuaries reports. Therefore, the purpose of this study was to collect representative data on nitrogen, phosphorus, and suspended sediment concentrations in tributaries to the Great Bay Estuary in 2013. The study design followed the tributary sampling design which was implemented by the New Hampshire Department of Environmental Services between 2001 and 2007 and by the University of New Hampshire between 2008 and 2012, so as to provide comparable data to the previous loading estimates

ENVIRO-ECONOMIC ANALYSIS OF PHOSPHORUS NONPOINT POLLUTION

The state of Minnesota seeks to reduce phosphorus loading to the Minnesota River by 40% from current levels. The state agency charged with achieving this reduction has indicated each watershed should reduce its current phosphorus loading by 40%. We hypothesized that policies targeting specific practices or regions would have a smaller negative impact on farm income than policies requiring every nonpoint polluter to reduce its contribution by 40%. Using a stylized version of one major watershed in the river basin as an example, we analyzed the cost-effectiveness of various nonpoint pollution reduction policies. We simulated current and alternative farming systems (designed to reduce phosphorus loading by changing tillage or fertilizer practices) in distinct regions within the watershed using a biophysical process model. For each system, estimates of phosphorus loading from biophysical simulation were combined with production cost and return estimates to create an enviro-economic model of the watershed. Additionally, risk premiums were estimated and included with cost estimates for each alternative system. We used a positive math-programming (PMP) version of the enviro-economic model to analyze nonpoint pollution reduction policies (pollution standard, phosphorus effluent tax, conventional tillage tax, and phosphorus fertilizer tax). When regions and practices within the watershed could be targeted for achieving the pollution reduction standard, 13,500 fewer hectares (6% reduction from the baseline cropland level) were farmed. When the same standard was uniformly applied to all regions (not targeted), cropland decline by 40,500 hectares (20%). Under either scenario, cropland was removed from production, implying some producers may exit farming. Cropland reductions resulted in farmers losing $2.8 million (5$11.4 million (21%). This finding illustrates how difficulty it is to reduce nonpoint pollution if one does not focus on specific regions. An effluent tax of $74 per kilogram of phosphorus reaching the river was needed to reduce phosphorus loading by 40$14 million (25% reduction from the baseline income level), $11 million of which were revenues from the effluent tax. Neither the conventional tillage tax nor the phosphorus fertilizer tax achieved a 40% reduction in phosphorus loading. This finding illustrates the difficulty of reducing nonpoint pollution by focusing only on one practice. Under a pollution-reduction standard, our results indicated it is more cost effective to reduce nonpoint pollution by targeting particular regions or practices in a watershed compared to not targeting. Specifically, producers farming on cropland susceptible to erosion in close proximity to water who switch from conventional tillage to conservation tillage and reduce phosphorus fertilization levels to those recommended by the state extension service will appreciably reduce phosphorus nonpoint pollution loading potential. Efforts to target those producers could minimize potential losses in farm income in the watersheds and the river basin.Environmental Economics and Policy,

Phosphate absorption by Arabidopsis thaliana : the effects of phosphorus nutritional status : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology and Biotechnology at Massey University, Palmerston North, New Zealand

The effect of phosphorus nutritional status on phosphate uptake within the concentration range of the high affinity uptake mechanism, and subsequent translocation to the shoot was investigated in the plant species Arabidopsis thaliana. Plants of different nutritional status were generated by exposure to different set phosphate concentrations throughout an aseptic hydroponic growing period. Alternatively phosphorus deficiency was induced by growth at high concentrations of phosphate followed by a period of 5 days in phosphate-free hydroponic solution. In effect these growth conditions resulted in plants of distinguishable phenotypic character with respect to phosphate absorption, phosphate translocation, arsenate sensitivity and root-shoot ratio. To determine absorption kinetics nutrient depletion trials were carried out in which phosphate uptake was measured by monitoring the loss of phosphate from depletion solutions of set initial phosphate concentration to which the root systems of intact plants were exposed. Km and Vmax kinetic parameters were calculated from the depletion trial data using the software package "Igor Pro". Influx and net phosphate uptake was determined by setting the initial phosphate concentration of the depletion trials using either 32 P labelled KH 2 P0 4 or non-labelled KH 2 P0 4 respectively. Radioactivity was measured by counting the Cerenkov radiation in a scintillation counter. Non-labelled phosphate depletion was measured by either spectrophotometric assay or ion chromatography. To asses the effect of the phosphate analogue arsenate on phosphate influx, 32 P labelled phosphate uptake was measured with arsenate (KH 2 AsO 4 ) present in the depletion solution at a concentration of 20 µM. Phosphate translocation was determined by counting the Cerenkov radiation in the roots and shoots separately of plants that had been exposed to the 32 P labelled depletion solutions. Under the conditions of this project, phosphorus deficient plants exhibited alterations in the kinetic parameters Km and Vmax for phosphate uptake that were dependent on how the deficiency was induced. For plants that were grown continuously at low phosphate concentrations Km was decreased without a concomitant change in Vmax. For plants that were grown at high concentrations of phosphate followed by a 5 day period of phosphate starvation, a significant increase in Vmax was recorded without an associated change to Km. Phosphate uptake was found to be severely inhibited by the presence of arsenate in the depletion solution. Greatest inhibition however was found not to occur at the level of absorption into the plant root system but rather appeared to be at a site involved in phosphate loading into the xylem. Inhibition at this site was also found to be greatest in low phosphorus status plants. From these results it is suggested that plants of low phosphorus status possess high affinity phosphate xylem loading mechanisms, induced under conditions of phosphorus deficiency, which have a greater susceptibility to arsenate competitive inhibition and toxicity than equivalent xylem loading mechanisms in high phosphorus status plants

Optimal phosphorus loading for a potentially eutrophic lake

dynamic programming;sustainable development;ecology