ABSTRACT: In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of ph... more ABSTRACT: In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (P), especially agricultural runoff and land application of animal manure. However, it has become apparent in the Ozarks that this shift in focus may be premature and neglect P from discrete sources, e.g. wastewater treatment plants (WWTPs). We sampled the water column at 30 sites in the Illinois River Basin [Ozark Plateaus, USA]; this catchment receives effluent from four municipal WWTPs. The average annual P load was approximately 208,000 kg from 1997 through 2001, and municipal WWTPs represented almost 45% of the average annual load. Water column P concentrations were significantly greater during surface runoff conditions compared to base flow conditions. Phosphorus concentrations and stream flow displayed distinct relations during base flow and surface runoff conditions. Water column P concentrations were increased by WWTP effluents during base flow conditions and the increa...
ABSTRACT Litter from broiler chicken (Gallus gallus domesticus) production is a beneficial soil a... more ABSTRACT Litter from broiler chicken (Gallus gallus domesticus) production is a beneficial soil amendment containing organic material and many nutrients essential for proper plant growth. However, repeated land application of litter in regions of concentrated broiler production has raised concerns regarding nutrient and trace element loading in soil and potential groundwater and surface water contamination via runoff and leaching. The objective of this study was to evaluate seasonal and annual effects of broiler litter application rate on soil leachate concentrations and leaching losses of several essential plant nutrients [nitrate-N (NO3-N), ammonium-N (NH4-N), P, K, Ca, Mg, and Na] from a silt-loam soil (fine-silty, siliceous, active, mesic Typic Fragiudult) under tall fescue (Festuca arundinacea Shreb.) vegetation in the Ozark Highlands of northwest Arkansas. Equilibrium-tension lysimeters were used to continuously monitor and collect soil leachate solution from below the undisturbed root zone of small plots for a two-year period after two annual broiler litter applications at rates of 0 (control), 5.6 (low), and 11.2 (high) Mg litter ha-1. In Year 1 (May 2003-April 2004), flow-weighted mean leachate concentrations of Ca, Na, P, and Mg differed among litter rates during one or more periods; however, there were no consistent treatment effects. In Year 2 (May 2004-April 2005), leachate concentrations of Mg and NH4-N differed among litter rates during one or more periods, in which all had the greatest concentration under the low-litter treatment. There were no differences in plant nutrient leaching losses among litter rates during either full year or cumulatively over the two-year period. The land use combination of a long history of litter application, followed by several years of no litter, followed by two consecutive years of additional litter application seems to cause few water quality concerns caused by nutrient leaching, with the exception of P if leachate and/or groundwater discharge to the soil surface.
... 6. The concentration of dissolved inorganic nitrogen (DIN) and the molar ratio of DIN to tota... more ... 6. The concentration of dissolved inorganic nitrogen (DIN) and the molar ratio of DIN to total dissolved phosphorus (TDP), appeared to be the main environmental factors controlling the extent of nitrogen or ... Rate and yield limitation (sensuO'Brien, 1972) were distinguished. ...
In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (... more In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (P), especially agricultural runoff and land application of animal manure. However, it has become apparent in the Ozarks that this shift in focus may be premature and neglect P from discrete sources, e.g. wastewater treat ment plants (WWTPs). We sampled the water column at
poultry litter was land applied as a fertiliser to meet forage N requirements, making it suscepti... more poultry litter was land applied as a fertiliser to meet forage N requirements, making it susceptible to transport from the landscape during episodic precipitation events. Nitrogen and P concentrations were measured in four sub-watersheds of Beaver Lake, a reservoir on the White River in Arkansas, USA, to assess possible relationships between pasture land use and stream nutrient concentrations and export. Surface water samples were collected 17 times annually for 2 years from ten total stream sites within the four watersheds. Samples were analysed for soluble reactive P (SRP), total P (TP), ammonium-N (NH4-N), nitrate-N (NO3-N), total Kjeldhal N (TKN) and total N (TN). Discharge was measured at four gauged stream stations, and nutrient export was calculated using the US Geological Survey ESTIMATOR software and non-biased re-transformation from log space. Stream SRP, NO3-N and TN concentrations (geometric-mean) increased linearly with per cent of pasture in watersheds, whereas N and P...
ABSTRACT: In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of ph... more ABSTRACT: In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (P), especially agricultural runoff and land application of animal manure. However, it has become apparent in the Ozarks that this shift in focus may be premature and neglect P from discrete sources, e.g. wastewater treatment plants (WWTPs). We sampled the water column at 30 sites in the Illinois River Basin [Ozark Plateaus, USA]; this catchment receives effluent from four municipal WWTPs. The average annual P load was approximately 208,000 kg from 1997 through 2001, and municipal WWTPs represented almost 45% of the average annual load. Water column P concentrations were significantly greater during surface runoff conditions compared to base flow conditions. Phosphorus concentrations and stream flow displayed distinct relations during base flow and surface runoff conditions. Water column P concentrations were increased by WWTP effluents during base flow conditions and the increa...
ABSTRACT Litter from broiler chicken (Gallus gallus domesticus) production is a beneficial soil a... more ABSTRACT Litter from broiler chicken (Gallus gallus domesticus) production is a beneficial soil amendment containing organic material and many nutrients essential for proper plant growth. However, repeated land application of litter in regions of concentrated broiler production has raised concerns regarding nutrient and trace element loading in soil and potential groundwater and surface water contamination via runoff and leaching. The objective of this study was to evaluate seasonal and annual effects of broiler litter application rate on soil leachate concentrations and leaching losses of several essential plant nutrients [nitrate-N (NO3-N), ammonium-N (NH4-N), P, K, Ca, Mg, and Na] from a silt-loam soil (fine-silty, siliceous, active, mesic Typic Fragiudult) under tall fescue (Festuca arundinacea Shreb.) vegetation in the Ozark Highlands of northwest Arkansas. Equilibrium-tension lysimeters were used to continuously monitor and collect soil leachate solution from below the undisturbed root zone of small plots for a two-year period after two annual broiler litter applications at rates of 0 (control), 5.6 (low), and 11.2 (high) Mg litter ha-1. In Year 1 (May 2003-April 2004), flow-weighted mean leachate concentrations of Ca, Na, P, and Mg differed among litter rates during one or more periods; however, there were no consistent treatment effects. In Year 2 (May 2004-April 2005), leachate concentrations of Mg and NH4-N differed among litter rates during one or more periods, in which all had the greatest concentration under the low-litter treatment. There were no differences in plant nutrient leaching losses among litter rates during either full year or cumulatively over the two-year period. The land use combination of a long history of litter application, followed by several years of no litter, followed by two consecutive years of additional litter application seems to cause few water quality concerns caused by nutrient leaching, with the exception of P if leachate and/or groundwater discharge to the soil surface.
... 6. The concentration of dissolved inorganic nitrogen (DIN) and the molar ratio of DIN to tota... more ... 6. The concentration of dissolved inorganic nitrogen (DIN) and the molar ratio of DIN to total dissolved phosphorus (TDP), appeared to be the main environmental factors controlling the extent of nitrogen or ... Rate and yield limitation (sensuO'Brien, 1972) were distinguished. ...
In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (... more In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (P), especially agricultural runoff and land application of animal manure. However, it has become apparent in the Ozarks that this shift in focus may be premature and neglect P from discrete sources, e.g. wastewater treat ment plants (WWTPs). We sampled the water column at
poultry litter was land applied as a fertiliser to meet forage N requirements, making it suscepti... more poultry litter was land applied as a fertiliser to meet forage N requirements, making it susceptible to transport from the landscape during episodic precipitation events. Nitrogen and P concentrations were measured in four sub-watersheds of Beaver Lake, a reservoir on the White River in Arkansas, USA, to assess possible relationships between pasture land use and stream nutrient concentrations and export. Surface water samples were collected 17 times annually for 2 years from ten total stream sites within the four watersheds. Samples were analysed for soluble reactive P (SRP), total P (TP), ammonium-N (NH4-N), nitrate-N (NO3-N), total Kjeldhal N (TKN) and total N (TN). Discharge was measured at four gauged stream stations, and nutrient export was calculated using the US Geological Survey ESTIMATOR software and non-biased re-transformation from log space. Stream SRP, NO3-N and TN concentrations (geometric-mean) increased linearly with per cent of pasture in watersheds, whereas N and P...
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