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Showing 1 to 20 of 65 for “"nitrate-N"”.
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Development of error correction techniques for nitrate-N load estimation models
… statistical models to estimate annual nitrate-N loads from two watersheds in central Illinois. The performance of three load estimation methods (the seven-parameter log-linear model, the ratio estimator, and the flow-weighted averaging estimator) applied at one-, two-, four-, six-, and …
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A framework for assessing viability of adoption of conservation practice for reducing nitrate-N
… This study shows that practices with higher Nitrate-N removal tend to be the less desirable to users. These practices tend to be less desirable due to high construction and maintenance efforts and long learning processes, and hence, less adoption potential, which makes state-of-art …
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Irradiance, total nitrogen, and nitrate-N: ammonium-N ratio requirements for optimal edible biomass production of basil
… at 100 to 250 mg N/L at a ratio of 50:50 nitrate-N : ammonium-N. All plants died in the 100% ammonium-N treatment. Regression models that allow analysis for optimum conditions suggest a nitrate-N : ammonium-N ratio of 50:50 to 75:25 yielded the greatest biomass of basil.</p>
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Phytoremediation of Nitrate in the Karlsruhe Aquifer, McHenry County, North Dakota
Nitrate concentrations in the Karlsruhe aquifer (23,070 acres), located in north central McHenry County, North Dakota have been monitored by the North Dakota State Water Commission since 2001. The average nitrate-N concentration in the top ten feet of the aquifer was determined to be about 14.0 …
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Effect of urinary nitrogen, dairy shed effluent and nitrogen fertiliser on nitrate leaching from a pasture soil
Environmental concerns over nitrate-N contamination of surface and groundwater have led to a number of studies on nitrate-N leaching from grasslands. Most studies of nitrate-N leaching loss from grassland have focused solely on single nitrogen (N) sources (e.g. fertiliser. urine, dung or effluent). …
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Measurement and Modeling of Nitrate-Nitrogen Transport in Subsurface Bioreactors
… was selected for this study. The nitrate-N concentrations of the bioreactor were monitored in 16 monitoring wells installed at 1.5 m intervals and 0.76 m from each corner. A Finite Element Method routine was used for transient, two-dimensional groundwater flow, and the Random Walk …
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Influence of nitrogen rate on corn grain yield, nitrogen use efficiency, and nitrate leaching on coarse-textured Minnesota soils
… Nitrogen poses a threat to water quality in its nitrate form because it is easily leached through the root zone of the corn (Zea Mays L.) crop following rain and irrigation events. Leaching is enhanced in sandy soil conditions because sandy soils are particularly well drained. In this study, N …
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Operating Rules for Improving the Firm Yield of an Off-Stream Blending Reservoir System Used for Reducing Nitrate in Drinking Water and Drought Storage
… which utilizes its OSBR to meet an internal nitrate-N concentration guideline of 8.0 mg/L through blending, is modeled as a case study. Using streamflow and nitrate-N data from May 1979 to April 1999, a firm yield of 2.21 mgd (million gallons per day) is attained under its current WQOR in …
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Characterizing transient and seasonal responses of bioreactors for subsurface drains
… concern in the Midwest, where increased nitrate leaching into the Mississippi River has been identified as a major contributor to growing hypoxia in the Gulf of Mexico. Scientists agree that solutions to the hypoxia problem lie in the use of a combination of practices to reduce nitrates …
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The Use of Selected Water Quality Parameters to Identify Fecal Coliform Sources in Support of the Sinking Creek Total Maximum Daily Load.
… to the fecal coliform loading. Concentrations of nitrate-N, orthophosphates, BOD, alkalinity, hardness, and optical brighteners (OB) were monitored at fourteen stations monthly for one year. Site 3 (agricultural region) exhibited the highest average nitrate-N loadings (627.34 mg/sec) and …
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Examination of synergism in nitrate and orthophosphate removal in bioreactors
… bioreactor known to have a high affinity for nitrate-N removal. The evaluation of materials was conducted via a bench-top batch study and led to the selection of a locally available iron-based scrap steel material, which was able to remove over 99% of orthophosphate from solution at the 24 …
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Improving the Fertilizer Value of Swine Manure: In-Depth Study of Nitrogen Transformations in Soils, Corn Nitrogen Uptake, and Swine Diet Manipulation to Optimize Manure as a Resource for Agriculture
… harvest were increased by 1.5 mg kg-1 Bray P1. Nitrate-N present in manured soils (0--90 cm) after harvest did not differ from soils receiving the same inorganic N rates, and averaged 17, 24 and 30 kg NO3--N for the low, medium, and high CP manures, respectively.
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Erosion and nutrient loading characteristics of two small agricultural watersheds in Piedmont Virginia
… and used to compute loading rates of sediment, nitrate N, ammonium N, TKN, orthophosphate P, and total P on an event basis. Yields from missed storms were estimated from log-log linear least squares regression rating curves. Seasonal and annual totals of loading rates were computed by summing …
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Tree Canopy Effects on Roof-Harvested Rainwater in East Texas
… cover types for all analyzed parameters except nitrate-N and nitrite-N, which were often below the method detection limit. Drinking water standards were exceeded in the ambient rainfall as well as the tank samples from open, pine canopy, and hardwood canopy covered roofs for pH, color, …
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Changes in soil properties and their effects on maize productivity following sesbania and pigeon pea improved fallow system in Eastern Zambia
… M+f had the highest pre-season soil inorganic nitrate-N and total inorganic N in 0-20 cm soil depths but was not significantly different with pigeonpea and S. sesban land use systems (LUSs). A polynomial regression model between maize grain yield and pre-season soil inorganic nitrate-N for 0-20 …
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Rock Outcrops in the Canadian Shield: an Investigation of Contaminant Transport From Surface Sources in Fractured Rock Aquifers
… 16% contained E. coli, and 1% contained nitrate-N at greater than 5 mg/L. Occurrence of E. coli increased when considering seasonality, where wells were drilled on rock outcrops, and for shallow well intervals. Nitrate-N did not occur above the Guidelines for Canadian Drinking Water …
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FLOW INJECTION INSTRUMENTATION FOR THE IN SITU MONITORING OF NUTRIENTS IN SEA WATER
… nutrient sensor for the in situ determination of nitrate in estuarine and coastal waters. Chapter One describes the role of nitrogen in the global and marine nitrogen cycles and provides an overview of laboratory and in situ methods for its determination. Chapter Two describes the key parameters …
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Effect of Golf Course Turfgrass Management on Water Quality of Non-tidal Streams in the Chesapeake Bay Watershed
… of best management practices (BMPs). Total N, nitrate-N, ammonium-N, phosphate-phosphorus (P), streamwater temperature, specific conductance (SpC), pH and dissolved oxygen (DO) were sampled at 12-14 golf course stream sites in the James River and Roanoke River watersheds during baseflow …
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An investigation of the pathway of nitrogen incorporation into the leaf and root metabolism of Helianthus annuus L
… and 300 ~g N cm feeding level was analysed for nitrate, ammonia, and amino compounds. Nitrate accounted for 771to 94% of the total nitrogen transported via the xylem stream. The pathway of nitrate-N assimilation into amino compounds by the leaves and roots of Helianthus annuus at different …
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Evaluation of Cover Crops, Conservation Tillage, and Nitrogen Management in Cotton Production in Southeastern Virginia
… uptake, soil compaction, soil N cycling, petiole nitrate-N (NO3-N) during the first week of bloom, cotton lint yield, and fiber quality parameters over two years. Legume mix cover crops resulted in greater N uptake, soil NO3-N during the growing season, and lint yields compared to LMR, rye, and …
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