bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multispecies Riparian Buffers Trap Sediment and Nutrients during Rainfall Simulations
Authors: Lee Kye‐Han , Isenhart Thomas M. , Schultz Richard C. , Mickelson Steven K. 
Published: July 2010

AbstractA study was conducted to evaluate the ability of a multispecies riparian buffer (MRB) to remove sediment, nitrogen, and phosphorus from cropland runoff. Simulated rainfall was applied to 4.1‐ by 22.1‐m bare cropland source areas paired with either no buffer, a 7.1‐m‐wide switchgrass (Panicum virgatum L. cv. Cave‐n‐Rock) buffer, or a 16.3‐m‐wide switchgrass‐woody plant buffer. Each treatment plot combination had three replicates. The switchgrass buffer trapped 70% of the incoming sediment, while the switchgrass‐woody buffer trapped more than 92%. In general, these buffers retained 93% of sand and silt particles and 52% of clay particles. During a 2‐h rainfall simulation at 25 mm h−1, the switchgrass buffer removed 64, 61, 72, and 44% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. The switchgrass‐woody buffer removed 80, 92, 93, and 85% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. During a 1‐h rainfall simulation at 69 mm h−1, the switchgrass buffer removed 50, 41, 46, and 28% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. The switchgrass‐woody plant buffer removed 73, 68, 81, and 35% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. The switchgrass buffer was effective in trapping coarse sediment and sediment‐bound nutrients. But the additional buffer width with high infiltration capacity provided by the deep‐rooted woody plant zone was effective in trapping the clay and soluble nutrients.
The Influence of Vegetation in Riparian Filterstrips on Coliform Bacteria: II. Survival in Soils
Authors: Entry James A. , Hubbard Robert K. , Thies Janice E. , Fuhrmann Jeffry J. 
Published: July 2010

AbstractSurvival of total and fecal coliform bacteria was measured in the 0 to 5, 5 to 15, and 15 to 30 cm soil depths at 1, 3, 7, 14, and 90 to 120 d after swine (Sus scrofa) wastewater application to riparian filterstrips in southern Georgia during each season of the year. Vegetative treatments evaluated were: (i) 20 m grass‐10 m forest, (ii) 10 m grass‐20 m forest, and (iii) 10 m grass‐20 m maidencane (Panicum hemitomon Schult.). During winter, spring, and summer vegetation type in riparian filterstrips did not affect survival of total and fecal coliform bacteria. Total and fecal coliform bacterial numbers were usually higher in the top 0 to 5 cm of soil than in the 5 to 15 and 15 to 30 cm soil depths in all treatments. Total and fecal coliform numbers in the 0 to 5, 5 to 15, and 15 to 30 cm depths declined approximately 10‐fold every 7 to 14 d after waste application in all seasons of the year. At 90 to 120 d after waste application, total and fecal coliform numbers in the three soil depths did not differ from riparian filterstrips that did not have animal waste applied. Total coliform bacteria in the 0 to 5, 5 to 15, and 15 to 30 cm soil depths correlated with temperature and moisture in a curvilinear relationship (r2 = 0.80, 0.77, and 0.64, respectively). Fecal coliform bacteria in 0 to 5, 6 to 15, and 16 to 30 cm of soil also correlated with temperature and moisture in a curvilinear relationship (r2 = 0.56, 0.53, and 0.53, respectively).
Effectiveness of Coal Combustion By‐Products in Controlling Phosphorus Export from Soils
Authors: Stout William L. , Sharpley Andrew N. , Landa Jennifer 
Published: July 2010

AbstractPhosphorus (P) export from high P soils is a major cause of eutrophication in fresh waters. Recent work has shown that the solubility of P in high P soils can be reduced with coal combustion by‐products (CCBs), decreasing the potential for dissolved phosphorus (DP) export from these soils. However, the effect of such treatments on plant‐available P and P export has not been quantified. We measured P uptake by canola (Brassica napus L.) from three high P (130–370 mg kg−1 Mehlich‐3 P) soils treated with two CCBs, fluidized bed combustion flyash (FBC), flue gas desulfurization (FGD) CaSO4 anhydride, and agricultural gypsum (GYP). We measured DP, particulate phosphorus (PP), and total phosphorus (TP) concentrations in runoff from grassed and bare soils treated with these materials and subjected to simulated runoff. Phosphorus, As, Cd, and Pb uptake by canola were unaffected by CCB treatment, and dry‐matter yields were unrelated to treatment. On grassed soils, FBC, FGD, and GYP reduced DP concentration in runoff by 20, 43, and 33%, respectively, but did not affect As, Cd, or Pb concentrations in runoff. Also on grassed soils, the high application rate of FGD reduced TP in runoff by 35%. On bare soils where erosion of PP controlled P loss, CCBs and GYP had no effect on DP concentration in runoff. Application of CCBs to high P soils in zones of high surface runoff potential, where there is little erosion, has the potential to reduce P export without affecting crop production.
Effectiveness of Constructed Wetlands in Reducing Nitrogen and Phosphorus Export from Agricultural Tile Drainage
Authors: Kovacic David A. , David Mark B. , Gentry Lowell E. , Starks Karen M. , Cooke Richard A. 
Published: July 2010

AbstractMuch of the nonpoint N and P entering surface waters of the Midwest is from agriculture. We determined if constructed wetlands could be used to reduce nonpoint N and P exports from agricultural tile drainage systems to surface waters. Three treatment wetlands (0.3 to 0.8 ha in surface area, 1200 to 5400 m3 in volume) that intercepted subsurface tile drainage water were constructed in 1994 on Colo soils (fine‐silty, mixed, superactive, mesic Cumulic Endoaquoll) between upland maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] cropland and the adjacent Embarras River. Water (tile flow, precipitation, evapotranspiration, outlet flow, and seepage) and nutrient (N and P) budgets were determined from 1 Oct. 1994 through 30 Sept. 1997 for each wetland. Wetlands received 4639 kg total N during the 3‐yr period (96% as NO3‐N) and removed 1697 kg N, or 37% of inputs. Wetlands decreased NO3−N concentrations in inlet water (annual outlet volume weighted average concentrations of 4.6 to 14.5 mg N L−1) by 28% compared with the outlets. When the wetlands were coupled with the 15.3‐m buffer strip between the wetlands and the river, an additional 9% of the tile NO3−N was apparently removed, increasing the N removal efficiency to 46%. Overall, total P removal was only 2% during the 3‐yr period, with highly variable results in each wetland and year. Treatment wetlands can be an effective tool in reducing agricultural N loading to surface water and for attaining drinking water standards in the Midwest.
Phosphorus Movement Through a Coastal Plain Soil After a Decade of Intensive Swine Manure Application
Authors: Novak J. M. , Watts D. W. , Hunt P. G. , Stone K. C. 
Published: July 2010

AbstractUnderstanding the movement of phosphorus (P) in soils receiving heavy animal waste application is important for nonpoint‐source pollution control. We investigated both P accumulation in soil and movement to ground water after 10 yr of intensive swine manure application (at atypical high rates) to a Coastal Plain spray field. Mehlich 3 phosphorus (M3P) was measured in soil cores collected in 1991 (following 4 yr of manure application) and 1997 (after 10 yr of application). Additionally, dissolved phosphorus (DP) was measured in ground water wells installed around the spray field. In both 1991 and 1997, the soil cores (0 to 15 cm) contained high contents of M3P (376–435 mg P kg−1) indicating substantial P accumulation. After 10 yr of manure application, soil cores at a depth of 107 cm were also high in soil M3P contents (151 mg P kg−1). Control soils were very low in M3P (<10 mg P kg−1) throughout the soil profile. Ground water DP concentrations were initially (1992–1995) very low (<40 µg P L−1), but by late 1996, DP concentrations in a few wells had increased substantially (40–480 µg P L−1). In contrast, ground water control wells (1994–1998) were very low in DP (<40 µg P L−1). Thus, the studied field, which received atypical high loading rates, had detectable leaching to shallow ground water as well as substantial P accumulation.
Nitrogen Fertilizer Equivalency of Sewage Biosolids Applied to Dryland Winter Wheat
Authors: Barbarick K. A. , Ippolito J. A. 
Published: July 2010

AbstractDetermining the N fertilizer equivalency or mineralization rates associated with continuous application of biosolids are paramount in estimating “agronomic rates” for various crops. We used 6 yr of field‐study data from sewage biosolids application to dryland hard‐red winter wheat (Triticum aestivum L., ‘TAM107’) to estimate the N fertilizer equivalency and mineralization rates of Littleton and Englewood (L/E) biosolids. We made three L/E biosolids and urea applications to two sites (Weld loam soil) using a dryland winter wheat summer‐fallow management system. Biosolids rates were 0, 2.2, 4.4, 6.6, 8.8, and 11 dry Mg ha−1 while N fertilizer rates were 22, 44, 66, 88, and 110 kg N ha−1; we replicated all treatments four times. Using N uptake data, we found application of 1 dry Mg of L/E biosolids before each planting delivered an equivalent of about 8.2 kg N fertilizer. By contrast, estimates ranged from 6.2 to 6.7 kg fertilizer N Mg−1 L/E biosolids using the USEPA plant‐available N calculations. We also calculated, from our field‐study results and USEPA estimations, first‐year mineralization rate ranges of 25 to 32%. In a companion greenhouse study, we found that a single application of biosolids provided an N response for only two wheat croppings. These approximations should help managers determine the “agronomic rate” for continuous biosolids additions to dryland winter wheat.
Depth Variation in Copper, Lead, and Zinc Concentrations and Mass Enrichment Ratios in Soils of an Urban Watershed
Authors: Sutherland R. A. 
Published: July 2010

AbstractPrevious studies in the Manoa watershed (Hawaii) have indicated significant anthropogenic enhancement of trace metals in road deposited sediment and fluvial bed sediments. This study was conducted to examine trace metal loadings with depth in soils of Manoa watershed. A total of 78 roadside (disturbed) and 10 background (control) soils were sampled at two depths for selected soil properties and for total and HCl‐extractable (labile) concentrations of Al, Cu, Pb, and Zn. Based on sample proximity to roads, typically <2 m, the automobile is considered the primary source of inputs. Concentration, mass loading, and mass per area enrichment ratio (MAER) data indicate that Pb was the most significantly enhanced trace metal. Labile Pb concentrations were log‐normally distributed with maximum values of 2870 and 3560 mg kg−1 in topsoil and subsoil samples, respectively. Roadside labile Pb was four to five times higher than in background soils. Mass loading and MAER data indicate that subsoils were statistically more enriched in labile Cu and Pb, while Zn had similar values with depth. More than 50% of the subsoils were classified as having significant to extreme labile Pb anthropogenic signals. Trace metals in this study have undergone significant translocation, possibly through processes of colloidal transport and/or preferential flow. The environmental significance of this research is discussed in terms of potential influence of Pb mobility on ground and surface waters, and the continued contribution of high levels of labile Pb to road surfaces with erosion of exposed subsoil layers.
A Time‐Dependent Model of Nitrogen Loading to Estuaries from Coastal Watersheds
Authors: Brawley John W. , Collins Glynnis , Kremer James N. , Sham Chi‐Ho , Valiela Ivan 
Published: July 2010

AbstractWe have developed a dynamic nitrogen loading model (NLM) that incorporates temporal and spatial trends in land use with a three‐dimensional ground water model. In conjunction with historical patterns of land use in the Waquoit Bay (USA) watershed, we have modified an existing steady‐state watershed NLM to estimate historical and future rates of total dissolved nitrogen (TDN) to the coastal margins of Waquoit Bay and its subestuaries. The model simulations indicated a significant increase in nitrogen loading to these systems in recent decades. We estimated that the TDN loading rate to Waquoit Bay increased from approximately 5000 to 23 000 kg yr−1 (0.8 to 3.7 g N m−2 yr−1) from 1930 to 1990. We also compared the dynamic model with steady‐state simulations where the lag effect of ground water travel time was not considered. These results indicate occasional significant differences (up to 37%) between the two modeling methods, especially between 1950 and 1990, when large areas of naturally vegetated and agricultural land within the watershed were converted to unsewered residential housing. Although all subestuaries experienced similar temporal trends in nitrogen load, heterogeneity in the timing, source, and magnitude indicates that these factors are dependent upon watershed size, shape, and spatio‐temporal trends in land use.
Transformation of 1,3‐Dichloropropene in Soil by Thiosulfate Fertilizers
Authors: Gan J. , Yates S. R. , Knuteson J. A. , Becker J. O. 
Published: July 2010

AbstractThe pesticide 1,3‐dichloropropene (1,3‐D) is considered to be the most promising alternative to methyl bromide for soilborne pest control. The high volatility of 1,3‐D, however, has been shown to result in excessive atmospheric emissions that may impose toxicological effects on workers or residents. This study demonstrated that 1,3‐D was rapidly transformed to nonvolatile products by thiosulfate fertilizers in soil, and that thiosulfate‐facilitated fumigant transformation may be used to reduce 1,3‐D emissions. Transformation of 1,3‐D by thiosulfate was chemically based, and 1,3‐D degradation in soil accelerated proportionally as thiosulfate level in soil increased. At a 4:1 thiosulfate to fumigant molar ratio, the half‐life of 1,3‐D was reduced to only a few hours, as compared with >10 d for nonamended soils. The rate of thiosulfate‐facilitated 1,3‐D transformation was independent of soil types and was higher in moist soils and at high soil temperatures. Transformation occurred at a similar rate for ammonium, calcium, and sodium thiosulfates. As these thiosulfate compounds are commercial fertilizers, amendment of these products at the soil surface during 1,3‐D fumigation may offer an effective and inexpensive approach for reducing 1,3‐D emissions.
Kinetics of Carbosulfan Degradation in the Aqueous Phase in the Presence of a Cosolvent
Authors: Wei Jiang , Furrer Gerhard , Schulin Rainer 
Published: July 2010

AbstractThe degradation of the carbamate pesticide carbosulfan (2,3‐dihydro‐2,2‐dimethyl‐7‐ben/ofuranyl [(dibutylamino)thio]methylcarbamate] was investigated in aqueous buffer solutions (pH 3.0–7.0) containing low (1%, v/v) and high (10–60%, v/v) concentrations of acetonitrile. The cleavage of the carbamyl N‐S bond yields carbofuran (2,3‐dihydro‐2,2‐dinicthyl‐7‐benzofuranol methylcarbamate). The rate of carbosulfan degradation depends on pH, the initial concentration of carbosulfan, acetonitrile concentration, shaking speed, ionic strength, and temperature. Carbosulfan was completely dissolved only in solutions with high acetonitrile concentrations. The concentration of acetonitrile needed for the complete dissolution of carbosulfan depended on the initial concentration of carbosulfan. In this case, the degradation is a pseudo‐second‐order reaction with respect to the concentration of carbosulfan and hydronium ion. The degradation reaction is promoted by the hydronium ion. In the case of low acetonitrile concentrations, where carbosulfan was not completely dissolved, the overall kinetics depend also on the slow dissolution process. The degradation of carbosulfan probably is not a pure hydrolysis reaction, but a protonation‐intermolecular rearrangement reaction. The results indicate that the abiotic degradation of carbosulfan in natural waters is a very slow process when organic solvents and minerals are absent or present in only minor concentrations.
Effect of Soil Texture on Nitrogen Mineralized from Cotton Residues and Compost
Authors: Egelkraut T. M. , Kissel D. E. , Cabrera M. L. 
Published: July 2010

AbstractThe N mineralized from microbial decomposition of crop residues is an important source of N for crop production. Our objective was to develop a better understanding of how soil properties affect the N mineralized from decomposing crop residues to help better account for spatial differences in N availability when applying N fertilizer. Four soils varying in texture and organic matter concentration were selected from a Georgia Coastal Plain field. In the laboratory, the soils were mixed with cotton (Gossypium hirsutum L.) leaves (C to N ratio = 15.5), cotton stems (C to N ratio = 28.8), or compost (C to N ratio = 28.8) and incubated at field capacity and 23°C for 179 d. Rates of application were 2056 mg plant material kg−1 soil and 15 000 mg compost kg−1 soil. The time spans of initial N immobilization and the amounts of N immobilized and mineralized differed considerably between soils. The soils with greater clay concentrations had longer time periods of initial N immobilization and mineralized less N from the added materials. The net N mineralized from the decomposing cotton residues was low after 179 d in all four soils (−2.6 to 11.0% of total), but greater amounts of N were mineralized from decomposition of compost (5.1 to 23.1% of total).
Statistical Evaluation of Effects of Riparian Buffers on Nitrate and Ground Water Quality
Authors: Spruill Timothy B. 
Published: July 2010

AbstractA study was conducted to statistically evaluate the effectiveness of riparian buffers for decreasing nitrate concentrations in ground water and for affecting other chemical constituents. Values for pH, specific conductance, alkalinity, dissolved organic carbon (DOC), silica, ammonium, phosphorus, iron, and manganese at 28 sites in the Contentnea Creek Basin were significantly higher (p < 0.10) in old (>20 yr) discharging ground water draining areas with riparian buffers compared with areas without riparian buffers. No differences in chloride, nitrate nitrogen, calcium, sodium, and dissolved oxygen concentrations in old ground water between buffer and nonbuffer areas were detected. Comparison of samples of young (<20 yr) discharging ground water samples from buffer and nonbuffer areas indicated significantly higher specific conductance, calcium, chloride, and nitrate nitrogen in nonbuffer areas. Riparian buffers along streams can affect the composition of the hyporheic zone by providing a source of organic carbon to the streambed, which creates reducing geochemical conditions that consequently can affect the chemical quality of old ground water discharging through it. Buffer zones between agricultural fields and streams facilitate dilution of conservative chemical constituents in young ground water that originate from fertilizer applications and also allow denitrification in ground water by providing an adequate source of organic carbon generated by vegetation in the buffer zone. Based on the median chloride and nitrate values for young ground water in the Contentnea Creek Basin, nitrate was 95% lower in buffer areas compared with nonbuffer areas, with a 30 to 35% reduction estimated to be due to dilution and 65 to 70% due to reduction and/or denitrification.
Curve Number Approach for Estimating Runoff from Turf
Authors: Haith Douglas A. , Andre Benjamin 
Published: July 2010

AbstractThe curve number equation is one of the simplest and most commonly used models for estimating surface runoff. However, its applicability to turfgrasses has not been previously demonstrated. This study evaluated the approach by comparing model estimates with measured runoff data from turf field plots in six different states, including three different soil hydrologic groups, four turfgrasses, and a range of antecedent moisture and turf conditions. A set of curve numbers were developed for short and long grasses with and without thatch, and curve number selection was based on linear functions of 5‐d antecedent precipitation. With the standard growing season antecedent moisture limits of 36 mm and 53 nun, the curve number model explained 78% of the observed variation in runoff and underpredicted the mean event runoff by 15%. With a downward adjustment of these limits to 22 nun and 53 mm in split‐sample calibration, the underprediction of means was reduced to less than 3%. More significantly, the model mean for the largest observed events was within 6% of the observed mean. Provided model results are interpreted in a statistical sense rather than as individual events, the curve number model, as modified in this study, is a relatively accurate means of estimating turf runoff.
Isotopic Evidence for Naturally Occurring Sulfate Pollution of Ponds in the Kankakee River Basin, Illinois‐Indiana
Authors: Sidle W. C. , Roose D. L. , Shanklin D. R. 
Published: July 2010

AbstractEcosystem restoration surveys across the Kankakee River Basin indicate that ponds in riparian zones contain elevated sulfate concentrations. The sources of high sulfate in many ponds were investigated by sampling ground waters, precipitation, and applied fertilizers in the Kankakee and Iroquois subwatersheds of the basin. The 34SSO4 and 18SSO4 analyses discriminated among possible regional anthropogenic and natural sources. Some sulfate‐bearing fertilizers may have contributed to elevated SO2−4 in ponds but there is isotopic evidence suggesting that pyritic glaciofluvial sediments in the surficial aquifer may be the source of larger SO2−4 concentrations in ponds. An isotopic analysis of one SO2−4−H2O system in a riparian zone revealed that FeS2 oxidation reactions are possible processes leading to local sulfate pollution in riverine ponds.
17β‐Estradiol and Testosterone in Soil and Runoff from Grasslands Amended with Broiler Litter
Authors: Finlay‐Moore O. , Hartel P. G. , Cabrera M. L. 
Published: July 2010

AbstractIn 1998, the U.S. poultry industry generated almost 12 million Mg of broiler (Gallus gallus domesticus) litter, most of which was applied to grasslands as fertilizer. This litter contains appreciable concentrations of estradiol and testosterone, sex hormones of environmental concern. We measured estradiol and testosterone concentrations in soil and runoff water from large (0.8 ha) grazed and ungrazed grasslands amended with broiler litter. Samples were analyzed by enzyme immunoassay. In runoff, background concentrations were 50 to 150 ng estradiol L−1 and 15 to 125 ng testosterone L−1. No significant differences were observed in runoff concentrations between hayed and grazed plots (p = 0.1). Therefore, grazing animals did not contribute hormones to runoff. When litter was applied, runoff concentrations were 20 to 2530 ng estradiol L−1 and 10 to 1830 ng testosterone L−1, depending on litter application rate and time between application and runoff. In soil, the background concentration for estradiol was 55 ng kg−1. Depending on litter application rate and time from application, the estradiol concentration in soil increased up to 675 ng kg−1. Testosterone followed a similar trend; however, concentrations of testosterone were significantly higher in grazed than in hayed plots (p = 0.1). These results show sizable edge‐of‐field losses of estradiol and testosterone from broiler litter‐amended grasslands, and are the first studies to measure estradiol and testosterone in soil. Future research needs to examine the persistence and degradation of estradiol and testosterone in broiler litter, soil, and runoff.