bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus Sorption in Manured Atlantic Coastal Plain Soils under Flooded and Drained Conditions
Authors: Vadas P. A. , Sims J. Thomas 
Published: July 2010

AbstractArtificially drained, agricultural soils that are high in P and have seasonally fluctuating water tables may be significant nonpoint sources of P to Delaware's Inland Bays. Topsoil, unamended and amended with 4 g kg−1 poultry litter (PL), and subsoil horizons from two soil series in the Inland Bays watershed were flooded for 28 d and drained for 14 d at 25°C. Soil pH and redox potential (Eh) were measured (mV) and P sorption isotherms were constructed for each horizon under oxidized, flooded, and drained conditions. For each isotherm, P sorption maxima (bmax), P sorbed at a solution P concentration of 1.0 mg L−1 (b1.0), and the equilibrium P concentration at zero sorption (EPC0) were calculated. Flooding decreased Eh and increased pH, and draining returned Eh and pH to near initial values. Flooding and draining decreased bmax in all horizons. The b1.0 values were always significantly less than bmax values; however, flooding and draining had inconsistent effects on b1.0 values. Flooding increased EPC0 in the unamended Pocomoke A horizon, but decreased EPC0 in the same PL‐amended horizon. Draining reduced EPC0 values in both Pocomoke A horizons. Flooding and draining had little effect on EPC0 in other horizons. Our data suggest that land application of PL and fluctuating water tables may increase the potential for P loss from soils through both a decrease in soil P sorption capacity and an increase in solution P concentrations in topsoils.
Agrichemicals in Ground Water of the Midwestern USA: Relations to Soil Characteristics
Authors: Burkart Michael R. , Kolpin Dana W. , Jaquis Robert J. , Cole Kevin J. 
Published: July 2010

AbstractA comprehensive set of soil characteristics were examined to determine the effect of soil on the transport of agrichemicals to ground water. This paper examines the relation of local soil characteristics to concentrations and occurrence of nitrate, atrazine (2‐chloro‐4 ethylamino‐6‐isopropylamino‐s‐trazine), and atrazine residue [atrazine + deethylatrazine (2‐amino‐4‐chloro‐6‐isopropylamino‐s‐triazine) + deisopropylatrazine (2‐amino‐4‐chloro‐6‐ethylamino‐s‐triazine)] from 99 wells completed in unconsolidated aquifers across the midwestern USA. The occurrence and concentrations of nitrate and atrazine in ground water were directly related to soil characteristics that determine the rate of water movement. The substantial differences in the relations found among soil characteristics and nitrate and atrazine in ground water suggest that different processes affect the transformation, adsorption, and transport of these contaminants. A multivariate analysis determined that the soil characteristics examined explained the amount of variability in concentrations for nitrate (19.0%), atrazine (33.4%), and atrazine residue (28.6%). These results document that, although soils do affect the transport of agrichemicals to ground water, other factors such as hydrology, land use, and climate must also be considered to understand the occurrence of agrichemicals in ground water.
Giardia Cyst and Cryptosporidium Oocyst Survival in Water, Soil, and Cattle Feces
Authors: Olson Merle E. , Goh Jeanette , Phillips Michael , Guselle Nicole , McAllister Tim A. 
Published: July 2010

AbstractGiardiasis and cryptosporidiosis are gastrointestinal diseases caused by protozoan parasites that may infect domestic animals, wildlife and human beings. The ability of cysts and oocysts of these parasites to persist in the environment was determined because agricultural fecal waste has the potential to contaminate municipal water supplies. The degradation rate and viability of Giardia cysts and Cryptosporidium oocysts in water, cattle (Bos taurus) feces, and soil was evaluated at temperatures of −4, 4, and 25°C for up to 12 wk. Cysts and oocysts were enumerated after staining samples with a specific fluorescent monoclonal antibody and the viability was determined using propidium iodide dye exclusion and mouse infectivity assays. Giardia cysts were noninfective in water, feces, and soil following 1 wk of freezing to −4°C and within 2 wk at 25°C. At 4°C Giardia cysts were infective for 11 wk in water, 7 wk in soil, and 1 wk in cattle feces. Cryptosporidium oocysts were more environmentally resistant. At −4 and 4°C, the oocysts could survive in water and soil for >12 wk but degradation was accelerated at 25°C. Cryptosporidium oocysts also were degraded more rapidly in feces and in soil containing natural microorganisms. Contaminated cattle feces should be distributed on fields during warmer weather and after 12 wk of storage to reduce potential waterborne transmission following heavy runoffs.
Practical and Innovative Measures for the Control of Agricultural Phosphorus Losses to Water: An Overview
Authors: Sharpley Andrew , Foy Bob , Withers Paul 
Published: July 2010

AbstractInputs of P are essential for profitable crop and livestock production. However, its export in watershed runoff can accelerate the eutrophication of receiving fresh waters. The specialization of crop and livestock farming has created regional imbalances in P inputs in feed and fertilizer and output in farm produce. In many areas, soil P exceeds crop needs and has enriched surface runoff with P. This paper provides a brief overview of P management strategies to maintain agricultural production and protect water quality that were discussed at the conference, “Practical and Innovative Measures for the Control of Agricultural Phosphorus Losses to Water,” sponsored by the Organization for Economic Cooperation and Development and held in Antrim, Northern Ireland, June 1998. The purpose of the conference was to assess current strategies for reducing the loads and concentrations of P from agricultural land to surface waters. Topics discussed at the interdisciplinary conference and reviewed here included sustainable P management in productive agriculture; assessing land application of P; evaluating and modeling P transport and transformations in soil, runoff, streams, and lakes; and implementation of integrated best management practices (BMPs). From these discussions, measures to control agricultural P transfer from soil to water may be brought about by optimizing fertilizer P use‐efficiency, refining animal feed rations, using feed additives to increase P absorption by the animal, moving manure from surplus to deficit areas, and targeting conservation practices, such as reduced tillage, buffer strips, and cover crops, to critical areas of P export from a watershed.
Terminology for Phosphorus Transfer
Authors: Haygarth P. M. , Sharpley A. N. 
Published: July 2010

AbstractThe transfer of P from agricultural land to water attracts scientists of varied expertise. The multidisciplinary nature of factors controlling P transfer has lead to confusions in communication because of inappropriate or ambiguous use of terminology. Therefore, we have attempted to classify terminology for P transfer into: (i) processes (or modes) (e.g., erosion, leaching, incidental) (ii) pathways (e.g., overland flow, subsurface flow, drainage flow), and (iii) form terms (e.g., those that can be described in soil or water samples). A method of classifying pathways by scale, plane, and time is suggested and a particular caution is noted for leaching, which is a process, not a pathway, and runoff (a vaguely defined pathway). Current terminology for forms in water is confusing because terms such as soluble, dissolved, particulate, inorganic, and organic can be technically incorrect if used inappropriately when describing P forms involving membrane filtration and Murphy‐Riley Mo‐blue chemistry. We suggest an improved method for describing the forms of P in waters, which is operationally defined and states the analytical method and size of filter used.
Nutrient Management Planning: Justification, Theory, Practice
Authors: Beegle D. B. , Carton O. T. , Bailey J. S. 
Published: July 2010

AbstractTraditionally, nutrient management has been concerned with optimizing the economic return from nutrients used for crop production. Today, the agronomic and economic requirements of nutrient management remain central, but in addition, the process must consider the potential impact of these nutrients on environmental quality. The nutrient‐management process is critical for maximizing the economic benefit from nutrients while minimizing the environmental impact. This process includes assessment, analysis, decision making, evaluation and refinement. A tactical nutrient‐management plan developed from this process must be based on a firm set of strategic objectives agreed upon by the farmers and society. The nutrient‐management process must also be practical to implement, if the performance goals are to be met. While nutrient‐management plans have resulted in benefits to farmers and society, implementation has not been as great as desired. Several factors have been identified as key to the successful implementation of nutrient‐management planning: the full participation of a broad range of stakeholders, the use of established infrastructure, targeted nutrient‐management planning efforts, voluntary vs. mandatory programs, and the economics of nutrient management. Experiences in Pennsylvania, the Republic of Ireland, and Northern Ireland illustrate aspects of the implementation of the nutrient management process.
Potential for Preferential Pathways of Phosphorus Transport
Authors: Simard R. R. , Beauchemin S. , Haygarth P. M. 
Published: July 2010

AbstractThis paper briefly reviews the existing literature and uses evidence from three studies to demonstrate the occurrence of preferential pathways of P transport through soil. Studies conducted in the St. Lawrence lowlands, Canada, indicated that particulate P (PP‐i.e., >0.45 µm) the main fraction of total P (TP) in tile‐drainage water generated by storm events after periods of low rainfall. In the remainder of the year, the concentration of TP and P forms were related to soil texture, primary tillage intensity and frequency, and showed wide seasonal variations. For a study conducted in the UK under grassland, higher TP concentrations were found in near‐surface runoff (0–30 cm) compared with concentrations measured in drainflow. Water passing through the artificial drainage system had a higher proportion of PP (43%) than water passing close to (<30 cm) or over the soil surface (31%). Installation of tile drainage in a poorly draining soil reduces P transfer by improving the infiltration capacity, thereby reducing overland flow volume and allowing P to be retained/sorbed by the soil matrix. Because of the absence of tillage, permanent grasslands accumulate P near the surface. We hypothesize that, if the soil P store is coincident with preferential flow pathways (either artificial mole drainage channels or natural macropores), permanent grassland will be vulnerable to transfer large amounts of P through subsurface pathways. Phosphorus transfer through preferential flow pathways may be particularly important after storm events that rapidly follow periods of drought and/or surface P inputs as inorganic fertilizer or manure.
Modeling Soil Phosphorus Levels and Phosphorus Leaching from Agricultural Land in the Netherlands
Authors: Schoumans O. F. , Groenendijk P. 
Published: July 2010

AbstractThe contribution of nonpoint‐source pollution of P leaching and P runoff from agricultural soils is very important, especially in those areas with intensive livestock production systems. Prediction of the impacts of fertilization reduction measures on P loads from agricultural soils to surface water requires a sound description of the accumulation of P. In this article an overview is given of the Dutch approach. The presented methodology has been developed for noncalcareous sandy soils in flat areas where P loss by subsurface runoff is the dominating pathway. Based on the kinetics of P sorption and desorption of these soil types, P accumulation in soils, and inorganic P concentrations in soil solution can be modeled. Furthermore, methods have been deduced to translate the description of soil chemical P processes into commonly used soil P tests. As a result of this interaction, soil P tests can be used as an initial approach to estimate the potential risk of P leaching and runoff from agricultural soils in noncalcareous sandy areas. The description of the kinetics of inorganic P reactions and the modeling of soil P tests have been implemented in the ANIMO model in addition to an organic P cycle that is related to organic C and N dynamics. With this model, the fixation and immobilization of P by soll components can also be assessed. As a result of annual losses by fixation, immobilization, and subsurface runoff/leaching, changes in soil P test values with time can be estimated.
Phosphorus Research Strategies to Meet Agricultural and Environmental Challenges of the 21st Century
Authors: Sharpley Andrew , Tunney Hubert 
Published: July 2010

AbstractThe accumulation, management, and transfer of P in intensive farming systems has increased P export from agricultural watersheds and accelerated eutrophication of surface waters. Even though much research on P has been done in the last 20 years, there are still too few answers to the many questions now being asked regarding agricultural production and environmental quality. To address these concerns, four areas of research are suggested: (i) Soil P testing for environmental risk assessment—What losses are acceptable and can these losses be determined by plot‐scale or watershed‐scale studies? Threshold P levels in soil and water should be established in combination with an assessment of site vulnerability to P loss. (ii) Pathways of P transport—An analysis of the relative importance of different flow pathways is needed at a watershed scale. (iii) Best Management Practice (BMP) development and implementation—Overall, BMPs must attempt to bring P inputs and outputs into closer balance and should be targeted first to critical source areas within a watershed. Alternative management recommendations, uses, and market demand for manures must be developed. (iv) Strategic initiatives to manage P—To initiate lasting changes, research should focus on consumer‐supported programs that encourage farmer performance and stewardship to achieve agreed‐upon environmental goals.
Nitrogen Fertilizer and Herbicide Transport from Tile Drained Fields
Authors: Gentry Lowell E. , David Mark B. , Smith‐Starks Karen M. , Kovacic David A. 
Published: July 2010

AbstractOffsite transport of N fertilizers and pesticides through subterranean drainage pipes (tiles) has been linked to surface water contamination in the U.S. Corn Belt. This study was conducted from water years 1995 to 1997 to evaluate N export from two tile systems (Tiles A and B) in adjacent fields [in seed corn‐soybean rotation (Zea mays L.‐Glycine max (L.) Merr.)] in response to timing and form of N application. In addition, during the 1997 water year, concentrations of two herbicides were determined on grab samples to relate tile herbicide losses with field application rates. During the 1995 and 1996 water years, Tile A exported approximately 20% more N per unit area than Tile B; however, during the 1997 water year, Tile A exported nearly 70% more N. This result was partly caused by the leaching of 142 kg of NH+4‐N following a winter application of (NH4)2SO4 fertilizer in the drainage area of Tile A. The fertilizer was applied on top of 10 cm of snow, and within 4 d, a series of afternoon melting events began. We hypothesize that increased tile flow rates were caused by rapid infiltration of melt water through partially frozen soil (Drummer silty clay loam, fine‐silty, mixed mesic Typic Haplaquolls) that allowed the NH+4 ion to bypass the soil matrix (conc. reached 278 mg NH+4‐N L−1). The incidence of elevated concentrations of N fertilizer and herbicides in tiles during high flow events following agrichemical application indicated rapid water transport via preferential flow paths, thereby limiting the contact of these solutes with the soil.
Salmonella spp. and Fecal Coliform Loads in Coastal Waters from a Point vs. Nonpoint Source of Pollution
Authors: Baudart J. , Grabulos J. , Barusseau J.‐P. , Lebaron P. 
Published: July 2010

AbstractCoastal areas are often contaminated by the dissemination of pathogenic bacteria from terrestrial inputs. In this study, we compared fecal coliforms (FC) and Salmonella spp. loads from a coastal Mediterranean river and from the submarine outfall of a coastal wastewater treatment station. A stratified sampling strategy was used to analyze storm events. Bacterial fluxes were estimated during a 16‐mo period. Salmonella spp. loads from the river were high during storm events, and the annual loads were higher than those estimated from the coastal outfall. Bacterial loads from the river represented 3.0 × 1016 FC yr−1 and 6.9 × 1012 Salmonella yr−1, with at least 95% occurring during high waterflow (21% of the year). Those from the submarine outfall represented 4.3 × 1016 FC yr−1 and 4.7 × 1010 Salmonella yr−1, with a regular temporal discharge. Bacterial loads from the river were associated with small clay particles (<2 µm), which originate from different reservoirs. These particles‐sediment‐trapped bacteria accumulated in the river‐bed during the lowest water levels in the downstream part of the river and were resuspended during storm events. The quantitative relationship between both bacterial parameters vary depending on the source point of contamination. Salmonella spp. loads from the river are of great sanitary concern since high loads were recorded in summer (bathing activities) and autumn (oyster production and consumption). Our results should help water quality managers to define priorities to improve the bacterial quality of river discharges.
Irrigation‐ and Nitrogen‐Management Impacts on Nitrate Leaching under Potato
Authors: Waddell J. T. , Gupta S. C. , Moncrief J. F. , Rosen C. J. , Steele D. D. 
Published: July 2010

AbstractAs potato (Solanum tuberosum L.) production increases in the North‐Central Region of the USA, so does the potential for deep seepage of nitrogenous compounds into the ground water. The objectives of this 2‐yr study were to determine how different irrigation schemes (sprinkler and drip), irrigation triggers (70 and 40% of the available soil water [AW] remaining), drip placement (at the soil surface or buried at 25‐cm depth), and various N sources (urea, sulfur‐coated urea [SCU], and turkey [Meleagris gallopavo] manure) and timings (three‐ vs. five‐N splits) affect percolation and NO3 leaching. As expected, water percolation was generally higher from the sprinkler‐irrigation than from the drip‐irrigation treatments. Within the sprinkler irrigation, percolation was higher when irrigated at 70% than at 40% of AW remaining. Small but frequent irrigation in drip treatments helped reduce water percolation. Within irrigation treatments, 70% AW had the most N leaching, followed by 40% AW and the drip, the last two treatments being about the same. The trend in N leaching among fertilizer treatments was similar for various irrigation methods. Splitting N applications five times vs. three times reduced N leaching from unforeseen rains. Sulfur‐coated urea reduced N leaching, whereas turkey manure‐amended treatments showed no significant difference in N leaching compared with the urea‐N treatment. In conclusion, alternatives such as 40% deficit irrigation, five‐N application splits, drip irrigation, S‐coated urea, and turkey manure not only reduce N leaching but also have a minimal impact on potato tuber yield and tuber quality.
Laboratory Estimates of Trace Gas Emissions following Surface Application and Injection of Cattle Slurry
Authors: Flessa H. , Beese F. 
Published: July 2010

AbstractApplying cattle slurry to soil may induce emissions of the greenhouse gases N2O and CH4. Our objective was to determine the effects of different application techniques (surface application and slit injection) of cattle (Bostaurus) slurry on the decomposition of slurry organic matter and the emissions of N2O and CH2. The effects of slurry application (43.6 m3 ha−1) were studied for 9 wk under controlled laboratory conditions using a soil microcosm system with automated monitoring of the CO2, N2O, and CH4 fluxes. The soil used was a silty loam (Ap horizon of a cambisol) with a constant water‐filled pore space of 67% during the experiment. About 38% of the organic matter applied with the slurry was decomposed within 9 wk. Production of CO2 was not affected by the application technique. Emissions of N2O and CH4 from the injected slurry were significantly higher than from the surface‐applied slurry, probably because of restricted aeration at the injected‐slurry treatment. Total N2O‐N emissions were 0.2% (surface application) and 3.3% (slit injection) of the slurry N added. Methane emission occurred only during the first few days following application. The total net flux of CH4‐C for 2 wk was −12 g ha−1 for the control (CH4 uptake), 2 g ha−1 for the surface‐applied slurry, and 39 g ha−1 for the injected slurry. Slurry injection, which is recommended to reduce NH3 volatilization, appears to increase emissions of the greenhouse gases N2O and CH4 from the fertilized fields.
Nitrous Oxide and Methane Emissions following Application of Animal Manures to Grassland
Authors: Chadwick D. R. , Pain B. F. , Brookman S. K. E. 
Published: July 2010

AbstractNitrous oxide (N2O) and methane (CH4) emissions were measured from grassland following manure applications at three times of the year. Pig (Sus scrofa) slurry and dairy cow (Bos taurus) slurry were applied in April, at equal rates of ammoniacal‐N (NH+4‐N), and in July, at equal volumetric rates (50 m3 ha−1). I n October, five manure types were applied to grassland plots at typical application rates: pig slurry, dilute dairy cow effluent, pig farm yard manure (FYM), beef FYM and layer manure. Emissions were measured for 20, 22, and 24 d, respectively. In April, greater cumulative emissions of N2O‐N were measured following application of dairy cow slurry (1.51 kg ha−1) than pig slurry (0.77 kg ha−1). Cumulative CH4 emissions following application in April were significantly greater from the dairy cow slurry treatment (0.58 kg ha−1) than the pig slurry treatment (0.13 kg ha−1) (P < 0.05). In July, significantly greater N2O‐N emissions resulted from pig slurry‐treated plots (0.57 kg ha−1) than dairy cow slurry‐treated plots (0.34 kg ha−1). Cumulative net CH4 emissions were very low following July applications (<10 g ha−1). In October, the lowest N2O‐N emission resulted from application of dilute dairy effluent, 0.15 kg ha−1, with the greatest net emission from the application of pig slurry, 0.74 kg ha−1. Methane emissions were greatest from the plots that received pig FYM, resulting in a mean cumulative net emission of 2.39 kg ha−1.