bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tillage and Nutrient Source Effects on Surface and Subsurface Water Quality at Corn Planting
Authors: Zhao Suling L. , Gupta Satish C. , Huggins David R. , Moncrief John F. 
Published: June 2010

ABSTRACTThis study quantified the effects of tillage (moldboard plowing [MP], ridge tillage [RT]) and nutrient source (manure and commercial fertilizer [urea and triple superphosphate]) on sediment, NH4+–N, NO−3–N, total P, particulate P, and soluble P losses in surface runoff and subsurface tile drainage from a clay loam soil. Treatment effects were evaluated using simulated rainfall immediately after corn (Zea mays L.) planting, the most vulnerable period for soil erosion and water quality degradation. Sediment, total P, soluble P, and NH+4–N losses mainly occurred in surface runoff. The NO−3–N losses primarily occurred in subsurface tile drainage. In combined (surface and subsurface) flow, the MP treatment resulted in nearly two times greater sediment loss than RT (P < 0.01). Ridge tillage with urea lost at least 11 times more NH+4–N than any other treatment (P < 0.01). Ridge tillage with manure also had the most total and soluble P losses of all treatments (P < 0.01). If all water quality parameters were equally important, then moldboard plow with manure would result in least water quality degradation of the combined flow followed by moldboard plow with urea or ridge tillage with urea (equivalent losses) and ridge tillage with manure. Tillage systems that do not incorporate surface residue and amendments appear to be more vulnerable to soluble nutrient losses mainly in surface runoff but also in subsurface drainage (due to macropore flow). Tillage systems that thoroughly mix residue and amendments in surface soil appear to be more prone to sediment and sediment‐associated nutrient (particulate P) losses via surface runoff.
Revegetation of an Abandoned Uranium Millsite on the Colorado Plateau, Arizona
Authors: Glenn E.P. , Waugh W.J. , Moore D. , McKeon C. , Nelson S.G. 
Published: June 2010

ABSTRACTWe attempted to restore native plants on disturbed sites at a former uranium mill on the Colorado Plateau near Tuba City, AZ. Four‐wing saltbush [Atriplex canescens (Pursh) Nutt.] was successfully established in compacted caliche soil and in unconsolidated dune soil when transplants were irrigated through the first summer with 20 L/plant/wk. The caliche soil was ripped before planting to improve water‐holding capacity. The diploid saltbush variety, angustifolia, had higher survival and growth than the common tetraploid variety, occidentalis, especially on dune soil. The angustifolia variety grew to 0.3 to 0.4 m3 per plant over 3 yr even though irrigation was provided only during the establishment year. By contrast, direct seeding of a variety of native forbs, grasses, and shrubs yielded poor results, despite supplemental irrigation throughout the first summer. In this arid environment (precipitation = 100 to 200 mm/yr), the most effective revegetation strategy is to establish keystone native shrubs, such as four‐wing saltbush, using transplants and irrigation during the establishment year, rather than attempting to establish a diverse plant community all at once.
Influence of Plant Growth on Degradation of Linear Alkylbenzene Sulfonate in Sludge‐Amended Soil
Authors: Mortensen G.K. , Egsgaard H. , Ambus P. , Jensen E.S. , Gr⊘n C. 
Published: June 2010

ABSTRACTWidespread application of sewage sludge to agricultural soils in Denmark has led to concern about the possible accumulation and effects of linear alkylbenzene sulfonate (LAS) in the soil ecosystem. Therefore, we have studied the uptake and degradation of LAS in greenhouse pot experiments. Sewage sludge was incorporated into a sandy soil to give a range from very low to very high applications (0.4 to 90 Mg dry wt. ha−1). In addition, LAS was added as water solutions. The soil was transferred to pots and sown with barley (Hordeum vulgare L. cv. Apex), rape (Brassica napus L. cv. Hyola 401), or carrot (Daucus carota L.). Also, plant‐free controls were established. For all additions there was no plant uptake above the detection limit at 0.5 mg LAS kg−1 d.w, but plant growth stimulated the degradation. With a growth period of 30 d, LAS concentrations in soil from pots with rape had dropped from 27 to 1.4 mg kg−1 dry wt., but in plant‐free pots the concentration decreased only to 2.4 mg kg−1 dry wt. When LAS was added as a spike, the final concentration in soil from planted pots was 0.7 mg kg−1 dry wt., but in pots without plants the final concentration was much higher (2.5 mg kg−1 dry wt.). During degradation, the relative fraction of homologues C10, C11, and C12 decreased, while C13 increased.
Radionuclide Transport above a Near‐Surface Water Table: III. Soil Migration and Crop Uptake of Three Gamma‐Emitting Radionuclides, 1990 to 1993
Authors: Wadey P. , Shaw G. , Bell J.N.B. 
Published: June 2010

ABSTRACTThis paper summarizes the vertical distributions of 22Na, 137Cs, and 60Co above controlled water tables in deep and shallow lysimeters during a four‐year experiment. The activity concentration profiles were all determined at the time of harvest of a winter wheat (Triticum aestivum L. cv. Pastiche) crop. Activity concentrations in different crop tissues were determined and crop uptake expressed as both an inventory ratio (IR) and a transfer factor (TFw), weighted to account for root and radionuclide distributions within the soil profile. Experimental variates were subjected to analysis of variance to determine the single and combined effects of the soil depth and the year of the experiment on the results obtained. Each radionuclide showed significant variations in activity concentration with soil depth, but the significance of these variations from year to year was dependent on radionuclide. A distinction in the behavior of weakly sorbed (22Na) and more highly sorbed (137Cs and 60Co) radionuclides was observed. The former exhibited significant variations in its distribution in the soil profile from year‐to‐year whereas the latter did not. Relatively high TFw values for 22Na were maintained throughout the experiment, whereas for 137Cs and 60Co, the highest TFw values were recorded in 1990 followed by a significant decline in 1991, with TFw remaining low in 1992 and 1993. The TFw values were, in general, significantly higher for deep lysimeters than for shallow lysimeters. This is thought to provide evidence of enhanced radionuclide absorption by the relatively small fraction of roots in the vicinity of the deeper water table.
Decomposition and Nitrogen Mineralization from Biosolids and Other Organic Materials: Relationship with Initial Chemistry
Authors: Rowell Douglas M. , Prescott Cindy E. , Preston Caroline M. 
Published: June 2010

ABSTRACTBiosolids are effective forest fertilizers. In order to facilitate their use it is important that one be able to predict the amount and rate of mineralization of nutrients, particularly nitrogen, and the relationship between substrate chemistry and N release. We examined the relationships between substrate quality and nitrogen release in a variety of organic materials. Rates of decomposition and net N mineralization from four biosolids, wheat straw, paper fines, and Douglas‐fir [Pseudotsuga menziesii (Mirb.) Franco] needle litter were measured during 391‐d incubations in a greenhouse, and at two field sites in wet coastal and dry interior forests. Decomposition rates were best predicted by a model incorporating the ratio of carbon to organic matter. The decomposition model extrapolated well to the field when site‐specific correction factors were applied. There was a weak relationship between rates of decomposition and net N mineralization. Rates of net N mineralization were best predicted by a model incorporating the initial organic N concentration and the proportion of phenolic C determined from solid‐state 13C nuclear magnetic resonance (NMR) spectroscopy. The mineralization model extrapolated less well to the field, but the effect of substrate chemistry was still apparent. Among the four biosolids there was a strong correlation between organic N concentration and indices of protein determined from 13C NMR, suggesting that these protein indices may be useful for predicting N mineralization from biosolids. There was some evidence that the protein content and N mineralization in biosolids may be predictable from the sewage treatment process employed.
Manure Sampling for Nutrient Analysis: Variability and Sampling Efficacy
Authors: Dou Z. , Galligan D.T. , Allshouse R.D. , Toth J.D. , Ramberg C.F. , Ferguson J.D. 
Published: June 2010

ABSTRACTReliable estimation of nutrient concentrations is required to manage animal manure for protecting waters while sustaining crop production. This study was conducted to investigate sample variability and reliable nutrient analysis for several manure types and handling systems. Serial samples were collected from dairy, swine, and broiler poultry operations while manure was being loaded onto hauler tanks or spreaders for field application. Samples were analyzed for total solids (TS), total nitrogen (N), ammoniacal nitrogen (NH4–N), total phosphorus (P), and potassium (K). The least number of samples needed for reliable testing of total N and P, defined as ±10% of the experimental means with 99% probability, was obtained for each farm using a computer‐intensive random resampling technique. Sample variability within farms, expressed as the coefficient of variation (CV), was mostly 6 to 8% for farms that used agitation of manure storages but several times higher (20–30%) on farms where no agitation was applied during the sampling period. Results from the random resampling procedure indicated that for farms that used agitation, three to five samples were adequate for a representative composite for reliable testing of total N and P; whereas for farms without agitation, at least 40 samples would be required. Data also suggest that using book values for manure nutrient estimations could be problematic because the discrepancies between book standards and measured farm data varied widely from a small amount to several fold.
Statistical Evaluation of Geochemical Parameter Distribution in a Ground Water System Contaminated with Petroleum Hydrocarbons
Authors: Lee Jin‐Yong , Cheon Jeong‐Yong , Lee Kang‐Kun , Lee Seok‐Young , Lee Min‐Hyo 
Published: June 2010

ABSTRACTA shallow‐depth ground water area was investigated to identify the dominant processes governing the distribution of hydrocarbon contaminants and hydrogeochemical parameters. The ground water in the study site has been highly contaminated with petroleum hydrocarbons. A preliminary pump‐and‐treatment remediation technology was applied for 4 yr at the site. Multivariate analyses were applied to hydrogeochemical data obtained before and after the rainy season. The pump‐and‐treatment application, indigenous biodegradation, and mixing by precipitation recharge are the major factors or events involved in the distribution of geochemical parameters of the ground water in the study area. Site‐specific artificial pavement also played an important role in the evolution of the ground water chemistry. A conventional graphical analysis method (Piper plot) of major ions did not effectively reveal these effects. In this study, we demonstrate the usefulness of multivariate analysis (factor and cluster analyses) using biodegradation indicator parameters, as well as major cations and anions, for the study of the ground water system in the hydrocarbon‐contaminated site.
Nitrate Leaching beneath a Containerized Nursery Crop Receiving Trickle or Overhead Irrigation
Authors: Colangelo David J. , Brand Mark H. 
Published: June 2010

ABSTRACTContainer production of nursery crops is intensive and a potential source of nitrogen release to the environment. This study was conducted to determine if trickle irrigation could be used by container nursery producers as an alternative to standard overhead irrigation to reduce nitrogen release into the environment. The effect of overhead irrigation and trickle irrigation on leachate nitrate N concentration, flow‐weighted nitrate N concentration, leachate volume, and plant growth was investigated using containerized rhododendron (Rhododendron catawbiense Michx. ‘Album’) supplied with a controlled‐release fertilizer and grown outdoors on top of soil‐monolith lysimeters. Leachate was collected over two growing seasons and overwinter periods, and natural precipitation was allowed as a component of the system. Precipitation accounted for 69% of the water entering the overhead‐irrigated system and 80% of the water entering the trickle‐irrigated system. Leachate from fertilized plants exceeded the USEPA limit of 10 mg L−1 at several times and reached a maximum of 26 mg L−1 with trickle irrigation. Average annual loss of nitrate N in leachate for fertilized treatments was 51.8 and 60.5 kg ha−1 for the overhead and trickle treatments, respectively. Average annual flow‐weighted concentration of nitrate N in leachate of fertilized plants was 7.2 mg L−1 for overhead irrigation and 12.7 mg L−1 for trickle irrigation. Trickle irrigation did not reduce the amount of nitrate N leached from nursery containers when compared with overhead irrigation because precipitation nullified the potential benefits of reduced leaching fractions and irrigation inputs provided under trickle irrigation.
Bioavailability of Biosolids Molybdenum to Soybean Grain
Authors: O'Connor G. A. , Granato T. C. , Basta N. T. 
Published: June 2010

ABSTRACTLegumes grown in biosolids‐amended soils and then fed to ruminants can represent problematic sources of molybdenum (Mo), but few field data are available to quantify the risk. We used a set of fields amended to high cumulative biosolids Mo loads (>18 kg ha−1) over 27 yr to generate additional data. Soybean [Glycine max (L.) Merr.] was grown on 29 fields (pH values >6.8) amended to a wide range of soil Mo loads. Soybean grain harvested from each field was analyzed for Mo and the concentrations regressed against soil Mo loads estimated from actual soil Mo concentrations in the 0‐ to 15‐cm depth. Slopes of such linear regressions represent uptake coefficients (UC values) used by the USEPA to assess risk of biosolids Mo to ruminants fed forage grown on biosolids‐amended land. The UC value for all 29 fields was estimated as 1.66, which agrees with the few soybean grain data in the literature. The UC value, however, is well below a conservative UC value of 4, recently recommended for all fresh legume materials fed to cattle. Soybean grain can contain high concentrations of Mo (>10 mg kg−1) and have low (<2:1) Cu to Mo ratios, which can exacerbate molybdenosis problems in cattle. However, soybean grain normally constitutes only ∼10% of dairy cattle diet, and other constituents (e.g., corn grain, stover, mineral supplements) are sufficient, or can be manipulated, to control molybdenosis.
Enzymatic Characterization of Organic Phosphorus in Animal Manure
Authors: He Zhongqi , Honeycutt C. Wayne 
Published: June 2010

ABSTRACTInformation on the forms of P present in animal manure may improve our ability to manage manure P. In most investigations of manure P composition, only inorganic and total P are determined, and the difference between them is assigned as organic P. In this study, we explored the possibility of identifying and quantifying more specific organic P forms in animal manure with orthophosphate‐releasing enzymes. Pig (Sus scrofa) manure and cattle (Bos taurus) manure were first sequentially fractionated into water‐soluble P, NaHCO3–soluble P, NaOH‐soluble P, HCl‐soluble P, and residual P. The fractions were separately incubated with wheat phytase, alkaline phosphatase, nuclease P1, nucleotide pyrophosphatase, or their combinations. The released orthophosphate was determined by a molybdate blue method. Part of the organic P in those fractions could be identified by the enzymatic treatments as phytate (i.e., 39% for pig manure and 17% for cattle manure in water‐soluble organic P), simple phosphomonoesters (i.e., 43% for pig manure and 15% for cattle manure in NaOH‐soluble organic P), nucleotide‐like phosphodiesters (2–12%), and nucleotide pyrophosphate (0–4%). Our data indicate that the enzymatic treatment is an effective approach to identify and quantify the organic P forms present in animal manures.
Phosphorus Losses from Grasslands Fertilized with Broiler Litter: EPIC Simulations
Authors: Pierson S. T. , Cabrera M. L. , Evanylo G. K. , Schroeder P. D. , Radcliffe D. E. , Kuykendall H. A. , Benson V. W. , Williams J. R. , Hoveland C. S. , McCann M. A. 
Published: June 2010

ABSTRACTBroiler litter, a mixture of poultry excreta and bedding material, is commonly used to fertilize grasslands in the southeastern USA. Previous work has shown that under certain situations, application of broiler (Gallus gallus domesticus) litter to grasslands may lead to elevated levels of phosphorus (P) in surface runoff. The EPIC simulation model may be a useful tool to identify those situations. This work was conducted to evaluate EPIC's ability to simulate event and annual runoff volume and losses of dissolved reactive phosphorus (DRP) from tall fescue (Festuca arundinacea Schreb.)–bermudagrass [Cynodon dactylon (L.) Pers.] paddocks fertilized with broiler litter. The EPIC simulations of event runoff volume showed a trend toward underestimation, particularly for runoff events > 30 mm. On an annual basis, EPIC also tended to underestimate runoff, especially at runoff volumes > 100 mm. Both event and annual runoff estimations were strongly associated with observed values, indicating that model calibration could improve the simulation of surface runoff volume. The relationship between simulated and observed values of DRP loss was relatively poor on an event basis (r = 0.65), but was stronger (r = 0.75) on an annual basis. In general, EPIC tended to underestimate annual DRP losses. This underestimation was apparently caused by the lack of an explicit mechanism to model broiler litter on the soil surface. These results suggested that additional work on the EPIC P submodel would be warranted to improve its simulation of surface application of broiler litter to grasslands.
Kraft Mill Residues Effects on Monterey Pine Growth and Soil Microbial Activity
Authors: Jordan Miguel , Sánchez Miguel Angel , Padilla Leandro , Céspedes Ricardo , Osses Miguel , González Bernardo 
Published: June 2010

ABSTRACTThe production of bleached Kraft pulp generates inorganic and organic residues that are usually deposited on the soil surface or land‐filled. Studies conducted to address the impact of these wastes on the environment are scarce. In this work, Monterey pine (Pinus radiata D. Don), an important tree for pulping, was evaluated for germination and development under greenhouse conditions in forest soils exposed to solid residues of the cellulose industry using the Kraft process. Soils exposed to 10 to 60% ashes, 10 to 70% fly ashes, or 10 to 30% dregs allowed substantial seed germination and seedling growth. In contrast, soils exposed to low proportions of brown rejects, grits, or a mixture of all these residues were detrimental for germination, plant growth, or both. The strongest negative effect (no germination) was observed with as low as 10% grits. The changes in pH and/or water content caused by solid wastes did not correlate with detrimental effects observed in various soil–residue combinations. No significant changes in the microbial community of soils exposed to these solid residues were observed by determination of culturable counts, or by terminal‐restriction fragment length polymorphism analysis of the microbial community DNA. The presence of organic residues did not affect the ability of the soil microbial community to remove typical pulp bleaching chloroaromatics. However, inorganic wastes strongly decreased the removal of such compounds.
Temperature and Wetland Plant Species Effects on Wastewater Treatment and Root Zone Oxidation
Authors: Allen Winthrop C. , Hook Paul B. , Biederman Joel A. , Stein Otto R. 
Published: June 2010

ABSTRACTConstructed wetlands are widely used for wastewater treatment, but there is little information on processes affecting their performance in cold climates, effects of plants on seasonal performance, or plant selection for cold regions. We evaluated the effects of three plant species on seasonal removal of dissolved organic matter (OM) (measured by chemical oxygen demand and dissolved organic carbon) and root zone oxidation status (measured by redox potential [Eh] and sulfate [SO2−4]) in subsurface‐flow wetland (SSW) microcosms. A series of 20‐d incubations of simulated wastewater was conducted during a 28‐mo greenhouse study at temperatures from 4 to 24°C. Presence and species of plants strongly affected seasonal differences in OM removal and root zone oxidation. All plants enhanced OM removal compared with unplanted controls, but plant effects and differences among species were much greater at 4°C, during dormancy, than at 24°C, during the growing season. Low temperatures were associated with decreased OM removal in unplanted controls and broadleaf cattail (Typha latifolia L.) microcosms and with increased removal in beaked sedge (Carex rostrata Stokes) and hardstem bulrush [Schoenoplectus acutus (Muhl. ex Bigelow) A. & D. Löve var. acutus] microcosms. Differences in OM removal corresponded to species' apparent abilities to increase root zone oxygen supply. Sedge and bulrush significantly raised Eh values and SO2−4 concentrations, particularly at 4°C. These results add to evidence that SSWs can be effective in cold climates and suggest that plant species selection may be especially important to optimizing SSW performance in cold climates.
Seasonal Dynamics of Denitrification along Topohydrosequences in Three Different Riparian Wetlands
Authors: Clément Jean‐Christophe , Pinay Gilles , Marmonier Pierre 
Published: June 2010

ABSTRACTWe investigated the seasonal patterns of denitrification rates and potentials in soil profiles along the topohydrosequence formed at the upland–wetland interface in three riparian wetlands with different vegetation cover (i.e., forest, understory vegetation, and grass). Denitrification was measured using the acetylene inhibition method on soil cores and slurries, which provided a means of comparing the relative activity of this process in different locations. We evaluated, on a seasonal basis, the respective importance of the vegetative cover and the hydromorphic gradient as factors limiting denitrification. Regardless of the season, vegetation type, or lateral position along each topohydrosequence in the riparian wetlands, strong significant gradients of both in situ and potential denitrification rates were measured within a soil profile. Results confirm that the upper organic soil horizon is the most active, when in contact with the ground water. In deeper soil horizons, denitrification activity was low (from 0.004 to 0.5 mg N kg−1dry soil d−1), but contributed significantly to the reduction of ground water NO−3load along the riparian ground water flowpath (from 9.32 to 0.98 mg NO3–N L−1). Along the soil topohydrosequence, the denitrifying community of the upper soil horizons did not vary significantly on a seasonal basis despite the large seasonal ground water fluctuations. Along each topohydrosequence, the denitrification‐limiting factor gradually shifted from anaerobiosis to NO−3supply. In situ denitrification rates in the forested, understory vegetation and grass sites were not significantly different. This result emphasizes the importance of the topography of the valley rather than the vegetation cover in controlling denitrification activity in riparian wetlands.