bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fertilizer Nitrogen Distribution Under Irrigation Between Soil, Plant, and Aquifer
Authors: Gerwing J. R. , Caldwell A. C. , Goodroad L. L. 
Published: July 2010

AbstractA field experiment was established on a Sverdrup sandy loam in Central Minnesota to evaluate the effects of amounts and timing of nitrogen (N) fertilizer applications on N uptake by irrigated corn (Zea mays L.) and the movement of N into the aquifer 4.5 m below the soil surface. Nitrogen was applied as urea at rates of 179 and 269 kg N/ha in one application at planting or in split applications through the season. Soil solution analysis showed NO3 moving below the rooting zone in all plots with much higher concentrations below the one‐time fertilizer applications. Split applications of N had only minimal effect on the concentration of NO3‐N in the aquifer but one‐time applications increased the concentration by 7 and 10 ppm. The use of 13N showed that splitting the 179‐kg rate increased the N in the plant derived from fertilizer from 33.1 to 54.5%, and increased the recovery of fertilizer N by the plant from 30.4 to 52.1%, even though whole plant yields were not affected. Nearly one‐fourth of the applied N remained in the upper 45‐cm soil layer at harvest regardless of treatment. No accumulation of NO3 was found in the soil profile or underlying material to a depth of 3.0 m.
Nutrient Chemistry in Herbicide‐treated Ponds of Differing Fertility
Authors: Peverly John H. , Johnson Robert L. 
Published: July 2010

AbstractPonds 0.04 ha in bottom area and 1.2 m uniform depth with similar densities of the submerged aquatic plant Elodea canadensis Michx. but with different previous nutrient additions were treated with 1 mg/liter diquat (6,7‐dihydrodipyrido [1,2‐a:2′,1′‐c] pyrazinediium ion) on 17 Nov. 1972. This was done to simulate normal weedkill conditions and to measure subsequent carryover effects of past nutrient inputs. Before treatment and for 1 year thereafter, soluble P, particulate P, NO3−, NO2−, NH4+, K+, and chlorophyll a were measured in treated and similar control ponds. After herbicide treatment soluble P concentrations rose dramatically within 24 hours but were reduced to control levels of 10 to 20 µg/liter within 3 weeks. All P forms in the fertilized treated pond remained low until the following June, when particulate and organic P increased to 100 to 300 µg/liter as a result of mineralization processes. Chlorophyll a rose soon after to about 200 µg/liter and NH2+‐N to 100 µg/liter. There were no other differences between control or treated ponds in NH4+ or NO3− concentrations, but both increased several fold each fall in all ponds. Definite carryover effects of previous nutrient inputs were demonstrated in the herbicidetreated ponds, but not in untreated ponds. The compartment in the pond which stored these nutrients and then released them upon herbicide treatment was the rooted macrophytes.
Effects of Soil‐applied Sewage Sludge on Concentrations of Elements in Earthworms
Authors: Helmke P. A. , Robarge W. P. , Korotev R. L. , Schomberg P. J. 
Published: July 2010

AbstractSamples of earthworms (Aporrectodea tuberculata [Annelida: Lumbricidae]) and their casts collected from field plots were analyzed by neutron activation analysis to evaluate the suitability of using earthworms to monitor the bioavailability of elements in soils, and to determine the effects of land application of sewage sludge on the concentrations of trace elements in earthworms. Culture of earthworms on soils treated with radioactive tracers shows that earthworms accumulate Cd, Co, Hg, and Zn, but not Hf, Sc, and Tb. The results for the earthworms from the field plots are corrected for the effects of contamination by uneliminated casts with the use of interelement ratios. The concentrations of Hg and Cr in the casts increase with increasing rates of sludge application, but the constant concentrations of these elements in the earthworms show that these elements are not bioavailable. The concentrations of Cd, Cu, and Zn in the earthworms increase, while those of Se decrease with increasing rates of sludge application. The very high concentrations of Cd in the earthworms, ranging from about 10 ppm in the control samples to over 100 ppm in the affected samples, show that earthworms efficiently accumulate Cd.
Metabolic Fate of Atrazine in the Spartina alterniflora‐Detritus—Uca pugnax Food Chain
Authors: Mc Enerney J. T. , Davis D. E. 
Published: July 2010

AbstractLeaves from Spartina alterniflora Loisee (smooth cordgrass) plants grown with their roots in solutions containing 14C ring‐labeled atrazine were converted to detritus in model ecosystems that simulated the salt marsh environment. Percentages of radioactivity in chloroform‐soluble, water‐soluble, and insoluble materials in the leaves were 55, 38, and 7, respectively. Twenty days later these values for detritus were 9, 78, and 13, respectively. Thus, there was a decline in the percentage of radioactivity in the chloroform fraction which contains atrazine and nontoxic metabolites and a concurrent increase in the water‐soluble fraction that contains only nontoxic metabolites.An important detritivore in the salt marsh, the mud fiddler crab, when fed detritus labeled with atrazine further decreased the percentage of the chloroform‐soluble atrazine or atrazine metabolites. Radioactivity originally present in either atrazine or atrazine metabolites fed to mud fiddler crabs was concentrated in the water‐soluble extract from the crabs, suggesting that either selective absorption through the gut or metabolism of the chloroform‐soluble form(s) to water‐soluble material by the fiddler crabs or the crabs' enteric flora. Atrazine and atrazine metabolite concentrations were reduced from lower (detritus) to higher trophic levels (mud fiddler crabs) in the simulated salt marsh ecosystem.
An Evaluation of Alternative Simulated Treatments of Septic Tank Effluent
Authors: Stewart L. W. , Carlile B. L. , Cassel D. K. 
Published: July 2010

AbstractSix modified soil columns (180 by 15 cm) with an upper unsaturated zone and a lower saturated zone were dosed twice daily for 220 days with 1.65 cm of septic tank effluent via a cinderblock cube. Examined were: (i) the performance of the cinderblock material as a means of introducing effluent into two soils having different textures, (ii) the treatment capability of the two soils under unsaturated flow to purify septic tank effluent, and (iii) denitrification in a saturated zone containing either a Histic epipedon‐sand mixture (9% OM) or gravel only.Water as simulated rainfall totaling 4.3 cm was added in five increments to the soil overlying the cinderblock cubes during the first 45 days of dosing. Severe biological clogging occurred after 50 days in the cinderblock material embedded in the loamy sand columns. This resulted in continuously ponded effluent inside the cinderblock cubes. Continuous ponding did not develop in the cubes placed in the sand columns.At a distance 95 cm below the cinderblock cube, conversion of total nitrogen to NO3 in sand columns ranged from 83 to 100% and the PO4‐P content of the percolating effluent averaged < 1 mg/liter. Column effluent samples analyzed for fecal coliform were all negative. Soil samples revealed no penetration of fecal coliforms below 30 cm in either the loamy sand or sand columns. In the saturated zone containing the Histic epipedon‐sand mixture, NO3 was reduced by 93% at 42 days, but only 22% at 95 days. Chemical oxygen demand in the column effluent gradually declined from 188 mg/liter at 42 days to 85 mg/liter at 220 days. No significant denitrification occurred in the saturated zones containing gravel only.
Commercial Production of Wheat Grain Irrigated with Municipal Waste Water and Pump Water
Authors: Day A. D. , McFadyen J. A. , Tucker T. C. , Cluff C. B. 
Published: July 2010

AbstractExperiments were conducted in southern Arizona to study the effects of irrigating wheat (Triticum aestivum L.) with a mixture of pump water and waste water and with pump water alone on wheat growth, grain yield, grain quality, soil properties, and irrigation water quality.In small plot research, wheat irrigated with the pump water‐waste water mixture produced taller plants, more heads per unit area, heavier seeds, higher grain yields, and higher straw yields than did wheat grown with only pump water. When large fields were compared, wheat grown with the pump water‐waste water mixture had taller plants, more lodging, lower grain volume‐weights, and higher grain yields than did wheat produced with pump water.The pH and exchangeable sodium of soil irrigated with pump water alone or the pump water‐waste water mixture were similar. Soluble salts and nitrate‐nitrogen were higher in soils irrigated with pump water than they were in soils irrigated with the pump water‐waste water mixture. Extractable phosphorus was higher in soils irrigated with the pump water‐waste water mixture than in soils irrigated with pump water.Total soluble salts and nitrate‐nitrogen were higher in pump water than they were in the pump water‐waste water mixture; however, the pump water‐waste water mixture had higher levels of total nitrogen and phosphorus than did pump water. The higher grain yields obtained when wheat was irrigated with the pump water‐waste water mixture than were produced when wheat was grown with pump water alone probably resulted from lower concentrations of soluble salts in the pump water‐waste water mixture than were present in pump water.
The Use of Zonal Centrifugation in Delineating Trace Element Distributions in Sewage Sludges from the Dayton, Ohio, Area
Authors: Bergman Steven C. , Ritter Charles J. , Zamierowski Edward E. , Cothern C. Richard 
Published: July 2010

AbstractDensity gradient zonal cenfrifugation, using tetrabromoethane‐ethanol solutions as density gradients, was used to fractionate two sewage sludges. The distributions of Cd, Cu, Pb, Ni, and Zn in the sludge fractions were determined using atomic absorption spectrophotometry. Trace element concentrations are related to density in a simple pattern. Seventy‐five weight percent of the total trace elements in the sludges are contained in low‐density (1.60 to Z.10 g/cm3), organic‐rich fractions. A small portion of the total trace elements in sludge is also associated with minerals such as sulfides and sulfates in high‐density fractions.Because organic‐rich fractions of sludge contain the highest absolute amount of trace elements, it is concluded that most of the trace elements are located in organic compounds in the sludges studied. Furthermore, it is suggested that particular organic compounds, within a limited density range, contain the greatest concentrations of trace elements.
Effects of Hypolimnetic Aeration on Nitrogen Transformations in Simulated Lake Sediment‐Water Systems
Authors: Chen R. L. , Keeney D. R. , Sikora L. J. 
Published: July 2010

AbstractMechanical aeration of the anoxic hypolimnion of small, eutrophic, thermally stratified lakes and impoundments has been proposed as a temporary water quality improvement technique. We hypothesized that proper manipulation of this technique could lead to significant N loss through nitrification‐denitrification. This hypothesis was examined by using simulated sediment‐water and batch incubation systems, and the use of 15N.Aeration of an NH4‐enriched hypolimnion should lead to disappearance of ammonium and formation of nitrate. If the sediment had a high oxygen demand, nitrate should rapidly disappear once aeration was discontinued. Nitrate should also disappear, although more slowly, during aeration due to reactions at the sediment‐water interface and in the surficial sediment. The amount of N removed from the sediments by nitrification‐denitrification would vary widely, depending on the lake, but would not be as large as predicted from nonlabeled N mass balances due to assimilatory nitrate reduction (immobilization).The results of this work indicate that nitrification is rapid, even at 10°C, when the hypolimnion is aerated, and that denitrification and nitrate immobilization is equally rapid when aeration is stopped and the hypolimnion again becomes anaerobic. However, at least in Cox Hollow Lake sediments, a considerable amount of nitrate (up to about 60%) is immobilized rather than denitrified. Thus, the net loss of N from the lake system is much less than would be predicted from strictly inorganic N mass balance calculations, and hypolimnion aeration does not offer much promise as a method for removing N from lakes.
Nitrogen Transformations and Microbial Population Dynamics in Soil Amended with Fermentation Residue
Authors: Volz M. G. , Heichel G. H. 
Published: July 2010

AbstractTo evaluate the fate of N in an agricultural soil treated with an N‐rich industrial byproduct, fermentation residue was applied to Yalesville fine, sandy loam at a loading rate of 75 dry metric tons/ha, or 2,130 and 1,780 kg N/ha during 1975 and 1976, respectively. Treated and control plots were planted to soybeans (Glycine max L. Merr.) each year. The treated plots yielded 4,350 kg/ha of soybean grain compared with 3,600 kg/ha for the controls in 1975, and 4,100 kg/ha compared with 3,700 kg/ha in 1976. Yield enhancements attributable to fermentation residue application were significant (P = 0.05) each year despite the severe repression of nodulation on treated plants compared with controls.During the growing season, NO3−‐N accumulations >80 µg/g oven dry soil were observed in the top 5 cm of treated soil, compared with accumulations of 15 µg/g or less in the control. Further, elevated NO3−‐N levels were observed in the top 91 cm of treated soil throughout the fallow and growing seasons, when compared with control plots, suggesting that some of the applied N may have been transported to the water table as NO3−.Populations of five physiological groups of microorganisms closely mirrored soil levels of NO3−‐N and NH4+‐N in both experiments. Denitrifying bacteria reached population densities of 3.0 × 109/g oven dry treated soil compared with a maximum of 6.8 × 105/g for control soil during the growing season. Enhanced N transforming activity by microorganisms in soil receiving fermentation residue compared with the control soil was supported by the elevated populations of NH4+ and NO2− oxidizing bacteria, and NO3− reducing‐, denitrifying‐, and heterotrophic aerobic bacteria observed throughout the fallow and growing seasons. Although application of fermentation residue significantly increased soybean yields, the limited recovery of added N by the crop and the likelihood of substantial N losses suggest a reassessment of application rates or efforts to stabilize N applied to soils from fermentation residues.
Soil Temperature and Sewage Sludge Effects on Metals in Crop Tissue and Soils
Authors: Sheaffer C. C. , Decker A. M. , Chaney R. L. , Douglass L. W. 
Published: July 2010

AbstractEffects of soil temperature and sewage sludge application on plant and soil Zn, Cu, Cd, Ni, and Pb levels, soil pH, and soil organic matter were determined in a field experiment in which corn (Zea mays L.) was grown for 2 years in a sandy Typic Hapludult soil amended with 0, 56, and 112 metric tons/ha of sewage sludge at the start of the experiment. Soil temperature regimes of 16, 27, 35°C, and ambient (x̄ = 22°C) were applied to sludge treatments from May to October each year. Following removal of corn at the conclusion of the 1975 growing season, oats (Avena sativa L.), wheat (Triticum aestivum L.), rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), and arrowleaf clover (Trifolium vesiculosum Savi) were grown until the following spring.Sewage sludge application resulted in significant increases in soil organic matter, pH, and DTPA extractable Zn, Cu, Cd, and Ni. Soil heating to 35°C significantly reduced soil pH for all sludge rates compared to 16°C and ambient (22°C) temperatures by the conclusion the experiment. This decrease was greatest for plots amended with 112 metric tons/ha sewage sludge and least for the check plots. Soil temperature had no effect on levels of soil organic matter or DTPA extractable metals. Extractable Zn, Cu, and Ni levels increased from the start to the conclusion of the experiment.Concentrations of Zn, Cu, Ni, and Cd were increased in corn, legume, and small grain tissue by sludge treatments. Corn seedling Zn and Cu concentrations exceeded that in ear leaves, stover, and grain; lowest metal concentrations were found in the corn grain. Increasing soil temperature did not consistently affect Cu, Ni, Cd, or Pb concentrations in corn tissue. Zinc concentrations in corn tissue generally increased as soil temperature rose, but exceptions did exist. No residual soil temperature effects were observed on metal concentrations in legumes or small grains.
Denitrification in Freshwater Wetland Soil
Authors: Bartlett M. S. , Brown L. C. , Hanes N. B. , Nickerson N. H. 
Published: July 2010

AbstractThe application of secondary treated waste water to fresh water wetlands has received recent attention as a tertiary treatment method. The fate of nitrate nitrogen in such applications is of concern because of the potential for leaching into ground and surface water supplies. Nitrate removal in wetland soil‐water suspensions was studied using a Warburg Respirometer. All important pathways of nitrate reduction were accounted for using a nitrogen mass balance. The data indicate that 90 to 95% of the nitrate added to wetland soil‐water suspensions is reduced to nitrogenous gases, with little or no transfer of nitrate to ammonia nitrogen or organic nitrogen fractions.
Disposal of Septic Tank Effluent in Mound and Sand Filter‐Trench Systems on a Clay Soil
Authors: Simons A. P. , Magdoff F. R. 
Published: July 2010

AbstractSmall‐scale mound systems and conventional sand filter‐trench systems for disposal of septic tank effluent were established on a clay soil. During a wet year (1976), major differences in soil moisture patterns were observed between the two systems. Unsaturated flow of effluent occurred through the gravel/sand interface of the mound systems, although a slight pressure‐head buildup occurred at the bottom of the mound fill. Conventional sand filter‐trench systems were under water throughout most of the 1976 monitoring season. However, when the dry conditions of 1977 allowed the water table to drop below 1.2 m, unsaturated conditions occurred below the gravel/sand interface of both the mound and sand filter systems. Water tension patterns below the gravel/sand interface indicated development of the early stages of clogging (but not permanent ponding) in the mounds, while those within the sand filter‐trench system indicated the development of a restricting layer. Rejuvenation of the mound infiltrative surface occurred during the warm and dry 1977 spring and early summer.Temperatures below the gravel/sand interface dropped to about −3°C during the winter in the mound systems, but stayed just above freezing in the sand filters. A lack of snow accumulation on top of the mounds probably allowed the subzero temperatures.
Incidence of Salmonellae in Feedlot Manure
Authors: Clinton N. A. , Weaver R. W. , Zibilske L. M. , Hidalgo R. J. 
Published: July 2010

AbstractManure from cattle in 11 major feefllots in Texas was sampled during summer and winter months to determine the presence of salmonellae. Both moist and dry samples of manure were collected. Of the 505 pens from which manure was sampled, 49 were positive for salmonellae. Only 2 of the 49 isolations were made from dry manure samples. One feedlot contained salmonellae in 44% of its pens. But no salmonellae were isolated from the manure in two of the feedlots. The frequency of isolating salmonellae from different feedlots varied with the season of the year but the overall frequency was similar for both seasons. Ten salmonella serotypes were isolated with the two most common being Salmonella typhimurium and Salmonella anatum. These results indicate that manure in feedlots may have an important role in the epidemiology of salmonellae.
Effects of Phosphorus Fertilizer and Lime on the As, Cr, Pb, and V Content of Soils and Plants
Authors: Goodroad L. L. , Caldwell A. C. 
Published: July 2010

AbstractThe occurrence in fertilizer materials of small quantities of chemical elements not essential to plants suggests that the soil may become contaminated with these elements due to the use of fertilizers. Two experimental sites: a Nicollet clay loam fertilized with 0, 1,111, 2,222, 4,444, and 8,888 kg/ha of concentrated superphosphate (CSP) and 20.2 metric tons of lime, and a Port Byron silt loam fertilized for 19 years with 99, 73, 82, and 352 kg/ha annually of CSP, calcium metaphosphate, phosphoric acid, and southern rock phosphate, respectively, were sampled to determine if significant amounts of arsenic (As), chromium (Cr), lead (Pb), or vanadium (V) had been added from use of these fertilizer materials. There was no indication of increased As, Cr, Pb, or V from the addition of P fertilizers to either the Nicollet or Port Byron soils. The addition of lime increased the Cr content of the Nicollet soil by approximately 3 ppm, but there was no increase in As, Pb, or V. There was no increase in As, Cr, Pb, or V from addition of CSP in soil samples from below the Ap horizon to a depth of 47.5 cm. Soil samples from a representative Nicollet soil suggest that higher As, Cr, Pb, and V concentrations in the A and B horizons are due to leaching of CaCO3 into the C horizon. Corn (Zea mays L.) plant growth and grain yields were similar for all CSP and lime treatments. The results of this study indicate that the use of P fertilizers at the rates presently applied would not add substantially to the natural levels of As, Cr, Pb, and V in the soil.
Nitrate Leaching from Sewage‐irrigated Perennials as Affected by Cutting Management
Authors: Hook J. E. , Burton T. M. 
Published: July 2010

AbstractA field study was conducted on two waste water‐treated sites to evaluate the effectiveness of various cutting treatments for controlling nitrogen (N) leaching. Secondary municipal sewage effluent was applied at 7.5 cm/week during the growing season to Kentucky bluegrass (Poa praetensis L.), which received treatments of no cutting, biweekly mowing, and triannual hay harvest. Effluent was also applied at rates of 0, 5.0, and 10.0 cm/week to indigenous vegetation in an abandoned field which received treatments of no cutting, once, and twice‐annual harvests. Soil‐water was sampled with porous‐cup samplers. The N concentration in the 120‐ to 150‐cm depth was taken as a measure of N which escaped the root zone and which would leach to the ground water. Recharge volume was calculated from irrigation, rainfall, and potential evapotranspiration.Soil‐water from the 150‐cm depth in the Kentucky bluegrass consistently contained < 10 mg/liter of mineral N. Mineral N concentration of soil‐water did not differ significantly among the cutting managements. Even though no vegetation was removed from the no‐cutting and the mowed plots, they were as effective as the harvested plots in controlling N leaching past the 150‐cm depth in the 2‐year study.For the oldfield vegetation, there was no significant difference in mineral N concentration in soil‐water at the 120‐cm depth between the 5.0‐ and 10.0‐cm/week irrigation rates. The mineral N concentration at 120 cm under both irrigation rates was affected by time of year and by cutting treatments. The twice‐annual harvest controlled N leaching more effectively than not cutting. The once‐annual harvest was more effective than not cutting for the 10‐cm/week rate but not for the 5.0‐cm/week rate. During the late summer and fall mineral N in the leachate increased to > 10 mg N/liter for the no cutting but not for the harvested oldfields. For reliable control of N leaching, removal of the N in harvested biomass was recommended.