bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Unreliability of Tile Effluent for Monitoring Subsurface Nitrate‐Nitrogen Losses from Soils
Authors: Thomas Grant W. , Barfield Billy J. 
Published: July 2010

AbstractInvestigation of a completely tiled field showed that only a small proportion of the total flow reaching the drainage ditch came from tile effluent. In two measurements, 63 and 89% of the flow to the drainage ditch came from seepage other than through tiles. The nitrate‐nitrogen concentrations in the tile effluent were far higher than those calculated in the nontile flow by mass balance. We conclude that nitrate‐nitrogen concentrations in tile effluents may not be reliable indicators of nitrate‐nitrogen losses from agricultural land, when the tiles do not intercept all subsurface flow.
Nutrient Losses from Fertilized Grassed Watersheds in Western North Carolina
Authors: Kilmer V. J. , Gilliam J. W. , Lutz J. F. , Joyce R. T. , Eklund C. D. 
Published: July 2010

AbstractThe transport of plant nutrients in drainage waters from two steeply sloping, differentially fertilized, grassed watersheds located in western North Carolina was determined over a 4‐year period. Watershed No. 1 has a drainage area of 1.89 ha, No. 2, 1.48 ha. The dominant slopes on both watersheds are 35 to 40%. During this period, watershed No. 1 received a total of 112‐48‐24 kg N‐P‐K/ha; watershed No. 2 received 448‐192‐24 kg N‐P‐K/ha.Average annual measured N losses were 3.28 and 12.08 kg/ha for watershed No. 1 and watershed No. 2, respectively; NO3‐N comprised 70% and 85% of the total N lost in discharge waters from the two watersheds. Total N lost over the 4‐year period from each watershed was 6 to 10% of the fertilizer N applied.Annual P losses were negligible, amounting to 0.15 kg/ha from watershed No. 1 and 0.27 kg/ha from watershed No. 2.Measured K losses averaged 3.99 and 5.83 kg/ha annually; S losses were 1.92 and 2.54 kg/ha from watershed No. 1 and watershed No. 2, respectively.Additional nutrient losses likely occurred because of deep seepage and an estimate of these losses was made.Losses of all nutrients were highest during the winter and spring months. Concentrations of nutrients in discharge waters from watershed No. 2 were consistently higher compared with watershed No. 1. However, NO3‐N concentrations exceeded 10 ppm on watershed No. 2 only once during the 4‐year period.The authors conclude from this study that steeply sloping pastures, judiciously fertilized, are not an important source of nutrients occurring in surface and ground waters.
Columns Representing Mound‐Type Disposal Systems for Septic Tank Effluent: I. Soil‐water and Gas Relations
Authors: Magdoff F. R. , Bouma J. , Keeney D. R. 
Published: July 2010

AbstractColumns were designed to represent the vertical dimensions of a mound‐type disposal system for receiving septic tank effluent on problem soils. The columns were filled with gravel (representing creviced bedrock), silt loam (representing the original topsoil), a sand or sandy loam till (fill material), gravel (the seepage bed), and another layer of silt loam (the mound cover). The columns were dosed with septic tank effluent at the rate of 2 cm every 6 hours. Until crusting caused permanent ponding at the fill‐gravel interface, the fill was aerobic and the silt loam at the bottom of the column was anaerobic. Redox potentials were higher in the fill (350 to 600 mV) than in the silt loam (200 to 410 mV). Moisture tension fluctuations after a 2 cm addition were greatest near the fill‐gravel interface and decreased with depth in the column. After continuous ponding, tension fluctuations almost ceased, the subcrustal soil became anaerobic, and the redox potentials decreased to around −250 mV. In a separate experiment, simulating field conditions, aerobic conditions were maintained in the subcrustal fill, by perforating column walls. The moisture tension regime and the rate of crust formation were similar to nonperforated columns.
Nitrogen Movement Resulting from Surface Application of Liquid Sewage Sludge
Authors: King Larry D. , Morris H. D. 
Published: July 2010

AbstractOne of the factors limiting the rate at which sewage sludge can be applied to soil is the speed at which inorganic N is formed and the fate of that inorganic N. A greenhouse lysimeter study was initiated in order to quantify some of the sinks into which N from sludge applications might move. For 12 weeks soil columns were treated at 3‐week intervals with a surface application of 2.5 cm of liquid sewage sludge. During each 3‐day interval 2.5 cm of water was applied to: (i) soil receiving no sludge (Soil‐2.5), (ii) soil receiving sludge (Sludge‐2.5), and (iii) soil planted to Coastal bermudagrass (Cynodon dactylon L. Pers.) receiving sludge (Grass‐2.5). Five centimeters of water was added to soil + grass + sludge (Sludge‐5) during each 3‐day interval. Another treatment was used to encourage a nitrification‐denitrification cycle. This treatment (Grass‐F) was identical to Grass‐2.5 except that during each third week sufficient water was added to bring the 3‐week total to the same as that in Grass‐5. Provisions were made to collect the leachate for NO3‐N analysis and to measure NH3 volatilization from the sludge.The average loss of N as NH3 was 36% of the applied NH4‐N in the Soil‐2.5 treatment and 24% in the three grass treatments. This represented 4.9 and 3.3%, respectively, of the total N applied. The Grass‐5 treatment resulted in the maximum NO3‐N leaching loss (5.4% of the applied N). The Grass‐F treatment did not result in reduced NO3‐N leaching. Grass removed 10.3% of the applied N. From 52 to 64% of the applied N remained in the sludge crust on the soil surface.
Lead, Cadmium, and Calcium Selectivity Coefficients on a Montmorillonite, Illite, and Kaolinite
Authors: Bittell J. E. , Miller Raymond J. 
Published: July 2010

AbstractSelectivity coefficients for Pb2+, Cd2+, and Ca2+ exchange adsorption with montmorillonite, illite, and kaolinite clays were determined over a wide range of clay surface concentration and found constant. The average selectivity coefficients describing the ion distributions for montmorillonite, illite, and kaolinite, respectively, were 0.60, 0.44, 0.34 for Pb‐Ca exchange, 1.04, 1.01, 0.89 for Cd‐Ca exchange and 0.58, 0.56, 0.31 for Pb‐Cd exchange. Whereas Cd2+ may compete more or less on an even basis with Ca2+ for clay adsorption sites, the adsorption of Pb2+ would be favored by a factor of 2 or 3 over Ca2+.
The Effect of Large Applications of Manure on Movement of Nitrate and Carbon in an Irrigated Desert Soil
Authors: Meek B. D. , MacKenzie A. J. , Donovan T. J. , Spencer W. F. 
Published: July 2010

AbstractFeedlot manure was applied in the field at rates of 0, 45, 90, 180, and 360 metric tons/ha to a Holtville clay under irrigated conditions. Holtville clay is a soil with restricted internal drainage. Ceramic cups were installed at various depths in the soil profile to monitor the movement of manganese, nitrate, and soluble organic carbon.The manure greatly increased the amount of soluble organic carbon in the soil solution. An increase in the manure application rate to 180 or 360 metric tons/ha increased the nitrate in the soil solution at 20 and 40 cm, but there were only small differences at 80 and 140 cm. The lack of movement of nitrate to the 80‐cm depth for the high rates of manure application appeared to be due to denitrification, because high nitrate levels were present in the surface soil and sufficient water was applied to leach to this depth. Nitrate leaching was less when manure was applied annually than when it was applied only the first year. Less movement of nitrate to the 80‐cm depth in treatments receiving manure annually seems to be the result of denitrification caused by the higher level of soluble organic carbon. The application of manure did not result in reducing conditions at 20 cm under regular irrigation as measured by redox potential, but the double irrigation schedule caused soil reducing conditions at 20 cm. At 80 cm, manganese in the soil solution was inversely correlated to nitrate level.
Changes in the Rhizosphere Effect of Millet Associated with Sprinkler Irrigation with Animal Wastes
Authors: Dazzo Frank B. , Smith Paul H. , Hubbell David H. 
Published: July 2010

AbstractThe microbial population changes in Scranton fine sand and adjacent millet rhizospheres resulting from sprinkler irrigation with cow manure slurry were investigated. Increasing the rate of irrigation with manure slurry resulted in a decline in the R/S ratio of ureolytic, proteolytic, amylolytic, and lipolytic microorganisms. A nutritional grouping study of the predominant bacteria indicated a significant increase in incidence of bacteria requiring amino acids and a decrease in incidence of bacteria requiring soil extract within non‐rhizosphere soil receiving manure applications. These findings, in addition to observed declines in the R/S ratio of microorganisms within soil receiving waste, are taken as evidence that the microbial environment created by irrigating Scranton fine sand with animal waste slurry may become similar to the microbial environment created by the roots of millet.
Column Studies of Soil Clogging in a Slowly Permeable Soil as a Function of Effluent Quality
Authors: Daniel T. C. , Bouma J. 
Published: July 2010

AbstractClogging as a function of effluent quality was investigated in cores of the very slowly permeable Almena silt loam soil which offers problems for conventional on‐site liquid waste disposal. Undisturbed 60 cm long cores were subjected for approximately 120 days to constant ponding with simulated septic tank effluent, extended aeration effluent and distilled water. Column influents and effluents were monitored with respect to chemical oxygen demand (COD), biochemical oxygen demand (BOD), and solid residue fractions. Column influents differed markedly in COD and BOD content but column effluents had consistently low contents indicating the high renovative capacity of the soil. In situ tensiometric, redox, and flow rate measurements indicated development of the most severe barriers to flow in columns ponded with low BOD aerated effluent, followed closely by those ponded with high BOD septic tank effluent. No barriers developed in columns ponded with water. Total concentrations of solid residue fractions in the two effluents and the cumulative load of solids applied to the columns did not differ significantly, but particle sizes in the aerated effluent were smaller. Increased pore clogging in aerated influent treatments points to the significant role of effluent solids in the clogging process in slowly permeable clayey soils. Additional studies are in progress to better define critical waste characteristics as related to soil clogging.
Microbial Activity in Soils Treated with Acephate and Monitor
Authors: Focht D. D. , Joseph H. 
Published: July 2010

AbstractA Hanford loamy sand, a Domino silt loam, and an Altamont clay loam were treated separately with three repeated applications (20 ppm) of the organophosphate insecticides, acephate (O,S‐dimethyl acetylphosphoramidothioate) and Monitor (O,S‐dimethyl phosphoramidothioate) over a 50‐day time span. Population levels of actinomycetes, bacteria, and fungi were not substantially affected by the addition of either pesticide. Neither could a marked effect be shown upon ammonification, nitrification, sulfur oxidation, or respiration rates. Replica plating failed to isolate bacteria from soils that were adversely affected by either pesticide. It is concluded that neither acephate nor Monitor had any adverse effect upon soil microorganisms.
Plant Nutrient Losses from Tile‐Outlet Terraces
Authors: Hanway John J. , Laflen John M. 
Published: July 2010

AbstractPlant nutrient losses in runoff water from four tile‐outlet terrace systems in Iowa and in tile drainage from two of the systems were measured annually from April to November over a 3‐year period. Total P losses in surface runoff varied from 0.44 to 1.06 kg/ha and, at any one location, were highly correlated with sediment losses. Average annual concentrations of total P in surface runoff ranged from 1.01 to 3.60 ppm and in tile drainage from two sites were 0.028 and 0.061 ppm. Soluble P concentrations in surface runoff were related to available P in the surface soils, and concentrations in tile drainage were related to available P in the subsoils. Annual average inorganic P concentrations in surface runoff varied from 0.013 to 0.204 ppm and in tile drainage were 0.004 and 0.018 ppm. Concentrations of inorganic N varied widely among locations, but were relatively constant at a location. Average annual inorganic N concentrations in surface runoff were 4 ppm or less at three of the four sites and 11 ppm at one site. Concentrations of inorganic N and sulfate S were similar and were lower in surface runoff than in tile drainage. There was no relation between the amounts of fertilizer applied and plant nutrient losses or concentrations in runoff or drainage water.
Application of Municipal Refuse and Liquid Sewage Sludge to Agricultural Land: I. Field Study
Authors: King Larry D. , Rudgers L. A. , Webber L. R. 
Published: July 2010

AbstractThe feasibility of using land for both waste disposal and crop production was studied by applying pulverized municipal refuse and liquid sewage sludge or liquid manure to land which was later planted to rye (Secale cereale L.) and subsequently to corn (Zea Mays L.). Refuse was applied at 188 metric tons/ha singly (R) or in combination with either 2.3 cm of liquid sewage sludge (RS) or 1.4 cm of liquid poultry manure (RM). Other treatments were a double waste rate—376 tons/ha of refuse + 4.6 cm of sludge (2[RS]), sludge alone (S), and a control (C) receiving no additions.Yield of rye forage was not affected by treatment. Highest corn grain yields were obtained with the R treatment while yields with the S and 2(RS) treatments were significantly lower than yields with R. No treatments resulted in corn yields significantly different from the control treatment. Levels of Zn, Cu, Cd, and Pb in the rye and corn tissue were usually increased by waste additions but were below levels toxic to the crops or to animals that might consume the crops. Soil nitrate was increased by the various waste treatments. A considerable fraction of the nitrate lost from the soil profile during the winter could not be attributed to crop uptake.
Precipitation Nitrogen Contribution Relative to Surface Runoff Discharges
Authors: Schuman G. E. , Burwell R. E. 
Published: July 2010

AbstractAmmonia and nitrate concentrations in precipitation and surface runoff from two adjacent watersheds, fertilized at 168 and 448 kg N/ha, respectively, were studied to determine the relative contribution of precipitation N in relation to surface runoff N discharge. The data show that 69% of the N discharged by surface runoff from the sampled events could be accounted for by precipitation‐originated N on the watershed fertilized at 168 kg N/ha, whereas 53% of the N discharged from the watershed fertilized at 448 kg N/ha could be attributed to N originating in the precipitation. However, the data indicate that, on an annual basis, the surface runoff N discharge accounts for only 20% of that in the total incoming precipitation. This difference can be accounted for by precipitation intensity or duration that did not cause runoff, absorption of NH4‐N by the soil material, or leaching of NO3‐N into the soil profile.
Some Effects of Beef‐Feedlot Effluent Applied to Forage Sorghum Grown on a Colo Silty Clay Loam Soil
Authors: Sukovaty J. E. , Elliott L. F. , Swanson N. P. 
Published: July 2010

AbstractBeef‐feedlot effluent and water additions to a forage sorghum [Sorghum bicolor (L.) Moench] were compared for two consecutive growing seasons. Applications of each at 2.5 and 5.0 cm/week were made in 1971 and 1972 for 11 and 10 weeks, respectively.The 2.5‐cm/week effluent application produced the highest forage yield in both years of the study, with the yield being significantly higher in 1972. In 1972, the lower 30 cm of the forage stalks (butts), receiving 5 cm of effluent/week, showed significantly greater NO3‐N than the other treatments. The application of beef‐feedlot effluent did not affect the concentrations of Ca, Mg, Na, and K in the forage during the 2‐year study.After 2 years of effluent application at 5.0 cm/week, available P in the top 10 cm of soil increased from 52 to 118 ppm; soil pH increased from 6.2 to 6.6. Electrical conductivity changes were not significant. Soil solution samples collected from plots receiving the effluent treatments showed only small increases in Ca, Na, and K, 60 cm below the soil surface. Soil solution NO3‐N was higher beneath the plots receiving 2.5 cm effluent/week than beneath the 5.0‐cm effluent/week treatment.
Foliar‐Applied Nitrogen for Citrus Fertilization
Authors: Embleton T. W. , Jones W. W. 
Published: July 2010

AbstractFifty‐six “experiment‐years” of citrus data are presented which show that kilogram for kilogram, foliar‐applied N was as effective as soil‐applied N for fruit production. However, while one annual soil application sufficed to supply adequate N, three to six or more foliar sprays per year were required. “N‐production efficiency” (kg fruit produced per kg applied N) varied from 97 to 484. At or near the maximum nutritionally‐attainable yield, “fruit‐N‐removal efficiency” (kg N removed in fruit per kg applied N × 100) varied from 11 to 75%. The kg of N per 1,000 kg of fresh California citrus fruit varied from 1.15 to 1.73 and increased with increasing N rates.
Computer Modeling of Nitrogen Transformations in Soils
Authors: Mehran Mohsen , Tanji Kenneth K. 
Published: July 2010

AbstractA nitrogen‐transformation model was formulated for simultaneous computation of various N transformations: nitrification, denitrification, mineralization, immobilization, ion exchange, and plant uptake. These processes were assumed to obey first‐order kinetics. Differential equations that describe the above processes are solved simultaneously by using the 4th‐order Runge‐Kutta method and the Adams‐Bashforth‐Moulton predictor‐corrector equations. The computer model was tested against data reported from several incubation studies. This model could be linked to a transport model to predict the temporal and spatial distribution of various N species in soil profiles.
Nitrate and Chloride Leaching in a Swelling Clay Soil
Authors: Kissel D. E. , Ritchie J. T. , Burnett Earl 
Published: July 2010

AbstractLeaching losses of applied NO3−‐N and Cl− from a swelling clay soil were measured using an undisturbed field drainage lysimeter. Nitrate‐N and Cl−, applied at 110 and 279 kg/ha, respectively, were detected in drainage water collected at a depth of 125 cm after the first large rainstorm. Applied fertilizer was leached when percolating rainwater carried the applied materials through large connected pores, bypassing other soil water inside soil structural units. Even though applied fertilizer began to be lost with the first rainstorm, concentrations of NO3−‐N and Cl− were not high until large amounts of water had drained below the root zone. For example, Cl− concentrations during the first 25 mm of drainage increased by about 7 ppm. The greatest increase in Cl− concentration did not occur until 60 mm of drainage accumulated after fertilizer application.Much more native soil nitrate was leached than soil nitrate concentrations in unfertilized plots would have indicated. The data indicate that leaching losses of nitrate from mineralization may be greater than those of applied nitrate when accumulated drainage is <50 mm following fertilizer application.
Nitrate Removal from Floodwater Overlying Flooded Soils and Sediments
Authors: Engler R. M. , Patrick W. H. 
Published: July 2010

AbstractThe floodwater NO3− removal rate of intermittently‐flooded fresh water swamp soils and continuously‐flooded saline marsh soils of southern Louisiana was quantitatively characterized in a laboratory study. Of the two areas studied, the marsh area was the more effective sink for NO3− contaminated waters with an average initial removal rate of 9.15 ppm N/day. After correcting for the rate of NO3− diffusion, the microbial NO3− removal rate was calculated to be 7.64 ppm N/day. The swamp soil had a removal rate of 4.38 ppm N/day. The microbial NO3− removal rate for this area, after correcting for diffusion, was 2.50 ppm N/day. Studies on samples of floodwater separated from the soil showed the active site of microbial NO3− reduction to be the soil‐water interface or within the soil, but not in the floodwater. Additions of organic matter to a mineral soil flooded for rice (Oryza sativa L.) culture decreased the thickness of the aerobic‐anaerobic zone at the soil‐water interface and increased the rate of NO3− reduction.
Fate of Insecticides in an Irrigated Field: Azinphosmethyl and Tetradifon Cases
Authors: Yaron Bruno , Bielorai Hanoch , Kliger Lilian 
Published: July 2010

AbstractThe fates of an organophosphorus (azinphosmethyl) and an organochlorine insecticide (tetradifon) in an irrigated potato field on a loessial sierozem soil were studied. Two amounts of irrigation water (5538 and 4015 m3/ha) were applied; the kinetics of persistence and the movement downward of the two pesticides were followed during the irrigation season. The azinphosmethyl was not transported deeply into the soil by the irrigation water, and it disappeared from the field 30 days after application. The tetradifon was found in trace amounts in the deeper layer of the soil and was persistent throughout the irrigation season. The pesticides' persistence was not affected by the irrigation treatments; however, tetradifon transport into the soil was affected by the amount of water applied. Residues of tetradifon were found in the potato peel.
A Comparison of the Effectiveness of 15N‐Enriched vs. Unenriched Fertilizer Nitrogen as a Tracer in Laboratory Experiments
Authors: Feigin Amos , Vaughan William M. , Smith Ray , Kohl Daniel H. , Shearer Georgia , Commoner Barry 
Published: July 2010

AbstractThe experiments reported in this paper were designed (i) to determine whether it is possible to detect the presence of fertilizer nitrogen in nitrate produced by four central Illinois soils during laboratory incubation by using variations in the natural abundance of 15N, (ii) to use such variations to estimate the fractional contribution of fertilizer nitrogen to the nitrate produced, and (iii) to compare these estimates with those based on the use of fertilizer nitrogen which was artificially enriched with 15N. The mean δ 15N per mill excess) value of nitrate produced during incubation of the soils which had received unlabeled (NH4)2SO4 was significantly lower in 11 out of 12 experiments compared with that produced by unfertilized soils. As expected, estimates of percent fertilizer derived nitrogen based on variations in natural abundance of 15N were less precise than those based on the use of (NH4)2SO4 artificially enriched with 15N. The use of natural variations in 15N abundance to compute the percent fertilizer derived nitrate resulted in a lower estimate than the estimate based on 15N enriched material in seven experiments. This underestimation appeared to be related to the so called “priming effect” and/or the exchange of fertilizer and soil nitrogen.