bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Implications of N Fixation by Soybeans
Authors: Johnson J. W. , Welch L. F. , Kurtz L. T. 
Published: July 2010

AbstractThe objective was to measure inorganic N removal from soil by soybeans (Glycine max L.) grown at different N levels. Nodulating and non‐nodulating isolines of ‘Clark’ soybeans were planted on Flanagan silt loam in 1972 and 1973. Fertilizer rates of 0, 112, 224, and 448 kg N/ha as Ca(NO3)2 enriched with 1% 15N were applied.Symbiotically fixed N decreased from 48 to 10% of the total N in the above‐ground plant as applied fertilizer N increased from 0 to 448 kg/ha. Net removals of N by soybean grain were 61, 109, 135, and 149 kg/ha at 0, 112, 224, and 448 kg fertilizer N/ha rates, respectively.Corn (Zea mays L.) grain grown on adjacent plots removed 62, 123, 129, and 133 kg N/ha at fertilizer N rates of 0, 112, 224, and 336 kg/ha, respectively.The study indicates that soybeans are good scavengers for inorganic N in soils. Inclusion of net N removal by soybeans in the calculated N removed by nonleguminous crops in Illinois from 1945 to 1973 increases net crop N removal by approximately 37%. Added fertilizer N has exceeded the N removed by the harvested portion of Illinois crops in only 5 years since 1945, all 5 of these occurring after 1965.
Phosphorus in Surface Runoff from a Deciduous Forest
Authors: Singer Michael J. , Rust R. H. 
Published: July 2010

AbstractPhosphorus losses from natural systems are the background levels against which losses from managed systems should be measured. In Minnesota many recreational lakes are surrounded by deciduous and mixed deciduous‐coniferous forests. The P losses from the forests contribute to the natural nutrient levels of the lakes. Phosphorus losses in leaching water are small. Thus, a logical mechanism for the loss of P from forests is surface runoff (overland flow). This research was conducted to study surface runoff amounts and P content.On a 16% slope, 0.09 kg ha−1 year−1 P of which 0.03 kg was bound to sediment and 0.06 kg was soluble was measured in surface runoff. The major period of runoff was during spring snowmelt when the soil was frozen. The source of P is the litter layer which undergoes freezing and thawing in fall and early winter.
A Comparison of Nitrogen, Phosphorus, and Carbon in Sediments and Soils of Cultivated and Noncultivated Watersheds in the North Central States
Authors: Ritchie Jerry C. , Gill Angela C. , McHenry J. Roger 
Published: July 2010

AbstractSoil and sediments from six cultivated watersheds and from six noncultivated watersheds were sampled and the concentration of nitrogen, phosphorus, and carbon was determined. No significant difference was found in the concentration of N, P, or C with depth in the soils or sediments. Concentration of N, P, and C were not significantly different in the soils and sediments of the cultivated watersheds; however, the sediments of the noncultivated watersheds had significantly less N and organic P than the watershed soils. Less accumulation of N, P, and C is occurring in the noncultivated watershed sediments than in the cultivated watershed sediments. These data indicate that sediment source is probably an important factor in determining N, P, and C concentration in reservoir sediments.
Distribution and Characterization of Plutonium in Soils from Nevada Test Site
Authors: Tamura Tsuneo 
Published: July 2010

AbstractThree surface soil samples, contaminated with plutonium by high explosive detonations of subcritical atomic devices at the Nevada Test Site (NTS), were analyzed for total plutonium content, plutonium distribution in different particle sizes, and leachability by HNO3. Total plutonium averaged about 2,640 disintegrations per minute (dpm) per gram of soil. The highest concentration of plutonium in two samples taken from the same area was in the very fine sand (125‐53 µm) fraction (38 and 47%); the third sample from another test area contained the highest concentration in the coarse silt (53‐20 µm) fraction (47%).Leaching with 8M HNO3 revealed that the extracted plutonium was related to the amount of plutonium associated with the finer sizes of soil particles. The highest extraction of 91% was associated with the sample containing 99% of the plutonium in particles < 125 µm; the lowest extraction (65%) with the lowest amount (55%) in the same size fractions. Density gradient separation of a silt and a clay fraction revealed that the plutonium in the silt size was associated with particles whose density was > 2.8 g/cm3; in the clay size the plutonium was associated with particles < 2.2 g/cm3.
Uptake of Iron and Copper by Sorghum from Mine Tailings
Authors: Fuller Wallace H. , Lanspa Kenneth 
Published: July 2010

AbstractTailings from a lead‐zinc‐copper mine, representative of mine wastes in the Southwest, were reacted with sulfuric acid and ammonia to develop a product which has agricultural value for supplying trace elements, primarily iron. Iron‐sulfur compounds (pyrites) are the dominant trace metal containing minerals. When reacted at 200C for 2 hours with concentrated H2SO4, the water‐soluble Fe content of the tailings increases manyfold. The greater the amount of acid used, the greater was the soluble Fe. Water‐soluble Cu also increased but to a very limited amount relative to Fe. Acid‐treated tailings stimulated plant growth and Fe uptake by two varieties of sorghum (Sorghum bicolor L.), ‘Kafir’ and ‘Plainsman’, when these materials were supplied to an agriculturally important calcareous soil of the desert Southwest. The evidence developed points to a practical possibility of combining two waste products from the mining industry, stack‐gas oxides of S (as H2SO4) and mine‐tailing wastes, into usable agricultural products. The research further revealed significant growth responses to elemental S applied to soil which could not be duplicated with SO4 ions. Growth response did not appear to be related to N, P, K, or Mn, Cu, or S deficiency of the soil. However, response was correlated with Fe and some factor(s) associated with acidification during oxidation of elemental S.
Potentially Beneficial Uses of Sulfuric Acid In Southwestern Agriculture
Authors: Miyamoto S. , Ryan J. , Stroehlein J. L. 
Published: July 2010

AbstractProduction of sulfuric acid is projected to exceed market demand in the southwestern USA if current air pollution control regulations are fully implemented by means of acid plants. Considerable quantities of surplus acid can be used beneficially for reclaiming sodium‐affected calcareous soils, increasing the availability of phosphorus and certain micronutrients, treating alkaline and ammoniated irrigation water, controlling certain weeds and soil‐borne pathogens, improving range grass establishment and growth, and for several other purposes. Principles involved in these uses are reasonably well‐established, but studies are required to determine effective use especially in the area of field application.
Effect of Cattle Feedyard Runoff on Soil Infiltration Rates
Authors: Lehman Oliver R. , Clark R. Nolan 
Published: July 2010

AbstractA compact clay soil from a playa lake and a relatively porous, blocky, buried soil, both representative of feedyard runoff holding basins in the Texas High Plains, were treated with clear ground water and synthesized feedyard runoff. Infiltration rates were measured by using constant heads of liquid on undisturbed laboratory cores and in field basins.Infiltration rates of clear water in both the cores and the basins stabilized at approximately 0.1 cm/hour for the clay and 5.0 cm/hour for the buried soil for test runs up to 60 days. Addition of feedyard runoff markedly lowered infiltration rates in both soils within a few hours, and the rates were <0.006 cm/hour after 2 to 3 weeks. However, initial infiltration rates were restored to the buried soil basin treated with runoff by removing the surface 2 cm of soil and applying clear water. The results from this study, and numerous others, strongly suggest that relatively concentrated feedyard runoff will effectively seal many soils. The study also indicates that the primary sealing effects occur within a few centimeters of the surface.
A Simulation Model of Biophysiochemical Transformations of Nitrogen in Tile‐Drained Corn Belt Soil
Authors: Duffy J. , Chung C. , Boast C. , Franklin M. 
Published: July 2010

AbstractA computer simulation model of nitrogen transformations and transport in soil in a Corn Belt field was developed to predict nitrate concentrations in tile effluent as a function of farm management practices and climatic conditions. Water flow in the unsaturated and saturated zones, evapotranspiration, and nitrogen flow due to mass flow, dispersion, and diffusion are simulated along with nitrogen transformations of mineralization, immobilization, nitrification, and denitrification. Growth of corn (Zea mays L.) and soybeans (Glycine max L.) is included. Predicted values of tile water flow, water table height, nitrate‐nitrogen concentrations in the soil water profile and in the tile effluent compared favorably to measured values for a field for 1972; also, predictions of nitrate‐nitrogen concentrations in tile effluent for 1970–71 agree well with actual data.
Natural 15N Abundance in Soil, Leaves, and Grain as Influenced by Long Term Additions of Fertilizer N at Several Rates
Authors: Meints V. W. , Boone L. V. , Kurtz L. T. 
Published: July 2010

AbstractSoil, leaf, and grain natural 15N abundance was measured in corn (Zea mays L.) and soybean (Glycine max L.) plots which had received various rates of fertilizer N for 20 years. Soil 15N abundance did not significantly reflect the amount of fertilizer N applied and should not be used to estimate fertilizer N additions. Corn leaf and grain 15N abundance reflected additions of fertilizer N only at low rates of fertilizer N applied. Soybean leaf 15N abundance reflected a decrease in symbiotic N fixation with additional increments of fertilizer N applied.
Leaching Losses of Ammonium and Nitrate in the Reclamation of Sand Spoils in Cornwall
Authors: Dancer W. S. 
Published: July 2010

AbstractReclamation studies on sand spoils in Cornwall have shown a difficulty in maintaining adequate levels of nitrogen for plant growth. Information is presented to show that the movement of NO3− and NH4+ is highly correlated with rainfall (r = 0.89 and 0.92, respectively). Nitrate leaching (4.1 cm/cm rain) is more serious than NH4+ leaching (2.5 cm/cm rain), and calculations show that more than 98% of the NO3− fertilizer applied to bare sand spoil will be leached beyond the surface 20 cm with an average month of summer rainfall (9.7 cm). Maximum inorganic‐N fertilizer recoveries of 40 kg/ha are predicted for grass swards established on spoils flattened by earth‐moving equipment, while recoveries < 20 kg N/ha are likely on steeply sloping sand heaps. Grass test crops recovered 26 and 35% of the fertilizer‐N on a level site when NaNO3 and (NH4)2SO4 were applied at 125 kg N/ha.
Wild Oat as an Indicator of Atmospheric Inputs of Lead to a Rangeland Ecosystem
Authors: Rains D. W. 
Published: July 2010

AbstractWild oat (Avena fatua L.) proved to be a sensitive indicator of atmospheric inputs of lead (Pb). The dried plant material accumulated Pb from the atmosphere with little or no inputs from Pb contaminated soils. Pb was shown to be relatively immobile within the plants even when the plants were grown in culture solutions in which the Pb was rendered more available with chelates. The contaminated, above ground plant tissue was also shown to retain Pb deposited on the tissue from the atmosphere. Leaching with water was ineffective in removing Pb from the tissue, but dilute acid was fairly effective and EDTA completely leached the tissue of Pb. These results are discussed in relation to the usefulness of the species as an indicator of atmospheric Pb.
A Model for Runoff of Pesticides from Small Upland Watersheds
Authors: Bruce R. R. , Harper L. A. , Leonard R. A. , Snyder W. M. , Thomas A. W. 
Published: July 2010

AbstractA mathematical model has been developed describing the rate and quantity of runoff water from separate rainfall events on a watershed and the rate and quantity of sediment and pesticides transported. The runoff water is calculated by convolving an area‐characteristic and variable state function to produce a variable response function which is then convolved with a computed effective rain. Rill and interrill erosion are conceptually distinguished which allows similar partitioning of associated pesticides. The sediment contribution from interrill erosion is a function of rainfall intensity and soil susceptibility to erosion. The rill erosion is a function of water runoff and the rate of change of water runoff. The concentrations of pesticides in the runoff are functions of the amount of runoff, the sediment concentrations derived from rill and interrill erosion, and the pesticide concentrations in the respective runoff‐erosion zones.Experience with the model in simulating the water, sediment, and pesticide runoff from an upland Piedmont plain watershed for four summer storms is related. Excellent simulations were obtained.
Nitrogen and Phosphorus Levels in Soils beneath Sewage Disposal Ponds
Authors: Lund L. J. , Page A. L. , Nelson C. O. 
Published: July 2010

AbstractSoil cores at various depths beneath sewage sludge and effluent ponds at two treatment plant locations were collected and the nature and extent of nitrogen and phosphorus movement in the soil was evaluated. The soil profiles at both treatment plants were open and coarse‐textured. Soils beneath sludge ponds were enriched in total nitrogen to 4 and 8 m, the maximum depths sampled. Compared to controls, effluent ponds used more than 10 to 20 years showed enrichment of total nitrogen to depths as great as 4.0 m. Concentrations of NH4‐N considerably in excess of controls were observed to depths of 4.0 m demonstrating movement of substantial amounts of NH4 in soil below sewage waste water ponds.Concentrations of NO3‐N in the soil solutions beneath disposal sites considerably in excess of those found below control sites were observed in situations where samples were collected to the water table (8.5 m and 12.0 m), demonstrating movement of NO3‐N the water table. Phosphorus enrichment of soil (NaHCO3 extractable) was evident to depths as great as 3 m below the ponds.
Phosphorus Distribution from Septic Tank Effluent in Coastal Plain Soils
Authors: Reneau R. B. , Pettry D. E. 
Published: July 2010

AbstractPhosphorus (P) accumulations in two soils with high perched water tables were monitored as a function of distance and depth to determine the fate of P from septic effluent in natural soil systems. The soils studied were Varina and Goldsboro sandy loams. Piezometers were placed at selected distances and depths from the drainfield in the direction of ground‐water flow to determine both vertical and lateral P movement. Soil P was fractionated to determine the type and extent of soil‐P fractions adjacent to the drainfield. Orthophosphate (PO4−3‐P) concentrations in the perched ground waters decreased with distance from the septic tank drainfield in both the Varina and Goldsboro soils. PO4−3‐P concentrations at the Varina soil location decreased from an average of 5.5 µg/ml in the undiluted effluent to 0.32 µg/ml in the soil solution at 3.0 m distance. No PO4−3‐P was detected in waters percolating through a very slowly permeable underlying plinthic horizon. PO4−3‐P concentrations in the Goldsboro soil solutions decreased from an average of 11.8 µg/ml in the drainline to <0.20 µg/ml at 3.0 m distance. In the Goldsboro soil P was concentrated in the 142 to 152 cm depth. Soil P fractions in the drainfield areas were present predominantly as NH4F and NaOH extractable P with some organic‐P present adjacent to the drainfield. At the Varina location, P accumulated in the argillic horizons. The NH4F and NaOH extractable P fractions increased from 2–4 and 40–50 µ/g in the control profile to a maximum of 460 and 425 µg/g in the argillic horizons at 0.15 m, respectively. At the Goldsboro location, septic effluent had not appreciably altered the quantities of “fixed” P or the distribution of soil P fractions.
Disposition of Fertilizer Nitrate Applied to a Swelling Clay Soil in the Field
Authors: Kissel D. E. , Smith S. J. , Dillow D. W. 
Published: July 2010

AbstractThis study was prompted by the present controversy over the role that N‐fertilizer use may have in reducing water quality. Our objective was to determine the disposition of N fertilizer (enriched with 15N) applied to level (< 2% slope) Houston Black clay near the economic optimum application rate (112 kg N/ha) for grain sorghum (Sorghum bicolor [L.] Moench). Particular emphasis was placed on determining the amount of applied N which leached below the root zone at different times during and after the growing season. A large, undisturbed, field‐drainage lysimeter was used to measure leaching of NO3−‐N below the root zone.During spring 1973 94 mm of drainage water containing a mean concentration of 2.4 ppm fertilizer‐derived NO3−‐N percolated through the soil profile. At crop maturity, only 55% of the N applied the previous spring was recovered by the crop or was present in drainage water. Large amounts of N not recovered by the crop were either measured as immobilized N (20% of the applied N) or were unrecovered and assumed denitrified (17%). During fall and winter approximately 120 mm of drainage water containing 0.5 ppm or less fertilizer‐derived NO3−‐N percolated through the soil profile. These results indicate that for rainfall conditions observed in this study (minimal crop water deficit), the application N fertilizer to grain sorghum at the near‐optimum economic rate probably will not seriously reduce ground‐water quality on a swelling clay soil, even though crop recovery of applied N may be low.
Nitrogen in Soil Cores and Ground Water under Abandoned Cattle Feedlots
Authors: Mielke L. N. , Ellis J. R. 
Published: July 2010

AbstractSoil core samples from four abandoned beef cattle feedlots were analyzed to determine their chemical and physical characteristics. These cores were compared with those from active upland, intermittently used feedlots, and croplands. The nitrate‐nitrogen (NO3‐N) in the abandoned feedlots averaged 7,200 kg/ha in a 9.1‐m soil core, while the active upland, intermittently used feedlot, and cropland averaged 1,800, 2,100, and 570 kg/ha NO3‐N, respectively. The abandoned feedlot core with the highest NO3‐N had 18,200 kg/ha in a 9.1‐m core. Nitrate‐N levels in an abandoned feedlot after 15 years of corn‐alfalfa rotation were comparable with cropland cores. Ground‐water samples obtained from three of the four abandoned feedlots contained 77.2, 43.7, and 0.6 ppm NO3‐N.
Nitrate Leakage from Soils Differing in Texture and Nitrogen Load
Authors: Avnimelech Y. , Raveh J. 
Published: July 2010

AbstractNitrogen and chloride distribution in soil profiles underlying plots differing in the nitrogen load and soil type were studied in the coastal plain of Israel. Nitrate leakage was defined as the product of the average nitrate concentration in subsoil solution times the annual water recharge. A large portion of the excessive nitrogen (nitrogen load minus nitrogen uptake by the removal crop) was not recovered. This portion is high for clay soils and for plots receiving high nitrogen dressings. Changes in the NO3/Cl ratio along the soil profile coincided with nitrate removal. This data supports the hypothesis that nitrate removal is mainly due to denitrification in the top layer of the soil.
Movement of Carbaryl through Congaree Soil into Ground Water
Authors: LaFleur Kermit S. 
Published: July 2010

AbstractCarbaryl (25.4 kg/ha) was applied to a Congaree sandy loam fieldplot containing a shallow (about −1.1 m) water table. Movement and loss in the soil profile, and accumulation in underlying ground water were monitored for 16 months. Rainfall during this time was 182 cm (3.5 pore volumes based on the upper 1 m of soil). The upper 1 m contained about 6% of the applied carbaryl after 16 months. No carbaryl was found in the 0–20 cm layer after the 4th month. Loss of carbaryl with time in the upper 1 m was concentration‐dependent. Time to half‐concentration within the upper 1 m was < 1 month.Carbaryl appeared in the underlying ground water within 2 months after soil application and persisted through the 8th month. Maximum ground‐water concentration, about 0.3 µmol/liter, occurred at the end of the second month.
Heavy Metals Application and Plant Uptake in a Land Disposal System for Waste Water
Authors: Sidle R. C. , Hook J. E. , Kardos L. T. 
Published: July 2010

AbstractMunicipal sewage effluent with sludge injected and effluent alone were spray‐irrigated on reed canarygrass (Phalaris arundinacea L.) and corn (Zea mays L.), respectively. In the maximum level (10 cm/week) reed canarygrass treatment, application rates for Cu, Zn, Cd, and Pb were 15.5, 25.5, 0.162, and 9.1 kg/ha in 1972 and 7.7, 13.2, 0.135, and 7.8 kg/ha in 1973. Rates of application for Cu, Zn, Cd, and Pb in the maximum level (7.5 cm/week) cornfield treatment were 0.6, 2.0, 0.029, and 1.1 kg/ha in 1972 and 0.6, 2.4, 0.032, and 2.4 kg/ha in 1973. Reed canarygrass was irrigated year‐round, while corn was irrigated only during the growing season. Copper and Zn concentrations and total uptake in the treated reed canarygrass area were generally higher than in the control for all cuttings of 1972 and 1973. Total uptake of heavy metals in the corn area control was usually as high or higher than in the treated areas. Copper and Zn concentrations and uptake in the effluent irrigated corn area were lower than in the treated reed canarygrass area. Data show a relative exclusion of Cd by Zn in the plant material, since Cd/Zn ratios in the harvested crops are lower than in either the applied waste water or the 0.1N HCl extractable fraction of the treated soils. Accumulation of applied heavy metals in the treated soils was > 93% of the amounts applied in 1972 and 1973 for all heavy metals in the reed canarygrass area and slightly less in the corn area.
Nitrogen and Sulfur Content and pH of Precipitation in Iowa
Authors: Tabatabai M. A. , Laflen J. M. 
Published: July 2010

AbstractAmmonium‐N, nitrate‐N, sulfate‐S, and phosphate‐P concentrations, along with pH of precipitation samples, were measured at six sites in Iowa from Sept. 1971 through Dec. 1973. The amounts of nutrient constituents added by precipitation were determined. The annual amounts of NH4‐N and NO3‐N added by precipitation at each site were about equal. The annual amounts of inorganic N added per hectare ranged from 10 kg in north‐central to 14 kg in west‐central Iowa, and the annual amounts of SO4‐S added per hectare ranged from 13 kg in northeastern to 17 kg in north‐central Iowa. It was estimated that, on an average basis, precipitation adds about 0.6 kg of NH4‐N, 0.6 kg of NO3‐N, and 1.5 kg of SO4‐S per hectare monthly in Iowa. However, seasonal variations were observed for SO4‐S, higher during fall and winter than during spring and summer.Average annual pH value of the rainfall and snowfall samples collected at each site during each year was about 6; individual samples were seldom as low as pH 4. The data indicated that the P content of precipitation is very small; at the most about 0.1 kg of water‐soluble PO4‐P was added per hectare annually, Nitrite‐N was not detected in any of the precipitation samples analyzed.