bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen and Sulfur Content and pH of Precipitation in Iowa
Authors: Tabatabai M. A. , Laflen J. M.
Published: July 2010

Ammonium‐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.
Treatment of Potato Processing Waste Water on Agricultural Land
Authors: Smith J. H.
Published: July 2010

The chemical oxygen demand (COD) and the total N and NO3−‐N concentrations in potato (Solanum tuberosum L.) processing plant waste water and in the soil solution at several depths in a treatment field where the waste water was applied were studied for a 2‐year period. The COD decreased 95 to 99% from 850 to 2,000 ppm in waste water to 4 to 40 ppm after passing through 150 cm of soil. A similar decrease in the total N concentration was found. The NO3−‐N concentration in the waste water ranged from 0.1 to 9.0 ppm and the concentration in the soil solution at the 150‐cm depth was generally < 1.0 ppm. During the second year 1,076 kg N/ha were applied in the waste water. The grass crop removed about 320 kg N/ha (about 30% of that applied). Results indicated that only about 10 kg N/ha passed into the water table each year. Land disposal is a practical method for disposing of potato processing waste waters with a low pollution potential.
Residual Effect of Liquid Sewage Sludge on Coastal Bermudagrass and Soil Chemical Properties
Authors: Touchton J. T. , King Larry D. , Bell Henry , Morris H. D.
Published: July 2010

The purpose of this study was to investigate the residual effect of liquid sewage sludge on soil and sludge crust properties and on yield and elemental composition of Coastal Bermudagrass (Cynodon dactylon L. Pers.) grown on a Cecil sandy clay loam (Typic Hapludult). Several applications of sewage sludge were made in 1969 and 1970 at total rates of 6.9, 13.8, 20.0, and 40.0 cm. A chemical fertilizer (NPK) treatment consisting of a total of 1,198 301, and 695 kg/ha of N, P, and K, respectively, from 1969 to 1973, and a control treatment were also included. In 1970 plots were split and 6.7 metric tons/ha of dolomitic limestone were broadcast on one subplot from each main plot. In 1973 an additional 4.5 metric tons/ha of dolomitic limestone were broadcast on the limed subplots which had received the two highest sludge rates.

Yields for 1971 and 1973 showed no detrimental effect from sludge application. In 1973 treatments had no significant effect on concentrations of P, Mg, Cu, Fe, Cd, Cr, or Pb in forage except for the NPK treatment. The K concentration of forage was below the deficiency level (1.5%) except for forage receiving the NPK treatment. The Ca concentration in forage from sludge and NPK plots was significantly higher than the concentration in forage from control plots. Plant concentration of Mn was reduced and Zn concentration was increased by sludge treatment. Lime decreased the Zn concentration in forage from plots receiving high sludge rates.

The depth of the sludge crust remaining on the soil surface increased with sludge rate up to 3.8 cm for the highest rate. Lime applications decreased concentrations of P, Fe, Zn, Cu, Pb, Cr, and Cd in the crust, but only Zn in the soil beneath the crust.
Nitrogen Effects on Mobility and Plant Uptake of Heavy Metals in Sewage Sludge Applied to Soil Columns
Authors: Giordano P. M. , Mortvedt J. J.
Published: July 2010

Cation movement in soil under leaching conditions has been associated with N fertilization. Therefore, this study was conducted to determine whether the mobility of some heavy metals applied in the inorganic form or in sewage sludge is enhanced in the presence of various sources of N. Columns of heavy metal‐amended soil in plastic well casings were cropped with tall fescue (Festuca arundinacea Schreb.) and leached three times with deionized H2O. Heavy metal concentrations above check values were not detected in leachates from any column. Mobility of the heavy metals from the inorganic sources was slightly greater than that from the sewage sludge. Nitrogen fertilization did not affect the downward movement of Zn, Cd, Cr, Pb, or Ni in soil but enhanced uptake of these metals by fescue because of increased growth. These results suggest that heavy metal contamination of ground water is not likely in heavy textured soils when sewage sludge applications are accompanied by N fertilization, at least for short periods of time.
Simplified Long Term Concept for Evaluating Leaching of Nitrogen from Agricultural Land
Authors: Fried Maurice , Tanji Kenneth K. , Van De Pol Ronald M.
Published: July 2010

A rather simple concept is proposed for predicting the contribution of crop production practices to ground‐water N pollution. It is a steady state long term concept. One of the consequences is that the myriad reactions that take place in the soil body itself need not be evaluated. Application of this concept indicates that, in general, the single most important practice under man's control that affects potential pollution is fertilizer use efficiency. As long as yield response is obtained to N fertilizer additions, fertilizer should contribute lesser amounts of N to the ground water providing fertilizer use efficiency is maintained at a high level.
The Fate of Disulfoton in Portneuf Silt Loam Soil
Authors: Clapp D. W. , Naylor D. V. , Lewis G. C.
Published: July 2010

The formation of metabolites of disulfoton (O,O‐diethyl S‐[2‐(ethylthio) ethyl] phosphorodithioate) was followed in a Portneuf silt loam soil. The insecticide oxidized to its sulfoxide and sulfone but none of its oxygen analogs were detected. The disulfoton and disolfoton sulfoxide degraded in 32 days or less while the disulfoton sulfone persisted for more than 64 days.

The influences of soil moisture content, temperature, and disulfoton concentration were found to be interrelated in their effects on the rate of disulfoton dissipation and sulfone formation. In general, the most rapid degradation of disulfoton on a percentage basis occurred at lower initial concentrations of disulfoton, irrespective of the moisture content of the soil and the temperature, and the slowest degradation occurred at higher initial levels of disulfoton in association with higher moisture levels and high or low temperatures. The conditions for the greatest percent conversion of disulfoton to its sulfone generally coincided with the conditions of the most rapid dissipation of the disulfoton.
Chemical and Microbiological Degradation of Malathion and Parathion in an Estuarine Environment
Authors: Walker W. W.
Published: July 2010

Malathion was essentially completely degraded during 18 days incubation in sterile and nonsterile water, while respective parathion losses ranged from 16 to 23% after 40 days. Malathion abatement was in direct proportion to increasing salinity, while parathion was quite persistent, even in high salinity (25 parts per thousand [ppt]) water.

Microorganisms capable of degrading malathion and parathion were isolated from insecticide‐enriched sediment. Four bacteria isolated from malathion‐enriched sediment readily degraded malathion, one to malathion half‐ester and another to malathion dicarboxylic acid through the half‐ester intermediate, and three bacteria isolated from parathion‐enriched sediment were efficient in parathion metabolism. One bacterium isolated from parathion‐enriched sediment was capable of degrading malathion to the diacid through the half‐ester intermediate.
Influence of Vanadium on Soil Phosphatase Activity
Authors: Tyler Germund
Published: July 2010

Acid phosphatase activity of an organic soil (spruce needle mor) from southern Sweden was significantly reduced by vanadium in concentrations occurring in urban and suburban areas and due largely to fuel oil combustion. The inhibiting power of different forms of added vanadium (100 mg/kg dry weight) decreased in the order Na3VO4 > NaVO3, VOSO4 > V2O5. Na2SO4 and NaCl did not influence the activity. Above 100 mg/kg dry weight, phosphatase activity was inversely proportional to the logarithm of the added NaVO3 concentration.
Effect of Dissolved Oxygen on Redox Potential and Nitrate Removal in Flooded Swamp and Marsh Soils
Authors: Engler R. M. , Antie D. A. , Patrick W. H.
Published: July 2010

The O2 depletion rates, NO3− loss, and the effects of added O2 on NO3− disappearance and redox potential in four flooded or intermittently flooded soils from the swamp and coastal marshes of Louisiana were quantitatively characterized in a laboratory study. The NO3− added either to the shallow floodwater or mixed with the soil in a suspension rapidly disappeared. Eighty to ninety parts per million NO3− was lost from the soil suspensions in 1 to 4 days and from the floodwater over a soil in 10 to 20 days. No NO3− was lost from floodwater separated from the soils. Oxygen depletion in the soil suspensions occurred in 15 minutes to 4 hours. Redox potential curves exhibited a characteristic inflection after O2 disappearance in all soils studied. Nitrate disappearance did not appear to be inhibited by as much as 16 ppm O2 dissolved in the soil suspensions because the O2 was rapidly consumed.
Effects of Sewage Sludge Composition, Application Rate, and Lime Regime on Plant Availability of Heavy Metals
Authors: John Matt K. , Van Laerhoven Cornelis J.
Published: July 2010

Primary digested sludge from the metropolitan Vancouver sewage treatment plant and commercially available Milorganite were applied to unlimed (pH 5.6) and limed (pH 6.4) silt loam at 0, 5, 10, 25, and 100 g/kg in a growth chamber study involving romaine lettuce (Lactuca sativa L. var. longifolia) and beets (Beta vulgaris L.). Concentrations of Cd, Zn, Pb, Cu, Ni, Mn, and Fe in lettuce, beet tops, and beet tubers were not simply or solely dependent upon the resultant sludge‐borne heavy metal contamination of the soil but a complexity of factors. Plant availability of the metals was influenced by the nature as well as the rate of sludge applied, lime regime, their interaction, the increase in soil acidity associated with Milorganite application and metal adsorption, and release from organic matter supplied.
Performance Evaluation of an Evaporative Pad Greenhouse System for Utilization of Power Plant Reject Heat
Authors: Olszewski M. , Trezek G. J.
Published: July 2010

The overall performance of an evaporative pad greenhouse is considered in terms of the pad heat and mass transfer, the energy budget of the vegetation, and the performance of the power plant. An analytical predictive model for the pad performance was developed utilizing the Merkel total heat approximation. Data obtained from actual greenhouse performance provides an experimental verification of the pad model. Energy balance considerations on the vegetation provide a means of viewing optimal plant growth in terms of the power plant energy dissipation. In general, the results indicate that when an evaporative pad greenhouse system is used for waste heat dispersal, the vegetation can be maintained within its thermal requirement zone, crop irrigation requirements are significantly reduced, and the power plant performance is comparable with conventional closed loop heat rejection systems.
Irrigation of Corn with Simulated Municipal Sewage Effluent
Authors: Karlen D. L. , Vitosh M. L. , Kunze R. J.
Published: July 2010

A field study was conducted to evaluate the effects of applying 25, 50, 100, and 200 cm of simulated municipal sewage effluent to corn (Zea mays L.) grown on a tile‐drained loam soil. A soil water balance was determined by measuring rainfall, irrigation, evapotranspiration, and tile flow. Deep percolation losses were estimated by difference. The effects of these annual loading rates were determined by measuring corn silage and grain yields. Silage yields were maximized at the 50‐cm loading rate, however, the grain yields were maximized at the 200‐ and 100‐cm rates in 1973 and 1974, respectively. The fate of applied nutrients was determined by measuring losses through drainage water, uptake by the corn, and changes within the soil profile. Nitrogen losses in the drainage water ranged from 0.1 to 18 kg ha−1 year−1 with maximum weekly losses of 3 kg/ha at the 100‐ and 200‐cm loading rates. The P concentration in drainage water was higher than expected due to an apparent short circuiting of the effluent through sand smears; however, the maximum loss was only 0.6 kg ha−1 year−1. Potassium losses ranged from 0.2 to 8.5 kg ha−1 year−1. Nitrogen recovery through plant uptake at the 25‐, 50‐, and 100‐cm loading rates exceeded 40% of the N applied through effluent and starter fertilizer when the corn was harvested as silage. Nitrogen uptake in the grain at these loading rates exceeded 50% in 1973, but was much lower in 1974. When the entire plant was harvested, P uptake at the 25‐ and 50‐cm loading rates exceeded the P applied; however, at the 100‐ and 200‐cm rates or when only the grain was harvested, P uptake was less indicating a gradual buildup in the soil. The K uptake exceeded 90% when the corn was harvested as silage, but was < 40% if only the grain was removed. The distribution of NO3 and Cl and the Cl/NO3 ratios suggested that much of the unrecovered N was denitrified. Measurements of exchangeable K and Na indicated that if effluents which are low in K and high in Na are to be renovated through land disposal supplemental K must be applied.
Accumulation of Nutrients in Soil Beneath Hog Manure Lagoons
Authors: Miller M. H. , Robinson J. B. , Gallagher D. W.
Published: July 2010

The soil beneath four hog manure lagoons was sampled and analyzed for NO3‐N, NH4‐N and soluble P. Nitrate levels were essentially zero in all samples taken shortly after the lagoons were emptied. Soluble P levels were high immediately below the lagoon but decreased to background levels within 20–30 cm. Ammonium levels were very high immediately below the lagoon. The levels decreased to background levels within 20–30 cm on two lagoons on fine‐textured soils that had been in use for 2 years. In a medium‐textured soil and a coarse‐textured soil beneath older lagoons, very high levels existed to the maximum depth sampled. It is suggested that this accumulation of NH4‐N presents a serious hazard should the lagoon be abandoned and the soil become aerobic. Earthen manure lagoons should not be recommended on medium or coarse‐textured soils.
Losses of Nitrogen in Surface Runoff in the Blackland Prairie of Texas
Authors: Kissel D. E. , Richardson C. W. , Burnett Earl
Published: July 2010

Our objective in this study was to determine NO3−‐N and total N losses in surface runoff from Houston Black clay, a swelling clay soil with a relatively low infiltration rate. The study was carried out on duplicate 4‐ha watersheds cropped to a rotation of grain sorghum (Sorghum bicolor [L.]), cotton (Gossypium hirsutum [L.]), and oats (Avena sativa [L.]), all fertilized at recommended rates of N application. The loss of NO3−‐N varied considerably during the study, depending on events before each runoff‐producing storm. Concentrations of NO3−‐N were usually highest just after fertilizer application when the soil was near field capacity and lowest when large amounts of water infiltrated into dry soil immediately before runoff. During runoff‐producing storms just after fertilizer application, the concentrations were lowest in the initial runoff and highest near the end of the runoff event. To compute NO3−‐N losses with reasonable accuracy on these soils, the shape of the entire NO3−‐N concentration curve needed to be well defined.

In general, the results of this study indicate that a small and probably insignificant amount of N is lost to surface waters when crops are fertilized at recommended N rates in the Texas Blackland Prairie. For the entire 5‐year study, the mean concentration of NO3−‐N in runoff was 2.9 and 2.3 ppm NO3−‐N for the duplicate watersheds. The mean total loss of NO3−‐N was 3.2 kg ha−1 year−1. Losses of sediment associated N were about 5 kg N ha−1 year−1.
The Availability of Environmental Radioactivity to Honey Bee Colonies at Los Alamos
Authors: Hakonson T. E. , Bostick K. V.
Published: July 2010

Data are presented on the availability of tritium, cesium‐137, and plutonium to honey bee colonies foraging in the environment surrounding the Los Alamos Scientific Laboratory. Sources of these radionuclides in the laboratory environs include liquid and atmospheric effluents and buried solid waste.

Honey bee colonies were placed in three canyon liquid waste disposal areas and were sampled frequently, along with honey, surface water, and surrounding vegetation, to qualitatively determine the availability of these radionuclides to bees (Apis mellifera) and to identify potential food chain sources of the elements.

Tritium concentrations in bee and honey samples from the canyons increased rapidly from initial values of < 1 pCi/ml moisture to as much as 9.2 nCi/ml in 75 days after placement of the hives in the canyons. Seasonal patterns in foraging activities as influenced by weather and food availability were apparent in the data. It appears that several sources of tritium were utilized by the colonies, including surface water in the canyons and vegetation receiving tritium from atmospheric effluents and buried solid waste.

Concentrations of cesium‐137 and plutonium were generally low or undetectable in bees throughout the study. However, levels of both nuclides increased by factors of 10–20 in bees from two of the canyon study areas during a 3‐month period in 1973. It was speculated that the liquid effluents in the two canyons were the source of the increased concentrations in bee samples, since this water was the only significant source of 137Cs in the environs.

The existence of at least three radionuclide sources in the Los Alamos Scientific Laboratory (LASL) environs complicates the interpretation of the data. However, it is apparent that honey bees can acquire 3H, 137Cs, and Pu from multiple sources in the environs.
Residues of Dichlobenil in Irrigation Water
Authors: Bowmer K. H. , O'Loughlin E. M. , Shaw K. , Sainty G. R.
Published: July 2010

Field trials were made on two unlined irrigation channels to measure the extent of water contamination due to residues of dichlobenil (2,6‐dichlorobenzonitrile) which had been applied to the empty channel the previous winter. Ten weeks after application, the herbicide remaining in the soil was about 6% of the initial application. About 4 months after application, water was passed through the channels and wasted into drains. The maximum herbicide concentration in this flushing water was 0.18 ppm and was judged to present no potential hazard to crops. The need for prolonged channel flushing is questioned. An alternative procedure, displacing the static water in the channel following by a period of ponding, is suggested as a means of avoiding high herbicide residues in irrigation water.
Nitrogen in Subsurface Discharge from Agricultural Watersheds
Authors: Burwell R. E. , Schuman G. E. , Saxton K. E. , Heinemann H. G.
Published: July 2010

The nitrogen in subsurface discharge and surface runoff was measured from four agricultural watersheds on Missouri Valley deep loess near Treynor, Iowa, from April 1969 through March 1974.

The data showed that, with the agricultural management practices used on the watersheds, the subsurface discharge of water ranged from 62 to 88% of the average annual stream flow. Nitrate in subsurface discharge accounted for 84 to 95% of the total average annual soluble N discharged in stream flow.

A terraced watershed continuously cropped to corn (Zea mays L.) had reduced surface runoff, sheet‐rill erosion, and associated nitrate‐nitrogen discharges, but had increased subsurface discharge of water and soluble N as compared with two contoured corn watersheds. Nitrogen fertilizer applied at a high rate (448 kg ha−1 year−1) exceeding crop needs on the terraced and contoured corn watersheds, increased five‐ and threefold the average annual subsurface discharge of NO3‐N, respectively, as compared with a contoured watershed fertilized with N at a normal rate (168 kg ha−1 year−1).

To control the watershed discharge of N and subsequent pollution of stream flow from the Iowa and Missouri deep loess hills requires N fertilizer application rates that do not exceed crop needs and using conservation practices that minimize soil erosion and deep percolation.
Interactions between Insects and Chemical Components of Sweetclover
Authors: Manglitz G. R. , Gorz H. J. , Haskins F. A. , Akeson W. R. , Beland G. L.
Published: July 2010

This review concerns the relationship between chemical components found in sweetclover [Melilotus officinalis (L.) Pall. and M. alba Desr.] tissues and insects feeding on these tissues. Coumarin and its related compounds did not appear to influence the feeding of sweetclover aphids [Therioaphis riehmi (Börner)], pea aphids [Acyrthosiphum pisum (Harris)] or potato leafhoppers [Empoasca fabae (Harris)], however, these materials appeared attractive to sweetclover weevils (Sitona cylindricollis Fåhraeus) and to adult sweetclover root borers [Walshia miscecolorella (Chambers)]. Conversely the feeding of four species of blister beetles (Epicauta sp.) was inhibited by cis‐o‐hydroxycinnamic acid glucoside and coumarin, but was not affected by trans‐o‐hydroxycinnamic acid glucoside. An artificial method of feeding sweetclover weevils was used to bioassay substances extracted from sweetclover. Three classes of feeding stimulants were found: (i) three sugars (sucrose, glucose, and fructose); (ii) a chloroform‐soluble stimulant(s) (possibly a lipid); and (iii) adenosine. Two feeding deterrents were found. Deterrent “A” was partially characterized as a substituted phenolic compound, and deterrent “B” was identified as the nitrate ion. The relative concentrations of the stimulant and deterrent substances in the resistant plants were found to change as the plant matured. Thus, no one substance is responsible for resistance throughout the life of the plant. In seedlings of resistant plants, the nitrate ion plays the principal role in resistance to weevil feeding, but in more mature plants resistance seems to result from the relative amounts of other deterrents and stimulants. It may be possible to use this knowledge to screen for resistance without using insects or to protect the plants artificially by increasing levels of deterring substances, such as nitrate ion, by means of fertilizer applications.
Effect of a Secondary Treated Effluent on the Movement of Viruses through a Cypress Dome Soil
Authors: Bitton G. , Masterson N. , Gifford G. E.
Published: July 2010

A study was undertaken on the movement of viruses through a sandy soil sampled in a cypress dome, north of Gainesville, Florida. It was found that the adsorption of bacterial phage T2 and poliovirus type 1 onto soil columns treated with a secondary effluent was substantially lower than in columns treated with tap water. The secondary effluent had also the ability to desorb viruses from soil particles. The interference of organic materials present in waste water effluents with the interaction between viruses and soil particles was suggested. The movement of the viruses through the cypress dome is discussed.
Soil Temperatures and Heat Loss for a Hot Water Pipe Network Buried in Irrigated Soil
Authors: Alpert J. E. , VanDemark S. C. , Fritton D. D. , DeWalle D. R.
Published: July 2010

A 0.09‐ha field prototype of a simultaneous waste heat and waste water disposal system was constructed and instrumented. Data are reported for soil, pipe, soil surface, and air temperatures; heat loss (0.068–0.117 cal cm−2 min−1); and soil thermal conductivity (3.61–5.63 mcal [cm sec°C] −1). The data are used to evaluate the heat flow theory which is currently being used to predict the land area required for waste heat disposal with a buried hot water pipe network. Predicted heat loss was consistently lower than experimental heat losses. The results of the experiment indicate that substantial improvements need be made in the existing theory to account for the transient heat flow and heat storage. Research is currently being conducted to develop better predictive models.
Effects of Ambient Photochemical Air Pollutants on Growth, Yield, and Ear Characters of Two Sweet Corn Hybrids
Authors: Thompson C. R. , Kats Gerrit , Cameron J. W.
Published: July 2010

Two sweet corn hybrids, ‘Bonanza’ and ‘Monarch Advance’ (Zea mays L.) were evaluated for their relative susceptibility to ambient photochemical air pollutants (principally ozone) in outdoor chambers at Riverside, Calif. The plants were exposed daily to ambient or activated carbon filtered air, from seedling emergence to fresh market harvest. Plant height, tiller number and length, and air‐dry weight of stalks were reduced by pollutants in both cultivars. However, the number and fresh weight of marketable primary ears and the number of fully developed kernels were much more severely reduced in ‘Monarch Advance.’ Some acute leaf tissue collapse and premature yellowing and senescence of leaves were prominent in ‘Monarch Advance’ but nearly absent in ‘Bonanza.’ These foliar symptoms agree with previous data on the behavior of the two cultivars in the field.
The Impact of Fertilizer Use and Crop Management on Nitrogen Content of Subsurface Water Draining from Upland Agricultural Watersheds
Authors: Chichester F. W.
Published: July 2010

Spring flow and stream base flow sites were sampled weekly on and adjacent to a 123‐ha agricultural watershed in the Allegheny‐Cumberland Plateau physiographic region of east‐central Ohio. Nitrogen content of samples was used to determine the influence of various N fertilizer and crop management practices on the quality of subsurface water draining from defined contributing areas.

Measured nitrogen contents of spring flow were related to fertilizer N regime of the different agricultural practices investigated. Changes in land management on the area contributing to spring flow were reflected in changes in nitrogen content of water from that spring. The amount of nitrogen which was transported into the stream channel was directly related to seasonal variation in subsurface flow rate in two ways. First, the concentration of N in spring flow increased with an increase in the amount of water percolating through the overlying soil and shale. Second, the extent to which downstream quality was affected, i.e., the distance from the area of fertilizer application at which an increase in nitrogen content could be detected, also increased with the volume of flow from the springs.
Chemical and Microbial Degradation of Malaoxon in an Illinois Soil
Authors: Paschal Daniel C. , Neville M. E.
Published: July 2010

Chemical and microbial degradation of malaoxon was studied in an Illinois silty loam. This soil sample is typical of the glacial till soil used for agriculture in the Midwest. This sample had no history of pesticide application and demonstrates high microbial activity as evidenced by rapid degradation of malathion. To differentiate between microbial degradation and chemical decomposition, both heat‐sterilized and nonsterile soil samples were prepared. Because pH has been shown to affect the rate of chemical hydrolysis, samples were adjusted to three different values of pH: 6.2, 7.2, and 8.3. Malaoxon (10 ppm) was added to both sterile and nonsterile samples, and chemical and microbial analyses were performed over a 5‐day period. Chemical analyses were performed as hexane extractions followed by electron capture gas chromatography. Microbial numbers were estimated by conventional dilution and spread‐plate techniques.

Half‐lives for malaoxon were determined for the samples. A pronounced effect was noted with pH; malaoxon has a half‐live of approximately 3 days in the basic samples and a half‐life of approximately 7 days in acidic samples. Only a minor effect on half‐lives was noticed from microbial activity. This may be due in part to a demonstrated biocidal effect of malaoxon on soil microorganisms. The disappearance of malaoxon in soil was interpreted to be chemical hydrolysis. The persistence of malaoxon in acidic soils may be of significance in agricultural usage where acidic soils is desirable.
Water Quality as Related to Linears, Rock Chemistry, and Rain Water Chemistry in a Rural Carbonate Terrain
Authors: Wagner George H. , Steele Kenneth F. , MacDonald Harold C. , Coughlin Terry L.
Published: July 2010

Water from wells, springs, and streams from a 259‐km2 area in rural, carbonate terrain of northwest Arkansas was analyzed for Na, K, Ca, Mg, NO3, PO4, and trace metals, Fe, Co, Cr, Ni, Cu, Zn, Cd, Pb, Mn, Li, and Sr. Bacterial counts for total coliform, fecal coliform, and fecal streptococci were also made. The same area was mapped for linears by means of aerial photographs and field observations. Average rain water chemistry was determined for the year 1974 when the various water sources were sampled. The average chemical composition of the St. Joe Limestone Member of the principal aquifer was determined from 22 samples collected in northwest Arkansas. Water sources on linears had higher nitrate and were more bacteriologically contaminated than those off linears. Trace metals pollution was negligible in all waters except for copper and zinc which were high due to contamination from household plumbing. Rain water is the main source of trace metals for wells, springs, and streams, and limestone is the main source of Ca and Mg. Rain water is a prime source of Na and K; however, clay, shale, animal waste, and agricultural fertilizer probably also contribute Na and K.
Synthesis and Stability of Dimethylnitrosamine in Cattle Manure
Authors: Mosier A. R. , Torbit S.
Published: July 2010

Beef cattle feedlots are a source of large quantities of organic and inorganic nitrogen compounds, among which are the precursors for the synthesis of N‐nitrosamines, compounds carcinogenic to laboratory test animals and, possibly, to man.

Our objectives in this study were: (i) to determine if N‐dimethylnitrosamine (DMNA) and N‐diethylnitrosamine (DENA) could be detected in cattle feedlot manure packs; (ii) to identify and quantify nitrosamine precursors; (iii) to determine whether DMNA could be synthesized from dimethylamine (DMA) and nitrite (NO2−) added to manure; and (iv) to determine the stability of DMNA in manures under aerobic and anaerobic conditions.

Although the precursors necessary are present in manures, no DMNA or DENA was found at minimum detection limits of 0.02 ppm in manure. Aerobic incubation of manure with DMA‐N (500 ppm) plus NO2−‐N (1,000 ppm) generates detectable DMNA, but DMNA was not detected in samples incubated anaerobically or with lower levels of precursors. DMNA added to manure was relatively stable under both aerobic and anaerobic conditions.
Phosphates in Soils Treated with Sewage Water: II. Fractionation of Accumulated Phosphates
Authors: Beek J. , de Haan F. A. M. , van Riemsdijk W. H.
Published: July 2010

Surface flooding of a sandy soil with raw domestic sewage water induced an accumulation of phosphates in the top 50‐cm layers. Evaluation of the waste disposal system and development of model considerations on phosphate behavior in soil require information on the different chemical forms in which the accumulated phosphates prevail. Three different soil phosphorus fractionation methods described in literature have been applied to samples of different soil layers. Two soil treatments were involved, viz., 30 and 50 years sewage water flooding. Accumulated phosphates mainly consisted of inorganic phosphate forms (80 to 85%). These inorganic phosphates are constituted particularly of aluminum‐bound phosphates; thus, indicating the dominant role of aluminum‐related reactions in the phosphate‐bonding mechanism in this case.
Phosphates in Soils Treàted with Sewage Water: III. Kinetic Studies on the Reaction of Phosphate with Aluminum Compounds
Authors: van Riemsdijk W. H. , Weststrate F. A. , Beek J.
Published: July 2010

The reaction of phosphate with aluminumhydroxide and αAl2O3 was studied at an initial phosphate concentration level of 0.35 mmoles/liter and a temperature of 20C. Solutions of KH2PO4 and synthetic inorganic sewage water were used as phosphate sources. In all experiments involved, a marked change of the reaction rate was found after about 1 day in the case of Al(OH)3 and about 4 days in the case of αAl2O3. This can be explained by the assumption that at these points the formation of a solid aluminum‐phosphate is initiated. This new phase was later identified as Sterrettite by means of electronmicroscopy, electron diffraction, and X‐ray diffraction.
Use of Laboratory Extraction Data to Predict Losses of Dissolved Inorganic Phosphate in Surface Runoff and Tile Drainage
Authors: Sharpley A. N. , Tillman R. W. , Syers J. K.
Published: July 2010

The mean concentration of dissolved inorganic phosphate (DIP) in each of several surface runoff events from established pasture was closely correlated with the amounts of inorganic P extracted by 0.1M NaCl from the top 5 cm of soil prior to the event. For three of the four combinations of treatments evaluated (undrained, unfertilized; drained, unfertilized; and drained, fertilized) the linear relationships obtained were similar, despite large variations in the P concentrations observed. The mean DIP concentrations in surface runoff from the drained plots were consistently lower than those from the undrained plots. The relationship between the mean DIP concentrations of surface runoff and the amounts of extractable inorganic P for the undrained, fertilized plot was also linear but a greatly different slope was obtained. Soil extraction data appear to be useful in predicting mean DIP concentrations in surface runoff from reasonably homogeneous surface soils under pasture. More complex relationships were obtained between the amounts of extractable inorganic P in the soil at different depths in the profile and the mean concentrations and total loadings of DIP in tile drainage from a minicatchment adjacent to the surface runoff plots. Total DIP loadings were best correlated with the amounts of inorganic P extracted by 0.1M NaCl from soil at 40–50 cm, a depth which corresponds to that of the mole channels.
Residual Properties of 2,4,5‐T and Picloram in Sandy Rangeland Soils
Authors: Scifres C. J. , McCall H. G. , Maxey R. , Tai H.
Published: July 2010

Two watersheds were treated with one application of 2,4,5,T + picloram (1:1) at 1.12 kg/ha while one other watershed was treated for 2 consecutive years at the same herbicide rates. Residues of 2,4,5‐T were reduced to trace levels [<10 parts per billion (ppb)] in soils 7 days after application at one location, after 28 days at the second, and after 56 days at the third. Residues of 2,4,5‐T were not detected below 15 cm and usually remained in the surface 2.5 cm of soil. Picloram was reduced to trace levels within 56 to 112 days after application, was not detected deeper than 60 cm, and was usually restricted to the surface 15 cm of soil. There was no evidence of subsurface lateral movement of either herbicide. Surface runoff water contained trace amounts of residue following storms for about 30 days after application. There was no evidence of residue carry over into the second year after treatment in water, soils, or vegetation. Monitoring of cumulative residues in water, soils, and vegetation showed that about 75% of the picloram was dissipated from the ecosystem within 28 days after application and over 90% was lost after 112 days.
Application of Municipal Refuse and Liquid Sewage Sludge to Agricultural Land: II. Lysimeter Study
Authors: King Larry D. , Leyshon A. J. , Webber L. R.
Published: July 2010

To determine if agricultural land could be used simultaneously for crop production and waste disposal‐utilization, a lysimeter study was conducted using liquid sewage sludge and unsorted, pulverized municipal refuse. Refuse (R) at 188 metric tons/ha and a 2.3‐cm depth of sewage sludge (S) were applied separately and in combination (RS). A double refuse‐sludge rate [2(RS)] and a control treatment (C) receiving no additions were also used. Treatments were applied in the fall of 1971 and 1973. The cropping sequence was wintdr fallow—corn (Zea mays L.)—winter fallow—spring barley (Hordeum vulgare L.)—winter rye (Secale cereale L.)—corn.

There was no effect of treatment on corn grain yields in 1972 but all treatments containing refuse increased grain yields in 1974. Treatments had little effect on levels of Cr, Fe, Mn, Ni, and Pb in the corn grain and stover. Levels of Zn, Cu, and Cd were increased mainly by treatments containing refuse. The 2(RS) treatment resulted in stover Cd levels greater than the acceptable level for foodstuffs.

Nitrate leaching losses were greater for S and RS than C. Although NO3‐N leached from 2(RS) was low, the chemical oxygen demand (COD) concentrations were high (> 1,000 ppm) and cumulative COD loss was 120 times that of the loss from C. The effect of treatment C/N was inconclusive, i.e., mixing sludge (C/N = 4.9) with refuse (C/N = 63) resulted in reduced NO3‐N leaching from RS (C/N = 41) as compared to that from S. However, refuse alone did not cause immobilization because NO3‐N losses from R were identical to those from C.
Solubility and Plant Uptake of Cadmium in Soils Amended with Cadmium and Sewage Sludge
Authors: Street Jimmy J. , Lindsay W. L. , Sabey B. R.
Published: July 2010

Adsorption and precipitation of Cd2+ in soil suspensions were investigated as possible factors controlling Cd2+ levels in soils. Both adsorption of Cd2+ onto soils surfaces and possibly precipitation of cadmium minerals were evident in this study. At low cadmium levels solubility relationships in soils are best described by adsorption and fit the empirical Freundlich adsorption isotherm. Based on current thermodynamic data the solid phases CdCO3 (log Ksp = −12.07) and Cd3(PO4)2 (log Ksp = −32.61) most likely limit Cd2+ activities in soils. Under alkaline conditions, Cd2+ activity decreased approximately 100‐fold for each unit increase in pH. In this study, CdCO3 precipitated in sandy soils, having low cation exchange capacity (CEC), low organic matter, and pH values >7.0.

DTPA‐extractable cadmium levels in soils were highly correlated (r = 0.96) with Cd concentrations in corn (Zea mays L.) seedlings grown on soils amended with Cd solutions, sewage sludge, or Cd‐spiked sewage sludge. Increasing Cd additions to the soil increased plant Cd regardless of the form of Cd added. Addition of inorganic Cd to the soil increased the Cd concentration of corn seedlings more than equivalent Cd additions in the form of sewage sludge or Cd‐spiked sludge.
The Phosphorus Status of Eutrophic Lake Sediments as Related to Changes in Limnological Conditions—Phosphorus Mineral Components
Authors: Wildung R. E. , Schmidt R. L. , Routson R. C.
Published: July 2010

Studies of the relationship between limnological factors and changes in the P status of noncalcareous sediments of a eutrophic lake previously indicated that changes in sediment inorganic P were directly related to the biological productivity of the surface waters. This relationship was particularly pronounced in a shallow bay where sediment P decreased with lake phytoplankton growth and increased with their decline. The present studies were undertaken to identify the inorganic P components responsible for these changes using chemical techniques for characterization of P in sediments where changes occurred.

Release of P from sediments during periods of maximal biological productivity in the shallow bay waters was due primarily to reductions in inorganic P mineral components soluble in NaOH (0.1M) and citrate‐dithionite, suggesting that P associated with hydrated Fe oxides was the principal source of P to the overlying waters and to the biota. Increases in sediment inorganic P, which occurred when phytoplankton growth diminished, were due principally to increases in P mineral components soluble in NH4F, indicating that resorbed P was F‐exchangeable and/or associated with crystalline and amorphous Al‐P components. Changes in the form of sediment P which occurred in the lake and in laboratory equilibrium studies, indicated that conversion of resorbed NH4F soluble‐P to NaOH (0.1M) and citrate‐dithionite soluble‐P, must be a relatively long term (>2 years) process. Taken together, the NH4F, NaOH (0.1M), and citrate‐dithionite fractions accounted for approximately 85% of the seasonal variance in total inorganic P which occurred at all sampling locations in the lake system.
Persistence and Activity of Dinitroaniline Herbicides in Soil
Authors: Stoller E. W. , Wax L. M.
Published: July 2010

Greenhouse and field studies were conducted to determine the relative activity and persistence in soils of dinitramine (N4,N4‐diethyl‐α,α,α‐trifluoro‐3,5‐dinitrotoluene‐2,4‐diamine), GS 38946 (N‐ethyl‐N‐tetrahydrofurfuryl‐4‐trifluoromethyl‐2,6‐dinitroaniline), oryzalin (3,5‐dinitro‐N4,N4‐dipropylsulfanilamide), trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine), profluralin [N‐(cyclopropylmethyl)‐α,α,α‐trifluoro‐2,6‐dinitro‐N‐propyl‐p‐toluidine], nitralin [4‐(methylsulfonyl)‐2,6‐dinitro‐N,N‐dipropylaniline], fluchloralin [N‐(2‐chloroethyl)‐2,6‐dinitro‐N‐propyl‐4‐(trifluoromethyl) aniline], benefin (N‐butyl‐N‐ethyl‐α,α,α‐trifluoro‐2,6‐dinitro‐p‐toluidine), chlornidine [N,N‐Bis(2‐chloroethyl)‐2,6‐dinitro‐p‐toluidine], isopropalin (2,6‐dinitro‐N,N‐dipropylcumidine), butralin [4‐(1,1‐dimethylethyl)‐N‐(1‐methylpropyl)‐2,6‐dinitrobenzenamine], and AC 92390 (N‐sec‐butyl‐2,6‐dinitro‐3,4‐xylidine). For all plant species tested, dinitramine was most toxic and butralin was least toxic. These herbicides were considered moderately persistent, but dinitramine and butralin were less persistent than the others, a fact which may be of some practical significance. At normal use rates none of the herbicides showed residual activity to wheat (Triticum aestivum L.) planted 5 months after application, or to corn (Zea mays L.) planted 12 months after application.
Persistence of Propanil, DCA, and TCAB in Soil and Water Under Flooded Rice Culture
Authors: Deuel L. E. , Brown K. W. , Turner F. C. , Westfall D. G. , Price J. D.
Published: July 2010

Field experiments were conducted to determine the residue levels of propanil (3′,4′‐dichloropropionanilide), DCA (3,4‐dichloroaniline), and TCAB (3,3′,4,4′‐tetrachloroazobenzene) in the flood water and Beaumont clay soil under normal rice (Oryza sativa L.) cultivation. Propanil applied as a foliar spray at 3.4 and 6.8 kg/ha 24 hours before flooding was dissipated from the flood water within 24 hours following the flood. The amount of propanil dissipated corresponded to the DCA concentration in the flood water at 24 hours, indicative of biological degradation of propanil to DCA. TCAB was never detected in other than trace quantities. Neither propanil nor its metabolites were detected in soil samples collected at 2.5–5.0 cm and 17.5–20.0 cm below the surface 24 hours following the application of the flood water.
A Steady‐State Conceptual Nitrogen Model for Estimating Nitrogen Emissions from Cropped Lands
Authors: Tanji Kenneth K. , Fried Maurice , Van De Pol Ronald M.
Published: July 2010

Details of a conceptual nitrogen model are presented. The model is based upon the principles of mass balance and steady state. It considers both water and N flows into and out of the crop root zone. Illustrative computations are given for estimating steady‐state N leaching losses from two corn (Zea mays L.) field sites and comparisons are made with measured values. This model may be applied to other crops or cropping practices.
Quality of Irrigation Water and Surface Return Flows from Selected Agricultural Lands in Nevada During the 1974 Irrigation Season
Authors: Miller W. W. , Guitjens J. C. , Mahannah C. N.
Published: July 2010

Agriculture has been identified as a major contributor of pollutants to surface waters. The purpose of this investigation was to gain knowledge of pollutants and pollutant loads carried in surface return flows to receiving waters. Information of this nature is needed by those agencies having administrative responsibility for water quality control. Quantitative and qualitative measurements of irrigation applications (head water) and surface return flows (tail water) were conducted on four sites at three locations in the Carson Valley area of Nevada to investigate the change in pollutant loads of surface waters entering the leaving agricultural units. Dissolved oxygen (DO), biochemical oxygen demand (BOD), total dissolved solids (TDS), NO3‐N, PO4‐P, SO4, and turbidity were considered as major constituents of water quality. Concentrations were combined with flow volumes to compute the constituent loading per irrigation and net infiltrated amounts or seasonal contributions in the surface return flow. Phosphorus and BOD were found to be the major agricultural pollutants contributed by irrigation surface return flows. Net infiltrated amounts of TDS, NO3‐N, and other soluble constituents were recorded. Dissolved oxygen concentrations in head and tail waters were found to be critically low. River standards for DO might be better expressed as a maximum permissible dissolved oxygen deficit (DOd) for water at a given temperature carrying a given amount of BOD. Additional investigations should be undertaken to delineate possible interactions among pollutant constituents. Water quality variations of individual samples should be expressed in statistical terms so that it is possible to identify pollutant interdependencies and to establish an optimized sampling frequency.