bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrate‐nitrogen Removal from Soil Profiles by Alfalfa
Authors: Mathers A. C. , Stewart B. A. , Blair Betty
Published: July 2010

Alfalfa (Medicago sativa L. ‘Cody’) was established in the fall of 1971 on plots previously treated with 0, 22, 45, 112, or 224 metric tons/ha of manure annually for 3 years. Additional plots had received 224 kg N/ha (as NH4NO3) annually for 3 years. Nitrate‐nitrogen and water contents of the soil profile were determined by 30‐cm increments to 6 m prior to planting. Nitrate‐nitrogen was found to 6 m, but the largest concentrations were in the top 1.8 m, where amounts of NO3−‐N varied from 100 to 2,400 kg/ha. Additional profile samples were taken in 1972 and 1973 after the final cutting of alfalfa. The data showed that alfalfa removed water and NO3−‐N to a 1.8‐m depth the first year and to 3.6 m the second year. These results indicate that alfalfa could remove NO3−‐N from the lower depth of soil profiles where annual crops were not effective. Yield, NO3−‐N, and P contents of alfalfa were increased by manure. Total N taken up by the crop was directly related to the yield.
Effect of 2‐Chloro‐6‐(Trichloromethyl)Pyridine and its Hydrolysis Product 6‐Chloropicolinic Acid on Soil Microorganisms
Authors: Laskowski D. A. , O'Melia F. C. , Griffith J. D. , Regoli A. J. , Youngson C. R. , Goring C. A. I.
Published: July 2010

The influence of nitrapyrin [2‐chloro‐6‐(trichloromethyl)pyridine] and 6‐chloropicolinic acid on soil microorganisms was studied in a series of pure culture and soil incubation tests with concentrations of chemicals ranging from 0 to 1,000 ppm.

Pure culture studies with 59 species of bacteria, fungi, and actinomycetes showed no inhibition of growth by nitrapyrin at concentrations < 10 ppm. Two species were inhibited between 10 and 100 ppm, 38 between 100 and 1,000, and 10 species showed no growth reduction at the highest concentration of 1,000 ppm nitrapyrin. Of 45 species studied, 6‐chloropicolinic acid inhibited one species at concentrations < 1,000 ppm. Forty‐one species did not show growth reduction in the presence of 1,000 ppm of this chemical.

Population counts of bacteria and fungi in seven soils incubated in the presence of nitrapyrin or 6‐chloropicolinic acid at concentrations of 1,000 ppm snowed little inhibitory influence. No consistent trend in terms of stimulation or suppression of carbon dioxide formation during soil respiration was evident for either chemical at 1,000 ppm.

6‐Chloropicolinic acid at 1,000 ppm had little if any effect on soil mineralization, variable effect on ammonium oxidation, and little or no effect on nitrite oxidation. Suppression of ammonium oxidation by 6‐chloropicolinic acid varies with soils, and appears most likely to be observed at concentrations of 100 ppm or more.
Uptake of Cadmium and Zinc from Sludge by Barley Grown Under Four Different Sludge Irrigation Regimes
Authors: Kirkham M. B.
Published: July 2010

Barley (Hordeum vulgare L. ‘Liberty’) was irrigated at four different rates with liquid sewage sludge containing three concentrations of Cd to determine an optimum irrigation frequency that would minimize Cd and Zn movement from the sludge crust into the soil profile. Concentrations of 65, 79, and 205 µg/g Cd in anaerobically digested sludge were used, attained by adding 14 or 140 µg Cd as CdSO4 to sludge containing 65 µg/g Cd. Zinc was 4,350 µg/g in all sludges. Barley was grown in 40 cm by 15 cm columns of soil under greenhouse conditions for 69 days. Beginning 28 to 39 days after planting, sludge was applied periodically to each column, but at four different frequencies: 50 ml daily, 200 ml every 4 days, 400 ml every 8 days, and 600 ml every 12 days. Concentrations of Cd and Zn in the roots, leaves, grain, soil, and sludge crusts were measured. Cadmium concentration in leaves was < 3 ppm and, in grain, Cd was < 0.25 ppm. The Cd concentration in the roots varied (3.3 to 16.2 ppm) with Cd concentration the sludge and increased with decreasing frequency of irrigation. Cadmium and Zn concentrations of the sludge crusts increased with increasing frequency of irrigation. Soil columns irrigated daily were continuously wet at the surface, whereas soil columns irrigated every 4, 8, or 12 days dried between irrigations.
Leaf Photosynthesis: The Influence of Environmental Variables
Authors: Incropera Frank P.
Published: July 2010

A model is presented for the effects of light intensity and ambient temperature, relative humidity, and carbon dioxide concentration on leaf photosynthesis. The model treats diffusion and chemical processes occurring within the leaf, as well as the transfer of mass and energy between the leaf and its environment. Calculations have been performed for Zea mays L. (maize) which suggest the influence of environmental changes. Although leaf energy exchange processes act to moderate the effect of changes in the atmospheric temperature, a severe cooling trend may cause as much as 20% reduction in photosynthesis. Under most conditions, the rate of photosynthesis is further diminished by a reduction in relative humidity. In contrast, a 20% increase in the atmospheric CO2 concentration, which is projected for the year 2000, will increase photosynthesis by approximately 15%. The calculations also suggest optimum ambient conditions for controlled growth environments, such as a greenhouse. In addition to a saturating light intensity of approximately 700 W/m2, these conditions include a temperature and relative humidity of approximately 30C and 90%, respectively, and a CO2 concentration of approximately 1,500 ppm.
Phytotoxicity in and Metal Uptake from Soil Treated with Metal‐Amended Sewage Sludge
Authors: Cunningham J. D. , Ryan J. A. , Keeney D. R.
Published: July 2010

A greenhouse experiment was conducted to evaluate yield and the concentration of Cd, Cu, Cr, Ni, and Zn in corn (Zea mays L.) and rye (Seceale cereal L.) tissue when grown on a soil limed to pH 6.8 and treated with a waste water sludge that had been amended with Cu, Cr, Ni, and Zn salts. Three rates of each metal in all combinations were used. The rates were obtained by adding the appropriate amounts of each metal to a bulk sample of anaerobic digested sludge. After equilibration for 2 weeks, the sludge was air‐dried, and mixed with a sandy loam soil at the rate of 63 metric tons/ha (solids). Corn, rye, and corn, in that order, were grown on the soil for 6 weeks each.

Yields decreased as the Cu and Zn concentration of the sludge increased, while Ni had no appreciable effect. Yields were increased significantly as the sludge Cr concentration increased, indicating that Cr may be inhibiting the uptake or translocation of other metals. This was substantiated by tissue analysis which showed that with increasing sludge Cr, tissue concentrations of the other metals decreased. Tissue concentrations of Cu and Zn were consistently >20 and 400 ppm, respectively, and thus were in the range considered toxic to plants. As the sludge concentration of Cu or Zn increased, tissue concentrations of the other metals were increased, and evidence of Cu‐Zn interactions on plant growth and metal concentrations was obtained. The only Cd sources were that in the soil and in the original sludges, yet the Cd concentration of plant tissue increased with increasing Cu concentration.

Yield reductions relative to the control were less and tissue concentrations of the metals decreased from the first to the second corn crop, indicating reversion of the metals to less available form with time.
Phytotoxicity and Uptake of Metals Added to Soils as Inorganic Salts or in Sewage Sludge
Authors: Cunningham J. D. , Keeney D. R. , Ryan J. A.
Published: July 2010

Crop growth and metal uptake on soil treated with inorganic salts of Cr, Cu, Zn, and Ni were compared with the results obtained when a sewage sludge was amended with these metals before addition to the soil. This mixture was then ground and added to the soil at the rate of 63 metric tons/ha (2.8%) solids. The treatments involving inorganic salts resulted in lower yields and, in general, higher metal concentrations than the equivalent sludge treatments. Lowest yields were generally observed for the high Zn treatment. These findings indicate that caution must be used when attempting to use results of inorganic salt treatments to evaluate phytotoxity and toxic metal uptake from sewage sludge amended soils.
Interaction between Aquatic Plants and Bed Sediments in Mercury Uptake from Flowing Water
Authors: Mortimer D. C. , Kudo Akira
Published: July 2010

Bed sediment from a known zone in the Ottawa River study area and cuttings of Elodea densa were set out in aquaria in a 24‐day controlled, flowing water experiment. Elodea was planted in sediment and in glass beads, and sediment was exposed with and without plants, all in the same aquaria for 7 days before the addition of mercury with 203Hg. Three concentrations each of mercuric chloride and methyl mercuric chloride were continuously metered into the input water to yield aquarium levels of 0.2, 2, and 10 µg/liter.

There was no significant difference in the uptake rate between the two forms of mercury. Uptake was proportional to water concentration over the entire 17‐day exposure period in both plants and sediment. Methyl mercury was more toxic to plant growth in this time interval than inorganic mercury. Elodea growing in sediment absorbed significantly less mercury than Elodea growing in glass beads. Sediment from which the plants had been removed contained about twice as much mercury as plant‐free sediment. The aquarium walls were the largest absorbing compartment in the system and methyl mercury was absorbed more strongly than inorganic mercury. The total recovery of input mercury over the 17 days averaged 91%.
Model Ecosystem Studies of Lead and Cadmium and of Urban Sewage Sludge Containing these Elements
Authors: Lu Po‐Yung , Metcalf Robert L. , Furman Rick , Vogel Raymond , Hassett John
Published: July 2010

The environmental fate and effects of cadmium and lead were studied in a laboratory model ecosystem with a terrestrial/aquatic interface, using silica sand, Bloomfield soil (sandy loam) and Drummer soil (silty clay loam) as substrates. Applications were made directly to the substrates as lead and cadmium chloride and as sewage sludge as a source of heavy metals. The mobilization and incorporation of cadmium and lead into food chain organisms were proportional to sorption capacity of the substrate and were highest in silica sand and lowest in Drummer soil. Following the application of sewage sludge there was clear cut mobilization and transfer of cadmium, copper, lead, and zinc into food chains, alga (Oedogonium cardiacum), daphnia (Daphnia magna), mosquito larva (Culex pipiens quinquefasciatus), snail (Physa), and fish (Gambusia affinis). Cadmium exerted a particularly adverse affect on the various organisms in the model ecosystem and its presence in relatively high levels in sewage sludge could become a limiting factor in its use on soils and for crop production.
Disposal of Beef‐Feedlot Manure: Effects of Residual and Yearly Applications on Corn and Soil Chemical Properties
Authors: Wallingford G. W. , Murphy L. S. , Powers W. L. , Manges H. L.
Published: July 2010

Land disposal of beef‐feedlot manure was studied. Annually, beginning in the fall of 1969, feedlot waste was applied to a silty clay loam soil at rates that after 4 years ranged from 114 to 2,750 metric tons/ha of dry manure. Included were three single applications made in the fall of 1969 (residual) that ranged from 123 to 590 dry metric tons/ha. For 3 years, in the spring and fall, surface soil samples and soil cores were taken. Yields of furrow‐irrigated corn (Zea mays L.) forage and plant contents of N, P, K, Ca, Mg, and Na were measured.

Chemical composition of manure from a single feedlot varied greatly. Average composition (dry weight basis) of samples collected for 3 years was 20.5% H2O, 0.92% N, 0.52% P, 1.14% K, 0.92% Ca, 0.41% Mg, and 0.26% Na. At all sampling dates electrical conductivities (EC) of extracts from saturated pastes of the surface soil samples from plots receiving yearly manure treatments were linearly related to cumulative tons of applied manure; EC values of more than 10 mmho/cm were recorded for the spring samplings. Both yearly and residual manure treatments caused Na and NO3‐N to move downward accumulating to depths of at least 1 m after 3 years; movement of K and P was restricted to 50 and 30 cm, respectively. Corn‐forage yields were increased by improved soil fertility at the low and intermediate yearly rates, but depressed at the high rates, probably because of salt injury. After 4 years forage yields were still increased on plots that received residual treatments. Uptake of N and P was also depressed at high yearly rates and followed trends similar to those of yield. Yearly rates ranging from 29 to 68 dry metric tons ha−1 year−1 produced near maximum forage yields without causing excessive salt accumulation in the soil.
The Effect of Oil Pollution of Soil on Germination, Growth and Nutrient Uptake of Corn
Authors: Udo E. J. , Fayemi A. A. A.
Published: July 2010

The effect of crude oil pollution of soil on the growth of plants and uptake of nutrients was investigated by growing corn (Zea mays L.) on a soil polluted by crude petroleum. The levels of the crude oil application varied from 0 to 10.6% by weight of soil. Three corn crops were raised in succession, each for a period of 6 weeks, in the same soil. The yields and plant contents of N, P, K, Ca, Fe, and Mn were determined. The soil was analyzed for organic C, total and available N, extractable P, and exchangeable K, Ca, Fe, and Mn after each cropping. Germination and yields were drastically reduced as the level of pollution increased. At 4.2% crude oil pollution level, the average reductions were 50% and 92% in germination and yield, respectively. The amount of organic C, total N, and exchangeable K, Fe, and Mn increased in the soil with level of crude oil addition, while extractable P, NO3‐N, and exchangeable Ca were reduced. The poor growth was attributed to suffocation of the plants caused by exclusion of air by the oil or exhaustion of oxygen by increased microbial activity, interference with plant‐soil‐water relationships, and toxicity from sulfides and excess available Mn produced during the decomposition of the hydrocarbons.
Factors Influencing Nitrate Transformations in Sediments
Authors: Terry R. E. , Nelson D. W.
Published: July 2010

The effects of environmental and procedural factors (e.g., aeration, size of sample, water/sediment ratio, nitrate concentration, glucose addition, temperature, and sterilization) on denitrification in lake and reservoir sediments were evaluated by incubating nitrate‐amended natural sediments in the laboratory. The standard laboratory procedure adopted for denitrification studies involved the incubation of small samples of sediment (undried) after addition of a nitrate solution. Incubations were conducted at 15C in polypropylene centrifuge tubes. Denitrification in sediment‐water samples was not enhanced by continuously purging samples with helium to create artificial anaerobic conditions. Experiments showed that denitrification rates in sediments could be satisfactorily measured using wet sediment (0.5 g solids) treated with 5 ml of 100 ppm nitrate‐15N solution and incubated for 5 to 10 days. The small sample size facilitated sample preparation, extraction of inorganic forms of N and micro‐Kjeldahl analysis of sediment.

Even though glucose additions enhanced denitrification by 25 to 30%, unamended sediments contained sufficient available organic‐C for near maximal rates of denitrification. Denitrification in sediments increased with increasing temperature over the range of 5 to 23C. However, significant denitrification occurred at temperatures as low as 5C. Nitrate was not lost from sterilized sediment samples, therefore, the nitrogen transformations observed in unsterilized sediment samples were mediated by biological mechanisms.

The evaluation of factors affecting denitrification in sediment shows that the environmental conditions likely to exist in natural sediments are suitable for denitrification. Anaerobiosis and the high organic matter of most sediments create an ideal environment for microbial denitrification. The levels of nitrate in surface water may in part be controlled naturally by denitrification in sediments.
Dinitroaniline Herbicides in Soils
Authors: Helling Charles S.
Published: July 2010

The behavior and fate of dinitroaniline herbicides in the soil environment is reviewed. This rapidly expanding class of herbicides is used particularly for pre‐emergence control of annual grasses and small‐seeded broadleaf weeds in cotton (Gossvpium hirsutum L.), soybeans [Glycine max (L.) Merr.], and peanuts (Arachis hypogaea L.). All dinitroaniline herbicides in use are 4‐alkyl (or ‐sulfonyl)‐2,6‐dinitro‐N,N‐(mono‐ or disubstituted) anilines, characterized by very low water solubility and basicity. Volatilization from surface applications to moist soil is substantial for trifluralin, benefin, and profluralin, but is low for nitralin and oryzalin. In water and on dry soil, dinitroanilines exposed to sunlight degrade to photoproducts that are often polar and include dealkylated and cyclic intermediates. Such photodecomposition greatly reduces bioaccumulation of dinitroanilines by aquatic organisms.

Physico‐chemical behavior of dinitroanilines in soils or sediments is influenced by volatilization and by strong soil adsorption. Nitralin and oryzalin may leach slightly, but dinitroanilines are essentially immobile. Short range diffusion may be important for herbicide efficacy or loss from the soil surface. Both solution and vapor phase transport components affect trifluralin diffusion; the extent and balance of diffusion are strongly affected by soil temperature, moisture, and bulk density. Phytotoxicity apparently cannot be correlated with adsorption strength, but may be related to volatility. Physical loss from soil, unless incorporated, is by sediment runoff and by volatilization.

Dinitroaniline herbicides degrade more rapidly in anaerobic, than aerobic soil. Metabolites are numerous and often resemble those produced by the photolytic mechanisms of dealkylation and cyclization. A gradually increasing quantity of residue becomes associated with soil organic matter, as bound residue. For normal use rates, persistence in soils ranges from about 2–3 months, for oryzalin and dinitramine, to 5–6 months for benefin and trifluralin. Persistence increases with decreasing soil temperature and moisture content; seasonal carryover sometimes occurs. Limited evidence suggests that dinitroanilines produce no lasting effect on soil microbial processes.
Retention of Metals in Sewage Sludge I: Constituent Heavy Metals
Authors: Lagerwerff J. V. , Biersdorf G. T. , Brower D. L.
Published: July 2010

Sewage sludge from Baltimore, Md. was compared to that of Washington, D.C. in terms of the tendency to release heavy metals under a variety of circumstances. Total and 1.0N HCl‐extractable concentrations of Cd, Cu, Pb, and Zn were determined by atomic absorption spectrophotometry. Fractionation of the metals by leaching columned samples of Baltimore sludge, with either a CaCl2 solution or H2O over extended periods of time, showed Cd and especially Zn were more leachable than Cu and Pb. Except for Pb, leachability of the metals was much lower in the sludge from Washington, D.C. than in the Baltimore sludge. Regarding the sign of charge of Cu species as a function of the progression of leaching of Baltimore sludge, anionic and, especially, amphoteric species increased, as cationic ones decreased. When aqueous sludge leachates were stored for 13 months at 5C, amphoteric Cu strongly increased, while all other Cu species decreased. In contrast, nearly all Zn species in the stored leachates were cationic. When sludge samples were subjected to simulated weathering by stirring with either H2O2 in a number of concentrations, or H2O, followed by steambath drying, the extractability of heavy metals with H2O and 0.01N HCl increased. Extractability of Cu increased more than that of Cd or Zn, suggesting that the stability of the amphoteric Cu species depended strongly on acidity. Because of the H2O2 treatments, the cation exchange capacity of the sludges diminished by 15 to 25% depending on their origin, although no C was lost.

Compared with Washington, D.C. sewage sludge, Baltimore sludge had a greater heavy metal contaminating potential for soil amended with it.
Persistence of Fecal Coliform Indicator Bacteria on Alfalfa Irrigated with Municipal Sewage Lagoon Effluent
Authors: Bell R. G.
Published: July 2010

Fecal coliforms on alfalfa plants (Medicago sativa L.) irrigated with sewage lagoon effluent were completely destroyed by exposure to 10 hours bright sunlight. No decrease in numbers was observed in the absence of bright sunlight under cool, damp, overcast conditions. Exposure to 10 hours bright sunlight was adequate to destroy all the fecal coliforms present in raw sewage.

In the event that sewage treatment failures such as lagoon short‐circuiting occurred while alfalfa was being irrigated with sewage effluent in the semiarid prairie region, livestock would be adequately protected from possible salmonella and enteropathogenic Escherichia coli infection if at least 2 sunny days elapse between the cessation of effluent irrigation and the consumption of the forage.
Evaluation of Methods for Preserving the Levels of Soluble Inorganic Phosphorus and Nitrogen in Unfiltered Water Samples
Authors: Klingaman E. D. , Nelson D. W.
Published: July 2010

Several methods for preserving the levels of soluble inorganic phosphorus (SIP), ammonium, and nitrate in surface runoff, tile drainage water, and river water were evaluated. The best overall technique for preservation of water samples for P and N analysis appeared to be storage at subzero temperatures. The SIP concentration in samples was also stabilized by addition of HgCl2 (40 mg/liter) and storage at 4C; however, the ammonium and nitrate levels in samples were not preserved for long periods of time (12 weeks) by this technique. The soluble inorganic N levels in water samples were preserved by addition of phenylmercuric acetate (20 mg/liter) and storage at 4C, but use of this procedure increased the SIP concentration in some samples during storage. Storage of samples at 4C or 23C without addition of a chemical preservative resulted in large changes in soluble inorganic P and N contents.
Nitrogen and Phosphorus Losses from Winter Disposal of Dairy Manure
Authors: Klausner S. D. , Zwerman P. J. , Ellis D. F.
Published: July 2010

An evaluation of surface runoff losses of inorganic nitrogen and total soluble phosphorus from fields receiving winter applications of dairy manure was conducted. Runoff losses, as derived from natural precipitation, were accumulated for the time period 1 Jan. to 31 Mar. for 3 consecutive years. The influence of rate of manure application (35, 100, and 200 metric tons/ha) and climatological variability within and between years was of primary importance. Average runoff values of inorganic nitrogen for the three rates of application were 16, 1, and 0.2 kg/ha for 1972, 1973, and 1974, respectively. Phosphorus values averaged 3.5, 0.7, and 0.01 kg/ha for the 3 respective years. Adverse weather conditions during the winter application in 1972 were largely responsible for increased nutrient discharges in runoff. Results indicated that manure disposal during active thaw periods can result in increased nutrient losses. Losses were minimized when manure was applied and then covered with snow, melting at a later date. The 35 metric tons/ha rate of application, applied on frozen soil and then covered with snow, resulted in nutrient losses that differed little from areas that received no manure.
Effect of Dairy Cattle Manure on Millet and Rye Forage and Soil Properties
Authors: Mugiwra L. M.
Published: July 2010

Dairy cattle manure was incorporated in plots of Decatur silty clay loam (Thermic Rhodic Paleudults) at rates of 0, 22, 44, 89, 178, and 267 metric tons/ha (dry weight) for 3 successive years. Pearl millet (Pennisetum americanum L. K. Schum) was grown in summer and was clipped twice and ‘Wrens Abruzzi’ rye (Secale cereale L.) was grown as a winter cover crop.

Annual applications of 22 and 44 metric tons/ha manure were more effective than higher rates in stimulating millet growth, but rye forage yields were generally not influenced by manure application. The uptake of P, Ca, and Mg tended to level out at 44 tons/ha, but the removal of N, K, NO3‐N, and Na by millet and rye from the soil continued to increase with the rate of manure applied. The high rates of manure caused excessive accumulation of nitrate in plants and soils. The range of nitrate‐N in millet was 5,037 to 8,675 ppm at 178 and 267 metric tons/ha compared with 602 to 4.010 ppm on the NPK check plots. Nitrate‐N in the top 90 cm of the soil over the 3 years averaged 840 kg/ha at 178 and 267 tons/ha compared with 239 kg/ha of NO3‐N on the check. Dry matter and soil and plant analyses indicated that 44 metric tons/ha was the highest annual application rate of manure that could be used on this soil with consistent increases in plant growth and nutrient uptake and without excessive nitrate accumulation in soils and plants.
Phosphorus Balance in Sewage Effluent Treated Soils
Authors: Kardos L. T. , Hook J. E.
Published: July 2010

Four field sites which have been irrigated with various levels of secondary treated sewage effluent for 9 to 11 years have been examined for phosphorus content in soil water extracted with suction lysimeters. The cornfield site on Hublersburg clay loam irrigated with effluent had an average P concentration of 0.329, 0.070, and 0.046 mg/liter in soil water at 15, 60, and 120 cm respectively compared to 0.043, 0.046, and 0.037 mg/liter, respectively, under an adjacent fertilized, but unirrigated control. Year round application of effluent including 2 years of effluent plus sludge to reed canarygrass (Phalaris arundinacea L.) on Hublersburg clay loam resulted in average soil water concentrations of 0.170, 0.100, and 0.052 mg P/liter at 15, 60, and 120 cm, respectively.

In an abandoned field on Hublersburg clay loam where no P was removed by crops, P concentrations were 0.140, 0.103, and 0.076 mg P/liter for the treated plot and 0.038, 0.047, and 0.042 mg P/liter for the control at 15, 60, and 120 cm, respectively. Only the 15‐cm depth had significantly higher P concentrations in the treated plot. A hardwood forest located on a Morrison sandy loam soil was irrigated year round. Phosphorus concentrations in soil water were 0.349, 0.080, and 0.087 mg/liter for the treated vs. 0.059, 0.039, and 0.039 for the control at 15, 60, and 120 cm, respectively. Leaching losses were calculated from concentration of P in soil water at 120 cm and from leaching volume which was rainfall plus irrigation minus potential evapotranspiration. Over all years of treatment no site had leaching losses of > 3% of the total applied.
Guidelines for Sediment Control in Irrigation Return Flow
Authors: Carter D. L.
Published: July 2010

Sediments in irrigation return flows arise mostly from erosion in furrows during irrigation, and sediment concentrations vary widely from near zero to several thousand ppm. Reducing both erosion and runoff would decrease the sediment in return flows. Technology is available for reducing both erosion during irrigation and soil loss from the land, and for removing sediments from return flows. This technology is discussed, and the following guidelines are suggested.

Eliminate or reduce irrigation return flows when conditions permit using irrigation methods with little or no runoff.

Control the irrigation furrow slope so that the run is across the steepest slope or on the contour. Decrease the slope near the end of the furrow to reduce the flow velocity and increase sedimentation.

Control the furrow stream size and make proper stream adjustments. Adequate water measuring equipment and controls are essential for proper stream size control.

Shorten the run length.

Control the irrigation duration to reduce the number of irrigations per season. Alternate furrow irrigation reduces the contact between soil and flowing water and subsequent erosion.

Cultivate only when necessary, avoiding excessive soil loosening which increases erosion and soil loss.

Control tailwater by assuring that it flows slowly enough that sediments settle before the water leaves the field. Filtering through grass strips removes sediments.

Utilize sediment retention basins to remove sediment from return flows.
Carbon Contents of Surface and Underground Waters in South‐central Minnesota
Authors: Maier W. J. , Gast R. G. , Anderson C. T. , Nelson W. W.
Published: July 2010

Data presented shows that the relatively ample supplies of water available from dependable stream flow in the upper Mississippi region will have to be supplemented on a seasonal basis by utilizing either surface or underground water storage. Such seasonal storage will affect the existing interflows of water between surface, subsurface, and ground waters. It could also affect the temporal variations in chemical content of both surface runoff and storage waters. Analysis of the inorganic and organic C contents of surface, subsurface, and ground water in the glaciated area of south‐central Minnesota was conducted to determine the extent that seasonal interchange of surface and ground waters may effect water quality. Organic C concentrations were 5–17, 1–6, and <2 mg/liter in surface, subsurface, and ground waters, respectively, indicating that most organic materials are decomposed or retained in the upper layers of the soil with minimal transfer to ground waters. The relatively high organic C concentration in surface waters are probably due to biodegradation of vegetation and animal tissues in stream channels or in top soil layers, marshes, and impoundments. Low organic C concentrations and relatively low flow volumes from tile drains indicate that their effect on organic C content of rivers in this area are minimal.
Resistance of Nitrosamines to Microbial Attack
Authors: Tate Robert L. , Alexander Martin
Published: July 2010

N‐Nitrosodimethylamine was not degraded in flooded soil or in microbial enrichments from bog sediments. Enrichment cultures inoculated with soil and sewage did not yield microorganisms capable of metabolizing N‐nitrosodimethylamine, N‐nitrosodiethylamine, or N‐nitrosodi‐n‐propylamine. N‐Nitrosodimethylamine was not metabolized by axenic cultures of bacteria, and it was not significantly inhibitory to individual bacterial cultures or to respiration of soil or sewage communities. The data suggest that the nitrosamines persist in samples of natural environments because of the resistance of the nitrogen‐nitrogen bond in nitrosamines.
Phosphorus Loss by Stream Transport from a Rural Watershed: Quantities, Processes, and Sources
Authors: Johnson Arthur H. , Bouldin David R. , Goyette Edward A. , Hedges Anne M.
Published: July 2010

Loss of dissolved and particulate phosphorus by stream transport was determined over a 20‐month period for Fall Creek, a stream draining a predominantly rural watershed of 330 km2 in central New York. Samples were taken several times daily during most high flow periods and at 3 to 20 day intervals during low flow periods. Samples were usually processed within 4 hours since redistribution of P among chemical forms was rapid. Losses of P from the watershed per unit time varied by several orders of magnitude and 75% of the P loss occurred in the highest flow which occurred in 10% of the time. In reaches well downstream from major point source inputs, dissolved inorganic P concentrations were highest during storm events due to two processes: desorption of P accumulated in the bed sediment from point source inputs during low flow, and inputs from diffuse sources in surface runoff. Dissolved organic P concentrations were not correlated with flow. Approximately 20% of the dissolved P lost from the watershed was derived from diffuse sources associated with farming, 45% was derived from natural geochemical processes, and 35% from point source inputs. Less than 1% of the P applied to the landscape in chemical fertilizer and manure was lost from the watershed in dissolved form.
Uptake of Cadmium by Soybeans as Influenced by Soil Cation Exchange Capacity, pH, and Available Phosphorus
Authors: Miller Joseph E. , Hassett John J. , Koeppe D. E.
Published: July 2010

The accumulation of cadmium (Cd) and its affect on vegetative growth of soybeans (Glycine max [L.] Merr. var. Amsoy) in soils with a range in cation exchange capacity (CEC), pH, and available phosphorus (P) were investigated in greenhouse experiments. Cadmium uptake decreased as soil pH and CEC increased, while increasing available soil P was related to increased Cd accumulation. Cadmium extracted from the soil by Bray P1 reagent, Bray P2 reagent, 2N MgCl2, and 0.1N EDTA was significantly correlated with plant Cd concentrations. The growth of the soybean shoots was generally depressed when tissue concentrations reached 3–5 µg Cd/g dry weight. Cadmium uptake by soybeans was correlated with the ratio of added Cd to the Cd sorptive capacity of soil.
Mineralogy and Related Parameters of Fluvial Suspended Sediments in Northwestern Ohio
Authors: Wall G. J. , Wilding L. P.
Published: July 2010

Stream water samples were collected weekly for 17 months at eight sampling sites in the Maumee River Basin to characterize the clay mineralogy of the suspended sediments and to determine the utility of mineralogy as a marker of the source (rural, urban, geologic) of the sediments. X‐ray diffraction analysis of the clay‐sized (< 2 µm) sediments indicated little seasonal or downstream variability in clay mineral composition. The quantities of mica, quartz, and vermiculite‐chlorite were 36 ± 5%, 29 ± 5%, and 20 ± 5%, respectively. The quantities of expandables, interstratified, and kaolinite minerals were usually < 10%. The cation exchange capacity (CEC), amorphous, fine clay, and organic matter content of the clay‐sized suspended sediments were approximately 44 meq/100 g, 4.4%, 25%, and 5%, respectively. Carbonate minerals were not detected in the clay‐sized fraction.

The 2 to 50 µm fraction was dominated by quartz in high flow periods and secondary calcite in low flow periods. The stream water was calculated to be saturated with calcium carbonate, thus calcite precipitation could be expected.

When fluvial suspended sediment properties were compared to properties of regional soil materials, mineralogy appeared to be a useful index to differentiate between surficial and geologic (parent material) sources of suspended sediments. The clay‐sized fraction of the suspended sediments contained percentages of mica and carbonates analogous to local surficial materials yet in contrast to local geologic (parent material) materials. A lack of carbonate minerals in the silt‐size (2–50 µm) fraction of the suspended sediments during high discharge events when stream bank erosion, hence geologic erosion, should be maximum further negated the geologic origin of the suspended sediments.

The mineralogical characterization of the fluvial suspended sediments in combination with chemical data led to the conclusion that the annual suspended sediment load of the Maumee River and tributaries was predominantly surficial in origin.
Pollution Potential of Manure Spread on Frozen Ground
Authors: Young R. A. , Mutchler C. K.
Published: July 2010

The nutrient content of snowmelt runoff was measured to determine the contribution of manure applied to frozen plots on which corn (Zea mays L.) and alfalfa (Medicago sativa L.) were grown. Nutrient concentrations in spring runoff were high from all manured plots, compared to unmanured plots, but total nutrient losses varied greatly depending on type of soil surface receiving the manure and time of application. Up to 20% of the N and 16% of the ortho‐P in the manure was carried away in spring runoff from alfalfa plots while no more than 3% of the N and 4% of the ortho‐P was lost from manured fall‐plowed plots. Applying manure to frozen plowed land reduced soil losses 100% and runoff up to 80%.
Spent Motor Oil Effects on Soil and Crops
Authors: Giddens Joel
Published: July 2010

Spent motor oil was applied to soil to determine the effects on soil and plant growth. At oil rates of up to 31,111 liters/ha, peanuts (Arachis hypogeae L.), cotton (Gossypium hirsutum L.), soybeans (Glycine max [L] Merrill), and corn (Zea mays L.) were successfully grown when amply fertilized, especially with nitrogen. Growth of sorghum (Sorghum vulgare Pers.) and weeds was significantly reduced by high oil rates. Corn grown on recently oil‐treated soil contained less nitrogen, and manganese, but the same phosphorus, potassium, calcium, magnesium, and lead as plants grown on untreated soil. Previous oil application increased the manganese and zinc content of corn tissue. Increasing nitrogen application rates increased the growth of corn.
The Uptake of Mercury from Water by the Grass Shrimp, Palaemonetes vulgaris (Say)
Authors: Ray G. L. , Tripp M. R.
Published: July 2010

In order to assess the toxicity of mercury to the grass shrimp (Palaemonetes vulgaris [Say]), the lethal concentration for 50% (LC50) of the tested population in a 24‐hour period for HgCl2 and MeHgCl were determined. The LC50 values were approximately 400 parts per billion (ppb) Hg for HgCl2 and 125 ppb Hg for MeHgCl. When shrimp were held in mercury solutions at sublethal concentrations (1.5 ppb Hg as HgCl2) for 15 days, a maximum of 500 ppb Hg was accumulated in the animal's tissues after 3 days. The average tissue concentration of mercury for the remaining 12 days was 450 ppb Hg. The actual tissue distribution of mercury was determined by exposure of shrimp to radioactively labeled HgCl2 and MeHgCl. No difference could be found in the tissue distribution of the two compounds. A significant difference is tissue mercury distribution occurred between the 24‐hour and 72‐hour exposures.
Dissolved Nutrient Losses in Storm Runoff from Five Southern Pine Watersheds
Authors: Schreiber J. D. , Duffy P. D. , McClurkin D. C.
Published: July 2010

Storm runoff from five reforested eroded watersheds in northern Mississippi (1.5 to 2.8 ha) was analyzed during the 1973 water year to determine the concentrations of soluble NO3‐N, NH4‐N, PO4‐P, Ca, Mg, and K. Storm runoff was measured with 0.91‐m H‐flumes and samples collected with a Coshocton wheel sampler. Analysis of precipitation which totaled 189 cm for the year, 40% above average, revealed that inputs of NO3‐N, NH4‐N, PO4‐P, Ca, Mg, and K for the year were 3.12, 5.73, 0.07, 7.72, 3.03, and 4.98 kg/ha, respectively. Soluble nutrient losses in the storm runoff on a unit area basis were similar for the five watersheds. Average losses in storm runoff of soluble NO3‐N, NH4‐N, PO4‐P, Ca, Mg, and K for the year were 0.32, 3.35, 0.04, 6.21, 3.05, and 3.31 kg/ha, respectively. As the annual storm runoff among the watersheds increased, the NO3‐N losses also increased linearly. Data for individual storms indicated that a critical storm runoff value must be exceeded before the watersheds would exhibit a net loss of each nutrient.
Effect of Microorganisms on the Sorption and Fate of Sulfur Dioxide and Nitrogen Dioxide in Soil
Authors: Ghiorse William C. , Alexander Martin
Published: July 2010

Sulfur dioxide was rapidly removed from the gas phase in contact with both nonsterile and sterile soil so that viable microorganisms are not directly involved in removal of this pollutant from the atmosphere. Sulfate was formed from the SO2 in nonsterile and sterile soil. About one‐fourth of the sulfur from the SO2 introduced was not recovered in inorganic form, but the recovery was quantitative if the soil was first ignited to destroy organic matter.

Nitrogen dioxide was also readily lost from the gas phase in contact with nonsterile and sterile soil, and both nitrite and nitrate were generated. The role of microorganisms in the fate of this pollutant is in the conversion of the nitrite to nitrate.
Effect of pH and Complex Formation on Mercury (II) Adsorption by Bentonite
Authors: Newton D. W. , Ellis R. , Paulsen G. M.
Published: July 2010

Reactions of Hg with bentonite clay were studied to determine behavior of the metal in aquatic ecosystems. Mercury (II) adsorption by bentonite as a function of pH and complex formation was investigated using a radioisotopic technique. Maximum Hg(II) adsorption in 0.01M Ca(NO3)2 systems occurred in the pH range 4.5–5.5. Varying the Ca(NO3)2 concentration only slightly influenced adsorption or the pH of maximum adsorption.

Chloride ions sharply reduced Hg(II) adsorption, especially at low pH's. At pH 6 or lower, increasing CaCl2 concentration from 10−5 to 10−4M depressed adsorption; higher CaCl2 levels were required to decrease adsorption at pH 7. At a given Cl− concentration, maximum observed Hg(II) adsorption occurred near the calculated pH where HgClOH occurred as a transition complex between HgCl2 and Hg(OH)2.

Chloride salts (0.01M CaCl2, NaCl, and KCl) were more effective desorbers of Hg(II) than was 0.01M Ca(NO3)2 or various 0.01N acids. HCl (0.01N) removed the most adsorbed Hg(II).
Influence of Crop Management Practices on Nutrient Movement Below the Root Zone in Nebraska Soils
Authors: Muir John , Boyce J. S. , Seim E. C. , Mosher P. N. , Deibert E. J. , Olson R. A.
Published: July 2010

Deep profile sampling under different water and crop management systems revealed limited movement of N and none of P from the rooting profile of nonirrigated Nebraska soils. Leaching of N to the water table was apparent in most irrigated soils located on valley positions and in sandy soils of the uplands. Alfalfa (Medicago sativa L.), with its deep rooting system, was noted to be an effective scavenger of inorganic N that may have accumulated under prior annual crops.
Variable Nature of Chemical Composition of Sewage Sludges
Authors: Sommers L. E. , Nelson D. W. , Yost K. J.
Published: July 2010

Sewage sludge samples were collected over a 2‐year period from eight Indiana cities and analyzed for C, N, P, K, Ca, Mg, Fe, Cd, Zn, Cu, Ni, and Pb. The sludges contained approximately 50% organic matter and 1–4% inorganic C. Organic and inorganic C, organic N, inorganic P, and Ca and Mg were found to be present in a given sludge at a relatively constant concentration with respect to sampling time. Inorganic N, organic P, K, and all metals were found to be quite variable with time for sewage sludge produced by a given city. In general, organic N and inorganic P constituted the majority of total N and P, respectively, in sludges. The largest deviations between the mean and median were found for Cd, Zn, Cu, Ni, and Pb. Variable nature of inorganic N and metal contents of sludges indicates that a sound sampling and analysis program is essential prior to formulating recommendations for rates of sewage sludge applications on soils used for crop production.
Efficiency of Nitrogen, Carbon, and Phosphorus Retention by Small Agricultural Reservoirs
Authors: Gill Angela C. , McHenry J. Roger , Ritchie Jerry C.
Published: July 2010

Total N, total C, and readily available organic and inorganic P contents, and particle‐size distributions were determined for samples of soils and sediments collected from three agricultural watersheds in north Mississippi. The total quantities of N, P, C, and clay accumulated in the sediments of each reservoir were calculated. These values were compared with those calculated from soil losses estimated by using the Universal Soil Loss Equation. The results showed considerable variation between the percentages of plant nutrients and of soil particles retained in the reservoirs. These reservoirs were highly effective in retaining eroded soil particles. However, the percentages of soil nutrients retained in the reservoir sediments were less than the percentages of retained soil particles.
Movement of Heavy Metals below Sewage Disposal Ponds
Authors: Lund L. J. , Page A. L. , Nelson C. O.
Published: July 2010

Coarse‐textured soils below sludge and effluent disposal ponds at two sewage treatment plants were studied. The concentrations of Zn, Cd, Cu, Cr, and Ni in the soils at various depths were determined to investigate the downward movement of these heavy metals below the two types of disposal ponds.

Concentrations of acid‐extractable metals (4N HNO3) were greater under disposal ponds than offplant control sites at both treatment plants. Metal enrichment was evident to depths as great as 3 m under some ponds. The depth and degree of metal enrichment depended on the specific pond type and the treatment plant. Metal concentrations were greater under anaerobically digested sludge‐holding ponds than effluent ponds. Concentrations of the metals in saturation extracts of soils beneath the ponds were much greater than those typically found for California soils.

The distributions of metals with depth were closely related to the changes in chemical oxygen demands of soil samples with depth. This suggests that the metals have moved as soluble metal‐organic complexes.
Surface Runoff Losses of Fertilizer Elements
Authors: Dunigan Edward P. , Phelan Robert A. , Mondart C. L.
Published: July 2010

Surface runoff losses of fertilizer N, P, and K were measured from a Loring silt loam soil with an average slope of 5%. Plots seeded to pearl millet (Pennisetum typhoides [Burm.]) in 1973 and 1974 were fertilized at the rate of 112‐49‐93 kg/ha of incorporated N, P, and K using two different fertilizer blends, a 33.3‐8.7‐16.6 and an 8‐3.5‐6.6. The percent of water‐soluble fertilizer elements lost in 1973 from the higher and lower blend concentrations, respectively, were N, 0.50 and 0.30%; P, 0.14 and 0.06%; and K, 0.67 and 0.92%. In 1974, N losses were 0.89 and 0.41%; P, 0.35 and 0.20%; and K, 0.42 and 0.35%. Precipitation during the experimental periods was 20.40 cm in 1973 and 11.03 cm in 1974. Two of the millet plots were then topdressed with NH4NO3 fertilizer at the rate of 112 kg N/ha. Topdressed fertilizer‐N losses were 2.68% in 1973 and 1.82% in 1974. Precipitation during these second tests was 27.97 cm in 1973 and 27.69 cm in 1974. Ryegrass (Lolium multiflorum L.) plots were fertilized with sulfur‐coated urea (SCU) and uncoated urea (U) at the rate of 224 kg N/ha during the growing seasons of 1973 and 1974. Total N losses (U vs. SCU) were 9.52 and 0.26% in 1973, and 1.67 and 0.42% in 1974. Precipitation was 23.89 cm in 1973 and 29.57 cm in 1974. A 10.08‐cm rainfall on the third day of the test in 1973 caused almost three‐fourths of the 9.52% N lost from the uncoated urea to be lost in that runoff and while it was still in the urea form. The sulfur coating prevented large surface losses of N from the SCU.
Correlations between Air Pollution Injury and Certain Agronomic, Chemical, and Physical Characteristics of Maryland Tobacco
Authors: Huang T. S. R. , Mulchi C. L. , Aycock M. K.
Published: July 2010

Thirty‐six Maryland tobacco (Nicotiana tabacum L.) entries including eight parent cultivars (‘Catterton,’ ‘Wilson,’ ‘Gertz,’ ‘Moore,’ ‘Maryland 59,’ ‘Maryland 10,’ ‘Maryland 64,’ and ‘Maryland 609’) and 28 hybrids (obtained by crossing the eight parent cultivars in all possible combinations including reciprocals) were grown at three locations with differing soil types in Maryland in 1972. The plants were scored for air pollution injury (weather fleck) at maturity.

Plants grown on deep sandy soils and showing drought stress symptoms exhibited less injury from air pollution than plants grown on sandy loam or silt loam soils. Correlations were made between weather fleck intensity and eleven agronomic, chemical, and physical characteristics of the tobacco. Reductions in yield, average price, and value of the cured tobacco were associated with increases in weather fleck intensity at two of the three locations. Also, taller plants and wider internode lengths were associated with increased fleck intensity at two of the three locations. Days to flower, filling capacity, and burn duration were associated with increased fleck intensity in a positive manner and total alkaloid contents in a negative manner at single locations only. Correlation values for either total nitrogen contents or leaves per plant with weather fleck intensity were nonsignificant at all locations.