bluuebunny/crossref_metadata_2025 huggingface dataset:
Fate of Insecticides in an Irrigated Field: Azinphosmethyl and Tetradifon Cases
Authors: Yaron Bruno , Bielorai Hanoch , Kliger Lilian
Published: July 2010

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

The experiments reported in this paper were designed (i) to determine whether it is possible to detect the presence of fertilizer nitrogen in nitrate produced by four central Illinois soils during laboratory incubation by using variations in the natural abundance of 15N, (ii) to use such variations to estimate the fractional contribution of fertilizer nitrogen to the nitrate produced, and (iii) to compare these estimates with those based on the use of fertilizer nitrogen which was artificially enriched with 15N. The mean δ 15N per mill excess) value of nitrate produced during incubation of the soils which had received unlabeled (NH4)2SO4 was significantly lower in 11 out of 12 experiments compared with that produced by unfertilized soils. As expected, estimates of percent fertilizer derived nitrogen based on variations in natural abundance of 15N were less precise than those based on the use of (NH4)2SO4 artificially enriched with 15N. The use of natural variations in 15N abundance to compute the percent fertilizer derived nitrate resulted in a lower estimate than the estimate based on 15N enriched material in seven experiments. This underestimation appeared to be related to the so called “priming effect” and/or the exchange of fertilizer and soil nitrogen.
Integrating Chemical Factors with Water and Sediment Transport from a Watershed
Authors: Frere M. H.
Published: July 2010

A mathematical model that calculates the movement of a chemical as it is transported through or off of an agricultural watershed is described. Loss of the chemical between storms by degradation or volatilization is described by a first‐order rate equation. Simple chromatographic theory is used to describe the chemical distribution in the soil during leaching, assuming a linear adsorption relation and dispersion that is proportional to the square root of the distance moved. The concentration at the surface during the storm is calculated to estimate the amounts lost in runoff water and with interril erosion. It is assumed that rill erosion removes the chemical in proportion to the fraction of the area in rills and to the fraction of the chemical distribution in the soil intercepted by the rills.

Mineralization and uptake are an additional source and sink for nitrate between storms. Lithium bromide movement on a microplot was used to examine some features of the model.
The Watershed Approach to Understanding our Environment
Authors: Woolhiser David A.
Published: July 2010

Current approaches used in modeling a particular part of the human environment—the agricultural watershed—are reviewed and questions are raised regarding the objectives, approaches, and interpretation of agricultural water quality models. Models—either symbolic (mathematical) or material—are essential to understanding and predicting environmental phenomena on agricultural watersheds. Models describing the transport of water, sediment, and chemicals through a watershed system can become very complicated and frequently must be simplified. Simplifications inevitably involve distortion and may make interpretation of model parameters difficult. The use of material models may assist in interpreting the parameters of mathematical models.
Phosphate Determinations in Waters Using an Anion Exchange Resin
Authors: Blanchar R. W. , Riego Domingo
Published: July 2010

Amounts of water samples from 1 to 1000 ml were passed through 10‐cc columns of 100‐ to 200‐mesh Dowex 1‐X8 anion‐exchange resin. Orthophosphate was quantitatively removed from the water sample by the resin and could be eluted from the column with 25 ml of 1M KCl. Phosphate in the 1M KCl eluent was reacted with ammonium molybdate, extracted into isobutanol, reduced with SnCl2, and the optical density of the blue complex measured. The working range of the method was between 1 and 8 µg of P.

Arsenic does not interfere in the phosphorus determination if the phosphomolybdate complex is extracted into isobutanol before reduction with SnCl2. Pyrophosphate if present will be approximately 20% hydrolyzed and the hydrolyzed portion indicated as orthophosphate in the method described. An alternate elution procedure to separate and determine ortho‐, pyro‐, and tripoly‐phosphate eliminated condensed phosphate interference in the orthophosphate determination. Glucose‐1‐phosphate, glucose‐6‐phosphate, and glycero‐phosphate are removed from the column with the ortho‐phosphate fraction but are not hydrolyzed and indicated as ortho‐phosphate. Phytic acid phosphate and para nitrophenyl phosphate are not leached from the column with KCl and do not interfere.

Analysis of water samples indicated that in the 1 to 20 ppb P range an appreciable amount of the phosphate exists as pyro‐ and tripoly‐phosphate. The resin method is not specific for dissolved orthophosphate in water, but may give a more valid estimate than direct reaction with the acid molybdate reagent.
Ethylene in Grassland Soil Treated with Animal Excreta
Authors: Burford J. R.
Published: July 2010

Ethylene was evolved in the surface layers of grassland following the application of 550 metric tons/ha of an unamended mixture of cow dung and urine (slurry) to the soil surface in the early spring (March). Concentrations in the gaseous phase of the slurry layer exceeded 2 ppm (vol/vol) during the first 3 weeks after the application, but thereafter were <0.25 ppm. In the underlying surface soil, ethylene was detected continuously for 4 months after the application: the concentration declined from about 1 ppm in April to about 0.2 ppm in July. After midsummer, significant evolution was detected only for a short period in the following winter.

Measurement of ethylene concentrations in columns of soil, incubated after an application of excreta to the soil surface, showed that fresh slurry promoted ethylene accumulation in the gaseous phase more than stored slurry, and that both dung and urine stimulated ethylene evolution.
Salt Tolerance and Suitability of Various Grasses for Saline Roadsides
Authors: Hughes T. D. , Butler J. D. , Sanks G. D.
Published: July 2010

Forage yields of five grass species: Agropyron cristatum (L.) Gaertn., A. smithii Rydb., Lolium perenne L., Poa pratensis L., and Puccinellia distans (L.) Parl., were studied in soil under greenhouse conditions with NaCl additions of 0; 5,000; 10,000; and 20,000 ppm. Forage yield of P. distans was reduced 23% by addition of 20,000 ppm NaCl, compared to a minimum reduction of 40% for the other grass species. Addition of 30,000 ppm NaCl to soil completely inhibited seedling survival of A. cristatum, A. smithii, Elymus triticoides Buckl., P. distans, Puccinellia lemmoni (Vasey) Scribn., and Sporobolus airoides (Torr.) Torr. Puccinellia airoides (Nutt.) Wats. and Coult. and P. distans were unusually toleran to foliar applications of NaCl in the field.

Mineral analysis of leaf tissue by emission spectroscopy showed that Na concentrations increased as NaCl addition to the soil increased. However, there was no relationship between salt tolerance of the various grasses and amounts of Na in leaf tissue. Increased NaCl addition to the soil resulted in decreased leaf Ca and Mg, but no relationship existed between leaf K and NaCl addition.

P. distans is of value for vegetating saline roadsides.
Calculated Drainage Water Compositions and Salt Burdens Resulting from Irrigation with River Waters in the Western United States
Authors: Oster J. D. , Rhoades J. D.
Published: July 2010

Drainage water compositions were calculated with a computer simulation model from irrigation water compositions, leaching fractions, aragonite and gypsum solubilities, and measured partial pressure of CO2. The calculated compositions were compared with measured values obtained from lysimeters filled with Pachappa soil, cropped with alfalfa, and irrigated with eight synthetic waters typical of rivers in the western U. S. Linear regression analysis of predicted vs. measured values for Na+ and SO42‐ concentrations, sodium‐adsorption‐ratio, electrical conductivity, and salt burden resulted in essentially one‐to‐one relationships. The gain in salt burden of drainage water at high leaching fractions due to mineral dissolution was adequately described by assuming the soil solution was saturated with respect to aragonite. Some evidence for Mg2+ precipitation was found.

The utility of the simulation model is demonstrated for evaluating the salinity, sodicity, and pollution hazards of irrigation waters. The evaluation of irrigation water quality in terms of minimum leaching fractions commensurate with maintaining satisfactory salinity, and sodicity levels is illustrated using recent crop tolerance data for alfalfa and the hydraulic conductivity characteristics of several representative soils. For salt‐tolerant plants leaching fractions between 0.05 to 0.1 should be safe for six of the eight waters. Salt burdens of drainage waters are predicted to decrease with decreasing leaching fraction and partial pressure of CO2. The predicted relative decrease in salt burden ranged from 0.32 to 0.85 for a decrease in leaching fraction from 0.33 to 0.04.
Nitrate Reduction and Associated Microbial Populations in a Ponded Hanford Sandy Loam
Authors: Volz M. G. , Belser L. W. , Ardakani M. S. , McLaren A. D.
Published: July 2010

A field plot of Hanford sandy loam was ponded for 2 weeks with a solution of KNO3 and Ca(NO3)2 containing 100 ppm NO3‐N in order to measure short term denitrification rates as well as growth and distribution of bacteria capable of reducing nitrate to nitrite and/or N2O and N2.

Denitrifying bacteria (101−2.9 × 104/g soil) generally decreased in number with depth and time and were not as numerous as nitrate reducers (101−6.9 × 105/g soil).

In the top 60 cm of soil, the concentration of NO2−‐N in soil solution corresponded to minima in NO3−‐N, suggesting that NO3− reduction gave rise to the NO2−. Denitrification rates calculated for the top 16 cm of water‐saturated soil were estimated to range from 0.013 to 0.046 µg N/hour g−1. The highest value was about 80% of that measured in a laboratory soil column studied previously. This difference in denitrification rates may be due to lower soil carbon content in the field.
Occurrence of 2,4,5‐T and Picloram in Subsurface Water in the Blacklands of Texas
Authors: Bovey R. W. , Burnett Earl , Richardson Clarence , Baur J. R. , Merkle M. G. , Kissel D. E.
Published: July 2010

This investigation was conducted to determine the concentration of 2,4,5‐T [(2,4,5‐trichlorophenoxy)acetic acid] and picloram (4‐amino‐3,5,6‐trichloropicolinic acid) in subsurface water after spray applications of the herbicides to the surface of a seepy area watershed and lysimeter in the Blacklands of Texas.

A 1:1 mixture of the triethylamine salts of 2,4,5‐T + picloram was sprayed at 2.24 kg/ha every 6 months on the same area for a total of five applications. Herbicide content in the Houston Black clay during the study ranged from 0 to 162 ppb. Herbicide content on grass was high (28 to 113 ppm) immediately after spraying, but degraded rapidly after each treatment. Concentration of 2,4,5‐T and picloram in seepage and well water from the treated area was extremely low (<1 ppb) during the 3‐year study. No 2,4,5‐T was detected from 122 drainage samples from a field lysimeter sampled for 1 year after treatment with 1.12 kg/ha of 2,4,5‐T + picloram (1:1). Picloram was detected in small amounts (1 to 4 ppb) 2 to 9 months after treatment in lysimeter water.
The Nitrogen Balance of Arctic Tundra: Pathways, Rates, and Environmental Implications
Authors: Barsdate Robert J. , Alexander Vera
Published: July 2010

The magnitude of the inputs and exports of nitrogen was estimated for the tundra ecosystem at Barrow, Alaska. Based on new data and on previous investigations, annual input of nitrogen from all sources was 92.4 mg N/m2 per year, with the most important sources being nitrogen fixation (75%) and ammonia in summer rain (18%). The low input of nitrogen by rain and snow results from both low annual precipitation and extremely low concentrations of nitrogen compounds in precipitation. Despite the meager nitrogen supply, the estimated retention is over 80% of the input, reflecting insignificant leaching due to the impermeable permafrost substrate, low precipitation, and restricted lateral movement of water over and through the nonfrozen soils. Denitrification also is low, at least partially due to nutrient deficiency.

Interpretations of these data in respect to the sensitivity of the environment to perturbations, suggest that resource development or other activities which would have minor or negligible effects in temperate latitudes, could alter substantially the nitrogen balance of this arctic ecosystem.
Rate of Chloride and Water Movement in Southern California Soils
Authors: Tullock R. J. , Coleman N. T. , Pratt P. F.
Published: July 2010

Column experiments in the laboratory showed an increase of 2 to 25% in the relative rate of chloride movement in soils to water when the movement of water was calculated on a total pore‐volume basis. The increase was explained as a result of anion exclusion next to the surfaces of negatively charged soil colloids. The relative rate of flow was decreased when the moisture retained by the air dry soils was deleted from the total pore solution. For soils containing sufficient clay to result in a cation exchange capacity greater than 10 meq/100 g, an equation was developed relating the fraction of the pore solution in equilibrium with anions to the cation exchange capacity. Calculated transit times for anion movement from the soil surface to ground waters should include a correction for the volume of exclusion.
Natural and Agricultural Ecosystems
Authors: Smith D. F. , Hill D. M.
Published: July 2010

It is argued that the task of creating awareness of environmental problems will require more than the bringing together of papers from a range of disciplines. It will depend on new consciousness and channels of communication. As an example of problems with terms, this paper analyses the use of natural and agricultural ecosystems, suggesting that on all valid criteria these form a continuum, rather than two discrete systems.
Oxygen Relationships in a Soil Treated with Sewage Effluent
Authors: Klausner Stuart D. , Kardos Louis T.
Published: July 2010

Field plots which have been irrigated with chlorinated secondary treated sewage effluent were examined for their aeration conditions using diffusion chambers and platinum microelectrodes. Average gaseous oxygen concentrations to a depth of 46 cm ranged from 19.6 to 19.0 to 18.4% as weekly application of effluent changed from 0 cm to 2.5 cm to 5.1 cm. Oxygen diffusion rates (ODR) measured by the polarographic method were not significantly different for the three effluent levels and ranged from 22.9 to 19.5 × 10−8 g O2 cm−2 min−1 from the control plot to the 5.1 cm per week plot. Oxygen diffusion rate values diminished with depth with a minimum of 15 at 46 cm and a maximum of 27 at 8 cm. Gaseous oxygen concentration was not affected by crop cover (corn or hay) but ODR was less under hay than under corn. Water samples obtained at depths of 15.2 and 61 cm with suction lysimeters showed significantly greater NO3−‐N levels in the 5.1 cm effluent treatment plots, in the corn plot and at the 61 cm depth. Nitrite‐N levels were also greater in the 5.1 cm effluent treatment but less in the corn plot than with hay. In all cases, nitrite levels were very low. Ammonium‐N levels were also greater in the 5.1 cm effluent treatment but there were no differences with respect to vegetative cover or soil depth. Manganese and iron levels in the soil water were not affected by effluent treatment. Application of 5.1 cm of sewage effluent at weekly intervals has not degraded the aeration status of the soil.
Nitrate Reduction and Nitrite Utilization by Nitrifiers in an Unsaturated Hanford Sandy Loam
Authors: Volz M. G. , Belser L. W. , Ardakani M. S. , McLaren A. D.
Published: July 2010

In order to discern any relationship between added nitrate and microbial growth in a field plot, a Hanford sandy loam was infiltrated for 5 weeks at a rate of 5 cm day−1 with a solution containing 100 ppm ‐N and 1.25 meq/liter Cl− as KNO3 and CaCl2 respectively. Nitrate‐N, NO2−‐N and Cl− concentrations in soil solution were determined and corresponding counts of nitrate reducers, denitrifiers, and NH4+‐ and NO2−‐oxidizer populations were made.

Ratios of measured to applied concentrations for both NO3−‐N and Cl− were nearly identical in all solution samples taken from the unsaturated soil profile, i.e., nitrate reduction was not pronounced and NO2−‐N was less than 1 ppm.

Nitrate reducer populations (6x104–6x105/g soil) were always larger than those of denitrifiers (3x103–3x104/g) and varied little with time and depth. Ammonium oxidizers (101–105/g) generally decreased with depth. In contrast, NO2− oxidizers (101–3x106/g) varied markedly with time at all depths. An increase in numbers of NO2− oxidizers, after 2 to 3 weeks, at a depth of 60 cm, is attributed to NO2− produced by reduction of NO3− at anoxic microsites within the profile. Evidently, a cyclic oxidation and reduction of nitrite and nitrate, occurring simultaneously, is responsible for growth of nitrite oxidizers in the profile.
Yield and Growth of Corn as Affected by Poultry Manure
Authors: Shortall J. Glenn , Liebhardt William C.
Published: July 2010

The effect of poultry manure on yield and growth of corn was studied on an Elkton sandy loam, typic ochraquults clayey mixed mesic, in southern Delaware. Plots with six levels of manure 0, 22, 56, 90, 168, and 224 metric tons/ha and a fertilizer treatment 224‐5‐186 kg/ha (N‐P‐K) and 22 metric tons/ha manure plus 224‐5‐186 kg/ha (N‐P‐K) were laid out in a randomized block design with four replications in 1971.

Germination and yield of corn (Zea mays L.) were reduced by higher rates of poultry manure. Leaf mineral nutrition, the nitrogen fraction, organic acids, total ethanol soluble sugars, leaf water potential, leaf area index, soil salinity, and soil test data were determined to find the factors that contributed most to the yield reduction. Excessive soil salinity was considered to be the most important cause of the yield reduction following the application of high rates of poultry manure.
Movement of Fluometuron Across and Through the Soil
Authors: Baldwin F. L. , Santelmann P. W. , Davidson J. M.
Published: July 2010

Experiments were conducted to determine the effect of rainfall intensity, antecedent soil moisture, and time and subsequent rainfall on the runoff and leaching of soil‐applied fluometuron [1,1‐dimethyl‐3‐(a,a,a‐trifluoro‐m‐tolyl)urea]. Fluometuron was applied to specially constructed field plots on a 1% slope and a simulated rainfall procedure was used to produce runoff. Runoff water and sediment, as well as vertical soil samples, were collected and analyzed for herbicide concentrations. The highest fluometuron concentrations were found on the sediment portion of the runoff, but the highest losses occurred in the liquid portion of the runoff. These losses were caused by the larger volume of water compared to sediment leaving the plot. The first 3.78 liters of runoff water leaving the plot contained a higher concentration of fluometuron than did a composite of the next 41.6 liters. Antecedent soil moisture had a greater effect on runoff losses than did rainfall intensity. Higher losses occurred when the herbicide was applied to a wet soil than to a dry soil. Fluometuron could not be detected in the runoff water collected 1 month after the first runoff‐producing water application. Total herbicide losses from each experiment were 1% or less of the total amount applied. Fluomeutron was leached to the 5‐ to 10‐cm soil depth with some treatments showing small quantities of herbicide in the 10‐ to 20‐cm layer.
Land Disposal of Broiler Litter—Changes in Soil Potassium, Calcium, and Magnesium
Authors: Jackson W. A. , Leonard R. A. , Wilkinson S. R.
Published: July 2010

Small plots of Cecil soil established in Kentucky‐31 tall fescue were surface applied semi‐annually with 0, 22.4, 44.8, 89.6, and 134.4 metric tons/ha of broiler litter for 2 years. Potassium and magnesium were more completely leached from the litter, 99% and 88% respectively, than calcium. At the end of two years at the highest rate, 80% of the calcium remained in the litter. After each year, chemical analysis of depth‐incremented soil samples, showed the extent of movement and redistribution of water soluble and exchangeable potassium, calcium, and magnesium. The results indicate that land disposal of broiler litter greatly enhances exchangeable K while reducing the exchangeable Ca and Mg.
Growth and Cadmium Accumulation of Plants Grown on a Soil Treated with a Cadmium‐Enriched Sewage Sludge
Authors: Bingham F. T. , Page A. L. , Mahler R. J. , Ganje T. J.
Published: July 2010

Corn, wheat, rice, field bean, soybean, cabbage, spinach, lettuce, curlycress, carrot, turnip, radish, tomato, and squash plants were grown to commercial harvest stage using as the substrate, soil pre‐treated with a municipal sewage sludge (1%) containing variable amounts of CdSO4 up to 640 µg Cd/g soil. Observations included injury symptoms, yield decrement, Cd level of diagnostic tissue, and Cd and Zn content of harvested produce. Cadmium‐sensitive plants such as spinach, soybean, curlycress, and lettuce were injured by soil Cd levels of 4–13 µg Cd/g soil; whereas, tomato and cabbage tolerated soil levels of approximately 170 µg Cd/g soil without exhibiting injury symptoms. Rice was tolerant at all levels tested. Leafy plants such as lettuce, spinach, and turnip greens (tops) accumulated 175 to 354 µg Cd/g; whereas, fruit and seed tissue of plants under comparable treatment, with the exception of soybean, accumulated no more than 10 to 15 µg Cd/g tissue. The concentrations for soybean extended up to 30 µg Cd/g tissue. Paddy rice exhibited no ill effects for soil Cd treatments up to 640 µg Cd/g soil. Grain of plants under the 640 µg Cd/g treatment contained 2 µg Cd/g tissue. DPTA‐extractable Cd correlated (r=0.99) with the level of CdSO4 added to the substrate.
A Six‐Year Water, Phosphorus, and Nitrogen Budget for Shagawa Lake, Minnesota
Authors: Malueg Kenneth W. , Larsen D. Phillips , Schults Donald W. , Mercier Howard T.
Published: July 2010

Water, phosphorus, and nitrogen budgets of eutrophic Shagawa Lake, Minnesota were determined from 1967–1972 to assist in defining the significance of the loading from the city of Ely secondary waste water treatment plant to the trophic state of the lake. Ely's municipal waste water accounted for about 80% of the P, 24% of the N, and only 2% of the water to Shagawa Lake while the major tributary, Burntside River, accounted for 66% of the water, 42% of the N, and only 11% of the P to the lake. An average of 30% of the P was retained within the lake.

The water and nutrient budgets, along with field and laboratory studies, indicated that high levels of P from the municipal waste water treatment plant were mainly responsible for the eutrophic condition of Shagawa Lake. These studies led to the construction of a tertiary waste water treatment plant designed to remove 99+% (⩽ 0.05 mg/liter) of the P from the secondary waste water effluent. Tertiary waste water treatment should increase the N:P ratio supplied to the lake from 10.5 to 50, and would tend to produce a body of water in which P is the limiting factor in primary production. The P specific loading value of 0.73 g P m−2 year−1 will be reduced to 0.15 g P m−2 year−1.
Effect of Incubation and Contact with Soil on Microbial and Nitrogen Changes in Poultry Manure
Authors: Giddens Joel , Rao A. M.
Published: July 2010

Microbial and chemical changes in poultry manure as affected by incubation and contact with soil were studied, as these changes may influence potential pollution hazards. Manure and litter mixed with soil contained greater numbers of bacteria and fungi than manure alone. Fungi decreased rapidly between 7 and 14 days incubation, increasing thereafter. Fungal population was inversely related to soil pH which was directly related to NH3. Total coliform bacteria decreased more rapidly when manure was mixed with soil than when not mixed. Few coliforms survived after 28 days. Higher total coliform survival occurred in the litter than in pure manure indicating a protective effect of wood shavings. Ammonia decreased survival of coliforms. Incorporation of manure into the soil greatly increased the amount of N oxidized to NO3. Split applications of manure reduced soil NO3. Air drying of manure resulted in greater N loss than rapid drying with heat.
Environmental Implications of N Fixation by Soybeans
Authors: Johnson J. W. , Welch L. F. , Kurtz L. T.
Published: July 2010

The objective was to measure inorganic N removal from soil by soybeans (Glycine max L.) grown at different N levels. Nodulating and non‐nodulating isolines of ‘Clark’ soybeans were planted on Flanagan silt loam in 1972 and 1973. Fertilizer rates of 0, 112, 224, and 448 kg N/ha as Ca(NO3)2 enriched with 1% 15N were applied.

Symbiotically fixed N decreased from 48 to 10% of the total N in the above‐ground plant as applied fertilizer N increased from 0 to 448 kg/ha. Net removals of N by soybean grain were 61, 109, 135, and 149 kg/ha at 0, 112, 224, and 448 kg fertilizer N/ha rates, respectively.

Corn (Zea mays L.) grain grown on adjacent plots removed 62, 123, 129, and 133 kg N/ha at fertilizer N rates of 0, 112, 224, and 336 kg/ha, respectively.

The study indicates that soybeans are good scavengers for inorganic N in soils. Inclusion of net N removal by soybeans in the calculated N removed by nonleguminous crops in Illinois from 1945 to 1973 increases net crop N removal by approximately 37%. Added fertilizer N has exceeded the N removed by the harvested portion of Illinois crops in only 5 years since 1945, all 5 of these occurring after 1965.
Phosphorus in Surface Runoff from a Deciduous Forest
Authors: Singer Michael J. , Rust R. H.
Published: July 2010

Phosphorus losses from natural systems are the background levels against which losses from managed systems should be measured. In Minnesota many recreational lakes are surrounded by deciduous and mixed deciduous‐coniferous forests. The P losses from the forests contribute to the natural nutrient levels of the lakes. Phosphorus losses in leaching water are small. Thus, a logical mechanism for the loss of P from forests is surface runoff (overland flow). This research was conducted to study surface runoff amounts and P content.

On a 16% slope, 0.09 kg ha−1 year−1 P of which 0.03 kg was bound to sediment and 0.06 kg was soluble was measured in surface runoff. The major period of runoff was during spring snowmelt when the soil was frozen. The source of P is the litter layer which undergoes freezing and thawing in fall and early winter.
A Comparison of Nitrogen, Phosphorus, and Carbon in Sediments and Soils of Cultivated and Noncultivated Watersheds in the North Central States
Authors: Ritchie Jerry C. , Gill Angela C. , McHenry J. Roger
Published: July 2010

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

Three surface soil samples, contaminated with plutonium by high explosive detonations of subcritical atomic devices at the Nevada Test Site (NTS), were analyzed for total plutonium content, plutonium distribution in different particle sizes, and leachability by HNO3. Total plutonium averaged about 2,640 disintegrations per minute (dpm) per gram of soil. The highest concentration of plutonium in two samples taken from the same area was in the very fine sand (125‐53 µm) fraction (38 and 47%); the third sample from another test area contained the highest concentration in the coarse silt (53‐20 µm) fraction (47%).

Leaching with 8M HNO3 revealed that the extracted plutonium was related to the amount of plutonium associated with the finer sizes of soil particles. The highest extraction of 91% was associated with the sample containing 99% of the plutonium in particles < 125 µm; the lowest extraction (65%) with the lowest amount (55%) in the same size fractions. Density gradient separation of a silt and a clay fraction revealed that the plutonium in the silt size was associated with particles whose density was > 2.8 g/cm3; in the clay size the plutonium was associated with particles < 2.2 g/cm3.
Uptake of Iron and Copper by Sorghum from Mine Tailings
Authors: Fuller Wallace H. , Lanspa Kenneth
Published: July 2010

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

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

A compact clay soil from a playa lake and a relatively porous, blocky, buried soil, both representative of feedyard runoff holding basins in the Texas High Plains, were treated with clear ground water and synthesized feedyard runoff. Infiltration rates were measured by using constant heads of liquid on undisturbed laboratory cores and in field basins.

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

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

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

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

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

A mathematical model has been developed describing the rate and quantity of runoff water from separate rainfall events on a watershed and the rate and quantity of sediment and pesticides transported. The runoff water is calculated by convolving an area‐characteristic and variable state function to produce a variable response function which is then convolved with a computed effective rain. Rill and interrill erosion are conceptually distinguished which allows similar partitioning of associated pesticides. The sediment contribution from interrill erosion is a function of rainfall intensity and soil susceptibility to erosion. The rill erosion is a function of water runoff and the rate of change of water runoff. The concentrations of pesticides in the runoff are functions of the amount of runoff, the sediment concentrations derived from rill and interrill erosion, and the pesticide concentrations in the respective runoff‐erosion zones.

Experience with the model in simulating the water, sediment, and pesticide runoff from an upland Piedmont plain watershed for four summer storms is related. Excellent simulations were obtained.
Nitrogen and Phosphorus Levels in Soils beneath Sewage Disposal Ponds
Authors: Lund L. J. , Page A. L. , Nelson C. O.
Published: July 2010

Soil cores at various depths beneath sewage sludge and effluent ponds at two treatment plant locations were collected and the nature and extent of nitrogen and phosphorus movement in the soil was evaluated. The soil profiles at both treatment plants were open and coarse‐textured. Soils beneath sludge ponds were enriched in total nitrogen to 4 and 8 m, the maximum depths sampled. Compared to controls, effluent ponds used more than 10 to 20 years showed enrichment of total nitrogen to depths as great as 4.0 m. Concentrations of NH4‐N considerably in excess of controls were observed to depths of 4.0 m demonstrating movement of substantial amounts of NH4 in soil below sewage waste water ponds.

Concentrations of NO3‐N in the soil solutions beneath disposal sites considerably in excess of those found below control sites were observed in situations where samples were collected to the water table (8.5 m and 12.0 m), demonstrating movement of NO3‐N the water table. Phosphorus enrichment of soil (NaHCO3 extractable) was evident to depths as great as 3 m below the ponds.
Phosphorus Distribution from Septic Tank Effluent in Coastal Plain Soils
Authors: Reneau R. B. , Pettry D. E.
Published: July 2010

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

This study was prompted by the present controversy over the role that N‐fertilizer use may have in reducing water quality. Our objective was to determine the disposition of N fertilizer (enriched with 15N) applied to level (< 2% slope) Houston Black clay near the economic optimum application rate (112 kg N/ha) for grain sorghum (Sorghum bicolor [L.] Moench). Particular emphasis was placed on determining the amount of applied N which leached below the root zone at different times during and after the growing season. A large, undisturbed, field‐drainage lysimeter was used to measure leaching of NO3−‐N below the root zone.

During spring 1973 94 mm of drainage water containing a mean concentration of 2.4 ppm fertilizer‐derived NO3−‐N percolated through the soil profile. At crop maturity, only 55% of the N applied the previous spring was recovered by the crop or was present in drainage water. Large amounts of N not recovered by the crop were either measured as immobilized N (20% of the applied N) or were unrecovered and assumed denitrified (17%). During fall and winter approximately 120 mm of drainage water containing 0.5 ppm or less fertilizer‐derived NO3−‐N percolated through the soil profile. These results indicate that for rainfall conditions observed in this study (minimal crop water deficit), the application N fertilizer to grain sorghum at the near‐optimum economic rate probably will not seriously reduce ground‐water quality on a swelling clay soil, even though crop recovery of applied N may be low.
Nitrogen in Soil Cores and Ground Water under Abandoned Cattle Feedlots
Authors: Mielke L. N. , Ellis J. R.
Published: July 2010

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

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

Carbaryl (25.4 kg/ha) was applied to a Congaree sandy loam fieldplot containing a shallow (about −1.1 m) water table. Movement and loss in the soil profile, and accumulation in underlying ground water were monitored for 16 months. Rainfall during this time was 182 cm (3.5 pore volumes based on the upper 1 m of soil). The upper 1 m contained about 6% of the applied carbaryl after 16 months. No carbaryl was found in the 0–20 cm layer after the 4th month. Loss of carbaryl with time in the upper 1 m was concentration‐dependent. Time to half‐concentration within the upper 1 m was < 1 month.

Carbaryl appeared in the underlying ground water within 2 months after soil application and persisted through the 8th month. Maximum ground‐water concentration, about 0.3 µmol/liter, occurred at the end of the second month.
Heavy Metals Application and Plant Uptake in a Land Disposal System for Waste Water
Authors: Sidle R. C. , Hook J. E. , Kardos L. T.
Published: July 2010

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