bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Ambient Photochemical Air Pollutants on Growth, Yield, and Ear Characters of Two Sweet Corn Hybrids
Authors: Thompson C. R. , Kats Gerrit , Cameron J. W. 
Published: July 2010

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

AbstractSpring flow and stream base flow sites were sampled weekly on and adjacent to a 123‐ha agricultural watershed in the Allegheny‐Cumberland Plateau physiographic region of east‐central Ohio. Nitrogen content of samples was used to determine the influence of various N fertilizer and crop management practices on the quality of subsurface water draining from defined contributing areas.Measured nitrogen contents of spring flow were related to fertilizer N regime of the different agricultural practices investigated. Changes in land management on the area contributing to spring flow were reflected in changes in nitrogen content of water from that spring. The amount of nitrogen which was transported into the stream channel was directly related to seasonal variation in subsurface flow rate in two ways. First, the concentration of N in spring flow increased with an increase in the amount of water percolating through the overlying soil and shale. Second, the extent to which downstream quality was affected, i.e., the distance from the area of fertilizer application at which an increase in nitrogen content could be detected, also increased with the volume of flow from the springs.
Chemical and Microbial Degradation of Malaoxon in an Illinois Soil
Authors: Paschal Daniel C. , Neville M. E. 
Published: July 2010

AbstractChemical and microbial degradation of malaoxon was studied in an Illinois silty loam. This soil sample is typical of the glacial till soil used for agriculture in the Midwest. This sample had no history of pesticide application and demonstrates high microbial activity as evidenced by rapid degradation of malathion. To differentiate between microbial degradation and chemical decomposition, both heat‐sterilized and nonsterile soil samples were prepared. Because pH has been shown to affect the rate of chemical hydrolysis, samples were adjusted to three different values of pH: 6.2, 7.2, and 8.3. Malaoxon (10 ppm) was added to both sterile and nonsterile samples, and chemical and microbial analyses were performed over a 5‐day period. Chemical analyses were performed as hexane extractions followed by electron capture gas chromatography. Microbial numbers were estimated by conventional dilution and spread‐plate techniques.Half‐lives for malaoxon were determined for the samples. A pronounced effect was noted with pH; malaoxon has a half‐live of approximately 3 days in the basic samples and a half‐life of approximately 7 days in acidic samples. Only a minor effect on half‐lives was noticed from microbial activity. This may be due in part to a demonstrated biocidal effect of malaoxon on soil microorganisms. The disappearance of malaoxon in soil was interpreted to be chemical hydrolysis. The persistence of malaoxon in acidic soils may be of significance in agricultural usage where acidic soils is desirable.
Water Quality as Related to Linears, Rock Chemistry, and Rain Water Chemistry in a Rural Carbonate Terrain
Authors: Wagner George H. , Steele Kenneth F. , MacDonald Harold C. , Coughlin Terry L. 
Published: July 2010

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

AbstractBeef cattle feedlots are a source of large quantities of organic and inorganic nitrogen compounds, among which are the precursors for the synthesis of N‐nitrosamines, compounds carcinogenic to laboratory test animals and, possibly, to man.Our objectives in this study were: (i) to determine if N‐dimethylnitrosamine (DMNA) and N‐diethylnitrosamine (DENA) could be detected in cattle feedlot manure packs; (ii) to identify and quantify nitrosamine precursors; (iii) to determine whether DMNA could be synthesized from dimethylamine (DMA) and nitrite (NO2−) added to manure; and (iv) to determine the stability of DMNA in manures under aerobic and anaerobic conditions.Although the precursors necessary are present in manures, no DMNA or DENA was found at minimum detection limits of 0.02 ppm in manure. Aerobic incubation of manure with DMA‐N (500 ppm) plus NO2−‐N (1,000 ppm) generates detectable DMNA, but DMNA was not detected in samples incubated anaerobically or with lower levels of precursors. DMNA added to manure was relatively stable under both aerobic and anaerobic conditions.
Phosphates in Soils Treated with Sewage Water: II. Fractionation of Accumulated Phosphates
Authors: Beek J. , de Haan F. A. M. , van Riemsdijk W. H. 
Published: July 2010

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

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

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

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

AbstractTo determine if agricultural land could be used simultaneously for crop production and waste disposal‐utilization, a lysimeter study was conducted using liquid sewage sludge and unsorted, pulverized municipal refuse. Refuse (R) at 188 metric tons/ha and a 2.3‐cm depth of sewage sludge (S) were applied separately and in combination (RS). A double refuse‐sludge rate [2(RS)] and a control treatment (C) receiving no additions were also used. Treatments were applied in the fall of 1971 and 1973. The cropping sequence was wintdr fallow—corn (Zea mays L.)—winter fallow—spring barley (Hordeum vulgare L.)—winter rye (Secale cereale L.)—corn.There was no effect of treatment on corn grain yields in 1972 but all treatments containing refuse increased grain yields in 1974. Treatments had little effect on levels of Cr, Fe, Mn, Ni, and Pb in the corn grain and stover. Levels of Zn, Cu, and Cd were increased mainly by treatments containing refuse. The 2(RS) treatment resulted in stover Cd levels greater than the acceptable level for foodstuffs.Nitrate leaching losses were greater for S and RS than C. Although NO3‐N leached from 2(RS) was low, the chemical oxygen demand (COD) concentrations were high (> 1,000 ppm) and cumulative COD loss was 120 times that of the loss from C. The effect of treatment C/N was inconclusive, i.e., mixing sludge (C/N = 4.9) with refuse (C/N = 63) resulted in reduced NO3‐N leaching from RS (C/N = 41) as compared to that from S. However, refuse alone did not cause immobilization because NO3‐N losses from R were identical to those from C.
Solubility and Plant Uptake of Cadmium in Soils Amended with Cadmium and Sewage Sludge
Authors: Street Jimmy J. , Lindsay W. L. , Sabey B. R. 
Published: July 2010

AbstractAdsorption and precipitation of Cd2+ in soil suspensions were investigated as possible factors controlling Cd2+ levels in soils. Both adsorption of Cd2+ onto soils surfaces and possibly precipitation of cadmium minerals were evident in this study. At low cadmium levels solubility relationships in soils are best described by adsorption and fit the empirical Freundlich adsorption isotherm. Based on current thermodynamic data the solid phases CdCO3 (log Ksp = −12.07) and Cd3(PO4)2 (log Ksp = −32.61) most likely limit Cd2+ activities in soils. Under alkaline conditions, Cd2+ activity decreased approximately 100‐fold for each unit increase in pH. In this study, CdCO3 precipitated in sandy soils, having low cation exchange capacity (CEC), low organic matter, and pH values >7.0.DTPA‐extractable cadmium levels in soils were highly correlated (r = 0.96) with Cd concentrations in corn (Zea mays L.) seedlings grown on soils amended with Cd solutions, sewage sludge, or Cd‐spiked sewage sludge. Increasing Cd additions to the soil increased plant Cd regardless of the form of Cd added. Addition of inorganic Cd to the soil increased the Cd concentration of corn seedlings more than equivalent Cd additions in the form of sewage sludge or Cd‐spiked sludge.
The Phosphorus Status of Eutrophic Lake Sediments as Related to Changes in Limnological Conditions—Phosphorus Mineral Components
Authors: Wildung R. E. , Schmidt R. L. , Routson R. C. 
Published: July 2010

AbstractStudies of the relationship between limnological factors and changes in the P status of noncalcareous sediments of a eutrophic lake previously indicated that changes in sediment inorganic P were directly related to the biological productivity of the surface waters. This relationship was particularly pronounced in a shallow bay where sediment P decreased with lake phytoplankton growth and increased with their decline. The present studies were undertaken to identify the inorganic P components responsible for these changes using chemical techniques for characterization of P in sediments where changes occurred.Release of P from sediments during periods of maximal biological productivity in the shallow bay waters was due primarily to reductions in inorganic P mineral components soluble in NaOH (0.1M) and citrate‐dithionite, suggesting that P associated with hydrated Fe oxides was the principal source of P to the overlying waters and to the biota. Increases in sediment inorganic P, which occurred when phytoplankton growth diminished, were due principally to increases in P mineral components soluble in NH4F, indicating that resorbed P was F‐exchangeable and/or associated with crystalline and amorphous Al‐P components. Changes in the form of sediment P which occurred in the lake and in laboratory equilibrium studies, indicated that conversion of resorbed NH4F soluble‐P to NaOH (0.1M) and citrate‐dithionite soluble‐P, must be a relatively long term (>2 years) process. Taken together, the NH4F, NaOH (0.1M), and citrate‐dithionite fractions accounted for approximately 85% of the seasonal variance in total inorganic P which occurred at all sampling locations in the lake system.
Persistence and Activity of Dinitroaniline Herbicides in Soil
Authors: Stoller E. W. , Wax L. M. 
Published: July 2010

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

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

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

AbstractAgriculture has been identified as a major contributor of pollutants to surface waters. The purpose of this investigation was to gain knowledge of pollutants and pollutant loads carried in surface return flows to receiving waters. Information of this nature is needed by those agencies having administrative responsibility for water quality control. Quantitative and qualitative measurements of irrigation applications (head water) and surface return flows (tail water) were conducted on four sites at three locations in the Carson Valley area of Nevada to investigate the change in pollutant loads of surface waters entering the leaving agricultural units. Dissolved oxygen (DO), biochemical oxygen demand (BOD), total dissolved solids (TDS), NO3‐N, PO4‐P, SO4, and turbidity were considered as major constituents of water quality. Concentrations were combined with flow volumes to compute the constituent loading per irrigation and net infiltrated amounts or seasonal contributions in the surface return flow. Phosphorus and BOD were found to be the major agricultural pollutants contributed by irrigation surface return flows. Net infiltrated amounts of TDS, NO3‐N, and other soluble constituents were recorded. Dissolved oxygen concentrations in head and tail waters were found to be critically low. River standards for DO might be better expressed as a maximum permissible dissolved oxygen deficit (DOd) for water at a given temperature carrying a given amount of BOD. Additional investigations should be undertaken to delineate possible interactions among pollutant constituents. Water quality variations of individual samples should be expressed in statistical terms so that it is possible to identify pollutant interdependencies and to establish an optimized sampling frequency.
Effects of Increased Fertilizer Rates on Nitrogen Content of Runoff and Percolate From Monolith Lysimeters
Authors: Chichester F. W. 
Published: July 2010

AbstractNitrogen (N) fertilizer was applied to meadow (Danthonia spicata L., Poa pratensis L., and Medicago sativa L. Dactylis glomerata L.)‐ and corn (Zea mays L.)‐cropped lysimeters at rates up to 322 and 672 kg/ha per year, respectively, to determine the effects on chemical quality of surface and subsurface water. Runoff and percolate samples collected from May 1971 through April 1975 were analyzed for inorganic and total N content. Results were evaluated from crop and soil cover treatment differences and compared with data from a similar, earlier study on the same lysimeters in which very low rates of N fertilizer were used.Nitrogen losses in runoff were greatest in the summer when intense rainfall events occurred shortly after the date of fertilizer application. Quantities of N transported in surface water decreased as the amount of effective soil cover increased. The N losses ranged from < 1 kg/ha per year for meadow to 10 kg/ha per year for clean cultivated corn.Nitrogen loss by leaching was greatest during the winter when percolation rates increased because of low evapotranspirational demand. Differences observed among management practices were primarily a function of the levels of soluble N remaining in the soil at the end of the growing season. Nitrogen flux was < 10 kg/ha per year under meadow, with N concentrations in the percolate not exceeding the 10 ppm NO3‐N level recommended for potable water by the U. S. Public Health Service. More than 250 kg/ha per year of N loss was measured under corn, with N concentrations in percolating water attaining 70 ppm—far in excess of recommended levels.Results of this study demonstrated that improved fertilizer management, involving application rates in balance with crop nutrient requirements, soil incorporation of fertilizer materials, and adequate soil cover, will minimize runoff and leaching losses which reduce fertilizer efficiency and adversely affect water quality.