bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Denitrification in Soils by Additions of Sulfur as an Energy Source
Authors: Mann L. D. , Focht D. D. , Joseph H. A. , Stolzy L. H.
Published: July 2010

Denitrification rates were studied in four large soil columns using Hanford sandy loam and Moreno silty clay loam soils. One column of each soil was amended with sulfur to serve as an energy source for the bacterium Thiobacillus denitrificans. Limestone was also added as a pH buffer. The other column of each soil was left untreated to serve as a control. A solution of Ca(NO3)2 containing 425 ppm NO3‐N was perfused continuously through the columns. The columns were monitored periodically at depths of 10, 30, 50, 70, and 90 cm for nitrate, nitrite, redox potential (Eh) and microbial numbers. Highly anaerobic conditions developed in all columns as was evidenced by low Eh values at each depth. All of the nitrate was reduced in each column, and nitrates penetrated to lower depths in the untreated columns. Nitrite concentrations were found to be negligible. Denitrification rate constants were established as 0.174, 0.520, 0.186, and 1.426 days−1, for the Hanford‐untreated, Hanford‐treated, Morneo‐untreated, and Moreno‐treated columns, respectively. Sulfur additions to field soils which are low in microbial energy sources could be an effective method of reducing the nitrate level in waters percolating through the profile.
Sediment‐Water Interactions
Authors: Oschwald W. R.
Published: July 2010

Sediment originating from soil erosion has physical, chemical, and biological effects on water resource use. Sediment particles pollute water to the extent that their presence reduces water quality for a particular use.

The physical presence of sediment produces turbidity. Turbid water has impaired water quality for most uses. Reduction in light penetration due to suspended sediment may alter oxygen relationships in surface water. Production of fish and other aquatic life is reduced by excess turbidity. Taste and odor, temperature, and abrasiveness of water may be altered by the physical presence of sediment.

Sediment in water provides a surface for the sorption and desorption of potential pollutants. The sediment particles may scavenge or remove substances such as nutrients, pesticides, heavy metals, and radioactive isotopes from water. The sorbed substances may be fixed so that they no longer are available as pollutants. They may be contacted by aquatic organisms and concentrated, in the aquatic food chain. Deposits of sediments with their sorbed constituents may be buried by later deposition. The buried deposits may be re‐exposed or transported to new locations. The effects of sorption and desorption may be different in short term and long term periods.

Sediment influences eutrophication through deposition of sediments and through nutrients released from the sediments. The deposition effects are more obvious and may have a greater effect on eutrophication than the nutrients in the sediments.
Bionomics and Integrated Control of Plant Parasitic Nematodes
Authors: Good J. M.
Published: July 2010

Plant parasitic nematodes occur naturally in undisturbed soils. Establishment of an agroecosystem promotes the rapid increase of endemic pathogenic species and allows introduction of nonendemic species that quickly establish dominance. Nematodes now cause about 10% loss of yields of crops in the United States. About 20 highly effective nematicides are available to control nematodes and associated plant diseases in a number of crops. Nematode populations can be regulated by a number of soil management practices, including clean transplant, seed production, and crop rotations. Biological control can be achieved by addition of various types of organic matter to soil, some of which are not presently utilized, especially biodegradable solid waste. Over 152 nematode‐resistant crop varieties representing 17 major crops are available with resistance from one to three species of the 10 most destructive nematode types. Physical methods of control, including quarantine, sanitation, and crop destruction, are not vigorously applied. All methods available for nematode control have not been utilized in integrated control systems. Further research and development will allow use of integrated management systems, using several basically different approaches to nematode control, with nematicides used to supplement other control methods.
Mild Thermal Degradation of Pesticides
Authors: Stojanovic B. J. , Hutto Fay , Kennedy M. V. , Shuman F. L.
Published: July 2010

Partial degradation of 12 selected analytical grade pesticides was produced by heating the chemicals at temperatures between 100 and 400C. Each pesticide was modified physically and chemically at a temperature at least 300–450C below its complete combustion temperature. At these relatively low temperatures eight of the original nine solids (zineb, picloram, dieldrin, atrazine, bromacil, carbaryl, DNBP, and 2,4‐D) remained solid, while dicamba was converted to a liquid. The three liquids (DBCP, vernolate, and malathion) were all converted to solids. Eight of the original 12 compounds also yielded gray to brown to black residues upon heating. Infrared spectroscopic analyses indicated that the extent of degradation of the heated pesticides ranged from formation of a single degradation product to production of a mixture of compounds. Most pesticides, however, were degraded through loss of one or two substituents of the molecule by processes such as dehalogenation and decarboxylation.
Leachate Quality from Acidic Mine Spoil Fertilized with Liquid Digested Sewage Sludge
Authors: Peterson J. R. , Gschwind John
Published: July 2010

The leachate quality from an acidic mine spoil was upgraded by the addition of liquid digested sludge. Mixing liquid sludge with acidic spoil material (pH 2.5) at a w/w ratio of 1:37 (61 metric tons/ha, dry basis), reduced leachate constituents as follows: total acidity, 17%; Al, 99%; Fe, 80%; and soluble salts, 41% for this 110‐day study. During this period leachate showed increases in: NH3‐N, 1689%; SO4, 49%; Zn, 1941%; and Mg, 827%. The pH of this leachate increased immediately to 4.6 (check column remained near 2.5) and continued with a gradual neutralization. The mixing of sludge with this spoil material at a w/w ratio of 1:18 (122 metric tons/ha, dry basis) was the second most efficient for water amelioration. This leachate had an immediate pH increase of 4.5 and an eventual increase to pH 8, a 99% reduction in Al, an increase in NH3‐N by 3131%, and total P by 1069% over the check column leachate. A third ratio of sludge to acidic soil of 1:37 mixed in the top quarter of the column showed the least leachate amelioration, but after 30 days of leaching, nitrification began in this column, indicating aerobiosis and a pH of > 5.4 in a part of the soil column. The columns were leached 1 hour/day with 1.36 cm of aerated deionized water so that unsaturated flow occurred during a part of each day.
Use of Municipal Compost in Reclamation of Phosphate‐Mining Sand Tailings
Authors: Hortenstine C. C. , Rothwell D. F.
Published: July 2010

Phosphate mining produces sand tailings that are nearly sterile and almost void of plant nutrients (except for relatively insoluble P). Tailings are pumped onto sections of land to a depth of 5 to 7 m after the phosphate has been removed in the flotation process. The reclamation of sand tailings presents a unique challenge in that there is no organic matter present and fertility approaches zero. An investigation was initiated in May 1968 to study the effects of compost and fertilizer on sand tailings. Composted municipal refuse (compost) was incorporated into the top 15 cm of tailings at rates of 35 and 70 metric tons/ha with and without N‐P‐K fertilizer. Compost and fertilizer were reapplied in 1969. Sorghum (Sorghum bicolor L. Moench.) and oats (Avena sativa L.) were planted in May and October of each year. Cation‐exchange capacity, water‐holding capacity, electrical conductivity, organic matter, and K‐Ca‐Mg contents of the sand tailings were increased by compost applications. Plant growth was relatively poor and yields were minimal; however, forage yields were increased greatly where compost and fertilizer were applied together as compared to where fertilizer was applied alone. Both sorghum and oat yields from compost without fertilizer were a fraction of yields where mineral fertilizer was applied.
Land Disposal of Liquid Sewage Sludge: II. The Effect on Soil pH, Manganese, Zinc, and Growth and Chemical Composition of Rye (Secale cereale L.)
Authors: King Larry D. , Morris H. D.
Published: July 2010

Rye was seeded in October 1969 and 1970 in a Coastal bermudagrass (Cynodon dactylon L. Pers.) sod on Cecil sandy clay loam to determine the residual effect of four rates of liquid sewage sludge and one chemical fertilizer treatment applied the previous summer. Sludge rates of 0.63, 1.25, 2.5, and 5.0 cm were applied in such a manner as to supply 4.4, 8.8, 10, and 20 cm of sludge, respectively, in 1969 and 2.5, 5.0, 10 and 20 cm, respectively, in 1970. Chemical fertilizer supplied 224‐37‐93 kg/ha of NPK in 1969 and 358‐112‐224 in 1970. The chemical fertilizer plots also received 56‐25‐47 kg/ha of NPK in October when the rye was planted and 84 kg/ha of N the following February. Soil and the accumulated sludge crust were sampled and lime (6.7 metric tons/ha) applied as a split plot treatment just prior to planting rye in 1970.

Sludge treatments decreased soil pH and increased exchangeable and water‐soluble Mn and exchangeable Zn in the soil. Up to 29 kg/ha of exchangeable and 12.7 kg/ha of water‐soluble Zn was found in the sludge crust. In 1969‐70 and at the zero lime rate in 1970‐71 maximum rye yields were obtained with chemical fertilizer and the 1.25‐ and 2.5‐cm rate. With lime there were no significant differences among the 0.63‐, 1.25‐, and 2.5‐cm rates and chemical fertilizer. In 1969–70 and at both lime rates in 1970–71 yields were reduced by the 5‐cm rate as compared to the 1.25‐ and 2.5‐cm rates. Significant yield increases due to liming occurred at the 5‐cm rate only. Reduced yields at the 5‐cm rate were probably due to high forage levels of Zn and possibly Cu rather than deficiencies of N, P, K, Ca, or Mg or high levels of Mn, B, Mo, or Al.
Land Disposal of Liquid Sewage Sludge: III. The Effect on Soil Nitrate
Authors: King Larry D. , Morris H. D.
Published: July 2010

A field experiment was conducted over a 2‐year period to determine the effect of liquid sewage sludge on soil nitrate content of a Cecil sandy clay loam (Typic Hapludults) to a 120‐cm depth. Periodic applications of four rates of sludge to coastal bermudagrass (Cynodon dactylon L. Pers.) supplied a total of 4.4, 8.8, 10.0 and 20.0 cm of sludge in 1969 and 2.5, 5.0, 10.0, and 20.0 cm in 1970. Respective amounts of N applied by the four rates were 1,037, 2,074, 2,580, and 5,160 kg/ha in 1969 and 492, 984, 1.970, and 3,940 kg/ha in 1970. A chemical fertilizer treatment supplied 364 kg/ha of N in 1969 and 489 kg/ha in 1970. The two highest sludge rates affected significant increases in soil nitrate in the 0‐ to 120‐cm profile. The other two sludge rates and the chemical fertilizer treatment did not increase soil nitrate and were deemed safe from the standpoint of potential groundwater pollution. At the 20‐cm rate 40% (287 kg/ha) of the NO3‐N present in the 0‐ to 120‐cm profile in October 1970 could not be accounted for the following May. Of the N supplied by the 10‐ and 20‐cm applications, 17 and 9%, respectively, was recovered through crop uptake while 56 and 54% remained in the sludge crust that had accumulated on the soil surface.
Differential Effect of Fungicides on Ozone Injury and Brown Spot Disease of Tobacco
Authors: Reinert Richard A. , Spurr Harvey W.
Published: July 2010

The differential effects of fungicidal applications on the incidence of ozone injury and injury from Atlernaria alternata Fr. Keissel infection on tobacco Nicotiana tabacum L. leaves were investigated. Spray applications of methyl 1‐butylcarbamoyl‐2‐benzimidazolecarbamate (benomyl) were made to two cigar wrapper cultivars, ‘Bel W3’ and ‘Florida 2612’ in the field. Applications of dodecylguanidine acetate (dodine) and manganous ethylenebisdithiocarbamate (maneb) were also observed on tobacco cultivar Bel W3. The ozone and A. alternata injuries were observed before and after fungicidal applications. All of the fungicidal applications significantly decreased ozone injury to tobacco leaves. Benomyl was most effective, decreasing leaf injury by 59%. Maneb and dodine were less effective. Maneb significantly decreased brown spot by 66% and benomyl and dodine produced smaller decreases in brown spot. The results demonstrated the differential responses of these two leaf diseases to fungicidal applications.
The Nitrogen Cycle in Sediment‐Water Systems
Authors: Keeney D. R.
Published: July 2010

The available literature on the fate of nitrogen in waters and sediments is reviewed. Emphasis is placed on the importance of N to aquatic productivity, the pathways leading to N gains or losses in aquatic ecosystems, and the availability of N in sediments to the overlying waters. Important biological reactions include N mineralization and immobilization, nitrification and denitrification, and N fixation. The effect of sediment properties, lake morphology and environmental factors (pH, temperature, dissolved oxygen, oxidation‐reduction potential) on the pathways and rates of turnover are considered. The mixing process in sediments appear to be the most important in releasing sediment‐N to waters. Several facets of the N cycle in waters and sediments require further elucidation. Research needs are outlined.
Carbon Cycle in Sediment‐Water Systems,
Authors: Kerr Pat C. , Brockway D. L. , Paris Doris F. , Craven S. E.
Published: July 2010

The availability of the specific molecular forms of carbon needed by different organisms regulates species selection, morphogenic response, and production of biomass.

This paper reviews the literature relevant to the extent and rate of carbon exchange between sediment and water and discusses the general implication of the role of carbon in regulating biological activity.
A Review of Transuranic Elements in Soils, Plants, and Animals
Authors: Price Keith R.
Published: July 2010

Published information concerning the distribution and fate of neptunium, plutonium, americium, and curium in terrestrial ecosystems is reviewed, and areas needing further study are identified. In the final analysis of environmental quality, radionuclides with very long half lives will become increasingly important to man as they continually constitute a greater proportion of environmental radioactivity. The transuranic elements have been identified as the most hazardous radionuclide by‐products of nuclear reactor operations. The relatively few studies conducted indicate that transuranic elements do not remain in solution in soils, plants, or animals, but organic complexes and chelation greatly enhance mobility. The elucidation of natural organic complexes and chelating agents has not been attempted. Oxidation state also influences mobility, but possible biological mechanisms permitting oxidation or reduction remain uninvestigated. Ingestion is the most important transfer mechanism in ecosystems, but assimilation of transuranics from natural food sources is mostly unknown. Evidence in the literature suggests three possible mechanisms leading to the observed increase in plant uptake with time: the formation of organic complexes or chelates, a buildup of radionuclide concentration at root surface, or the slow but continual uptake by perennial plants. Each of these mechanisms deserves further study.
Plutonium Mobility in Soil and Uptake in Plants: A Review
Authors: Francis C. W.
Published: July 2010

A survey of the published literature pertaining to the movement of plutonium in soil and uptake in plants reveals that a major portion of the investigations pertain to soils developed under arid or semiarid climates. In some instances subsoil samples were used to describe plutonium adsorption characteristics and often short‐term greenhouse experiments were used to predict plant uptake. Some recent long‐term greenhouse studies indicate a substantially greater plant uptake of plutonium from a highly contaminated soil after 5 years of cropping as compared to the first year. It appears the most likely mode of plutonium entry into food chains leading to man would be that chelated with naturally occurring organic soil components. Chelation mechanisms have not been established.
Water‐Leachable Nutrients from Frozen or Dried Prairie Vegetation
Authors: White E. M.
Published: July 2010

Runoff from agricultural lands in South Dakota is mainly from melting snow and spring rains. Nutrient enrichment of this water may be enhanced during the fall and winter by the rupturing of plant cells by freezing. Native prairie vegetation and mulch were sampled in late summer, early fall, and spring to determine the effect freezing, in comparison to drying, would have on nutrient release to water. Release of Ca, Mg, K, P, NO3‐N, and NH4‐N by freezing was related to stage of growth or decomposition of the vegetation. Freezing increased nutrient release if the vegetation were growing when it was frozen. Soil genesis, ecological relations between plant species, and runoff water quality could be affected by the relative release of different kinds of nutrients.
Effect of Bulk Density on the Diffusion and Volatilization of Dieldrin from Soil
Authors: Farmer W. J. , Igue K. , Spencer W. F.
Published: July 2010

The rate of volatilization of dieldrin from a buried soil layer generally increased as the bulk density of an overlying soil layer decreased. The rate of diffusion through soil and, therefore, the rate of volatilization is controlled by the bulk density of the soil. The rate of volatilization of dieldrin from a buried soil layer increased with time, reaching a maximum level when diffusion through the overlying soil layer neared a steady state. The volatility rate was proportional to the initial dieldrin concentration in the buried soil layer. The volatilization of dieldrin from treated soil is concluded to be controlled by a diffusion process once the surface soil pesticide concentration is reduced.
Recycling and Recovery of Nitrogen, Phosphorus, and Potassium by Coastal Bermudagrass: I. Effect of Sources and Rates of Nitrogen Under a Clipping System
Authors: Matocha J. E. , Rouquette F. M. , Duble R. L.
Published: July 2010

A field experiment was conducted to determine recovery efficiencies for applied N, P, and K under a system of total removal of forage (Cynodon dactylon L. Pers. ‘Coastal’) over a 3‐year period. Ammonium nitrate, (NH2)2CO, and (NH4)2SO4 were each applied in split applications of 0, 280, 560, and 840 kg N/ha each season. Soil levels of total N, chemically extractable P, and K were monitored each season. Results show that N recovery percentages ranged in the following order: (NH4)2SO4>NH4NO3 > (NH2)2CO. Characteristic decreases in recoveries occurred with increasing N rates. Source effects on recovery efficiencies for P were as follows: NH4NO3 ⩾ (NH4)2SO4 > (NH2)2CO. Average P recovery percentages for NH4NO3 were 34, 46, and 52% for rates of 280, 560, and 840 kg N/ha, respectively. Plant recovery of applied K was greatest for (NH4)2SO4 and lowest for (NH2)2CO. Average values for (NH4)2SO4 were 108, 165, and 222% for the low, medium, and high rates of N, respectively. Ammonium sulfate gave greater accumulation of soil N with time than NH4NO3 or (NH2)2CO while chemically extractable soil P and K were highest for NH4NO3.
Degradation of 2,4‐D and Atrazine at Three Soil Depths in the Field
Authors: Lavy T. L. , Roeth F. W. , Fenster C. R.
Published: July 2010

Soil from three depths was treated with (2,4‐dichlorophenoxy) acetic acid (2,4‐D) and 2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine (atrazine) and buried in the soil profile for 5, 17, 29 and 41 months at two locations in Nebraska. Degradation of 2,4‐D stored in field pits at 15‐, 40‐, and 90‐cm depths was rapid under aerobic soil conditions at both locations. Rates of atrazine degradation decreased with increasing soil depths. In Sharpsburg silty clay loam, phytotoxic amounts of atrazine dissipated during the first 5 months at the 15‐cm depth, and during the first 17 months at the 40‐cm depth. Atrazine treated samples buried at 90 cm in the same profile contained phytotoxic amounts of atrazine after 41 months as shown by a soybean bioassay and gas chromatographic analysis.
Agronomic Potential of Nectariless Cotton
Authors: Meredith William R. , Ranney C. D. , Laster M. L. , Bridge R. R.
Published: July 2010

We compared three BC6F4 nectariless strains of cotton (Gossypium hirsutum L.) with their recurrent parent varieties for yield, yield components, and fiber properties at six environments in 1971. A slight decrease (4.3%) in yield for nectariless ‘Stoneville 7A’ and a slight increase (3.8%) in yield for nectariless ‘Deltapine Smooth Leaf’ was detected. Nectaried and nectariless ‘Dixie King’ did not differ in yield. Nectariless strains, especially Deltapine Smooth Leaf tended to mature earlier. Slight but inconsistent differences in yield components of nectariless and nectaried strains were detected. Nectariless cottons tended to have shorter fibers.

Significant genetic variability within BC6F3 nectariless populations of Stoneville 7A was detected, indicating that we were not working with isogenic nectariless varieties. Selection within BC5 nectariless Stoneville 7A resulted in yield improvement equal to that of nectaried Stoneville 7A. Fiber properties between nectaried and nectariless strains were essentially the same.

The nectariless trait reduced boll rot. While the results from large field test were inconclusive, there were fewer tarnished plant bugs, fleahoppers, and less bollworm damage in nectariless cotton. Two predatory insects, lady beetles and big‐eyed bugs, were not affected by the presence or absence of nectaries.

We detected no strong deleterious associations of nectariless and agronomic performance. This trait appears to have a good potential for insect and boll rot suppression in the Mississippi Delta.
Salinity‐Ozone Interactive Effects on Yield and Water Relations of Pinto Bean
Authors: Hoffman G. J. , Maas E. V. , Rawlins S. L.
Published: July 2010

The interaction of salinity and ozone on the growth of pinto bean (Phaseolus vulgaris L.) was evaluated in a controlled temperature light room. Salinity treatments having osmotic potentials of −0.4, −2.0, and −4.0 bars were studied in combination with 2‐hour daily exposures to 0, 0.15, 0.25, and 0.35 ppm of ozone.

Ozone at 0.15 ppm decreased the yield of nonsaline plants nearly 50%; and at 0.25 ppm and higher, no significant yield was obtained. The results were essentially the same for plants salinized to −2.0 bars. At −4.0 bars, the yield at 0.25 ppm was only reduced to half that of the ozone‐free treatment. The results indicate no interaction between salinity and ozone below 0.15 ppm. Above 0.15 ppm, however, there is a large interaction. At salinities of −0.4 and −2.0 bars, water‐use efficiency decreased as ozone increased. Ozone did not appear to influence leaf water potential or its components.
Lead Uptake by Selected Tree Seedlings
Authors: Rolfe Gary L.
Published: July 2010

Most of the numerous investigations concerning Pb in the environment have dealt with the Pb concentrations in various environmental components. These investigations have failed to describe the movement of Pb in the environment and factors influencing this movement. Several sources including soil, water, and air give rise to Pb in plants. Soil as a source of Pb is the concern of this study.

The experiment was a completely random design in a factorial arrangement with eight tree species, five soil Pb levels (0 to 600 ppm), three soil types, and two phosphate levels (0 to 336 kg/ha) replicated three times.

Results indicate statistically significant levels of Pb in the leaves, stems, and roots of all eight tree species with all treatment combinations except the control. Uptake was significantly affected by soil Pb concentration with higher uptakes associated with higher soil Pb levels. Lead uptake by plants was reduced by approximately half when high levels of soil P were present. Other soil factors had no significant effects on Pb uptake in the study.
Environmental Control in Animal Shelters Using Power Plant Thermal Effluents
Authors: Hirst Eric
Published: July 2010

Waste heat could be used by farmers to provide environmental control for broilers and swine. The amount of waste heat which could be so used is about 1 to 2% of the total available from electric power plants. A proposed system for using waste heat involves conventional pad and fan systems with finned‐tube coils mounted downstream of the pads. The potential savings to farmers in fuel and feed costs are significant. However, major problems exist which must be investigated to determine whether incentives exist to develop and implement such systems. These problems include economics, management, marketing, disposal of animal wastes, dispersion of farming units, size of agricultural operation, climate, and seasonality of waste heat demands.
Heat Transfer Models for a Subsurface, Water Pipe, Soil‐Warming System
Authors: Kendrick J. H. , Havens J. A.
Published: July 2010

Mathematical models are developed for the prediction of heat losses from subsurface pipes carrying hot water. The method of images is used to calculate the heat loss from a hot water pipe buried at a given depth below the surface of a homogeneous soil with a constant soil surface temperature. The heat loss is described as a function of the difference between the temperature of the water and the temperature of the soil surface. The energy balance is used to determine the longitudinal temperature distribution of the water. The method is extended to describe the heat loss and the longitudinal temperature distribution for a system of equally spaced, parallel, subsurface pipes with water flowing in the same direction in neighboring pipes. Finally, the method is extended to calculate the heat loss and the longitudinal temperature distribution for a system of equally spaced, parallel, subsurface pipes with water flowing in opposite directions in neighboring pipes. Soil temperature profiles around the buried pipes are presented. The models are used to calculate the land area which can be heated with an underground piping system carrying the cooling water from the condensers of a 1000‐megawatt nuclear‐powered steam generation electric power plant.
Heat Budget of Cooling Basins
Authors: Lindstrom F. T. , Boersma L.
Published: July 2010

A system of open water basins which allows beneficial use of heated discharges from thermal power stations while at the same time providing a heatsink is proposed. These are large, shallow compartments filled with water which is well mixed, while cooling water is pumped through conduits below the basins. They might be used for the production of single‐cell protein and fish. Equations were derived for the temperature distribution in the warm water conduit and basins of the system used in conjunction with a 1000‐megawatt electric power plant. The rate of heat loss is controlled by the rate of heat loss at the air‐water interface which may vary widely as a function of windspeed and relative humidity. The rate of heat exchange between the basins and the conduits was not critical. The surface area of basins required may vary from about 100 ha to over 500 ha.

For a constant surface area of the basins the temperature of the cooling water would fluctuate as a result of changing rates of heat loss. It might be difficult to develop commercial uses for a large number of basins. Use of such basins in conjunction with other methods of heat dispersion is therefore suggested.
The Effects of Herbicides on Soybean Seed Constituents
Authors: Stoller E. W. , Weber E. J. , Wax L. M.
Published: July 2010

The effects of 24 herbicides on soybean [Glycine max (L.) Merr.] seed yield, weight, protein, nonprotein nitrogen, oil, and fatty acid composition were investigated for several cultivars in 1969, 1970, and 1971 at Urbana, Illinois. Significant, but very small alterations in the measured parameters were noted for some herbicides, applied alone or in combination. The greatest difference observed was a reduction in seed yield due to injury from excessive herbicide rates or competition from weeds not controlled. The practical importance of the apparent alterations in seed composition caused by the herbicides is considered inconsequential.
Effects of Air Pollution on Maryland (Type 32) Tobacco
Authors: Menser H. A. , Hodges G. H. , McKee C. G.
Published: July 2010

Six Maryland tobacco (Nicotiana tabacum L.) cultivars were tested for resistance to air pollutants. Fumigation chamber tests disclosed that ozone used at 5 pphm for 6 hours destroyed about 10% of the leaves of ‘Catterton’, and injured 5 to 8% of the leaves of other cultivars. Ozone administered for three hours at 15 pphm damaged about one‐third of the leaves and injured about two‐thirds of the leaf surfaces when the concentration was increased to 30 pphm. When plants were exposed to 22 pphm for 3 hours, injury was 2 to 8% greater than was observed at 15 pphm. ‘Wilson’ was more resistant to ozone than ‘Maryland 10’, ‘Maryland 59’, ‘Maryland 64’, ‘Maryland 609’, and Catterton. Maryland 10 and Maryland 59 tended to be as ozone‐susceptible as Catterton. Maryland 64 and Maryland 609 resembled the ozone response of Wilson. None of the differences in susceptibility were statistically significant except between Catterton and Wilson.

Ozone and sulfur dioxide mixtures acted synergistically to inflict ozone‐type symptoms on all Maryland cultivars. No injury resulted when plants were fumigated singly for 4 hours with ozone at 3 to 3.5 pphm and sulfur dioxide at 45 to 50 pphm. The combination of these gases at the same concentrations and time interval produced 5 to 15% leaf injury. Twice as much injury occurred when mixed gases were used for 2 hours at 10 to 12 pphm ozone and 45 to 50 pphm sulfur dioxide. Sulfur dioxide injury thresholds were barely reached by a 3‐hour exposure at 150 pphm. Estimated injury ranged from 2 to 6%.

Stomatal characteristics of the six cultivars varied within a 3 cm2 area of a leaf at prime ozone susceptibility. Stomatal frequency may have been a more important factor controlling ozone injury than the diameter of apertures. Catterton and Maryland 10 showed almost 10 stomata/field compared to 6 stomata/field on leaves of Wilson.

Field studies in the five‐county Southern Maryland District disclosed a general correlation between resistance to ozone and resistance to weather fleck. Wilson, Maryland 64, and Maryland 609 were more fleck tolerant than Maryland 10, Maryland 59, and Catterton. Fleck was more severe in counties that were adjacent to Washington, D. C., and Baltimore, Maryland. Extensive fleck damage occurred, however, at a location 42 miles south/southeast of the District of Columbia. The severity of symptoms on Maryland cultivars and on such fleck‐susceptible cultivars as ‘BeI‐W3’, ‘Burley 21’, and ‘Havana 142’ suggested that during periods of air stagnation, oxidants probably exceed 10 pphm (Mast) throughout most of the Type 32 area, and are responsible for most of the fleck damage.
Responses of Plant Parasitic and Saprophytic Nematode Populations to Composted Municipal Refuse
Authors: Hunt P. G. , Hortenstine C. C. , Smart G. C.
Published: July 2010

The effective disposal of composted municipal refuse poses important ecological problems. Efforts to recycle this material must be guided by knowledge of its ecological impact upon a natural environment. The influence on nematode populations of incorporating composted municipal refuse in Leon fine sand was investigated over a period of 2 years. This study was a randomized complete block experiment with oat (Avena sativa L.) and sorghum (Sorghum bicolor L. Moench) used as test crops. Mineral fertilizer (10‐4.4‐8.3) applied at the rate of 0.9 tons/ha was compared with compost applied at rates of 1, 2, 4, 8, 16, or 32 tons/ha. Populations of Helicotylenchus spp., plant parasitic nematodes, were highest in the fertilized and lowest in the 8, 16, and 32 tons/ha compost plots. Populations of another parasitic nematode, Criconemoides spp., were not greatly reduced by compost. Populations of cephalobids and rhabditids (saprophagous nematodes) were highest in the soil receiving 32 tons/ha of compost.
Suppression of Ozone Injury to Phaseolus vulgaris L. with Thiophanate Ethyl and its Methyl Analogue
Authors: Seem R. C. , Cole H. , Lacasse N. L.
Published: July 2010

Two systemic fungicides, 1,2‐bis (3‐ethoxycarbonyl‐2‐thioureido) benzene (thiophanate ethyl) and 1,2‐bis (3‐methoxycarbonyl‐2‐thioureido) benzene (thiophanate methyl) were tested for their ability to suppress ozone injury to Phaseolus vulgaris L. ‘Pinto III’ bean seedlings in greenhouse‐grown plants fumigated with air containing 25–35 pphm of ozone for 4 hours. Treatments included foliar sprays of 100, 500, and 1,000 µg fungicide/ml of spray solution and soil amendments of 50, 100, 200, and 500 µg/g soil. Thiophanate ethyl resulted in significant reduction of injury at foliar spray dosages as low as 500 µg per ml solution and soil amendment levels as low as 100 µg per g soil. Nearly complete protection was achieved at 200 µg/g soil. Thiophanate methyl provided significant protection as a foliar spray at dosages of 500 and 100 µg/ml spray solution; when used as a soil amendment, results were inconsistent. Internode shortening with a mottled greening and yellowing effect was noted at the higher levels of thiophanate methyl foliar sprays and soil amendments.
Chlorinated Hydrocarbon Insecticide Residues in Crops and Soil
Authors: Nash Ralph G. , Harris William G.
Published: July 2010

A series of small Congaree sandy loam field plots at Beltsville, Maryland, were treated with 0, 56 or 112, and 224 kg/ha of aldrin, dieldrin, isodrin, endrin, heptachlor, chlordane, BHC, toxaphene, or Dilan in 1951. Sixteen years later the parent compounds were still detectable with mean total residues of 29 (pure aldrin), 35 (technical aldrin), 23, 16, 39, 10, 9, 7, 49, and 15%, respectively, remaining. Aldrin, isodrin, and heptachlor had oxidized primarily to their epoxide.

Soybeans (Glycine max L., Merr.), corn (Zea mays L.), oats (Avena sativa L.), and wheat (Triticum aestivum L.) were grown consecutively in the plots beginning 15 years after treatment. Soybean seeds contained dieldrin, endrin, heptachlor epoxide, and alpha and gamma BHC; endrin transformation products, which include endrin aldehyde, endrin alcohol, and endrin ketone; and a gamma BHC degradation product, pentachlorocyclohexene. Only BHC and dieldrin were found in crop seeds other than soybeans, and no aldrin, isodrin, heptachlor, chlordane, toxaphene, or Dilan were detected in the seeds of any crop.
Nitrogen and Phosphorus Composition of Surface Runoff as Affected by Tillage Method
Authors: Römkens M. J. M. , Nelson D. W. , Mannering J. V.
Published: July 2010

The effect of tillage methods on the N and P composition in runoff water and runoff sediment from corn (Zea mays L.) plots was studied on Bedford silt loam soil by applying simulated rainstorms. Five tillage‐planting systems were compared: coulter‐plant, till‐plant, chisel‐plant, disk and coulter‐plant, and conventional‐plant. The coulter and chisel systems controlled soil loss, but runoff water contained high levels of soluble N and P from surface‐applied fertilizer. The disk and till systems were less effective in controlling soil erosion, but had lower concentrations of soluble N and P in runoff water. Conventional tillage, in which fertilizers were plowed under, had the highest losses of soil and water but small losses of soluble N and P. However, high percentages of the total nutrients removed by runoff were components of the sediment from all treatments.
Long‐Term Effects of Manure, Fertilizer, and Plow Depth on Chemical Properties of Soils and Nutrient Movement in a Monoculture Corn System
Authors: Vitosh M. L. , Davis J. F. , Knezek B. D.
Published: July 2010

An evaluation of soil chemical properties, organic matter and nutrient accumulations, and nutrient movement and recovery after 6 and 9 years of annual fertilizer and manure applications to continuous corn (Zea mays L.) was conducted on two soil types (Conover‐Hodunk loam and Metea sandy loam). Plow depths of 18 versus 30 cm had little or no effect on soil test values or nutrient accumulation patterns in the surface of a Conover‐Hodunk loam soil. The pH value of both soils decreased slightly more than 0.1 pH unit per year with the annual application of 168 kg of N/ha as ammonium sulfate.

Soil organic matter, available P, and exchangeable K, Ca, and Mg increased with increasing rates of manure. The organic matter content of the Metea sandy loam soil increased about 0.1% each year by the yearly application of 67.2 metric tons/ha (fresh wt.) cattle manure. The differential removal of nutrients by grain and silage had no effect on soil available P. Soil test changes for K, Ca, and Mg were proportional to the net addition of each nutrient; but less than 30% of the net nutrients added could be accounted for in surface samples from the silage area where 67.2 tons of manure was annually applied.

The most favorable rate of manure for the Metea sandy loam soil was found to be 22.4 metric tons/ha (10 tons/acre). Larger applications caused a significant buildup of exchangeable K in the surface and subsurface horizons and resulted in inefficient use of all nutrients. The K buildup was less critical on the loam soil or where silage rather than grain was removed.
Dissipation and Phytotoxicity of Dicamba Residues in Water
Authors: Scifres C. J. , Allen T. J. , Leinweber C. L. , Pearson K. H.
Published: July 2010

The herbicide, 3‐6‐dichloro‐o‐anisic acid (dicamba), dissipated most rapidly from water under non‐sterile, lighted conditions. Pond sediment evidently contained microbial populations capable of decomposing the herbicide. Temperature was crucial in dicamba dissipation, especially in the presence of sediment. Influence of sediment on dissipation rate of dicamba was apparently augmented by light in some cases. Under summer conditions, dicamba at 4.4 kg/ha per surface area of ponds dissipated at about 1.3 ppm/day. Dicamba dissipated as a logarithmic function of concentration with time. Reaction of seedling crops to irrigation water containing dicamba varied among species and cultivars. Relative tolerance from these studies was ranked from most to least tolerant as follows: sorghum [Sorghum bicolor (L.) Moench. ‘RS‐626’ and ‘Pioneer 820’] > cotton (Gossypium hirsutum L. ‘Blightmaster’ > ‘Paymaster’ > ‘Dunn’) > cucumbers (Cucumis sativa L. ‘Straight eight’).
Agriculture's Place in the Environment: Considerations for Decision Making
Authors: Garman Willard H.
Published: July 2010

Chemical elements at or near the earth's surface and in the air are in a continuing state of movement or subject to forces which can cause movement. The outstanding characteristic is that outgo of inorganic elements (including plant nutrients) from land to water greatly exceeds input over most land surfaces of the earth. Nutrients have been accumulating under water along the shorelines of the world for ages of time.

When man entered the geological picture, this movement (or water‐enrichment process) became more active as the soil was worked to grow food. This caused more soil particles, nutrients, and organic matter to move into water bodies.

Eutrophication is nature's age‐old geological process of utilizing these nutrients and the sun's energy for the accumulation of organic matter in aqueous environments. Without eutrophication, there would be no marine life or coal, oil, or muck deposits on our planet.

All bodies of water have four stages of life: birth, existence, old age, and disappearance. Examples of each stage are found in the USA, Canada, Siberia, Brazil, and Africa, in surroundings practically untouched by man and certainly untouched by agriculture.

Only very small quantities of nitrates and mineral nutrients are necessary to sustain luxuriant growth of aquatic plants. Most water bodies contain ample amounts for this purpose. Few situations likely can ever be found where stopping agricultural's contribution would stop eutrophication. Slowing the process of eutrophication will be difficult because it will require control over C inputs. Organic matter from sewage, manure runoff, industrial waste, or wildlife is utilized by bacteria, which evolve CO2 for promoting the growth of aquatic plants. Once the process is in operation, it is difficult to control because photosynthesis releases oxygen to stimulate bacteria. When they and other plants die, their C and nutrients are consumed by more bacteria, which in turn, evolve more CO2 to grow more algae, thus continuing the cycle. Although details of this symbiosis are not fully understood, enough is known to realize that removing P or N from city effluents or from farm fertilizers will not control growth of aquatic vegetation in natural or man‐made bodies of water.
Leaf Pubescence of Field Grown Wheat: A Deterrent to Oviposition by the Cereal Leaf Beetle
Authors: Gallun R. L. , Roberts J. J. , Finney R. E. , Patterson F. L.
Published: July 2010

Leaf pubescence, a deterrent to oviposition by the cereal leaf beetle [Oulema melanopus (L.) Diptera Cecidomyiidae], is being bred into wheats in an attempt to replace insecticides as a means of controlling damage by this insect pest. Experimental wheats (Triticum aestivum L.) having more than 71 trichomes/mm2 of flag leaf surface were nonpreferred for oviposition by the cereal leaf beetle compared with Arthur wheat which has 28 trichomes/mm2. The leaf pubescence of three Purdue wheats was responsible for over 94% reduction in the number of eggs that were laid by the beetle and the number of leaves damaged by feeding larvae.
Mineralization and Gaseous Loss of Nitrogen in Soil‐Applied Liquid Sewage Sludge
Authors: King Larry D.
Published: July 2010

Because of the current interest in land disposal of sewage sludge, experiments were conducted to determine the rate of N mineralization in sludges. Sludge applications can then be adjusted to supply adequate N for maximum crop production but prevent excessive applications which would lead to NO3‐N pollution of ground water.

A 2.5‐inch depth of liquid sewage sludge was either surface applied or incorporated with a quantity of soil and incubated under laboratory conditions. At the end of 18 weeks, NO3‐N accumulation was 22% of the applied N when the sludge was applied to the soil surface and 38% when the sludge was incorporated with the soil. Gaseous N losses ranged from 16 to 22% of the applied N in the incorporated treatment and 21 to 36% in the surface‐applied treatment. Only a small part of the gaseous N loss resulted from NH3 volatilization.
Absorption of Mercuric Cation by Tannins in Agricultural Residues
Authors: Waiss A. C. , Wiley M. E. , Kuhnle J. A. , Potter A. L. , McCready R. M.
Published: July 2010

Two common environmental pollutants are agricultural residues (skins, pits, husks, tannin bark, grape pomace) and waste streams of water containing only traces of heavy metals (such as mercury at 10 or more ppb) from mining or manufacturing operations. Agricultural residues contain tannins, polyphenolic substances, pectin, and other polymers—all with chemically reactive groups that can chelate, reduce, oxidize, demonstrate ion exchange properties, and aid in removing traces of heavy metals from dilute waste water streams at low cost.

Finely ground and water‐washed agricultural residues were slurried in water and packed into columns for absorption tests with heavy metals. Solutions of known concentrations of heavy metals were passed through the packed columns which were then eluted with water or with alkaline or acidic solutions. The fractions and the column absorbents were then analyzed by standard atomic absorption methods.

The nature of the physical and chemical forces that are effective in metal absorption from agricultural residues is not clear.
Injury to Sweet Corn Inbreds and Hybrids by Air Pollutants in the Field and by Ozone Treatments in the Greenhouse
Authors: Cameron J. W. , Taylor O. C.
Published: July 2010

Five inbreds of Zea mays L. and three of their F1 hybrids were grown in the field under natural summer air pollution conditions in 1971. During the following fall, four of the inbreds and two hybrids were grown in greenhouses and received controlled ozone treatments. The cultivars showed highly significant differences in injury under field conditions, but much smaller differences in the greenhouse tests. In the field, four inbreds were relatively resistant; the fifth was highly susceptible. The three hybrids showed some correlation with the resistance of their parents. In the greenhouse, with repeated dosages of ozone, all tested inbreds showed substantial damage when 4 to 7 weeks old, but at flowering the field‐susceptible inbred was the most severely damaged. The hybrids also showed severe damage as young plants, while at flowering their damage from greenhouse treatments was related to their field susceptibility. Injury symptoms in the field were typical of the ozone injury in the greenhouse. In all cultivars, young leaves were less injured than fully mature leaves.
Reducing Mercury Pollution from Kjeldahl Determination of Total Nitrogen
Authors: Worsham H. M. , Blackmon B. G.
Published: July 2010

Mercury as a digestion catalyst in Kjeldahl determination of nitrogen in soil and plant tissue is a potential pollutant if washed into laboratory drains. In an effort to reduce this pollution hazard, a study was conducted to develop a means of freeing Kjeldahl waste solutions of mercury. By using an inexpensive polyethylene trap, developed in our laboratory, and increasing the quantity of zinc in the distillation phase of the Kjeldahl procedure, more than 90% of the mercury was recovered and retained in the laboratory.
Land Disposal of Liquid Sewage Sludge: IV. Effect of Soil Phosphorus, Potassium, Calcium, Magnesium, and Sodium
Authors: King Larry D. , Morris H. D.
Published: July 2010

Over a 2‐year period a total of 6.93, 13.75, 20.0, and 40.0 cm of liquid sewage sludge (6.2% solids) was applied to Coastal bermudagrass (Cynodon dactylon L. Pers.) on Cecil sandy clay loam (Typic Hapludult). The area was sod‐seeded to rye (Secale cereale L.) during the winter. A chemical fertilizer treatment supplied a total of 722‐177‐366 kg/ha of N‐P‐K to the bermudagrass and rye during the experimental period. Sludge applications resulted in increased Na but decreased the dilute acid‐extractable K, Ca, and Mg and had no effect on P. Chemical fertilizer increased P, decreased K, and did not affect Ca and Mg. Results indicate that additions of dolomitic limestone and supplemental K fertilization would be required for sustained productivity of soils receiving sewage sludge.
Interaction of S‐2,3,3‐trichloroallyl N,N‐diisopropylthiolcarbamate (Triallate) with Montmorillonite
Authors: Khan S. U.
Published: July 2010

Adsorption of S‐2,3,3‐trichloroallyl N,N‐diisopropylthiolcarbamate (triallate) by montmorillonite saturated with various cations was studied by infrared spectroscopy. The coordination of triallate to the exchangeable cations on the clay occurred through the oxygen of the carbonyl group. The triallate‐montmorillonite complexes were stable even on heating to 50C for 15 days, but when shaken with distilled water, the herbicide was completely displaced from the clay.
Soil‐Plant Response to Surface‐Applied Mercury
Authors: Estes G. O. , Knoop W. E. , Houghton F. D.
Published: July 2010

Mercury from an organomercurial fungicide accumulated in surface soils, with negligible lateral migration, following annual applications of 2.10 kg/ha over a period of 15 years. No toxicity was apparent from relatively high soil levels of Hg (455 ppm) on the growth of velvet bentgrass (Agrostis canina L.). Elemental composition of turf plants showed 1.68 ppm Hg with normal levels of other transition elements (Mn, Fe, Cu, Zn).