bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen and Sulfur in Precipitation and Sulfur Dioxide in the Atmosphere in Wisconsin
Authors: Hoeft R. G. , Keeney D. R. , Walsh L. M. 
Published: July 2010

AbstractA monitoring program to determine the seasonal distribution of sulfur and nitrogen from the atmosphere and a greenhouse experiment to evaluate the absorption of atmospheric SO2 by alfalfa (Medicago sativa) was conducted. Atmospheric SO2 levels at all rural and urban locations were low in the summer months and increased markedly in the winter months and, on the average, the values in urban areas were about twice those in rural areas. The SO2 collected 2 km from an industrial location was 10 to 15 times as high as the urban locations. At a distance of 5 km this value dropped to levels comparable to urban areas and to rural levels at 10 km. Sulfur (as SO4) in precipitation followed the same seasonal and location trends as did SO2 with 16, 42, and 168 kg of S/ha per yr being deposited in rural, urban and industrial locations, respectively. An overall state average of 30 kg S/ha per yr was estimated. Sulfur‐deficient alfalfa plants grown in a greenhouse at Madison from January to May obtained as much as 73% of their S from the atmosphere. The amount of NH4‐N and organic N deposited by precipitation was highest during the spring months and lowest during the winter months. Both NH4‐N and organic‐N were higher in areas adjacent to barnyards than in areas removed from the barnyard. However, NO3‐N deposition was relatively constant for all locations and was slightly lower in the winter months. Total N additions ranged from 13 to 30 kg/ha per yr, and an overall state average of about 20 kg/ha per yr was estimated.
Techniques in the Evaluation and Development of Host‐Plant Resistance
Authors: Dahms R. G. 
Published: July 2010

AbstractA thorough knowledge of both insect and plant and their inter‐relationship is required to evaluate cultivars for insect resistance. Cultivars from all possible sources are obtained and subjected to an adequate and uniform insect infestation. Resistance may be measured by (i) visual observation, (ii) the effect of insects on plants, (iii) the effect of plants on insects, or (iv) indirect methods. Resistance may be transferred to usable cultivars by grafting, selection, or hybridization. Germ plasm obtained from a wide genetic base will help to insure a more permanent resistance.
Genetic Interrelationships Between Host Plants and Insects
Authors: Gallun R. L. 
Published: July 2010

AbstractGrowing plant varieties that are resistant to insects is the ideal way to protect the crop against insect losses and at the same time prevent pollution of the environment. Resistance to insects is genetically controlled and expressed as antibiosis, nonpreference, and tolerance. The ability of the insect to attack the plant is also genetically controlled and expresses itself in the form of insect variants called biotypes. Biotypes develop because of selection pressure from resistant varieties and are able to survive, interbreed and develop into epidemic numbers. The genetic interrelationship that exists between the host plant and insect has been studied for some insects and has resulted in a better understanding of how to control insects by resistant varieties. Dynamic plant breeding programs can utilize insect biotypes for locating new sources of resistance, distinguishing between sources of resistance, and determining the inheritance of resistance. In some cases, biotypes having genes that are dominant for avirulence can be systematically released in populations of insects having recessive genes for virulence, resulting in genetic control of the insect after a few generations of release.
Arsenic Interference in the Determination of Inorganic Phosphate in Lake Sediments
Authors: Shukla S. S. , Syers J. K. , Armstrong D. E. 
Published: July 2010

AbstractThe interference from As in the colorimetric determination of inorganic P by the method of Murphy and Riley was evaluated in water and sediment extract systems. Whereas up to 20 µg As/ml as arsenite (AsIII) did not interfere, arsenate (AsV) showed a positive interference and the extent of interference was independent of the level of inorganic P in both systems. On a weight basis, 1.0 µg of As is equivalent to 0.33 µg of “apparent inorganic P.” The amounts of As extractable by 3N HCl from nine surficial Wisconsin lake sediments ranged from <0.1 to 45 µg/g. The overestimation of inorganic P in 3N HCl extracts due to the positive interference from As was less than 1% in all cases. Calculations indicate that the maximum possible interference from As in a variety of extracts of these sediments is less than 2%, even if all of the As exists as arsenate, which is unlikely in reduced sediments. Arsenic was concentrated in the most recent sediments in a core from a Wisconsin lake, indicating that As interference in the determination of inorganic P in the older sediments is also not significant in view of the very low levels of As relative to inorganic P.
Photooxidative Approach to Annual Ryegrass (Lolium multiflorum Lam.) Straw Modification with Corresponding Increases in Microbial Response
Authors: Park J. E. , Rockhill R. C. , Klein D. A. 
Published: July 2010

AbstractThe biodegradability of cereal straw in soil is low because of lignin and lignin‐cellulose complexes in their structure. Photooxidation prior to soil incorporation was evaluated as a means of modifying these structures to improve biodegradability. Microbial activity increased significantly when an annual ryegrass straw was photooxidized as a 0.5% w/v mixture in water by ultraviolet light in the presence of hydrogen peroxide.
Escape of Elemental Phosphorus from Soil when Applied as White Phosphorus or the Phosphorus‐Sulfur Eutectic Solution
Authors: Warnock R. E. 
Published: July 2010

AbstractWhen molten white phosphorus was applied to soil and not adequately covered, oxides of P issued from the soil surface. The escape of P from soil fertilized with pellets of white phosphorus or the eutectic solution of P4‐S8 was determined. Most of the P recovered from the atmosphere was P4 rather than oxides, furthermore, P4 escape was considerably greater from phosphorus applied as the P4‐S8 eutectic solution than from pellets of white phosphorus. The escape of P4 from the eutectic solution also persisted longer than from a like application of white phosphorus. No appreciable difference was found in phosphorus escape from a calcareous soil as compared to that from an acid soil. Phosphorus escape was reduced by deeper placement, but was not prevented by placement at a depth of 10 cm or by increased soil moisture levels up to field capacity. Phosphorus sulfides applied to soil did not release phosphorus as did the eutectic solution of P4‐S8. Calculations suggest that hazardous levels of P4 might accumulate in the air above fields fertilized with the P4‐S8 eutectic solution.
Arsenic Toxicity to Cotton and Soybeans
Authors: Deuel Lloyd E. , Swoboda Alien R. 
Published: July 2010

AbstractArsenic toxicity levels for ‘Lankert’ cotton (Gossypium hirsutum L.) and ‘Patterson’ soybeans (Glycine max L. merr.) were determined in a green house experiment using an Amarillo fine sandy loam and a Houston Black clay. The treatments ranged from 28 to 280 kg As/ha in the Amarillo soil and from 56 to 560 kg As/ha in the Houston Black soil. The vegetative cotton yields were significantly decreased below the checks at the 56 and 280 kg/ha rates of applied As in the Amarillo and Houston Black soils, respectively. Soybeans were found to be more sensitive to As than cotton. Vegetative soybean yields were significantly decreased at the applied rates of 28 kg As/ha in the Amarillo soil and 168 kg As/ha in the Houston Black soil. Yield limiting As concentrations in plant tissue were 4.4 ppm and greater in cotton, and 1 ppm and greater in soybeans. Water soluble As levels of 8 ppm in the Amarillo soil and 28 ppm in the Houston Black soil were required for a significant decrease in the vegetative growth of cotton. The water soluble As levels detrimental to soybeans were 3 and 12 ppm in the Amarillo and Houston Black soils, respectively.
Suitability of Freezing as a Method of Preserving Runoff Samples for Analysis of Soluble Phosphate
Authors: Nelson D. W. , Römkens M. J. M. 
Published: July 2010

AbstractSlow freezing of surface runoff samples decreased the levels of soluble orthophosphate in the water phase from 2 to 27%, but low temperature storage at 2C for 3 days or freezing of the water phase after sediment removal did not alter the orthophosphate concentrations of samples. Rapid freezing of runoff samples in liquid nitrogen resulted in decreases in orthophosphate content which were about one‐half of those observed for conventional freezing. Frozen storage is not a good method for preserving runoff samples to be analyzed for soluble phosphate unless sediment is removed prior to freezing.
Economic Impact of Restricting Herbicide Use
Authors: Fox Austin S. 
Published: July 2010

AbstractThe economic impact of restricting herbicide use is directly related to their real benefits. Farmer and consumer benefits from using herbicides are associated with the differences between a production function in which herbicides are used to control weeds and a similar but lower function for combinations of alternative weed control practices—not including herbicides. The lower function shows production without herbicides for the same dollar value of alternative resources—primarily land and labor. It also shows the additional dollar value of the alternative resources needed to get the same production when herbicides are not used. The latter is implicit in evaluating costs of restricting specific herbicides while maintaining production. In one study, it was estimated that banning the use of 2,4,5‐T on 8 million acres of farm and nonfarm land in 1969 would have increased costs to farmers about $32 million, assuming current levels of production were maintained. However, if substitutes for 2,4,5‐T could not include the related phenoxy herbicides, it was estimated that additional costs to farmers as a result of replacing 2,4,5‐T would have been $44 million. In a related study it was determined that restricting the use of all phenoxy herbicides would increase United States farmers production costs about $290 million. In addition about 20 million more hours of family labor would be used and about 6 million more crop acres would be required.
Soil Absorption of Air Pollutants
Authors: Bohn Hinrich L. 
Published: July 2010

AbstractSoil emits some, but absorbs many, air pollutants. The net effect of the soil is to reduce air pollution by absorbing air pollutant gases and particulate matter and converting them into less harmful forms, forms unavailable to plants and nutrients. The gases emitted by soils, such as H2S, N2O, CH4, and CO, are products of reactions largely outside of man's control and are natural parts of the carbon, nitrogen, and sulfur cycles.Soils absorb organic gases faster and in greater amounts with increasing molecular weight and with increasing number of nitrogen, phosphate, oxygen, sulfur, and other functional groups in the compound. The absorption of lower‐molecular weight and less‐substituted organic gases depends upon the buildup of an appropriate microbial population.The absorption of inorganic air pollutants by soils is primarily by chemical and physical means. Many of the air pollutant gases oxidize after being absorbed and produce acidity which is countered by the pH‐buffering capacity of the soil.Soils are also a source and the major absorbent of siliceous particulate matter in air. Heavy metal, fluoride, and other pollutant aerosols are absorbed and rapidly rendered unavailable to plants. The extent of unavailability of most absorbed elements increases with soil pH. The inactivation of heavy metals by soils is approximately Cu > Pb > Zn > Cd > Ni.
Organic Compounds in Soil Water of Some Ultisols of the Atlantic Coastal Plain
Authors: Nettleton W. D. , McCracken R. J. 
Published: July 2010

AbstractWater samples collected from undisturbed, uncultivated, forested soils of the Atlantic Coastal Plain in Wilson County, North Carolina, were analyzed for content and composition of natural organic substances. Sugars, organic acids, and polyphenols were detected. These results should be useful “baseline data” for comparison with water in and from soils to which agricultural chemicals and organic wastes have been added.
A Simple Digestion Procedure for Estimation of Total Nitrogen in Soils and Sediments
Authors: Nelson D. W. , Sommers L. E. 
Published: July 2010

AbstractA simple and convenient digestion procedure for total N analysis of soils and sediments is described. The digestion is carried out in pyrex Folin‐Wu tubes heated in an aluminum block placed on a hot plate. Samples up to 1 g in size may be used and a digestion time of 3 hours after clearing is adequate. The proposed and conventional semimicro‐Kjeldahl methods gave essentially the same values for total N in a wide variety of soils and sediments. The precision of the proposed method was almost as good as those reported for other semimicro‐Kjeldahl methods. The tube digestion method allows simultaneous digestion of 60 samples in a relatively inexpensive and maintenance‐free aluminum heating block, which occupies a minimum of laboratory space and appears applicable for routine determination of total N in soils having diverse properties.
Concentrations of Nitrogen, Phosphorus, Potassium, and Total Soluble Salts in Soil Solution Samples from Fertilized and Unfertilized Histosols
Authors: Hortenstine C. C. , Forbes R. B. 
Published: July 2010

AbstractLake Apopka, in central Florida, ranked at one time among the most productive bass and panfish bodies of water in the United States. During recent years this lake became highly eutrophic and fishing declined drastically. Farming operations on the rich organic soil along the northern shore of the lake were implicated as one cause of this eutrophication.In an attempt to measure agriculture's contributions to the nutrient concentration in the lake, soil solution samples were extracted from uncleared, swampy Everglades mucky peat; newly cleared, drained Everglades mucky peat; and Everglades mucky peat that had been under cultivation for approximately 15 years. Nitrate‐N, orthophosphate P, and K concentrations were relatively low in soil solution samples from the swampy area. Concentrations of each nutrient in soil solution extracted at the 60‐cm depth in the newly cleared area increased by as much as 8 to 12 times as compared to the 60‐cm depth in the swampy area. Further increases were noted in the cultivated area. Indications were that the peat itself was a heavy contributor of nutrients to the drainage water.
Chemical and Biochemical Considerations for Maximizing the Efficiency of Fertilizer Nitrogen
Authors: Parr J. F. 
Published: July 2010

AbstractFertilizer nitrogen is subject to loss from the soil‐root zone, and immobilization by the soil and rhizosphere microfloras, which can result in low recovery and use efficiency of the applied nitrogen. With increasing rates of application, fertilizer nitrogen efficiency decreases progressively, while leaving an increasing amount of unused nitrogen as a potential pollution hazard. Since the point of greatest economic return from this nutrient is usually somewhere below the point of maximum yield, it should be possible to adjust fertilizer nitrogen rates for maximum return and minimum loss to the environment. This can be achieved through improved soil and crop management practices, including proper timing of application of conventional nitrogen fertilizers and use of deep‐rooted crops for recovery of leached nitrate. A rational approach to more meaningful nitrogen recommendations is needed, one which would account for residual fertilizer nitrogen and mineralizable soil nitrogen, and allow an accurate prediction of the amount of supplemental fertilizer nitrogen necessary to produce the desired yield. Efficiency of fertilizer nitrogen might also be increased with controlled release fertilizers, including the use of coated granules, and compounds of limited water solubility blended with conventional nitrogen fertilizers, to achieve a specific release rate coincident with the nitrogen requirements of a crop. Formulation of ammoniacal fertilizers with nitrification inhibitors offers considerable opportunity for increasing fertilizer nitrogen efficiency.
Movement of Nitrate Nitrogen in Some Grassland Soils of Southern Alberta
Authors: Sommerfeldt Theron G. , Smith A. Douglas 
Published: July 2010

AbstractThe downward movement of NO3‐N in dryland soils under native grass [Agropyron smithii Rydb., Bouteloua gracilis (HBK.) Lag., and Stipa comata Trin. & Rupr.] 6 to 8 years after N was applied at rates up to 976 kg/ha reached a depth of 180 cm. Phosphorus fertilizer did not affect NO3‐N movement. Under seeded grasses, there was no evidence of NO3‐N accumulation 2 years after a single application of N at rates up to 944 kg/ha. After repeated annual applications of N that totaled up to 3776 kg/ha over a 4‐year period, NO3‐N accumulations were found to depths of 90 to 120 cm. The depth of NO3‐N movement under bromegrass (Bromus inermis Leyss.) was similar to that under crested wheatgrass [A. cristatum (L.) Gaertn.], but more NO3‐N accumulated in the soil under the bromegrass. In irrigated soil underlaid by drains, NO3‐N leaching was greater in a loam soil over till growing a mixture of bromegrass and alfalfa (Medicago sativa L.) than in a loam soil over sandy loam‐loamy sand growing an irrigated pasture‐grass mixture [A. elongatum (Host) Beauv. and Festuca arundinacea Schreb.]. These studies indicate that, with good management, fertilizer N on grassland soils is not an important contributor to pollution in semiarid southern Alberta.
Persistence and Microbiological Effects of Acarol® and Chlorobenzilate in Two Florida Soils
Authors: Wheeler W. B. , Rothwell D. F. , Hubbell D. H. 
Published: July 2010

AbstractThe influence of the miticides Acarol® (benzilic acid, 4,4′‐dibromo‐isopropyl ester) and chlorobenzilate (benzilic acid, 4,4′‐dichloro‐ethyl ester) on nitrification capacity and relative microbial numbers in Lakeland and Leon fine sands was determined. Since chlorobenzilate is now used commercially and a proposal is pending for the registration and sale of Acarol®, it is important to assess the effects of these materials on soil microbial populations.The miticides were applied to Lakeland and Leon fine sands at rates of 0, 0.25, 0.50, and 1.0 ppm, incubated in the laboratory for 16 weeks, and sampled for analysis at periodic intervals.Neither chemical influenced the nitrification capacity of either soil or the numbers of fungi, bacteria, and actinomycetes. Acarol® was more persistent than chlorobenzilate; both chemicals remained at higher levels for longer periods of time in Leon soil than in Lakeland soil. The miticides had finite rates of disappearance from both soils.
Chemical Distribution of Residual Fertilizer Nitrogen in Soil as Revealed by Nitrogen‐15 Studies
Authors: Allen A. L. , Stevenson F. J. , Kurtz L. T. 
Published: July 2010

AbstractChemical distribution patterns were obtained for the residual N in field plots previously amended with 15N‐labeled urea and oxamide. From 25 to 40% of the fertilizer N was present in the soil (0 to 25 cm) after the first growing season, about half of which still remained after 5 years. Essentially all of the fertilizer‐derived N (97.0%) occurred in organic combination; only a small fraction (3.0%) was accounted for in inorganic forms, chiefly as fixed NH4+. In comparison to the native humus N, higher percentages of the fertilizer N left after the first growing season occurred as amino acids (52.0 vs. 33.7%) and amino sugars (8.2 vs. 7.5%); lower percentages occurred in acid‐insoluble forms (9.0 vs. 15.2%), as acid‐hydrolyzable organic NH3 (9.0 vs. 17.0%), and as unidentified acid‐soluble N (8.8 vs. 20.3%). Considerable humification occurred during the subsequent 4 years with relocation of amino acids N (and possibly amino sugar‐N) to more resistant humus forms. The findings suggest that fertilizer N, once incorporated into soil organic matter, becomes increasingly stable with time and is not readily mineralized or subject to leaching.
Chlorodioxins in Pesticides, Soils, and Plants
Authors: Helling C. S. , Isensee A. R. , Woolson E. A. , Ensor P. D. J. , Jones G. E. , Plimmer J. R. , Kearney P. C. 
Published: July 2010

AbstractChlorodioxins, such as 2, 3, 7, 8‐tetrachlorodibenzo‐p‐dioxin (TCDD), are highly toxic impurities found in certain pesticides. A review is made of (i) the sources and toxicology of TCDD and its relationship to the herbicide 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T), and (ii) pesticide analyses and soil‐related environmental studies of TCDD conducted by the U. S. Department of Agriculture. TCDD was persistent and immobile in soils. The dioxin was not detected, however, 6 years after abnormally high applications of 2,4,5‐T to Lakeland sand. TCDD was not photodegraded on soil and only slightly, in aqueous suspension. Plants grown in soil containing 0.06 ppm TCDD had no detectable quantity (⩽ 1 ppb) at maturity. It was not translocated when applied to leaves, but wash‐off or volatilization occurred. TCDD was undetected (< 50 ppb) in 19 bald eagle (Haliaeetus leucocephalus) carcasses.
An Economic Analysis of Selected Agricultural Uses of Warm Water in the Pacific Northwest Resulting from Electric Power Generation,
Authors: Johns R. W. , Folwell R. J. , Dailey R. T. , Wirth M. E. 
Published: July 2010

AbstractBetween 1970 and 1990, 85% of all new electric power generating capacity is estimated to require water for cooling. This poses a question for research scientists from several disciplines of finding some productive use for the waste water required by steam generating plants. Since there is usually a finite amount of water available for cooling purposes adjacent to the plant sites, the problem becomes one of finding an economic use for a scarce resource. Several possibilities are discussed for making use of waste water: aquaculture, soil heating, and greenhouse heating.Two alternatives were considered for using cooling reservoirs (i) the production of carp for feed or fish meal, and (ii) catfish for the fresh market. Soil warming and greenhouse heating would involve locational problems relative to plant production, processing facilities, and transportation.None of the uses studied showed clear‐cut advantages in terms of profits which would attract economic investment. The price of carp must be greater than $59.52/metric ton to pay for the rental costs; the current market price ranges from $55 to $60/metric ton. The market demand for catfish has been overestimated and prices have been declining for the past 5 years. Using a 607‐ha (1,500‐acre) cooling pond, the market price for catfish would have to be $.44/kg ($.20/lb) or the enterprise would not pay for the use of the facilities. Catfish prices for 1970–71 were $.57/kg ($.26/lb); further increases in production in the southern USA will likely cause even lower prices. Relocating greenhouses in order to use warm water for heating appears to be a marginal investment. The size of soil‐warming systems is limited by the high initial investment, estimated yield response, and vegetable prices. A soil‐warming technique costing only $4,942/ha ($2,000/acre) to install would be profitable for 20 or 29 vegetable crops considered; an investment cost of $12,355/ha ($5,000/acre) would be profitable for only 1 of the 29 crops considered.