bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solubilization of Soil and Rock Phosphate as Related to Root Cation Exchange Capacity
Authors: Drake Mack , Steckel J. E. 
Published: July 2010

AbstractPlants with root cation exchange capacities ranging from 10 to 60 me./100 g. dry root, were grown in greenhouse pots on B horizon Merrimac silt loam very low in available and total phosphorus. Rock phosphate at the rate of 1,000 pounds per acre was mixed throughout the soil. Plants with high cation exchange root systems (ragweed and smartweed) were more effective in obtaining phosphorus from soil and rock phosphate for themselves, and were two to three times as effective as the lower exchange root systems (Lamb's quarters and wheat) in solubilizing soil and rock phosphate for the following crop of sudan grass. Oats with relatively low cation exchange roots, when grown in association with red clover (high cation exchange roots) contained 60% more phosphorus than oats alone. Plant roots with high cation exchange capacity bond Ca with greater energy than low cation exchange roots. Two important mechanisms of P release are believed to be involved, (a) bonding of Ca by the plant root colloid to dissolve the rock phosphate crystal and (b) complexing of Al and Fe by organic anions to solubilize soil Al and Fe phosphates.
Application of Solubility Product Principles to the Variscite‐Kaolinite System
Authors: Kittrick J. A. , Jackson M. L. 
Published: July 2010

AbstractThe reaction of variscite with H+ and OH‐ in water solutions was investigated and the [OH‐] exponent in the variscite solubility product expression was found to be dependent upon solution pH, being proportional to [OH‐]2 only at pH 4. An increase from 1 to 10 g. of kaolinite to 0.5 g. of variscite in 50‐ml. volume increased the aluminum concentration in solution from 2.3 × 10‐5 to 4.8 × 10‐5 molar and diminished the phosphate concentration in solution from 2.5 × 10‐4 to 0.7 × 10‐4 molar in accord with solubility product principles.
Subirrigation and Plant Nutrition I. Alfalfa Root Distribution and Soil Properties
Authors: Fox R. L. , Lipps R. C. 
Published: July 2010

AbstractRoot systems of subirrigated alfalfa plants and some associated soil properties have been studied. Under certain conditions a concentration of fibrous roots occurred in saturated soil above and below the water table. Roots occurred in abundance in pockets of fine sand and silt while adjacent pockets of moist sand and gravel were essentially devoid of roots. These observations and soil analyses suggest that root distribution is, in part, governed by nutrient availability.Nodules occurred in abundance in the A horizon of a buried soil while the surface soil, which was more acid, contained roots without nodules and with only limited branching. Alfalfa roots penetrated soil horizons which contained much sodium. They branched extensively in a region of high sodium where calcium and magnesium were present in abundance.Root distribution of subirrigated alfalfa suggests two important regions of water and nutrient sorption. These are the moisture fringe above the water table and the surface soil. Both should be considered when interpreting soil tests, evaluating results of fertilizer experiments, and explaining plant growth variations.
A Comparison of Several Chemical Methods With the Bio‐assay Procedure for Extracting Zinc from Soils
Authors: Tucker T. C. , Kurtz L. T. 
Published: July 2010

AbstractA study was made to evaluate the forms of soil zinc removed by the Aspergillus niger bio‐assay method and to compare several chemical procedures for extracting soil zinc. Soils used were from humid regions; only one was calcareous.For 0.1N HCl, the effects of extraction time and ratio of soil to extracting solution were investigated. A ratio of 1:10 and a 45‐minute shaking period were considered most satisfactory. Longer extraction periods and wider ratios resulted in removal of larger amounts of zinc, but the rate of zinc release diminished appreciably. The amount of soil zinc removed by 0.1N HCl during a 6‐week extraction period, by successive extractions with 0.1N HCl, and the bio‐assay values were approximately equal. This agreement suggests the existence of an acid soluble form which made up around one‐fifth of the total soil zinc in the soils studied. Very little zinc was found in the exchangeable form, and the organic form, if present, was apparently small.Amounts of zinc extracted with 0.1N HCl, acetic acid, EDTA, and dithizone were significantly correlated with the bio‐assay values. Dithizone and EDTA removed about the same amounts of zinc. The bio‐assay, dithizone, and 0.1N HCl procedures were most convenient and rapid. The acetic acid procedures appeared to be the least satisfactory since the range among soils was small at narrow soil to solution ratios, and extracts were too dilute for ready determination at wider ratios.Zinc fertilization of the soil was reflected in zinc soil test values and plant content.
A Study of the Genesis of a Podzol—Gray‐Brown Podzolic Intergrade Soil Profile in Michigan
Authors: Cann D. B. , Whiteside E. P. 
Published: July 2010

AbstractA modification of the resistant mineral method used by Marshall and Haseman was applied to a study of the genesis of a Podzol—Gray‐Brown Podzolic Intergrade soil profile in Michigan. Changes in the method were (1) the use of quartz, instead of zircon, as the reference mineral, (2) the determination of quartz with a Geiger counter X‐ray spectrometer, and (3) the use of the coarser fractions of the soil.Results show that: (1) There is a total loss in weight of the solum, but a 20% gain in volume, which takes place largely in the A1, A2P and BP horizons; (2) About 85% of the soluble material originally present has been removed from the profile; (3) Orthoclase feldspars showed a slight gain in the profile, about equal to the net loss in weight. This indicates that they are very resistant to weathering. Plagioclase feldspars had decreased considerably in A2P and BP horizons but very little in B2GB horizons. (4) Marked increases in organic matter in the BP horizons and in organic matter and clay in the B2GB horizons seem to indicate that both of these are illuvial horizons. However, the principal constituent concentrated is organic matter in the Podzol B and silicate clay in the Gray‐Brown Podzolic B. It seems certain that the two illuvial processes are now occurring simultaneously in this soil.
The Influence of Soil Crusts on Gaseous Diffusion
Authors: Domby C. W. , Kohnke Helmut 
Published: July 2010

AbstractA method is described for forming crusts on soils in special containers in the laboratory using artificial rainfall, and for measuring gaseous diffusion through these soils without further disturbance of their structure.Unless the surface is completely impervious, the rate of diffusion through a soil does not depend solely on the properties of this layer. When various proportions of the soil surface were sealed with paraffin, the rate of diffusion was not reduced in proportion to the area covered.The effects of soil crusts upon diffusion depended to a very great extent on the soil moisture tension. There were no significant differences in the rates of diffusion through air‐dry silt loam having different degrees of crusting. Surface crusts on this soil restricted diffusion only at low moisture tensions; the wetter the soil, the greater the influence of the crust on diffusion. Except in the very wet range, even minor variations in soil moisture tension had more influence on diffusion than did the presence of a thin surface crust.A saturated soil crust could provide a very effective seal against diffusion at the time when soil aeration is most critical, i.e. during and for a short time after a rain or irrigation. Except during a period of complete sealing, however, crusted soils actually may permit more rapid diffusion and be better aerated than mulched or other uncrusted soils, because of differences in moisture content.
A Study of the Properties of Molybdenum in Everglades Peat
Authors: Fiskel John G. A. , Mourkides G. A. , Gammon Nathan 
Published: July 2010

AbstractAnalyses of samples of Everglades peat from the vicinity of Lake Apopka, Fla., showed a tenfold variation in total molybdenum between fields, while the water‐extractable molybdenum varied from 0.017 to 2.60 ppm. on the basis of the weight of oven‐dry peat. The water‐extractable fraction was found in appreciable quantity at all depths. Subsequent leaching with other extracting solutions used in sequence on the same samples, showed the following range of values expressed as ppm. Mo of the oven‐dry peat: one sequence 0.017 to 1.10 using borax in the rate of 50 pounds per acre in water, and 0.22 to 0.37 in the leachate following addition of superphosphate at the rate of a ton per acre; another sequence 0.03 to 0.07 ppm. removed by neutral N NH4Ac, followed by 0.044 to 0.120 ppm. removed in the leachate using 0.05% hydroquinone in 50% alcohol, and finally 2.5 to 10 ppm. with 1 N NH4OH. Several materials were added to the peat on pasture areas, the rates being 750 pounds per acre each for kaolin, vermiculite fines, ball clay, colloidal phosphate, bauxite and attapulgite; 500 pounds per acre of a Krilium‐9 formulation and of sulfur powder; 200 pounds per acre of Krilium‐931 formulation; and 150 pounds of a manganese source material (Nu‐M) and of a copper source material (Tribasic copper sulfate). Of these materials attapulgite, Krilium, and bauxite reduced the water‐extractable and ammonium hydroxide‐extractable molybdenum in the peat and also significantly reduced the molybdenum content of the herbage. Attapulgite and perhaps bauxite offered a longer lasting and less expensive measure of controlling molybdenum availability than the sulfur or the Krilium formulations.
Sulfur and Nitrogen Composition of Fertilized and Unfertilized Alfalfa Grown on a Sulfur‐Deficient Soil
Authors: Rendig V. V. 
Published: July 2010

AbstractA study was made of the effects of three levels of S fertilization (0, 200, 400 lbs. gypsum per acre) on several forms of S and N present in alfalfa grown on Delhi sand in the San Joaquin Valley of California. Previous studies with alfalfa on this soil have shown that the annual yield could be approximately doubled by an application of 200 lbs. gypsum per acre and that phosphate fertilizer had no significant effects on yield or P content.Yield data were obtained at each of five successive cuttings of alfalfa. Forage samples were analyzed for total N, amide‐N, free‐amino‐N, total S, SO4‐S, and methionine.At all harvests, yields were increased by S; slightly higher yields were produced by 400 than by 200 lbs. gypsum per acre, the difference being significant for only the first two cuttings. For the first three harvests, the percentage of total S in the plant was approximately 3 times as great in alfalfa grown with 400 lbs. gypsum as in that grown without fertilization; the differences were progressively smaller at the fourth and fifth harvests. Most of the differences in S content could be accounted for as SO4‐S; however, a consistent difference in reduced‐S was also noted, with maximum variation occurring at the third harvest, when the reduced‐S contents were 0.11 and 0.17%, respectively, for alfalfa from plots receiving 0 and 400 lbs. gypsum per acre. This difference in reduced‐S could not be accounted for as methionine; actually the percentage of the reduced‐S present in this form was higher in the unfertilized alfalfa.Marked differences in N content were found only at the first harvest, when crude protein values were 17 and 24%, respectively, for alfalfa grown with 0 and 400 lbs. gypsum per acre. Contents of amide‐N, free‐amino‐N, and NO3‐N were interpreted as indication that the lower crude protein content of the unfertilized alfalfa was not caused by lack of S in the plants.The conclusions were drawn that (1) the alfalfa was not enriched in methionine by fertilization with S, and (2) the synthesis of some form of reduced‐S was impeded in the unfertilized alfalfa by lack of sufficient available S.
Molybdenum in Everglades Soils and Plants
Authors: Kretschmer Albert E. , Allen Robert J. 
Published: July 2010

AbstractEverglades organic soils are underlain with limestone rock, and with continued cropping subsidence occurs and pH values rise. A rather high total Mo content in these soils encouraged work to determine the Mo accumulation by plants as affected by soil factors. A survey of Mo and Cu contents of forages grown throughout the area also was made to determine the Mo status of forages being grazed. As an index of forage not harmful to grazing cows, a Cu content of 10 ppm., or greater and a Mo content of 3 ppm. or less in the forage was chosen from previous animal tests.It was found that increasing the pH of the soil resulted in Mo accumulations of greater than 25 ppm. by clover plants. Not only is there a great difference between Mo contents of various winter forages grown under the same conditions, but contents seem to vary as a result of plant maturity and season. Roselawn St. Augustinegrass and Bermudagrass growing in commercial pastures were found to absorb less Mo than other grasses tested, while pangolagrass and white clover absorbed larger amounts. Furthermore, trends seem to indicate that plants grown on a given soil will accumulate more Mo as the period of cropping increases, even though the soil pH remains constant.Although the Mo contents of permanent pastures are not as high as those reported in other troubled areas, the Mo‐Cu status indicates the possibility of unfavorable forage quality during the fall. Average Mo and Cu contents of approximately 100 survey samples were found to be 5.5 and 7.4 ppm., respectively, in the fall, and 2.9 and 10.9 ppm. in the spring.
Influence of Moisture on Erodibility of Soil by Wind
Authors: Chepil W. S. 
Published: July 2010

AbstractThis study was undertaken to determine the general influence and the specific quantities of moisture that soils must have to resist wind.Erodibility by wind was about the same for soil that was oven‐dried or air‐dried in sun or in shade when moisture did not exceed one‐third of the 15‐atmosphere percentage. Beyond this range of moisture a distinct decrease in erodibility was manifested. Erodibility decreased rather slowly at first, then more rapidly with each successive increment of moisture added, reaching zero, on the average, at about 15‐atmosphere percentage. Increasing the moisture even slightly above the 15‐atmosphere percentage required a relatively great increase in wind velocity to produce movement of soil.It was shown that erodibility by wind is a function of the cohesive force of adsorbed water films surrounding the soil particles. Equations were derived indicating the relationships between cohesive force due to adsorbed water films, quantity of adsorbed water, and erodibility by wind.
Soil Moisture Distribution on Irrigated Corn Plots
Authors: Dreibelbis F. R. , Youker R. E. 
Published: July 2010

AbstractAn account of the soil‐moisture distribution obtained by fiberglas‐gypsum blocks on irrigated plots is presented as an aid in evaluating the needs of water for irrigation on field corn and sweet corn in Southeastern Ohio. Soil moisture depletion was determined from moisture changes in the Keene silt loam and presented as total depletion in the 0 to 7‐, 0 to 10‐, 0 to 12‐, 0 to 14‐, and 0 to 18‐inch depths on sweet corn for various periods during the growing season in 1954. The data for 1954 indicate that on this soil type the 0 to 7‐inch depth would suffice as a criterion for irrigation requirements up to July 14, and the 0 to 12‐inch depth from July 15 to Sept. 17.A summary of the data to evaluate the quantitative needs of water for irrigation purposes is presented for the Keene and Muskingum soils. Data on the moisture content at saturation, at field capacity, and at the wilting point are given in inches water for the 0 to 7‐, 0 to 10‐, 0 to 12‐, 0 to 14‐, 0 to 18‐, and 0 to 24‐inch soil depths together with the amount of water necessary to raise the moisture content to field capacity from the ½ available water level. From this level in the 0 to 24‐inch depth on the Keene silt loam, 2.76 inches water are needed to raise the moisture content to field capacity, while 2.40 inches are required on the Muskingum silt loam. In the 0 to 7‐inch depths, the values are 0.81 and 0.73 inches respectively for the same soil types.Additional data obtained on field corn plots in 1953 are also presented as a contrast to those obtained on sweet corn in 1954. Daily depletion rates were lower on the latter.
Anomalies in Capillary Intake as Explained by Capillary Rise Experiments
Authors: Swartzendruber Dale 
Published: July 2010

AbstractIn an earlier study of soil structure, an attempt was made to utilize as a soil structure index, the proportionality constant in the square‐root‐of‐time equation of horizontal capillary flow. In the present paper, anomalous variations of this constant—the capillary absorption coefficient—are considered in greater detail.As a starting point, the movement of the meniscus in a single round capillary tube was assumed amenable to treatment on the basis of Poiseuille's law. Using data from the literature, it was found that there is validity in the Poiseuille analysis. However, quantitiative agreement with the experiments depended somewhat on the conductivity K of the capillary tube.The Poiseuille analysis was then utilized in a theoretical treatment of the capillary absorption coefficient, assuming an idealized soil model consisting of parallel, non‐interconnected capillary tubes. From the intersection behavior of capillary rise curves, it was found possible to predict within limits the behavior of the capillary absorption coefficient as affected by changes in pore radius, surface tension, wetting angle, and viscosity.Experimental curves of capillary rise versus time were then obtained for the soils of the previous structure study for which values of capillary absorption coefficient had already been measured. The observed behavior of the coefficient, especially when a large variation was induced in it by a given structure treatment, was found to be consistent with the behavior predicted on the basis of capillary rise curves.The favorable qualitative comparisons of the capillary tube theory with the experimental data for the soils tested, suggest that the theory can be refined for determining more simply the now difficulty determinable soil physical property—the wetting angle.
The Effect of Green and Stable Manure on the Yield of Crops and on the Physical Condition of a Tappan‐Parkhill Loam Soil
Authors: Guttay J. R. , Cook R. L. , Erickson A. E. 
Published: July 2010

AbstractThe effect of sweet clover‐green manure and stable manure on the yields of grain and row crops have been studied since 1936. The treatments include the application of these manures every 2, 4, and 6 years. Sweet clover‐green manure had a more beneficial effect on the yield of crops than did stable manure. The greatest effects of both manures on crop yields occurred where the manures were applied every 2 years. In the 4‐ and 6‐year treatments, marked beneficial effects were noted immediately following, or 1 year after the application of the manures, with much less or no benefit occurring thereafter until reapplication.The effects of these treatments on the physical condition of the soil have been studied for 2 years. Granulation of the soil was enhanced by the 2‐year treatments. The effects of the treatments on the soil physical condition cannot be completely evaluated until a 6‐year study is completed.
Crop Response to Different Soil Fertility Levels in a 5 by 5 by 5 by 2 Factorial Experiment: II. Peanuts
Authors: Robertson W. K. , Hutton C. E. , Hanson W. D. 
Published: July 2010

AbstractFour years' data are reported from a 5 by 5 by 5 by 2 experiment in which nitrogen, phosphorus, potassium and lime respectively, were the variables. The experiment was conducted on Red Bay fine sandy loam in west Florida.No response to nitrogen was obtained.There was a negative response to potash every year when more than 15 pounds of K2O per acre as potassium chloride were applied. The level of exchangeable potassium in the soil did not seem to be responsible for the negative response. Ninety pounds of exchangeable potassium per acre was adequate for maximum yields. The lack of response to potassium may have been associated either with the application of the fertilizer potassium in the peanut row or with increasing rates of phosphorus applied as superphosphate. Since high rates of phosphorus are necessary for maximum yields of other crops grown in rotation with peanuts, excess potassium, equivalent to that removed by the peanuts, probably should be applied to the other crops in the rotation.There was a significant yield response to phosphorus every year. When the soil was adequate limed, maximum yields were obtained when the soil contained 45 pounds per acre of P2O5 extractable with 0.002N H2SO4 buffered at pH 3 with (NH4)2SO4 or 110 pounds per acre of P2O5 extractable with 0.03 N NH4F in 0.1 N HCl; 10 of extractant to 1 of soil.Calcium gave significant yield responses three out of four years. Three tons per acre of dolomitic lime were better than one. One ton per acre of lime raised the pH from 5.3 to 5.6 and the exchangeable calcium from 300 to 500 pounds per acre of Ca approximately. When 3 tons per acre of lime were applied, the pH was 6.2 and the exchangeable Ca 850 pounds per acre.Phosphorus interacted with lime. Less fertilizer phosphorus was necessary to give maximum yields on limed than unlimed soil.
Chlorine and Other Constituents in Relation to Tobacco Leaf‐Burn
Authors: Myhre D. L. , Attoe O. J. , Ogden W. B. 
Published: July 2010

AbstractA study was made to evaluate the influence of chlorine and other constituents on tobacco leaf‐burn (capacity to hold fire when ignited). Samples of tobacco plants and soil at different depths were taken from 33 fields located in the 2 tobacco growing districts in Wisconsin in 1952, and the data concerning chemical composition and leaf‐burn were subjected to statistical analyses. The amount of chlorine taken up by the crops was most closely correlated (r = 0.79) with that found in the 0 to 12‐inch layer of soil. On the average, about ½ of the chlorine found in this layer was taken up by the crops. A highly significant coefficient of multiple correlation, R = 0.80, was found for the relation between log leaf‐burn and the contents of chlorine, sulfur, nitrogen, and potassium of the tobacco leaves. A comparison of the standard coefficients indicated that potassium is about 1.2 times more beneficial to leaf‐burn than either chlorine or nitrogen is detrimental, and about 2.4 times as beneficial as sulfur is deterimental.
Transect from Lake Tahoe, California, to the Pacific Ocean Showing Relationship Between Soils, Physiographic Position, Geology, Climate, Natural Vegetation, and Land Use
Authors: Storie R. Earl , Brown Lloyd N. 
Published: July 2010

AbstractThis transect starts on Highway No. 40, near the crest of the Sierra Nevada Mountains, in an area of pine and fir timber. At the beginning of the transect are granitic upland soils of the Holland series; following these are red upland soils of the Aiken series, derived from basic igneous rocks, and next, at a lower elevation, the reddish, grass‐covered Auburn soils. The higher terrace lands of the eastern Sacramento Valley are composed of the cobbly‐hardpan Redding soils, and the gravelly claypan Corning soils; on the lower terraces, the red‐iron hardpan San Joaquin soils with the recent and young alluvial soils of the Columbia and Sacramento series along the Sacramento River; and on the wet‐side alluvial fan, soils dominated by the Yolo series in the vicinity of Davis. Other noncalcic Brown valley, terrace, and upland soils are encountered west of Davis. The western Coast range of higher rainfall gives rise to the lithosolic Maymen series, and the Hugo series having a Douglasfir and redwood cover. The ocean side of the Coast Range, where there is lower rainfall, is represented by the Cayucos and Rohnerville soils having Prairie‐like characteristics.