bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Investigation of Some of the Relationships between Copper, Iron, and Molybdenum in the Growth and Nutrition of Lettuce: II. Response Surfaces of Growth and Accumulations of Cu and Fe
Authors: Moore D. P. , Harward M. E. , Mason D. D. , Hader R. J. , Lott W. L. , Jackson W. A. 
Published: July 2010

AbstractA study was made to determine some of the interrelations of Cu, Fe, and Mo in the growth and nutrition of lettuce. The objectives of this study were: (1) to determine the importance of interactions among Cu, Mo, and Fe; (2) to determine if form of N or source of Fe affects interactions involving Cu; (3) to determine which concentrations of Cu, Mo, and Fe result in the greatest growth; and (4) to determine if levels of Fe and Mo, sources of Fe, or form of N affect the critical level of Cu in the plant.Solutions with varying concentrations of Cu, Fe, and Mo were imposed on four series of treatments involving combinations of ferrous iron, ferric iron, all nitrate nitrogen, and 1/4 ammonium plus 3/4 nitrate nitrogen. The experiment was conducted using solution culture in a rotatable design. This design permitted calculations of response surfaces from a much smaller number of treatments than would have been necessary with complete factorials.All of the variables affected growth and accumulation of ions. Illustrations are given for some of the relationships which appear to exist among Cu, Mo, Fe, sources of N, and sources of Fe. Pronounced interactions were obtained between Cu and Fe. The growth of lettuce at any one level of Cu was affected by Fe supply. The reverse relationship was also observed. The Cu content of leaves was affected by Fe supply as was Fe content by Cu supply. The interaction between Cu and Fe on Cu content was affected by source of N and source of Fe. The effects of Cu and Mo on Fe content and the interactions between Cu and Mo, Cu and Fe, and between Fe and Mo were much more pronounced in the series containing all NO3 ‐ nitrogen. Curves of yield vs. Cu content of tops suggested that there is not any single level of Cu in the plant which represents an optimum level. The Cu content corresponding to maximum yield appeared to be influenced by levels of Fe and Mo in solution, source of Fe, and source of N. In general, form of nitrogen had a more pronounced effect on growth and accumulation than did the valence of Fe.Implications of the relationship suggested by this study and the use of response surfaces as an aid in studying nutrient interactions are discussed.
The Effects of Exchangeable Calcium on the Retention and Fixation of Phosphorus by Clay Fractions of Soil
Authors: Ragland J. L. , Seay W. A. 
Published: July 2010

AbstractLaboratory studies were made of the phosphorus retaining and fixing properties of four Kentucky soils. The soils studied were: Armour, Pembroke, and Memphis silt loams, and Loradale silty clay loam. All work was done with the clay fraction of the soils. The effect of percent calcium saturation of the clay, rate of phosphorus application, and initial saturating cation were studied. Retained phosphorus was considered to be that portion of the added phosphorus removed from a water solution by the clay separate. Fixed phosphorus was considered to be that portion of the retained phosphorus not recovered from the clay separate by extraction with 0.005N H2SO4. Radioactive phosphorus was used in the experiment. Phosphorus retention and fixation were determined by a solution counting technique.With a rate of 100 parts of P2O5 per million parts of clay, phosphorus retention and fixation by the four initially acid saturated clay fractions increased as the percent calcium saturation of the clay was increased. No sizeable increase occurred until the clay separates were about 60% calcium saturated. When phosphorus was applied to Loradale clay separate at a rate of 800 or more parts of P2O5 per million parts of clay, fixation decreased with increasing percentages of calcium saturation. This would indicate that fixation studies should be carried out with rates of phosphorus application comparable with those used on field crops if laboratory results are to be extrapolated to field conditions.Initially aluminum saturated clay separate retained much more of the added phosphorus but fixed no more of it than initially acid saturated clay separate.Phosphorus fixation by clay separates with “natural” base saturation decreased with increasing pH, whereas fixation by initially acid saturated clay separate increased or remained unchanged with increasing pH. This may indicate that fixation studies made with initially acid saturated clay separates are not accurate indications of fixation as it occurs under natural soil conditions.
The Influence of Straw and Straw‐Fertilizer Composts on the Uptake of Fertilizer Phosphorus by Plants
Authors: Fuller W. H. , Nielsen D. R. 
Published: July 2010

AbstractThe application of solutions of inorganic phosphorus fertilizers to crop residues before the residues are tilled into the soil is now a widespread practice in the Southwest. This practice is centered around the hope that the fertilizer phosphorus will remain at a higher level of availability as a result of this procedure than if it were added directly to the soil. The hypothesis is that phosphorus fixed by microorganisms during the decomposition of the crop residue is only temporarily unavailable to plants. Phosphorus fixed by this method presumably would be made readily available to plants during the latter stages of decomposition of the residues in contrast to the irreversible fixation by the inorganic constituents of the soil.Results with wheat straw and wheat straw composts containing tagged phosphorus indicate that a relatively greater amount of phosphorus is utilized by plants from compost than from noncompost material. The compost had lost 40 to 50% of its original weight as a result of decomposition before being added to the soil. On the other hand, results with phosphorus‐free extracted oat straw showed that the less decomposed material (oat straw plus KH2PO4) supplied more P to ryegrass growing on Mohave clay loam than the compost (oat straw composted with KH2PO4). However, the extracted oat straw composts did not decompose to an extent to exceed 20% before being added to the soil.According to the data obtained, it must be concluded that there is no particular advantage of adding liquid phosphoric acid fertilizers directly to straw before incorporating them into calcareous soils over the practice of applying the fertilizer and straw residues independently.
Availability of Residual Phosphorus from Long‐Time Rock Phosphate and Superphosphate Applications to Groseclose Silt Loam
Authors: Moschler W. W. , Krebs R. D. , Obenshain S. S. 
Published: July 2010

AbstractThe availability of residual phosphorus from long‐time superphosphate applications to Groseclose silt loam exceeded that of rock phosphate. Based on A values, residual phosphorus from superphosphate was approximately four times as available as that from rock phosphate.Data on total, Truog, and NaHCO3‐soluble phosphorus showed that: (1) more of the superphosphate had reacted with the soil than had rock phosphate; (2) more of the phosphorus applied as superphosphate had accumulated in the silt and clay factions of the soil and, based on solubility in NaHCO3, was relatively available; and (3) more of the phosphorus applied as rock phosphate had accumulated in the sand fraction of the soil and was relatively unavailable, as judged by solubility in NaHCO3.Apparently, some of the rock phosphate had not reacted with the soil and was still in its original molecular combination. X‐ray analysis revealed the presence of apatite or a mineral similar to apatite in the sand fraction of soil that had received rock phosphate. The mineral, which gave pronounced reflections at the same values obtained from rock phosphate fertilizer, was not found in soil receiving superphosphate.Approximately three‐quarters of the phosphorus applied over a 40‐year period from either source was present in the soil as residual phosphorus. This quantity nearly doubled the total phosphorus content of the soil. Crop yields on plots receiving the two fertilizers have been equal except for the first few years when superphosphate produced higher yields.
A Biological Slope‐Ratio Method for Evaluating Nutrient Availability in Soils
Authors: McCants C. B. , Black C. A. 
Published: July 2010

AbstractThe slope‐ratio method employed in biological assay was investigated as a means of evaluating the relative availability of a nutrient in different soils. This type of assay is used when the biological response increases linearly with the dose of the active ingredient. Under certain conditions the relative concentration of the active ingredient in two or more sources tested is equal to the ratio of the slopes of the lines representing the responses. To obtain linear responses, conditions of strong nutrient deficiency were imposed by growing the test plants in sand cultures to which increasing quantities of soil were added. Nutrients other than the one being evaluated were supplied in ample amount. In an experiment with nitrogen the results of three different types of experimental tests indicated that the ratio of the slopes of the lines representing the response functions provided a satisfactory estimate of the ratio of the availabilities. In an experiment with phosphorus, the tests indicated that for the various soils in general the ratio of the slopes was not a valid estimate of the relative phosphorus availabilities. In two instances in which there was no evidence that the slope ratios did not indicate the relative availabilities, the ratios of the availability of fertilizer phosphorus in the presence of soil to that in the absence of soil were found to be 0.2 and 0.5. These results demonstrate the invalidity of methods in which inferences about availabilities of soil phosphorus are based on the assumption that fertilizer phosphorus has the same availability in all soils.
Manganese Toxicity and Soil Acidity in Relation to Crinkle Leaf of Cotton
Authors: Adams Fred , Wear John I. 
Published: July 2010

AbstractA Kalmia fine sandy loam having a pH of 4.5 on which crinkle leaf of cotton occurred in the field was studied in the laboratory and greenhouse.An application of CaCO3 and Na2CO3 to the soil prevented the occurrence of crinkle leaf, whereas the addition of a neutral calcium salt did not prevent the abnormality. Water‐soluble manganese in the soil was greatly reduced by CaCO3 or Na2CO3; however, these salts had little effect on the amount of exchangeable or reducible manganese. CaCl2 had little or no effect on the abundance of any form of soil manganese.A technique was used that maintained high acidity of the soil solution while controlling the amount of manganese and aluminum in solution. By this technique, the symptoms of crinkle leaf were shown to be the result of a high level of manganese in the soil solution and not because of some other factor associated with high soil acidity.Crinkle leaf of cotton can be expected as sufficient acidity develops in those soils that have a high potential supplying power of soluble manganese. The necessary preventive measure for crinkle leaf in the field is an adequate liming program.
Preliminary Studies of Molybdenum in Illinois Soils
Authors: Haley L. E. , Melsted S. W. 
Published: July 2010

AbstractVarious methods of extracting molybdenum from soils have been examined and results compared with the total soil molybdenum and plant composition. The reagents employed for extracting molybdenum were 0.1 N NaOH, 0.275 M oxalate, 0.1 N HCl + 0.03 N NH4F, and 0.03 N NH4F. Total molybdenum was determined by a modification of the method of Grigg and Perrin. Plant analyses were made by the method of Johnson and Arkley.Total molybdenum in the soils studied ranged from 1.90 ppm. to 3.20 ppm. whereas the plant samples ranged from 0.27 ppm. to 10.65 ppm. molybdenum. The following sequence of extraction of molybdenum was observed: 0.1 N NaOH > Tamm's acid ammonium oxalate > 0.03 N NH4F > 0.1 N HCl + 0.03 N NH4F. The only forms of soil molybdenum that gave statistically significant correlations with plant composition were the forms extracted by sodium hydroxide and acid ammonium oxalate.
Design of Plots Conforming to the Land for Evaluating Moisture Conservation Practices
Authors: Daniel Harley A. , Cox Maurice B. , Tucker Billy B. , Viets Frank G. 
Published: July 2010

AbstractA system of plots designed to conform to the land was in operation on the Wheatland Conservation Experiment Station, Cherokee, Oklahoma, from 1942 through 1951. The arrangement permitted the use of moderately sloping land for plot sizes approaching field conditions. The experiment was designed to compare the effectiveness of different seedbed preparations for the conservation of runoff water for plant growth. The tillage practices conducted on both terraced and unterraced land in a factorial arrangement of plots were plowing, listing, basin listing, and stubble mulch tillage. This report evaluates the experimental technique of such a system of plots and determines the variability experienced and differences assessable from measurements of runoff, soil moisture, and crop yields.Runoff was measured with type H flumes and Friez FW‐1 waterstage recorders. Amounts and intensities of rainfall were measured by Ferguson recording rain gages and checked by standard gages at 10 points located systematically on the station. Annual yields of winter wheat and soil moisture to a depth of 3 feet at planting and in the spring were measured.The system for measuring runoff water has been satisfactory. For the 10 years of data, the variability in all quantities measured was high. Nevertheless, significant differences were obtained on a site typical of a large area where soils and slopes were highly variable. The amount of runoff water from the terraced and contour cultivated land was significantly less than that from plots cultivated with the slope. When the four methods of seedbed preparation were compared, stubble mulching significantly reduced the yield of wheat.
Fixation and Release of Potassium by Some Clay Minerals
Authors: Mortland M. M. , Lawton K. , Uehara G. 
Published: July 2010

AbstractRelease of potassium from fixed forms in an illite, montmorillonite, and vermiculite and from the native forms of an illite, biotite, and muscovite was investigated. Methods used in studying potassium release were chemical, electrochemical, and biological. Changes in minerals following potassium release were followed with X‐ray diffraction and chemical techniques. Results of the study indicated the potassium “fixed” by vermiculite and montmorillonite to be available for plant growth. The native potassium of biotite was a great deal more available for plant growth than that of an illite or muscovite.
Some Aspects of the Relationship of Soil, Plant, and Meteorological Factors to Evapotranspiration
Authors: Lemon E. R. , Glaser A. H. , Satterwhite L. E. 
Published: July 2010

AbstractEvapotranspiration is a function of soil, plant, and meteorological factors. Attempts to predict evapotranspiration without considering all pertinent factors can meet with only qualified success.It is found that evapotranspiration is controlled by: soil moisture tension, physiological factors, the relation of soil moisture of an irrigated area to that of its surroundings as well as purely meteorological factors of radiation, wind, air temperature, and humidity.Examples are given of the effects of these factors on measured evapotranspiration.
Water Uptake of Corn Roots as Influenced by Soil Moisture Content and Soil Moisture Tension
Authors: Peters D. B. 
Published: July 2010

AbstractExperiments conducted on prepared mixtures of a sand and clay soil indicate that the uptake of water by corn roots is a function of the specific moisture content as well as the moisture tension.The data show that uptake of water and elongation of corn roots are decreased as the moisture tension increases and that the uptake of water and root elongation decreases as the moisture content per unit tension decreases. Calculations made upon the distance from the root surface from which roots extract water indicate that some dynamic factor may be operative in controlling water uptake by plant roots.
Relationships of Atterberg Limits and Cation‐Exchange Capacity to Some Physical Properties of Soil
Authors: Gill William R. , Reaves Carl A. 
Published: July 2010

AbstractThe relationship between some physical and chemical properties of several soils were studied with a view of associating these properties with the mechanical strength of the soils. Shrinkage of natural clods in the tillable range of soil moisture was more closely correlated with the cation‐exchange capacity than with the specific area or the plastic index. The correlations with these values were not as close in the case of puddled soils due to residual shrinkage. The sticky point is more a reflection of the water retention characteristic than a specific indicator of stickiness and has little value in tillage implement design; however, it may be of practical assistance in field work. The modulus of rupture was correlated with the specific area, plastic index, and cation‐exchange capacity of the soils. With the exception of compressibility, the cation‐exchange capacity appeared to be the value most closely correlated with the properties of the soils studied. Since the cationexchange capacity is frequently reported in nonphysical studies of the soil, a significant piece of information of physical property is available which should not be over‐looked.
The Movement of Nitrate Nitrogen Through Columns of Coarse‐Textured Soil Materials
Authors: Bates Thomas E. , Tisdale Samuel L. 
Published: July 2010

AbstractA laboratory investigation was undertaken in which the movement of nitrate nitrogen through columns of coarse‐textured soil materials was studied. Eight soil materials from the Coastal Plain region of North Carolina were used, and the movement of added nitrates as a function of the porosity of these soils and the quantity of water added to the columns was determined. A multiple regression equation was developed which permitted an estimate of the mean nitrate movement from a knowledge of the value of these two variables.
Control of Magnesium Deficiency in Utah 10B Celery Grown on Organic Soil
Authors: Johnson K. E. E. , Davis J. F. , Benne E. J. 
Published: July 2010

AbstractThis paper reports the results of a 2‐year study of the effects of several compounds of magnesium, potassium, and sodium on magnesium deficiency in Utah 10B celery grown on organic soil. Data obtained show the effects of the treatments on the yields, incidence of magnesium deficiency symptoms in the crops, and composition of the soils on which they were grown. Two to four tons of hydrated magnesium sulphate broadeast and worked into the soil were required to control symptoms of magnesium deficiency in this celery variety. Equally effective control could be obtained by applying 10 pounds of magnesium sulphate per acre in 100 to 150 gallons of water was a foliar spray at 10‐day intervals, beginning 4 weeks after transplanting and continuing throughout the remainder of the growing season. No magnesium carriers used produced any increase in yields of celery, but use of them generally improved quality and increased the value of the crops. Potassium fertilizers individually and jointly with sodium fertilizers tended to increase the incidence of magnesium deficiency symptoms. These symptoms were reduced to a minimum when the exchangeable calcium to magnesium ratio in the soil was less than 3:1 and when the magnesium saturation of the exchange complex was greater than 22%.
Hydraulic Conductivity as Related to Certain Soil Properties in a Number of Great Soil Groups—Sampling Errors Involved
Authors: Mason D. D. , Lutz J. F. , Petersen R. G. 
Published: July 2010

AbstractThis study was undertaken to provide information about hydraulic conductivity, percent large pores, and bulk density, their interrelationships, and the magnitude of the sampling error components involved over a wide range of soil conditions. Data from approximately 10,000 individual core samples from about 900 sites in 7 states, furnished in a cooperative project with the Soil Conservation Service, United States Department of Agriculture, were analyzed. Each sample was classified according to management, genetic unit (great soil group, high family, low family, and series), texture, and horizon.Mean values for hydraulic conductivity, percent large pores and bulk density, when classified by textural groups, showed a consistent decrease in magnitude with increases in silt and clay content. Mean values for the three properties, when classified by great soil groups, showed consistent differences between groups. Correlations between hydraulic conductivity and percent large pores was positive and comparatively consistent; correlations between hydraulic conductivity and bulk density were negative and generally of a low absolute value. The indicated conclusion was that bulk density, in itself, is a poor indicator of soil permeability.Variance components for among cores within sites and horizons, and between sites, after removal of all other classifiable variation, indicated that the between site component of the sampling error was 2 to 3 times larger than the within site component. These components are used to estimate “distinguishable permeability classes” for various sampling schemes, and by assuming various cost ratios, optimum sampling rates are estimated.
Soil Aeration as Affected by Organic Matter Application
Authors: Epstein Eliot , Kohnke Helmut 
Published: July 2010

AbstractThe effect of the method of incorporation of organic matter under various conditions of soil moisture and soil compaction on the composition of soil air was the object of this research. Application of fresh chopped alfalfa resulted in a pronounced depression of the oxygen content of the soil air. The order of decreasing oxygen content for the different methods of application was: check > surface mixed > layer at 2‐inch depth > surface application. High moisture content and compaction of the soil increased the time during which the oxygen content remained below 15% at 8‐inch depth. Both the oxygen and the carbon dioxide contents were determined at the 1‐, 3‐, and 8‐inch levels, as well as the amount of carbon dioxide given off at the soil surface.
A Method for Measuring Short‐Term Nutrient Absorption by Plants: I. Phosphorus
Authors: Stanford George , DeMent J. D. 
Published: July 2010

AbstractA method has been devised which permits measurement of P absorption by plants during relatively short periods of root‐soil contact. Plants are grown without added P in sand during which time a mat of roots develops at the bottom of the container. The exposed root mat with plants intact is then placed in contact with the soil or soil‐fertilizer system. Results obtained using oats as the principal crop and concentrated superphosphate applied to Hartsells fine sandy loam support the following conclusions: (1) P uptake by oats from applied fertilizer increased linearly with time between 1 and 7 days and increased linearly with rates of applied P ranging from 0 to 50 mg. or more per 200 g. soil. (2) Moisture equivalent was approximately the optimum soil moisture level for P absorption. (3) Recovery of applied P commonly ranged from 2 to 5% after absorption periods of 3 to 7 days. The method holds considerable promise as a means of studying the influence of various factors on P absorption by plants. These include environmental factors as well as soil and fertilizer characteristics.