bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relationships among Corn Yields, Leaf Composition and Fertilizers Applied
Authors: Viets F. G. , Nelson C. E. , Crawford C. L. 
Published: July 2010

AbstractThe purpose of this study was to determine the effect of fertilizer application on corn yields and the composition of certain leaves, and the relationships between leaf composition and yields. Three experiments differing in details were conducted under irrigation with hybrid Iowa 939 corn in central Washington.Leaves were selected at several growth stages, but the second leaf below the ear collected at silking was studied most intensively. Analyses were made for total N, P, Ca, Mg, K, and Mn and for P soluble in 2% acetic acid. Only N increased yields significantly; K and P applications did not. Calcium nitrate was least effective of the five N sources used. Total N content of leaves selected prior to silking gave lower correlations with yield than those selected at silking. Yields were highly positively correlated with both N and total P contents of leaves selected at silking, and total P and N contents of leaves were also highly correlated. Partial regression analysis showed that leaf N was probably the dominant determinant of yield, but that the leaf P content was sometimes important.For the three experiments the regression coefficients of yield on leaf N content were not significantly different, but the intercepts were markedly different.In one experiment, yields declined 15 bushels per acre for each leaf per plant showing N deficiency symptoms at silking. The minimum leaf N percentage associated with no evidence of the characteristic tip firing of N deficiency appears to be far below the reported critical N concentrations for maximum yield.Ammonium sulfate produced the highest leaf P and K contents and the lowest Ca and Mg contents in comparison with Ca(NO3)2 and NH4NO3 as N sources. The sum of the determined cations Ca, Mg and K in leaves selected at silking tends to be a constant at about 100 m.c. per 100 gm.Phosphorus soluble in 2% acetic acid was a linear function of and equal to about two‐thirds of the total P over a wide range of total P in the leaves.
Soil Factors Affecting Molybdenum Uptake by Cauliflower
Authors: Gammon N. , Volk G. M. , McCubbin E. N. , Eddins A. H. 
Published: July 2010

AbstractMolybdenum deficiency of cauliflower (whiptail) has been observed on the acid (pH 4.2 to 5.0) flatwoods soils of Florida. Considerable differences have been noted between cauliflower varieties in their development of molybdenum deficiency symptoms on these soils. Direct applications of molybdenum with and without lime were used as means of correcting the deficiency. Soil and plant analyses indicate that these soils can supply an adequate amount of molybdenum for plant growth by increasing the soil pH.The growing of cauliflower seedlings in acid, heavily fertilized soils limits the molybdenum taken up by the plant. These plants are set in the field in acid soils made even more acid by current fertilization. The plants with low molybdenum content and root systems restricted by transplanting are set in a soil with a low molybdenum supplying power. These conditions result in a temporary molybdenum deficiency in the plants. Subsequently, this deficiency becomes apparent when the damaged buds develop and the whiptailed leaves appear. As the roots grow and the acidity from the fertilizer dissipates, conditions become more favorable for molybdenum uptake by the plants. The degree of bud damage and the subsequent availability of molybdenum to the plants will be major factors in determining the degree of recovery and production of marketable heads by the plants. Failure of the leaves to develop chlorosis is further evidence of the temporary nature of the deficiency.Because molybdenum does not readily leach, there could be a possible danger to livestock if the fields were converted to pastures, following repeated applications of molybdenum for correction of whiptail. The molybdenum supply of the soils is low but probably adequate under favorable soil pH. The safest way to avoid molybdenum deficiency under these conditions is to grow varieties less susceptible to whiptail; to lime soils to as high as is commensurate with other crops grown in the area (pH 5.5 for potatoes); to lime seed beds to pH 6.0 to 6.5; and to use fertilizers containing fewer materials forming temporary acidity, especially in seed beds.
The Movement of Soil Moisture in Response to Temperature Gradients
Authors: Taylor Sterling A. , Cavazza Luigi 
Published: July 2010

AbstractUsing an air gap technique, it has been shown that the flow of moisture in the soil from warm to cool regions might occur largely in the vapor phase. This is accompanied by a return flow of liquid water in response to an induced flow potential gradient. The use of wire screens to make air gaps interferes with this process.The measured diffusion coefficient for vapor flow was higher than had been expected from diffusion data, but was substantially in agreement with that of other workers. The reasons for this high diffusion coefficient might be that the diffusion of moisture and heat is coupled in soils; the phenomena of surface migration and molecular hopping of adsorbed water might also cause this increase.The factors having greatest effect on the moisture distribution in continuous soil columns in a closed system are: (1) the diffusion and the convection of vapor or some related processes; (2) the evaporation and condensation occurring in the two end regions of the cylinders; (3) the hydraulic conductivity of the soil.The thickness of the air gap in broken columns influences the amount of water that will be transferred in the vapor phase and must be considered whenever an air gap is used to prevent fluid flow.The existence of two distinct drying and wetting moisture characteristic curves has been verified, and they play an important part in determining the liquid flow of moisture in the soil. The influence of this factor as well as the reason for the large vapor transfer need further study in relation to the transfer of soil moisture.
Conductometric Titration of Soils for Cation‐Exchange Capacity
Authors: Mortland M. M. , Mellor J. L. 
Published: July 2010

AbstractThe reaction of barium‐saturated soil with the sulfate anion of a standardized titrating solution to form insoluble barium sulfate is utilized for determining soil cation‐exchange capacity. The endpoint of the reaction is determined by conductometric titration. Specific conductance remains comparatively constant while the barium on the exchange complex is being titrated. After the barium has been titrated, conductance increases as increments of the titrating solution are added. The endpoint of the reaction is obtained from the intersection of the two linear portions of the curve. Cation‐exchange capacity data obtained by this method are compared with data obtained by other methods on the same soils.
Decomposition of the Soil Conditioning Polyelectrolytes, HPAN and VAMA in Ohio Soils
Authors: Mortensen J. L. , Martin W. P. 
Published: July 2010

AbstractC14 labeled synthetic polyelectrolytes, HPAN (hydrolyzed polyacrylonitrile) and VAMA (a copolymer of vinyl acetate and maleic anhydride) were added to Brookston silty clay loam and Hoytville silty clay respectively, to determine the extent of decomposition of these compounds. In an incubation period of 130 days, radioactive carbon dioxide equivalent to 2.74% of the added HPAN and 0.20% of the added VAMA was produced as a result of microbial metabolism. The addition of 1% carbon as rye grass increased the decomposition of VAMA to 0.30%.Microbial activity, as evidenced by CO2 evolution, was increased by polyelectrolyte treatment and a correlation between total carbon loss and decomposition of polyelectrolyte is suggested. Biochemical aspects of polyelectrolyte decomposition in soil substrates are discussed.
Soil Aggregation as Influenced by Microbial Gums, Level of Fertility and Kind of Crop
Authors: Rennie D. A. , Truog Emil , Allen O. N. 
Published: July 2010

AbstractA study was made of the effect on soil aggregation of microbial gums produced in vitro and in soil. Attention was also given to the effects of fertility treatments, kind of crop, and season on the aggregation of Spencer silt loam.The bacterial polysaccharide synthesized by Agrobacterium radiobacter in pure culture had a marked aggregating effect when added to Spencer and Miami silt loams. Addition of as little as 0.02 gm. of this gum to 100 gm. of soil caused a 50% increase in aggregates > 0.1 mm. in diameter. The gum content of numerous samples of Miami and Spencer silt loams correlated well with their respective levels of aggregation. The addition of extracted soil gum to a poorly aggregated soil increased significantly the degree of aggregation.Undecomposed pulverized plant residues added to soil increased the gum content to a maximum in six days. The maximum percentage of aggregates > 0.5 mm. in diameter was not reached until the twelfth day.In a four‐year rotation of corn, oats, and two years of alfalfa‐brome on plots which were variously limed and fertilized, increases in percentage of soil aggregates occurred at pH 6.0, 6.5, and 7.5 as compared with the aggregation level of the check plot (pH 5.5). High levels of available phosphorus and potassium as compared with low levels promoted aggregation. In general, structural deterioration began under corn and continued until the following crop of oats attained considerable growth. Thereafter improvement continued and reached a maximum during the second year of hay.Seasonal variations in soil aggregation occurred on all plots, irrespective of soil treatment or crop, and was characterized by a gradual increase in percentage of water‐stable aggregates during the spring and summer followed by a sharp decline in September.
Boron Materials of Low Solubility and Their Use for Plant Growth
Authors: Wear John I. , Wilson Clarence M. 
Published: July 2010

AbstractThree sources of boron including high‐grade Fertilizer Borate, Colemanite and Howlite were compared as to their water‐soluble boron contents, effect on plant growth and movement within the soil profile.Based on mill‐run samples, the water‐soluble boron in Fertilizer Borate was 5 times greater than in Colemanite and 25 times greater than in Howlite.Particle size had only a slight effect on the water‐soluble boron recovered from Fertilizer Borate, but for Colemanite and Howlite the amount of water‐soluble boron recovered was 6 to 8 times greater for finer than 80‐mesh material as compared to coarser than 10‐mesh material. This indicates the importance of particle size in controlling the rate of solubility of the more slowly soluble sources of boron.Although the water‐soluble boron in Fertilizer Borate, Colemanite and Howlite was in the ratio of approximately 1:5:25, the boron contents and toxicity symptoms of turnips and soybeans grown in the greenhouse in Norfolk loamy sand indicated a requirement of about twice as much Colemanite as Fertilizer Borate and 2 to 3 times as much Howlite as Colemanite to produce the same degree of toxicity.Results of the field leaching study on Norfolk loamy sand indicate that high‐grade Fertilizer Borate leached out of the topsoil very rapidly and collected in the lower zones of 8 to 16 and 16 to 24 inches. Twelve months later most of the water‐soluble boron had been leached past the 2‐foot depth. Howlite leached out of the topsoil slowly; the concentrations of water‐soluble boron remained fairly constant for the 6 and the 12‐month periods. Colemanite was found to be intermediate between the highly soluble sodium borate and the less soluble borosilicate from the standpoint of loss by leaching.
Yields of Cotton and Other Crops as Affected by Applications of Sulfuric Acid in Irrigation Water
Authors: Christensen P. D. , Lyerly P. J. 
Published: July 2010

AbstractEffects of sulfuric acid on crop yields and on some physical and chemical properties of a calcareous soil were investigated in a field experiment from 1947 through 1952. On cotton plots, the treatments consisted of applications of irrigation water containing no acid (pH 8.3), water acidified to pH 6, and water acidified to pH 2.3. Cotton was grown five season followed by sesbania the sixth season. A test on alfalfa was established using irrigation water not acidified and water acidified to pH 4. Alfalfa was grown for 3 years. The fourth year the alfalfa was plowed under and a crop of corn was raised.Cotton yields on the acid plots relative to the checks became progressively higher (with two exceptions) from one year to the next; however, in only one year (1950) were differences in yield statistically significant. With sesbania following cotton, highly significant yield increases resulted from the high acid treatment.Alfalfa yields on the acid plots became progressively greater relative to the non‐acid plots, but yield differences were not significant.In cotton leaves, the acid treatments resulted in increased uptake of magnesium, sulfur, and phosphorus, but the increases were probably not significant. Uptake of sodium, potassium, calcium, manganese, and iron were not appreciably affected.In sesbania, the acid treatments did not significantly alter the uptake of any of the plant nutrients determined. There was some indication, however, that the uptake of sodium and iron was reduced by the acidification.The results of this study support the view that soil acidification on calcareous soils may improve the soil physical conditions and result in increased yields, particularly in some crops. The application of acid in the irrigation water did not prove to be economically feasible.
The Effect of Magnesium upon the Growth and the Phosphorus Content of Soybean Plants
Authors: Webb J. R. , Ohlrogge A. J. , Barber S. A. 
Published: July 2010

AbstractAn investigation was made of the effect of magnesium upon the growth, the phosphorus absorption and translocation, and the cation content of soybean plants. The plants were grown in sand culture in the greenhouse, and the main treatment consisted of removing magnesium from the nutrient medium for various periods during the life cycle of the plants.The removal of magnesium from the nutrient medium for any of seven different periods of 21 to 121 days during the life of soybean plants reduced growth, but its absence early in the life of the plant caused a greater reduction than its absence later in life.Omission of magnesium from the nutrient solution did not retard phosphorus absorption but did have a significant effect upon the movement and final location of phosphorus in the plants. The chemical composition of the component parts of the mature plants revealed that the magnesium deficient plants contained a higher percentage of phosphorus in the vegetative organs and a lower percentage in the seeds than normal plants. A definite positive relationship existed between the magnesium and phosphorus content of the seed, and a definite negative relationship between the content of these two elements in the leaflets. This finding offers support to the theory that magnesium may function as a carrier of phosphorus in plants.The magnesium deficient plants absorbed slightly larger amounts of calcium and potassium on a percentage basis.
Yield‐of‐Phosphorus Curves
Authors: Dean L. A. 
Published: July 2010

AbstractThis paper embraces a study of the curves relating the total phosphorus absorption by plants with the fertilizer phosphorus additions (yield‐of‐phosphorus curves) and may be summarized as follows:For applications up to 160 pounds P2O5 per acre mixed throughout the soil, the “normal” yield‐of‐phosphorus curve was found to be an ascending straight line. Extrapolation of the yield‐of‐phosphorus curves to the point of intersection with the X axis gave a measure of the available soil phosphorus which approximated the ‘A’ value. Estimates obtained by extrapolation of yield curves gave values about half has large. The slope of the yield‐of‐phosphorus curves is to a degree influenced by the phosphate fixation processes.
Compression Studies of Illite Suspensions
Authors: Bolt G. H. , Miller R. D. 
Published: July 2010

AbstractIt can be shown that the classical Gouy‐Chapman theory of the electric double layer formed on planar surfaces provides and acceptable means of predicting the “osmotic” pressure of clay suspensions for various particle spacings and electrolyte contents.A compression apparatus was designed for the measurement of the swelling pressures of clay suspensions over the range 0.1 to 100 atm. The results obtained with this apparatus for a number of illite samples are consistent with those predicted by theory.Consideration of the implications of these experiments for the mechanism of flocculation favors the following conclusions: (1) The attractive forces acting between clay particles in flocculated suspensions are probably a simple Coulombic attraction between negative and positive sites on the respective particles; (2) Van der Waal's forces are of no consequence in flocculation phenomena in the suspensions studied; (3) The energy of flocculation is small and cannot contribute significantly to the resistance of aggregates to mechanical breakdown.
Effect of Moisture and Phosphate Variables on Alfalfa Hay Production on the Yuma Mesa
Authors: Stanberry C. O. , Converse C. D. , Haise H. R. , Kelley O. J. 
Published: July 2010

AbstractAlfalfa was grown on Superstition loamy fine sand on the Yuma Mesa for the 4‐year period, 1949–52, to evaluate the effects of moisture and phosphate variables on hay production and associated factors. The three moisture treatments were based on tension levels, tensiometers being installed at 9 depths from 6 to 120 inches. A total of about 125,000 tensiometer readings were recorded during the 4 years. Ten phosphate (superphosphate) rates and/or frequencies varying from 100 to 1,300 pounds P2O5 for the 4‐year period were employed as subplots in the split plot design.Average annual hay yields for the 4‐year period varied from 6.4 to 12.3 tons per acre, being greatly affected by either moisture or P level. Small frequent irrigations and an initial fertilizer application of more than 200 pounds P2O5 plus 100 pounds P2O5 annually appeared to be the goals to approach. Phosphorus movement was largely limited to the surface 18 inches, which was less than expected. As measured by tensiometers the depth for the greatest relative activity of roots decreased with decreasing moisture tension, increased with decreasing supplemental phosphate, and increased with increasing temperatures.Soil sampling during a 32‐month period revealed that for “dry”, “medium”, and “wet” treatments respectively, 80, 74, and 27% of the available moisture and 72, 82, and 85% of the total water utilized by the plant was removed from the surface 48 inches of soil. During a 3‐year period the mean water use per day varied from 0.21 to 0.25 inch, the greatest amount being used in the “wet” or low‐tension treatment. Water used per ton of hay produced varied from 7.1 to 16.5 inches, high rates of moisture and phosphate giving greatest efficiency.The alfalfa stand thinned rapidly, correlation analysis indicating a reduced stand was an important cause for declining yields. Root grading analyses at the termination of the experiment demonstrated that moisture and phosphate levels had no effect upon root shape and nematode infection. Moisture and/or phosphorus had significant effects on crown and root weight, root diameter, amount and distribution of feeder roots, and crown‐ and root‐rot. A barley crop was grown following the alfalfa to measure residual productivity levels due to previous moisture and phosphate variables. The only significant difference was caused by moisture, the “dry” treatment resulting in the greatest grain yields.
A Chemical and Mineralogical Study of Clay Materials from Several Gray‐Brown Podzolic Soils of Minnesota
Authors: Caldwell A. C. , Farnham R. S. , Hammers F. L. 
Published: July 2010

AbstractSoil samples were collected from two Fayette soils developed from Peorian loess, one Milaca formed from non‐calcareous glacial till of Cary substage of the Wisconsin, and one Hayden soil developed from calcareous glacial till of Mankato substage of the Wisconsin. Morphological observations placed these soils in the Gray‐Brown Podzolic group. Mechanical analysis showed these soils to be silt loams. Some accumulation of clay in the B2 horizon substantiated field observations of some podzolization having occurred.The clay material less than 0.5µ in size was separated from the A1, A2, B1, B2, and C horizons of these profiles. Total chemical analysis of the clay fraction showed little differentiation in content of inorganic constituents within and between profiles. X‐ray diffraction and differential thermal analysis of some of the clays indicated clay minerals largely of the montmorillonitic type. Relatively high total exchange capacities of the clays were indicative also of montmorillonitic types of clay minerals.
Investigations on the Mobilization and Transport of Iron in Forested Soils. II. The Nature of the Reaction of Leaf Extracts and Leachates with Iron
Authors: Schnitzer M. , DeLong W. A. 
Published: July 2010

AbstractElectrodialysis of poplar leaf extracts enriched with iron indicated that the major part of the iron was present either as ferric hydroxide or in a form readily convertible to the latter. Interaction of such solutions with iron produced only a general increase in light absorption: no absorption maxima indicative of chelation were observed. The major part of the iron present in these enriched aqueous solutions could be recovered by extraction with 8‐quinolinol in chloroform.Fractions isolated from poplar leaf extracts and leachates by precipitation in 80% aqueous ethanol possessed the major part of the capacities of these solutions to react with iron. Evidence was obtained that the principal component of these active fractions had the characteristics of an acidic polysaccharide. Potentiometric titrations of these active fractions in presence and absence of ferric ions failed to reveal evidence of chelation.It is concluded that both the forest canopy and the forest floor contribute solutions capable of the mobilization and transport of iron, and conclusions are drawn relative to the conditions favourable to such action of these solutions.
Some Site Factors Affecting the Success of Reforestation and Afforestation Activities in the Willamette Valley Foothills
Authors: Youngberg C. T. 
Published: July 2010

AbstractThe majority of the land in the low‐lying hills adjacent to the Willamette Valley is not suited for agriculture due to the nature of the soils and topography, and supports a cover of Douglas fir, mixed Douglas‐fir‐Oregon white oak, and oak stands. Scattered through the area are non‐forested openings supporting grass or grass and oak. The soils are clay loam or clay textured derived from basalt, shales, and sandstones with some alluvial fan soils on the lower foot slopes. Summer rainfall is negligible and humidities are generally low during the growing season.This paper reports some preliminary findings of the studies of soil moisture relations and the physical factors affecting them on several areas where reforestation or afforestation has been attempted. Soil profile descriptions are given, and results of laboratory analysis including mechanical analysis, bulk density, range of available moisture, and nutrient status are also reported. Several seasonal soil moisture curves are presented. The results of the study suggest that the narrow range of readily available moisture, i.e., water held at low tensions, in many of the soils of this area is responsible for the difficulties encountered in the attempts at reforestation and afforestation.