bluuebunny/crossref_metadata_2025 huggingface dataset:
Membrane‐Covered Electrode for Measurement of Oxygen Concentration in Soil
Authors: Willey C. R. , Tanner C. B.
Published: July 2010

The membrane‐covered polarographic electrode has been modified to permit a continuous in situ measurement of the oxygen concentration (partial pressure) of soil air. The modifications include temperature compensation (for a 30°C. temperature range) and a probe design that permits sealing in a soil access tube. The temperature‐compensated signal is proportional to oxygen concentration and is about 20 mv. in atmospheric oxygen. The (1/e) time constant of the probe following a step change in oxygen concentration is ¼ minute. The relative error for routine measurements is about 2%. General design features of the probe and example measurements are presented.
Uptake of Rubidium by Plants from Cation‐Exchange Resin Suspensions and Their Equilibrium Solutions
Authors: Werkhoven C. H. E. , Ohlrogge A. J.
Published: July 2010

Two laboratory experiments were performed to evaluate absorption of Rb86‐labeled rubidium by rye and corn from suspensions of a cation‐exchange resin and their equilibrium solutions as affected by a small distance, defined by high‐porosity filters, separating the roots from the exchanger.

With one exception, the absorption from the suspensions was from 3% to more than 100% higher than that from the solutions, depending on the length of the absorption period, the presence or absence of a filter, and the rubidium concentration.

The data are in agreement with those of other workers, who demonstrated the existence of two‐phase effects on ion absorption; the increased uptake from the suspensions is possibly due to a replenishment effect which is effective over a distance of at least 150µ from the colloids.
Investigations of Nitric Oxide Reactions in Soils
Authors: Cady F. B. , Bartholomew W. V.
Published: July 2010

The equilibrium reaction between NO (nitric oxide) and nongaseous compounds in the denitrification process was studied. Increments of NO were added to or removed from denitrification systems during the course of incubation.

Nitric oxide rapidly equilibrates isotopically with non‐gaseous products during the early stages of denitrification. Under acid soil conditions NO appeared in the gaseous phase. Under basic soil conditions NO did not appear from denitrification reactions but added NO persisted in the system and isotopically equilibrated with the non‐gaseous products in the soil. The equilibrium reactions between NO and the nongaseous compounds in the denitrification system could not be adequately explained by the conventional equation 3NO2‐ + 3H+ ⇄ NO3‐ + H+ + 2NO + H2O. The hypothesis is advanced that other reactions and products are involved.
Critical Soil Temperature for Tomato Plant Growth
Authors: Martin George C. , Wilcox Gerald E.
Published: July 2010

Fireball and Kokomo variety of tomatoes were used to study the effect of root temperatures at 56°, 58°, 60° and 70°F., and of P concentration on plant growth and chemical composition. It was found that the early and late tomato varieties responded similarly to the respective root temperatures. The response to P fertilizer was between 5 and 50 ppm., with no further growth increase at 100 ppm. There was a growth increase as expressed by dry weight between 56° and 58° and 58° and 70°F., but not between 58° and 60°F. Although in all cases increasing the temperature from 56° to 58°F. increased nutrient uptake, the difference was not great enough to have any practical importance. The growth of tomato shoots was doubled by increasing the root temperature from 56° to 58°F.
The Effects of Levels and Times of Fertilizer Application on the Growth of White Spruce Seedlings
Authors: Armson K. A.
Published: July 2010

Four levels of nitrogen and phosphorus were added in combination on three different time schedules to white spruce seedlings during their second growing season. The three time schedules were: (1) “Periodic,” in which fertilizer was applied in five dressings from May to September; (2) “Normal,” in which fertilizer was applied in May, June, and July; and (3) “Summer and Fall,” in which fertilizer was applied in May, June, and September.

Seedling dry weight increased with increasing level of fertilizer application but was not significantly affected by time of application. Seedling height showed a general increase with increase in amount of fertilizer. Shoot/root ratios increased with increasing level of fertilizer, however, by using a “Periodic” time schedule the increase was minimized. Nitrogen concentrations and contents in the foliage increased with increase in fertilizer level and “Periodic” and “Summer and Fall” applications resulted in larger concentrations than did those under the “Normal” time schedule. Foliage concentrations of phosphorus were not affected by any of the treatments.
Fission Product‐Soil Organic Matter Complexes: I. Strontium‐90 (Yttrium‐90) in Water Extracts and HCl Hydrolysates of Soil
Authors: Mortensen J. L. , Marcusiu E. C.
Published: July 2010

Brookston silty clay loam was incubated with 40 µc. Sr90(Y90) for 60 days and extracted with hot water or hydrolyzed with 6N HCl. The supernatant liquid was centrifuged, concentrated, and subjected to electrodialysis, dialysis, gel filtration, and paper electrophoresis.

Some Sr90(Y90) and organic matter migrated to the anode compartment during electrodialysis suggesting the presence of low molecular weight, negatively charged Sr90(Y90)—organic matter complexes. Dialysis did not remove all of the Sr90(Y90) from the extracts.

Gel filtration separated the extracts into several organic matter containing components and showed that Sr90(Y90) was complexed or held on exchange sites by high molecular weight polymers. Presence of radioactivity in the components was correlated with the presence of polyuronides.

Phenols, α‐amino acids and α‐keto acids were separated from the 6N HCl hydrolysate by paper electrophoresis but no clear correlation between these components and radioactivity on the paper strips was obtained.
Relationship Between Yield Response to Applied Fertilizers and Laboratory Measures of Nitrogen and Phosphorus Availability
Authors: Grunes D. L. , Haise H. R. , Turner F. , Alessi J.
Published: July 2010

Surface soils (generally 0‐ to 7‐inch depth) and subsoils (generally 7‐ to 21‐inch depth) were collected from sites in 13 Western states. Total N, initial NO3‐N, NO3‐N present after incubation, and NaHCO3‐soluble P were determined on all samples. On 14 surface soils these laboratory measures were correlated with values of N and P availability obtained in a controlled light‐temperature plant growth chamber. Growth response to applied N was highly correlated with nitrates in nonincubated soils, as well as with nitrates present following incubation. However, correlations were better with the sum of the NO3‐N produced during incubation and the NO3‐N present in nonincubated soils, than with only the NO3‐N produced. Correlation coefficients were higher when the soils were incubated 3 weeks, rather than 6 weeks, and also when no CaCO3 was added to the soil prior to incubation. The following measurements were good predictors of increase in barley yields following N fertilization in growth chamber experiments: NO3‐N in nonincubated soils; NO3‐N present following incubation; total N in plants from non‐N plots; “N” values of Munson and Stanford; and relative uptake of total N by plants in the P and NP plots.

The following measurements were good predictors of yield increases of barley when P was applied in the growth chamber: NaHCO3‐soluble P; A values of Fried and Dean; total P in plants from non‐P plots; and relative uptake of total P by plants in the N and NP plots.

In 46 field trials, laboratory measures of available N in the soil were compared with yield response to applied N fertilizers. Similarly, in 44 field trials, yield response from applied P was compared with NaHCO3‐soluble soil P. When the laboratory estimate for available soil N or P was low, growth response to fertilization was generally obtained in the field studies. When the soil level of available P was high, there was generally no yield increase following the addition of P fertilizer. However, yield response sometimes occurred on sites having high soil test values for available N. Differences, in the ability of the N and P laboratory tests to predict response to fertilization in field trials, are attributed to the influence of climate. Except for the relatively small amounts of initial available N in the soil, soil moisture and temperature determine the N supply from mineralization. However, mineralization of organic P may not be very important for supplying P to plants on soils having fairly high initial NaHCO3‐soluble P levels.
Estimates of Field Infiltration by Numerical Solution of the Moisture Flow Equation
Authors: Green R. E. , Hanks R. J. , Larson W. E.
Published: July 2010

The numerical procedure of Hanks and Bowers was used to solve the moisture flow equation for boundary conditions corresponding approximately to those existing for infiltration into a field soil. Water diffusivity and retention data, necessary for theory calculations of infiltration, were measured on field cores by the outflow method. Infiltration estimates were obtained for a simulated two‐horizon soil with three nonuniform antecedent moisture profiles.

Calculated infiltration rates were in good agreement with field rates measured with a sprinkling infiltrometer. Although not considered a substitute for field measurement, the numerical procedure appears to be a useful means of supplementing field measurement data by providing estimates of infiltration for simulated conditions of practical interest which are difficult to evaluate in the field.
Correlations of Phosphorus Availability by Chemical Tests With Inorganic Phosphorus Fractions
Authors: Pratt P. F. , Garber M. J.
Published: July 2010

Linear and multiple correlations are presented between and among data for 3 soil tests for available P, 4 inorganic P fractions, clay content, and pH of acid soils.

Water‐soluble P was positively correlated with NH4Cl‐soluble P, NH4F‐soluble P, and negatively correlated with clay content. In a multiple correlation analysis, water‐soluble P was correlated only with NH4Cl‐soluble P. The P extracted by the Bray reagent was positively correlated with NH4Cl‐soluble and NH4F‐soluble P and negatively correlated with clay content. In a multiple regression analysis, an expression of the NH4Cl‐soluble plus NH4F‐soluble P as ppm. P in the clay fraction was the only significant factor. The P extracted by NaHCO3 was positively correlated with NH4Cl‐soluble, NH4F‐soluble, and NaOH‐soluble P. In a multiple regression analysis, the NaHCO3‐P was related to NH4Cl‐soluble, NH4F‐soluble plus NaOH‐soluble P in parts per million P in the clay fraction. The effect of increasing clay content in decreasing the effectiveness of the Bray and NaHCO3 reagents to extract P from soils was related to exhaustion of the reagent in the case of the former and to exhaustion of the reagent and secondary precipitation in the case of the latter.
A Technique for Magnetic Susceptibility Determination of Soil Materials
Authors: Jones Robert L. , Beavers A. H.
Published: July 2010

A simple and inexpensive magnetic balance can be erected by replacing the weighing pan of an analytical balance with a plastic pan containing a well which receives a sample pellet. The force set up between the pellet and a magnet centered beneath the pellet is measured by adding weight to the weighing pan until the break‐away point of the centering needle is slightly exceeded. Results compare favorably with those obtained with the Faraday balance. Data obtained with the balance can be used to determine discontinuities in parent material and to follow soil forming processes.
Nutrition of Corn on a Calcareous Soil: II. Effect of Zinc on the Yields of Grain and Stover in Relation to Other Micronutrients
Authors: Fuehring H. D. , Soofi G. S.
Published: July 2010

The effect of row‐applied Zn, B, Fe, Mn, and Cu on grain and stover yields and on the sixth leaf composition of corn grown on a calcareous soil was studied using a central composite factorial. Grain yield was decreased by application of the micronutrients studied. The yield of stover, however, was considerably enhanced at all levels of applied Zn indicating that response to Zn was directly opposite between vegetative and storage parts of the plant. Concentration of Zn in the sixth corn leaf ranged from 20 to 145 ppm. Grain yield was relatively high at 20 ppm. while yield of stover was highest at the 145 ppm. Zn content. A highly significant positive interaction between Zn and Mn on grain yield indicated that increasing either element decreased the toxic effect of the other. However, the Zn‐Mn interaction was negative for yield of stover, and increasing Mn tended to decrease yield at the higher levels of applied Zn. A possible interference of Zn with the translocation of carbohydrates to the storage organs was postulated. The optimum Zn level in the leaves for grain production was affected to the greatest extent by the level of Mn, low Mn in the leaves resulting in a low Zn requirement while higher concentrations of Mn in the leaves resulted in a high Zn requirement for both grain and stover.
Interrelations of Calcium and Rubidium Absorption by Excised Roots of Barley and Plantain
Authors: Noggle J. C. , de Wit C. T. , Fleming A. L.
Published: July 2010

The uptake rates of Rb and Ca, applied alone or together, by excised barley and plantain roots were compared. The barley roots absorbed Rb at a faster rate than Ca, whereas the reverse was true for plantain roots. The presence of Ca increased the rate of Rb uptake by barley roots, but the presence of Rb had very little effect upon the Ca uptake. The uptake rate of either ion by plantain was reduced by the presence of the other ion.

Calculations indicate that the depressing effect of one ion on the uptake of the other by plantain was due predominantly to ionic competition when the ions were present in the concentration range of 10‐2N, but factors in addition to competition were responsible in the concentration range of 10‐4N. The significance of the differences in response of the two species is discussed.
Corn Stover Mulch for Control of Runoff and Erosion on Land Planted to Corn After Corn
Authors: Taylor R. E. , Hays O. E. , Bay C. E. , Dixon R. M.
Published: July 2010

A mulch of corn stover and barnyard manure has given excellent control of soil and water losses from corn after corn on a steeply sloping deep loess soil. During 9 years of measurement in Wisconsin, losses of soil and water from corn after corn with a mulch were less than from corn or oats without mulch in a corn‐oats‐hay rotation and were about equal to the losses from the meadow in the rotation. Corn yields averaged 3 bushels more from the corn after corn than from the corn in the 3‐year rotation.
Differential Effects of Phosphorus Fertility on Soybean Varieties
Authors: Fletcher H. F. , Kurtz L. T.
Published: July 2010

Chief and Lincoln soybeans, previously shown to be tolerant and intolerant, respectively, to very high P levels were grown in the greenhouse in soil admixed with ordinary superphosphate at rates varying from 0 to 4,400 pounds of P per acre. The varieties were similar in P response, dry weight, and mineral composition to around 870 pounds per acre of added P. Higher levels of added P were better tolerated by Chief than by Lincoln. At 2,620 pounds or more P per acre, marginal browning of the leaves, chlorosis, leaf drop, and severe stunting occurred in the Lincoln variety. In the Chief variety, stunting occurred only at much higher levels of P and the other toxicity symptoms never developed. Number of nodules, but neither size nor appearance, was reduced more on the Lincoln variety than on the Chief at intermediate P levels. At highest levels of P, no nodules were found on either variety. In mineral composition, Lincoln increased more than Chief in percent P and K as the P additions increased. Percent P and percent Si showed a reciprocal relationship in both varieties. No striking differences between varieties were observed in the contents of Fe, Mn, Ca, Mg, and B.
The Effect of Ammonium Phosphate and Other Chemicals on the Germination of Cotton and Wheat Seeds
Authors: Hood J. T. , Ensminger L. E.
Published: July 2010

Field and greenhouse studies with cotton and wheat showed that fertilizers containing ammonium phosphates were especially detrimental to germination and could result in very poor stands. In order to study the cause of this harmful effect, seeds were soaked in salt solutions (including ammonium phosphates) and acids for various time intervals. The seed surfaces were then washed free of the solutions and allowed to germinate. The (NH4)2 HPO4 solutions reduced germination more than any other salt solution including NH4H2PO4. In studies with cotton seed, a solution of (NH4)2SO4 adjusted with NH4OH to pH 8.2 did not reduce germination as much as did (NH4)2 HPO4. Germination was lowered more by H2SO4 than by H3PO4 at the same pH. Soaking the seed in salt solutions such as CaSO4 before soaking in (NH4)2HPO4 did not improve germination. When the seeds were soaked in MgSO4 or MgCl2 after being soaked in (NH4)2HPO4, there was an improvement in germination as compared with (NH4)2HPO4 alone. Soaking in MgSO4 and MgCl2 did not increase the germination of seed that had been soaked in H3PO4. It appears that the detrimental effect of ammonium phosphate is not due to the ammonium or phosphate ion per se.
Properties of Selected Soils Developed Near the Forest‐Prairie Border in East‐Central Illinois
Authors: Bailey L. W. , Odell R. T. , Boggess W. R.
Published: July 2010

Two Gray‐Brown Podzolic soils and two Gray‐Brown Podzolic to Brunizem intergrade (transition) soils which occur near the forest‐prairie border in east‐central Illinois were studied to determine the effect of vegetation upon soil properties. All four profiles developed in loess and calcareous till of similar age and in the same climatic area so that soil differences are related to length of occupancy by trees, forest composition, and natural drainage.

The Gray‐Brown Podzolic soils are more highly weathered and show more forest influence than the transition soils. This is indicated by higher organic carbon content and base status in the Al horizons; higher clay maxima, higher cation‐exchange capacities, lower Ca/Mg ratios, and lower base status in the B2 horizons; and less organic matter in the lower horizons of the Gray‐Brown Podzolic soils than in the transition soils.

The relationships between soil properties and the vegetation sequence in north‐central United States are reviewed.
Effects of Long‐Time Cropping on Hydrolyzable Organic Nitrogen Fractions in Some Great Plains Soils
Authors: Porter L. K. , Stewart B. A. , Haas H. J.
Published: July 2010

Virgin soils and their long‐time cropped counterparts were hydrolyzed with HCl. The N separated into three fractions. The proportion of N that each N fraction contributed to the total N was altered when comparisons were made between virgin soils and their cropped counterparts. Cultivation and cropping caused losses in all three N fractions, however, the nondistillable acid‐soluble N fraction lost a greater proportion of its N than did the other two fractions.
Carbon Determination in Soils and Organic Materials with A High‐Frequency Induction Furnace
Authors: Young J. L. , Lindbeck M. R.
Published: July 2010

Application of established procedures for determination of carbon (C) in metals yielded about 60 to 90% C recovery from soils and pure organics. Systematic instrument and procedural changes showed that low recovery was due to escape of pyrolysis products or other volatile organic materials. Complete C recovery from dry soils and pure organics was achieved by adaptations employing an internal quartz‐enclosed graphite ignitor or an external auxiliary resistance furnace. The procedures also permit analysis of total C in residues from soil extracts or other solutions and for inorganic C and organic C in soils.
Moisture, Pore Space, and Bulk Density Changes in Frozen Soil
Authors: Krumbach A. W. , White D. P.
Published: July 2010

In the upper 15 inches of 2 frozen loam soils, one bare and one under alfalfa, moisture contents usually exceeded prefreeze field maximum. Total pore space was always above that before freezing; bulk density was predominantly less than the lowest expected prefreeze bulk density. Moisture changes in the frozen soils are attributed solely to internal moisture movement.
Terminal Elongation of Loblolly and Shortleaf Pine Seedlings under Soil Moisture Stress
Authors: Stransky J. J. , Wilson D. R.
Published: July 2010

During the spring growth flush, height growth of potted seedlings was inhibited by soil moisture tensions not greater than 2 atm. and it stopped completely as tension increased to 3.5 atm. Incipient wilting of the young flush occurred near 5 atm. and all plants died at 15 atm. Leaf moisture content and corresponding leaf water deficit changed little before growth stopped. Water deficit was not a reliable indicator of the seedling's internal moisture regime once leaf moisture content fell from an initial 210% to below 105%.
The Movement of Water and Nitrate Around Bands of Sodium Nitrate in Soils and Glass Beads
Authors: Burns G. R. , Dean L. A.
Published: July 2010

The movement of water and nitrate (NO3‐) around bands of NaNO3 was studied in soils and glass beads in the laboratory. A hypothesis was developed and tested concerning the predominantly downward movement of NO3‐ from a band of NaNO3 in soils with moisture contents greater than field capacity. The hypothesis of events is as follows: Soil water moves, under the osmotic force generated, to the band of NaNO3; then the NaNO3 dissolves and diffuses away from the band. However, the effect of the diffusion is reduced when sufficient mobile water is present in the surrounding soil to maintain the influx of water. As a result, the NaNO3 solution accumulates in the vicinity of the band. Once the accumulating solution exceeds that which can be held by the capillary forces of the soil, the excess NaNO3 solution literally drops out of the band under the force of gravity. The drop‐out of NaNO3 solution continues until essentially all of the NaNO3 has been dissolved.

This drop‐out phenomenon occurred in systems in which the water was present initially in quantities greater than field capacity, was moved through the system by leaching, or was moved into the system by capillarity from a shallow water table. Evidence supporting the details of the hypothesis resulted when various shields were used to alter the NO3‐ movement around the fertilizer bands under the leaching and “static” moisture conditions.
Profile of Natural Radioactivity in Hartsells Loam
Authors: Burton J. D. , Guenther W. B. , Owen H. M.
Published: July 2010

During summer of 1961 bulk samples at 4‐inch to 30 inches depth increments were collected at 15 random locations within an apparently uniform single acre of forest soil, Hartsells loam, under oak‐hickory sawtimber on the Cumberland Plateau in Tennessee. Net radioactivity, total potassium content, and mechanical fractions were determined in the laboratory. After samples were stored in sealed containers for 7 days, activity was counted again and found to be increased. Linear regressions of initial activity on silt‐plus‐clay and on K, K on silt‐plus‐clay, and 7‐day activity on clay, on K, and on 1‐day activity were highly significant. Distributions of K, and of initial activity in the soil profile were more closely related to the profile of total fines than to the clay curve. Initial activity was believed to be due largely to K40, but activity gain during storage was probably due to daughters of U238.
Boron in Some Saline and Nonsaline Soils in Southeastern Saskatchewan
Authors: Werkhoven C. H. E.
Published: July 2010

The hot‐water soluble B content of salt‐affected chernozemic soils of southeastern Saskatchewan, determined colorimetrically with quinalizarin, was found to range from 0.1 to 2.0 ppm. Wheat and alfalfa were grown in the greenhouse on six different soils with three added levels of B. The mean B content of wheat ranged from 1.4 to 30.5 ppm., and that of alfalfa from 49.4 to 69.3 ppm. No toxicity symptoms were observed; on the contrary, the first level of added B tended to increase the dry matter yield of alfalfa on three soils. In a 34 factorial experiment, alfalfa and wheat were grown in the greenhouse on a saline soil with three levels of B, Ca, Mg, and Na. The dry matter yield of both crops decreased linearly with the application of 200 and 400 ppm. of Mg as MgSO4. Increased Na levels decreased the B content of wheat and the dry matter yield of alfalfa. Added Ca and Mg had no statistically significant effect on the B content of either wheat or alfalfa. The correlation between the B content of wheat and hot‐water soluble soil B content was highly significant (r = 0.689), but no such correlation was evident for alfalfa. In the case of wheat, the correlation appeared to be valid only for a specific soil type.
Iron or Aluminum Coatings in Relation to Sulfate Adsorption Characteristics of Soils
Authors: Chao T. T. , Harward M. E. , Fang S. C.
Published: July 2010

Studies were conducted to investigate the effects of hydrous Fe‐ and Al‐oxides in relation to pH upon SO4 retention by Soils. “Less SO4‐retentive” soils exhibited SO4 adsorption of the Latosols or Ando soils after coating with the hydrous oxides. The pH‐dependent SO4 retention was much more marked after the coatings were applied. Retentive soils are made much less retentive by treatments for the removal of the hydrous oxides while the less retentive soils show appreciable SO4 adsorption when the hydrous oxides are added. In the acid range, the amount of SO4 adsorption is essentially proportional to the amounts of hydrous Fe‐ or Al‐oxides present. Aluminum‐oxides are more effective in retaining SO4 than Fe‐oxides when both are present as coatings on soil particles. The Fe system exhibited increasing adsorption with increased acidity whereas the Al system showed a maximum at pH 4.0. Subsequent decreases of SO4 adsorption by Al‐coated soils at lower pH values were shown to be associated with dissolution of the hydrous Al oxide phase.
Effect of Lime on Availability of Phosphorus in Zamorano Soils
Authors: Awan Abdul Bari
Published: July 2010

Field studies were conducted over a 2‐year period on experimental plots at the Escuela Agricola Panamericana situated in the valley of the Rio Yeguare at El Zamorano, Honduras, to study the effect of lime on the availability of soil P.

Yields of corn (Zea mays), sorghum (Sorghum vulgare), beans (Phaseolus vulgaris), and cowpea (Vigna sinensis) green manure were recorded. Highly significant yield increased were obtained when the acid soil (pH 5.5) was limed to raise the pH to 6.5. The highest yields were obtained on plots receiving both lime and P.

The major portion of the potentially available P in Zamorano soils is in the organic fraction. Analysis of the final soil samples showed that liming liberated the P locked up in the organic form and increased the efficiency of applied P for crop use.
Nutrient Utilization by Young Pitch Pine
Authors: Voigt G. K. , Richards B. N. , Mannion E. C.
Published: July 2010

Ten pitch pines (Pinus rigida Mill.) ranging in age from 5 to 9 years were excavated from an abandoned gravel pit in southern New Jersey. Lateral and vertical distribution of the root systems were recorded and total soil volume occupied by roots was calculated (root system sorption zone). In addition, the volume of soil within 1 cm. of any root surface was calculated (root surface sorption zone). Contents of total and exchangeable Ca and K in these zones were related to contents of Ca and K in the trees. Exchangeable Ca and K contents in the root system sorption zone were generally higher than the total content of these nutrients in the trees while the reverse was true for the relationship between the root surface sorption zone and the tree. Annual uptake of K by the trees was approximately equal to exchangeable K content of the root surface sorption zone. Annual uptake of Ca by trees was only about one‐third of the exchangeable Ca in the root surface sorption zone indicating that average distance of movement of Ca from soil to root surface was less than that for K. Less than 10% of the total soil volume occupied by roots was utilized in absorption of Ca and K.
Infiltration into Vertical Columns of Soil under a Small Positive Head
Authors: Gupta R. P. , Staple W. J.
Published: July 2010

Experimentally measured soil moisture profiles during infiltration into vertical columns of air‐dry Grenville silt loam, under a small positive hydrostatic pressure, were compared with those predicted by the iterative procedure of Philip, and by an explicit finite difference method. Philip's solution predicted the shape of the drier portion of the moisture profile satisfactorily but the predicted depth of the zone of zero soil moisture tension and the total depth of infiltration were less than found experimentally. Satisfactory estimates of the shape and depth of the moisture profile were provided by the second method when the high conductivities in the saturated and transition zones near the surface were taken into account.
X‐Ray Spectrographic Analysis of Zinc, Manganese, Iron, and Copper in Plant Tissue
Authors: Dixon Joe B. , Wear John I.
Published: July 2010

X‐ray spectrographic analyses for Zn, Mn, Fe, and Cu in Bermudagrass, pecan, pine, and corn foliage were made employing standard curves prepared from composite samples and from additions of the element to each sample. Interferences by various elements were determined by analysis of enriched samples. An increase in Cu concentration in Bermudagrass reduced the value obtained for Zn. First order Kα radiation was used for all elements except Cu. Interference of W Lα radiation occurred with Cu, but was reduced by using second order reflection of Cu Kα. Simplified techniques for preparing ground sample standards were examined. Results obtained by X‐ray spectrographic and chemical methods were found to compare satisfactorily in most cases.
Effect of Incubation Method and Storage Conditions on Nitrate Production of Incubated Soil Samples
Authors: Munro D. C. , MacKay D. C.
Published: July 2010

Samples of Charlottetown fine sandy loam were incubated for 2 weeks at 30°C. and four different moisture tensions, with sand added in four different soil to sand ratios. Tension of 0.24 atm. and 1:1 soil‐sand ratio was optimum for production of NO3‐‐N. Incubation in an atmosphere of less than 85% relative humidity severely restricted nitrate production due to drying of the soil.

Samples of the same soil at air‐dry, 10% and 20% moisture were stored at −20, −5 and +5°C. for 0.7, 3, 6, 9, 12, and 15 weeks in a complete factorial experiment, then incubated at 30°C. and 0.24 atm. moisture tension for 2 weeks. Air‐drying increased nitrate production by 15 to 20 ppm. N over moist samples. Storage at 20% moisture caused a 2 to 3 ppm. decrease compared to 10% storage. Minus 20° and −5°C. storage gave constant nitrate production with changing storage time, but −20° samples were 2 to 3 ppm. N higher than −5° samples at 10 and 20% moisture.

Air‐drying soil from field capacity to the wilting point had little effect on nitrate production, but further drying to the air‐dry state caused a marked increase. Moisture content of soil samples during storage affected the correlation of nitrate production with ryegrass yields in the greenhouse.
Effect of Soil Temperature and Length of Reaction Period on Water Solubility of Phosphorus in Soil Fertilizer Reaction Zones
Authors: Beaton J. D. , Speer R. C. , Brown G.
Published: July 2010

Pellets containing 15 mg of P prepared from each of the following salts: KH2PO4 (MKP), NH4H2PO4 (MAP), (NH4)2HPO4 (DAP), Ca(H2PO4)2·H2O (MCP), and CaHPO4·2H2O (DCPD) were placed in cavities in the surface of Bradwell very fine sandy loam (pH = 7.8) and Monroe silt loam (pH = 5.8). The treated soils were stored at 5, 20, and 35C. Extent of dissolution of fertilizer pellets and development of soil‐fertilizer reaction zones were measured during the first 14 days of storage. At the end of 2, 7, 14, 28, and 56 days the soil‐fertilizer reaction zones were sampled and the concentration of water‐soluble P and the percentage of fertilizer P soluble in the reaction zones were determined.

Rate of dissolution of the water‐soluble P fertilizers increased markedly as temperature increased. Some pellets were incompletely dissolved at the end of 14 days at 5C, whereas, at 35C dissolution was usually complete in less than 4 days. For each 15C increase in temperature there was about a 33% reduction in concentration of water‐soluble P and the proportion of fertilizer P soluble in water.

During the first 14 days after adding the water soluble fertilizers there was a rapid decrease in concentration of water‐soluble P and proportion of dissolved fertilizer P while after 14 to 28 days the changes were much samller. Extraction of water‐soluble P decreased in the order MKP>MAP = DAP>MCP>DCPD>check. Differences among sources became smaller with increased time of contact with soil. DCPD was more soluble in the acid Monroe soil than in the calcareous Bradwell soil.
Surface Soil Textural and Potential Erodibility Characteristics of Some Southern Sierra Nevada Forest Sites
Authors: Willen Donald W.
Published: July 2010

Analyses of texture and potential erodibility were made on 208 samples of residual, upland forest soils collected at elevations from 6,500 to 8,000 feet in the southern Sierra Nevada in California. Multiple regression tests showed that soil texture and erodibility indexes were significantly related to variation in parent rock type, vegetative cover type, aspect, slope, and elevation. Prediction equations implied that granitic forest soils at high elevations may be twice as erodible as soils developed under similar soil forming conditions at low elevations.
Changes in Fiber‐Glass Soil Moisture‐Electrical Resistance Elements in Long‐Term Installations
Authors: England C. B.
Published: July 2010

The entrance of soil constituents into the interelectrode material of Colman soil moisture units causes changes in calibrated moisture‐resistance relations. The degree and abruptness of change is related to depth of placement in the soil. Regular field calibration checks must be performed in order to correct for these changes.
Description of Soil Characteristics for Partially Saturated Flow
Authors: King L. G.
Published: July 2010

Two empirical equations are presented for describing relative permeability as a function of capillary pressure. Of the two, Gardner's equation appears to fit the experimental data better and is easier to use because of its simple form. An equation is also presented for representing saturation as a function of capillary pressure. This equation is differentiable.

The equations are used to calculate relative permeability and diffusivity as functions of saturation. The main utility of the equations is in the ease of handling input data and programming for numerical solutions, using digital computers. The equations may also prove useful in some theoretical studies where a wide range of possible soils may be described by changing a small number of parameters.
Relative Availability of Phosphorus in Fertilizers Varying in Solubility of the Phosphorus
Authors: Wright Bill C. , Murphy B. C. , Gilliam J. W.
Published: July 2010

Twenty‐eight NPK fertilizers varying in solubility of the phosphorus were compared by band application and cropping to corn (Zea mays L.) in the greenhouse. Phosphorus uptake and per cent superphosphate equivalent were determined for each of two crops and for a combination of both crops. The per cent superphosphate equivalent ranged from 14 to 135 in the first crop, from 15 to 98 in the second crop, and from 13 to 111 for the total of both crops. Correlation coefficients for the relationships between superphosphate equivalent and water‐soluble and Netherlands alkaline ammonium citrate‐“available” P (NAAC‐“available” P) were highly significant for crop I, crop II, and the total of both crops. The correlation coefficients relating superphosphate equivalent to AOAC‐“available” P were barely significant at the 5% level. It is concluded from these results that both water‐soluble and NAAC‐“available” P are good criteria to use in judging phosphate fertilizer quality for crops and it is obvious that AOAC‐“available” P is poorly related to plant available P.
Quantity, Distribution, and Variability of Organic Matter and Nutrients in a Forest Podzol in New York
Authors: McFee W. W. , Stone E. L.
Published: July 2010

The organic matter under yellow birch‐red spruce forest (Betula alleghaniensis Britton‐Picea rubens Sarg.) growing on well‐drained, outwash sands of the Adams series was sampled intensively on eight one‐tenth acre plots in the Adirondack Mountains of New York. Under old, undisturbed stands the mean depth of the forest floor was 6.4 inches (16 cm) and the mean weight was 216,300 ± 8,800 (90% confidence interval) lb/acre (242 metric tons/hectare). There was approximately 175,000 lb/acre of organic matter in the forest floor and about 142,000 lb/acre in the upper three horizons of the mineral soil. The average bulk density of the forest floor was 0.14 g/cm3. A theoretical O horizon accumulation curve was drawn based on samples from plots having different ages of accumulation. These ages were inferred from ecological information and from evidence of fire history. The concentration of organic matter in the B2h horizon was positively correlated with age of the forest floor. The undisturbed forest floor contained approximately 2,850 lb/acre of nitrogen or about 43% of the estimated total in the nutrient cycle. It also contained approximately 150, 90, and 620 lb/acre of phosphorus, potassium, and calcium, respectively.

Coefficients of variation ranged from .33 to .67, determined on the basis of 96 sample weights from the forest floor of each plot. Approximately 50 samples were needed to reduce the standard errors to 10% of the mean weights. Similar variability was found in the thickness of mineral soil horizons. Horizon thicknesses measured from a single soil pit in a 0.1‐acre plot were not reliable estimates of thicknesses when compared with those determined by taking 12 to 24 core samples spaced throughout the same plot.
The Dickson and Zanesville Soils of Washington County, Arkansas: I. Their Properties and Genesis
Authors: Rutledge E. M. , Horn M. E.
Published: July 2010

The Dickson and Zanesville soils of Washington County, Arkansas, exhibit very similar morphology although underlain by different bedrock. Purposes of this study were to determine certain chemical, mineralogical, and physical properties in order to establish their general composition and whether all or part of their sola were developed in loess. Data on three profiles of each series are similar. Some property ranges of their B22t horizons are: pH, 4.2 to 4.9; CEC, 12 to 16 meq/100g; base saturation, 14 to 27%; and clay content, 24 to 36%. Variations within series are of the same order as between series except the Zanesville has about 10% more fine or very fine sand and is usually somewhat lower in bases. A loess parent material is suggested by high silt contents (50% to 80%) and a lack of abundant coarse fragments in upper horizons. Conversely, uniform heavy mineral distributions and very fine‐to‐fine sand ratios with depth in both soils suggest that a definite upper loess layer does not exist and that Zanesville soils are mainly developed from underlying sandy siltstones and the Dickson soils from cherty limestone. It is postulated that porous cherts of the Boone formation can weather to silt as do siltstones. Since both are siliceous, similar soils could result.
Effect of Chemical and Mechanical Fallow Methods on Moisture Storage, Wheat Yields, and Soil Erodibility
Authors: Black A. L. , Power J. F.
Published: July 2010

Neither complete chemical fallow (no tillage) nor combinations of chemical and mechanically tilled fallow methods resulted in more moisture conserved than conventional stubble‐mulch fallow. Grain yields (Triticum aestivum L., ‘Lee’ ‘Rescue’, or ‘Centana’) were highest on stubble‐mulch fallow, or other tillage plots receiving no spray at any time. Lowest moisture conservation and grain yields resulted from complete chemical fallow. Yields were lower even in the absence of visual residual effects of chemical treatments.

Wind erodibility of the surface of complete chemical fallow soils was considerably lower than stubble‐mulch fallow. Complete chemical fallow methods increased surface residue cover at least 10% and significantly decreased the erodible fraction of the 0‐ to 2‐inch soil layer in comparison with stubble‐mulch fallow.
Tracing Soil Particle Movement with Fe‐59
Authors: Wooldridge David D.
Published: July 2010

Rates and patterns of actual soil particle movement were established by measuring changes in radiation intensity with time on an eroding sandstone soil. Applying 300 µc of Fe59 in a 5‐foot line along the contour gave a better measure of soil erosion pattern than 100 µc applied to a point. More than 70% of the isotope applied moved 3 or more inches downslope from the line of application. Apparently Fe59 forms mainly stable precipitates or reacts with existing ferric compounds on clay and silt particles because it is not found in the soil solution or on the soil base‐exchange capacity. Only 20% of the Fe59 was temoved by 72‐hour treatment with 30% H2O2. Over 90% of the Fe59 was retained in the surface 1 cm of soil.
Soil‐Peels and a Method for Estimating Biopore Size Distribution in Soils
Authors: Bouma J. , Hole F. D.
Published: July 2010

Soil‐peels are thin blankets of soil taken in a nearly vertical position from the sides of soil pits. The soil‐peels are cemented on one side by cellulose acetate or vinyl plastic, and show dry colors and natural structure in three dimensions on the other more fragile side. Methods are described for taking soil‐peels in the field, and for systematically studying biopores in them with the aid of a binocular microscope.
Hydrolysis of Condensed Phosphates in Soils
Authors: Allmaras R. R. , Black C. A.
Published: July 2010

Hydrolytic degradation of the condensed phosphates of fertilizer‐grade calcium metaphosphate (CMP) in soils involves several steps, including formation of a dense, viscous liquid from the vitreous portion of the CMP. Experiments indicate that the rate‐controlling step in the early stages of transformation of condensed P to orthophosphate in soils treated with solid particles of CMP was the degradation of the viscous liquid and not the hydrolysis of the condensed P in the solution derived from the viscous liquid.
Loess Composition in Southeastern Illinois and Southwestern Indiana
Authors: Fehrenbacher J. B. , White J. L. , Beavers A. H. , Jones R. L.
Published: July 2010

Peorian loess in southeastern Illinois and southwestern Indiana varied more in composition among the Wabash, Ohio, and Mississippi river source areas than did soils developed in the upper portion of the loess.

Very low magnetic susceptibility was found in the gray, basal (Iowan or Morton) Peorian loess in the Wabash valley. Carbonate content was lower in Peorian loess of the Ohio valley than in that of the Wabash valley. Peorian loess was lower in clay and higher in silt content than Farmdale or Loveland loesses. Composition of the silt fraction, other than carbonates, did not vary greatly in Peorian loess of the three major source areas. Opal phytoliths and sponge spicules were present in all calcareous Peorian loess samples, and one unidentified microfossil was found in the Wabash valley loess. Illite was the dominant clay mineral in Peorian loess of the Ohio and Wabash valleys and expandable 2:1 minerals were dominant in Mississippi river loess. A high proportion of the expandable minerals in all samples was vermiculite. Chlorite and kaolinite were comparable in the Peorian loess of the three valleys.

In comparison with the Peorian, the Farmdale loess had somewhat similar magnetic susceptibility, only secondary carbonates, and greater clay content. In the silt fraction, the Farmdale had lower Fe and Mn contents, less opal phytoliths, and similar sponge spicule content as the Peorian. The Farmdale was lower in illite, equal to or slightly higher in expandable clay minerals, and somewhat higher in chlorite and kaolinite contents than the Peorian.

In comparison to the overlying Farmdale, the Loveland loess had strongly developed soils and less secondary carbonates. The silt fraction was lower in K2O and CaO contents, and lacked sponge spicules. The Farmdale and Loveland appeared to have similar clay mineral composition.

The Ohio valley loess was most weathered and the five Wabash valley loess soils were least weathered as indicated by CaO/ZrO2 molar ratios of the A horizons. Alford and Sylvan soils, developed in Peorian loess of the Wabash, Ohio, and Mississippi valleys, appear to have no real differences in clay mineral composition in the B2 horizons, although illite may be higher than expandable clay minerals in the Ohio valley loess soils. A high proportion of the expandable clay minerals in all of the B2 horizons appeared to be vermiculite. The rather marked similarity of the clay of B2 horizons of the loess soils in contrast to the varied clay mineral composition of underlying loess, suggests that the surficial loess may have varied less than that deeper in the sections.
Rooting Volume of Corn and Alfalfa in Shale‐Influenced Soils in Northwestern Illinois
Authors: Fehrenbacher J. B. , Ray B. W. , Edwards W. M.
Published: July 2010

Corn roots (Zea mays L.) did not penetrate calcareous Maquoketa shale (IIC) horizons appreciably in four soils derived from thin loess on shale in northwestern Illinois. Alfalfa roots (Medicago sativa L.), in contrast, penetrated the shale horizons to considerable depths. This difference in rooting behavior of the two plants probably explains the better adaptation of a perennial taprooted plant such as alfalfa to these soils than an annual plant such as corn. The shale (IIC) horizons had low total porosities (<38%), very low noncapillary porosities (<1.5%), high bulk densities (>1.69 g/cc), and were impermeable to water. Bulk density slightly greater than 1.80 g/cc and intraped porosity of slightly less than 32% of discrete peds in the IIC horizons appear to be limiting to corn root penetration. Seepage and erosion problems on these soils are related to the impermeable nature and depth to the underlying shale.
Influence of Plowing, Disking; Cultivation, Previous Crop and Surface Residues on Corn Yield
Authors: Van Doren D. M.
Published: July 2010

The influence of plowing, disking, cultivation, previous crop, and organic matter residue management on corn grain yield has been measured on structurally unstable Wooster silt loam soil for two years. Precipitation during the growing season was 8.6 and 10.5 inches per year. On plowed soil, disking reduced yield by 6% and cultivation increased yield by 6%. When the soil was not plowed, management systems providing a high percentage of organic residue surface cover or which included cultivation increased yield much more than disking or previous crop per se. The top producing nonplowed treatments yielded 13% more corn than the best plowed treatments. Of the lowest yielding treatments, nonplowed conditions produced 17% less corn than the plowed treatments.
Variation in the Ability of Slash Pine Progeny Groups to Absorb Nutrients
Authors: Walker Laurence C. , Hatcher Robert D.
Published: July 2010

Twenty‐seven variables were tested to determine whether five slash pine (Pinus elliottii var. elliottii) progeny groups of known parentage differed in ability to absorb and efficiently utilize nutrients. Fertilization × progeny group interactions were significant for N and K in needles and stems, and for CO2 absorption by needles during the first year of growth in an environmental control room. Phosphorus‐32 in stems varied between progeny groups, and relative amounts of P32 absorbed were ascertained from radioautographs.