bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus Retention in Coastal Plain Forest Soils: I. Relationship to Soil Properties
Authors: Ballard R. , Fiskell J. G. A. 
Published: July 2010

AbstractPhosphorus‐retention capacities in the surface horizons of 42 forest soils of the US Southeastern Coastal Plain were determined from the adsorption maximum of the Langmuir isotherm and by saturation with 2,500 µg P/g soil. Both indices were closely correlated (r = 0.986) although on the average the saturation method gave retention capacities two to three times greater than those derived from the Langmuir equation. Range in retention capacities were from 0 to 1,288 µg P/g soil from the concentrated solution. Spodosols generally had the lowest retention capacities although there was considerable overlap between soil orders.Several soil properties (% clay, % silt, pH, loss on ignition) were significantly correlated with P retention but partial correlation analysis showed that, except for pH and to a lesser extent clay, the relationship was indirect through association with extractable Al. Extractable Al and Fe provided the best indices of P retention. The most successful of the extractants of Al for predicting P retention (r = 0.934) was 1N NH4OAc (pH 4.8), while 0.3M (NH4)2C2O4 (pH 3.2) was the most successful of the extractants of Fe (r = 0.903) for predicting P retention.Multiple regression analysis of P retention on exchangeable, amorphous, and crystalline forms of Al and Fe showed that on a per unit weight basis, the order of activity in P retention was exchangeable > amorphous > crystalline with apparently little distinction between Al and Fe within these categories. The greater contribution of Al than Fe to P retention in these soils was primarily a function of the greater amount of Al than Fe in the active forms.
Biodegradation of Nitrilotriacetate (NTA) in Soils
Authors: Tiedje J. M. , Mason B. B. 
Published: July 2010

AbstractNitrilotriacetate (NTA) was biodegraded in a variety of soils as measured by total CO2 and 14CO2 production from 14C‐carboxyl‐NTA. Production of CO2 and 14CO2 followed similar patterns and suggested complete degradation of NTA; 14CO2 production was used routinely to assay NTA dissimilation. At 40 ppm of NTA in soils receiving sewage effluent and in muck soils, maximum rates of degradation were 8 to 10 ppm/day while in mineral surface soils, they ranged from 0.5 to 6 ppm/day; the rates in subsoils were always less than for the surface soils from the same site. Degradation rates did not correlate with pH, drainage, texture, or plant cover. Rates of degradation increased from 2 to 64 ppm/day as NTA concentration was increased from 10 to 600 ppm. 14CO2 production from NTA did not occur anaerobically and was severely limited under microaerophilic conditions. NTA was degraded at 24 and 12.5C; it was also degraded at 2C if previously acclimatized at 12.5C. Iminodiacetate was a possible intermediate in NTA degradation while N‐methyliminodiacetate was not.
Differential Response of Two Maize Inbreds to Molybdenum Stress
Authors: Brown J. C. , Clark R. B. 
Published: July 2010

AbstractThis study was done to determine why Pa36 maize failed to grow and WH maize grew well on acid Bladen soil. The soil is known to be relatively high in Al which often interferes with P uptake and utilization by plants. We were surprised that Pa36 grew so poorly because Pa36 utilized P more efficiently than WH when the two inbreds were subjected to P stress associated with Al toxicity in nutrient solutions.The slight chlorosis and twisting of Pa36 leaves looked very much like cooper deficiency symptoms in barley and wheat, but adding copper to the soil did not correct the symptoms.Spectographic analysis of the plant material showed that Mo concentrations in Pa36 leaves were lower than in those of WH. Adding Mo to the soil corrected the deficiency. The Modeficient Pa36 contained higher concentrations of nitrate than WH, but the nitrate contents of Mo‐sufficient Pa36 and WH were approximately equal.The Mo in the seed could not account for the difference in growth and Mo content of the two inbreds. We conclude that WH has the ability to take up more Mo than Pa36 from the acid Bladen soil.
Effects of Calcium Carbonate on the Availability of Nutrients in an Acid Soil
Authors: Helyar K. R. , Anderson A. J. 
Published: July 2010

AbstractThe four pasture species alfalfa (Medicago sativa L.), subterranean clover (Trifolium subterraneum L.), Harding grass (Phalaris tuberosa L.), and perennial ryegrass (Lolium perenne L.) were grown in pots on an acid sandy loam soil treated with CaCO3 and H2SO4 to give a pH (0.01M CaCl2) range from 4.0 to 5.0.Calcium carbonate application increased exchangeable calcium and decreased exchangeable aluminum and manganese but had little effect on the exchangeable levels of other cations. All soil solution cations except calcium decreased in concentration with CaCO3 application. These trends are explained in terms of effects of CaCO3 on the exchange equilibria through effects on the exchangeable levels of calcium and aluminum and on the cation exchange capacity. Soil solution sulfate levels were increased by liming while phosphate and nitrate levels were decreased.Effects of H2SO4 and CaCO3 on plant growth were explained as effects of aluminum toxicity at low pH and phosphorus deficiency at higher pH values. Nutrient concentrations in the plants generally followed the trends in the soil solutions. Some inconsistencies were interpreted as effects of aluminum toxicity.
Sulfur and Manganese Release from Soils Treated with Prilled Sulfur and Sulfur‐Bentonite
Authors: Lindell D. L. , Sornsen R. C. 
Published: July 2010

AbstractSeven Nebraska soils were used to compare prilled sulfur and a sulfur‐bentonite formulation in regard to the amount of sulfate‐sulfur, manganese, and hydrogen released to a leaching solution after successive incubations. Also the effects of sulfur fertilizer granule concentrations in the soil were studied. Generally, the amount of sulfate‐sulfur and manganese and the pH values in leachates from the columns containing sulfur‐bentonite were not different from those from columns containing prilled sulfur. Differences among soils could not be explained on the basis of measured soil properties. The relationships between the amounts of sulfate‐sulfur or manganese released and percentage sulfur or sulfur‐bentonite in the soil were generally quadratic with the maximum release occurring in the range 30 to 60% sulfur. The greatest amount of sulfur released per gram sulfur added occurred at the lowest sulfur to soil ratio studied. (0.1).
On the Interaction of Water and Heat Transport in Frozen and Unfrozen Soils: I. Basic Theory; The Vapor Phase
Authors: Kay B. D. , Groenevelt P. H. 
Published: July 2010

AbstractA theory is presented for the transport in porous media of water in response to a temperature gradient and the transport of heat in response to a water pressure gradient. These processes are formulated by exploiting the appropriate equation of energy dissipation and the Clapeyron equation. Several general forms of the Clapeyron equation are developed in order to readily find expressions for the transport coefficients of concern. The cause of the coupled flow processes is related to the heat of vaporization, the heat of fusion, and the partial specific heat of wetting of the soil water. The present paper applies the basic theory to the transport processes via the vapor phase. A second paper is concerned with the liquid phase.
Relation Between Nitrate Absorption and Water Transpiration by Corn
Authors: Liao C. F.‐H. , Bartholomew W. V. 
Published: July 2010

AbstractThe relationship between the absorption of NO3‐N by young corn plants (Zea mays L.) and the quantity of water transpired was studied in solution and soil culture. Tracer N (15N) was employed to measure NO3 absorption. Gravimetric methods were used to monitor evapotranspiration. From solution culture, NO3 was absorbed at rates relatively greater than water. From soil culture, NO3 was absorbed at a relative rate close to that of water when the soil was not pretreated. However, when the soil material was wetted and leached of soluble N before planting corn, NO3 was absorbed at a relative rate 1.5 to 2.0 times that of water. In soil situations where water was not being absorbed by plants, NO3‐N likewise was not absorbed. Mass flow and diffusion both were involved in NO3 transport to roots. Prior cultural conditions had a marked influence on active uptake of NO3 presumably through an influence on specific rates of N absorption.
Investigations in an Oxisol‐Ultisol Toposequence in S.Paulo State, Brazil
Authors: Lepsch I. F. , Buol S. W. 
Published: July 2010

AbstractFour soil profiles were sampled along a 550‐m toposequence traverse in São Paulo State, Brazil and were characterized with physical, chemical, mineralogical, and micromorphological analyses. The soils were classified and hypotheses were developed concerning their genesis based on soil differences observed.The soil on the upper part of the traverse has an ochric epipedon over an oxic horizon and is classified as clayey, oxidic, isothermic Typic Haplorthox. Slightly downslope organic matter content increases to form a Typic Umbriorthox of the same family. The soil below these two has an argillic horizon over an oxic horizon and is classified as clayey, oxidic, isothermic Orthoxic Palehumult. The soil in the lowest part has an argillic horizon over decomposed shale and is classified as clayey, Kaolinitic, isothermic Typic Paleudult. The main characteristics distinguishing the soils in the lower part of the toposequence from those in the upper part were the increase in depth and eventual loss of the oxic horizon, decrease in gibbsite content, decrease in chlorite/vermiculite intergradient clay minerals, increase in 2:1 clay minerals, decrease in fine clay to coarse clay ratio, increase in fine silt to clay ratios, increase in illuviated clay, and increase in bulk density.The genesis of these soils appears to be controlled mostly by the age of the geomorphic surfaces and by the nature of the parent material.
A Similarity During Early Stages of Rain Infiltration
Authors: Ahuja L. R. , Romkens M. J. M. 
Published: July 2010

AbstractA similarity is shown to exist during early stages of rain infiltration into a relatively dry soil in which the diffusivity varies exponentially with the water content. The similarity leads to simple expressions for describing the wet‐front progress and the water‐content change at the soil surface. The wet‐front equation adequately describes the experimental data for four different soils. The approach can be extended to some cases of rainfall when the intensity is time‐dependent, and to infiltration with transient surface sealing.
Time‐Dependent Linearized Infiltration: II. Line Sources
Authors: Lomen D. O. , Warrick A. W. 
Published: July 2010

AbstractWater flow from line sources is analyzed using a linearized form of the moisture flow equation. Both single and parallel line sources are considered. Results are particularly relevant for high‐frequency irrigation, such as by trickle sources, for which the soil moisture at any particular point varies over a relatively small range. Numerical calculations include lines of constant matric flux potential (or equal moisture content) as a function of time and the time‐dependent response to a cyclic input. Although the results are developed for surface sources, the analysis may easily be extended to buried sources.
Assessing Soil Salinity and Identifying Potential Saline‐Seep Areas with Field Soil Resistance Measurements
Authors: Halvorson A. D. , Rhoades J. D. 
Published: July 2010

AbstractThe recent widespread increase in the occurrence of seep areas high in salinity in the northern Great Plains has increased the need for soil salinity research. The objective of the study was to examine the use of soil conductivity values calculated from resistance measurements obtained with the four‐probe‐Wenner electrode configuration to identify potential saline‐seep areas and estimate soil salinity in the field.Plots of apparent soil conductivity (ECa) vs inner‐electrode spacing (a) yielded different types of curves for saline‐seep areas, recharge areas, and intermediate areas. Plots of ECa vs a or ECa values alone can be used to identify potential saline‐seep areas. Significant correlations were obtained in May (r = 0.98) and August (r = 0.96) between apparent soil conductivity (ECa) and electrical conductivity of saturation extracts (ECse) showing that four‐probe soil resistance measurements can also be used to estimate soil salinity (ECse) in the field.
Nitric Oxide Sorption by Calcareous Soils: III. Effects of Temperature and Lack of Oxygen on Capacity and Rate
Authors: Prather R. J. , Miyamoto S. 
Published: July 2010

AbstractThe sorption of NO by oven‐dry soils from dry air (relative humidity < 5%) containing a concentration of 1.5% NO by volume decreases exponentially with increasing temperature from 24 to 120C. From a moist stream (relative humidity > 95%), both NO and H2O sorption capacities and rates decrease with increasing temperature from 24 to 77C. The sorption capacity of NO relative to H2O changes little, while the relative sorption rate to that of H2O decreases markedly when the temperature increases from 24 to 36C but not for higher temperatures. The lack of gaseous oxygen severely inhibits the sorption of NO from both dry and moist nitrogen gas streams.
Effect of Hydrogen Clay on Calcium and Potassium Activities and Uptake by Excised Soybean Roots from Vermiculite and Kaolinite Suspensions
Authors: Baweja A. S. , McLean E. O. 
Published: July 2010

AbstractLibby vermiculite and Peerless kaolinite clay suspensions were H‐saturated by resin treatment, and then Ca‐ or K‐saturated by addition of the respective hydroxides. Reciprocal saturations of Ca‐H, K‐H, and Ca‐K with variable amounts of H‐clay added were prepared. Activities of Ca and K in the suspensions were measured by specific‐ion electrodes. Excised‐soybean root (Glycine max L., var. ‘Corsoy’) uptake from the suspension phases of membrane‐equilibrated systems of both clays was measured using 45Ca and 86Rb as tracers for Ca and K, respectively.Cationic fractions active in Ca‐H and K‐H systems reached minimal values in kaolinite, but only when the H‐saturation reached almost twice the measured pH‐dependent CEC (30 vs 18%), while those in vermiculite did not reach minima when H‐saturation was nearly three times the measured pH‐dependent CEC (20 vs 7%). Additions of H‐clay to the Ca‐K systems progressively decreased cationic activities (or dialyzate concentrations) and uptake; the effect being more pronounced for Ca than for K. In general, the uptake of each cation was highly correlated with its effective concentration in solution. Failure of root uptake to reflect marked increases in Ca concentration of dialyzates when Ca saturation increased from 80 to 100% suggested that much of the Ca uptake at lower Ca saturations was the result of direct root‐clay contact in the mechanically‐shaken systems. Consequently, the uptake of Ca was more highly correlated with total concentration of Ca in the systems than with the dialyzate concentrations of Ca. Average Ca/K upake ratios were about 2.5 times higher from kaolinite than from vermiculite clays, and the ratios decreased significantly with increasing levels of H‐clay added in kaolinite but much less so in vermiculite.
Nitrification and Denitrification during Miscible Displacement in Unsaturated Soil
Authors: Kirda C. , Starr J. L. , Misra C. , Biggar J. W. , Nielsen D. R. 
Published: July 2010

AbstractNitrification and denitrification during the leaching of a pulse of NH4NO3 applied to the surface of soil columns are analyzed experimentally and theoretically. Experimentally, unsaturated soil columns of two lengths were leached steadily with a tracee solution containing NH4NO3 while the air‐filled portions of the columns were being flushed simultaneously with air. During these steady state conditions, a pulse of tracer solution containing either 15NH4+ or 15NO3‐ was leached through the columns. The words tracee and tracer signify that both solutions were chemically identical with the latter containing a greater proportion of 15N. Steady‐state tracee concentration distributions within the columns as well as the transient tracer concentration distributions in the effluent were analyzed assuming first‐order kinetics. Values of both the rate coefficients and the concentration distributions stemming from the tracee and tracer measurements were in general agreement. The agreement between the measured and theoretical results are discussed in terms of soil water properties and the kinetics of microbial populations.
Rice Response to Nitrogen and Phosphorus in Flooded and Nonflooded Soils
Authors: Terman G. L. , Allen S. E. 
Published: July 2010

AbstractPot experiments were conducted in a greenhouse to study nutrition of rice (Oryza sativa L., cv. Nato) under flooding and upland conditions. Yields of rice grown in one experiment on Mountview silt loam increased rectilinearly with 0‐, 400‐, and 800‐mg rates of N/pot (5 kg of soil). Concentrations of N in grain + straw at maturity were uniformly low. Yields with the various water regimes were in the order: no flooding < flooding after 10 weeks < flooding after 6 weeks < flooding after 3 weeks. Multiple rates of N from 250 to 2,000 mg/pot and P from 0 to 1,000 mg/pot (6.25 kg of soil) were applied for Nato rice grown on Mountview silt loam and Sango silty clay loam in a second experiment. Marked yield responses to N and P were obtained. Yields of straw and of grain + straw, N uptake, and N recovery were higher on nonflooded than on flooded soils. Grain yields, however, were slightly higher with flooding.Uptake of N, P, Ca, Mg, Mn, and Zn increased with yield response to N and P, while K uptake decreased on the Mountview soil. Concentrations of N and P increased with applied N and P, respectively, while concentrations of other nutrients were diluted in most situations with yield response to N or P on both flooded and nonflooded soils.These results indicate that with adequate applied nutrients, especially N, yields of rice with adequate water but without flooding can equal or even exceed those under flooding.
The Effect of Calcium Salts on the Degradation of Parathion in Sand and Soil
Authors: Mingelgrin Uri , Yaron Bruno 
Published: July 2010

AbstractThe effect of CaCO3 and CaSO4 on 0,0‐diethyl 0‐(P‐nitrophenyl) phosphorothioate (parathion) degradation was investigated. The decomposition in dry acid‐washed sand as a relatively inert matrix, as well as in two dry soils, was measured. As shown previously in the case of other Ca‐containing surfaces, both CaCO3 and CaSO4 enhanced parathion degradation in the inert medium. In every soil‐salt mixture the parathion decomposition curves were different. In one soil CaCO3 even slowed down the decomposition. In another soil, CaSO4 enhanced decomposition up to 5% salt concentration, but additional CaSO4 did not produce further enhancement.
Microbial Degradation of 2‐Carbon‐14 Bromacil and Terbacil
Authors: Wolf D. C. , Martin J. P. 
Published: July 2010

AbstractStudies were conducted to determine the degradation rate of 2.88 ppm 2‐14C bromacil, 3‐sec‐butyl‐5‐bromo‐6‐methyluracil, and terbacil, 3‐tert‐butyl‐5‐chloro‐6‐methyluracil, in a neutral sandy loam soil. After a 600‐day incubation period at 60% water holding capacity (approximately ⅓ bar), 22.1% of the added 14C from bromacil was recovered as 14CO2. The addition of 0.5% corn stalks (Zea mays L.) or lima bean straw (Phaseolus limensis) increased the value to 32.5% and 33.6%, respectively. Under the same conditions, 27.5% of the activity added as 2‐14C terbacil was recovered as 14CO2 and the addition of 0.5% corn stalks or lima bean straw increased this value to 37.0% and 38.2%, respectively. No 14CO2 was evolved from sterile soil. Under saturated conditions less than 0.5% of the added activity for both bromacil and terbacil was evolved as 14CO2 in 145 days but essentially all of the activity in the bromacil treated soil was present as a metabolite. In a second test about 53% of added bromacil was still present as the parent compound after 115 days. The presence of bromacil or terbacil in the soil did not affect the activity of the soil microbial population as measured by total CO2 production.
The Physical and Chemical Properties of the Gray Hydromorphic Soils of the Hawaiian Islands
Authors: Hussain M. S. , Swindale L. D. 
Published: July 2010

AbstractGray hydromorphics, a heterogeneous group of soils of the Hawaiian Islands, have developed some common characteristics during pedogenesis under impeded drainage. These soils are characterized by their poor physical properties, high moisture‐holding capacity, and high clay content. The mean clay/15‐bar moisture ratio is 2.56.Under the gleization process of soil formation, free iron and free manganese were found to be concentrated near the surface and above the fluctuating groundwater table. A net loss of these elements was observed from the soil profiles. The gray hydromorphic soils were found to constitute a typical hydrologic sequence. The SiO2/R2O3 and SiO2/Al2O3 ratios of the soils increased with increasing degree of hydromorphism. The SiO2/R2O3 and SiO2/Al2O3 ratios in the fine clay fractions of the soils increased with increasing drainage impedance. Al2O3/Fe2O3 ratios in the fine clays of these soils decreased with increasing degree of hydromorphism and increasing percentage of montmorillonite. Conditions of poor drainage maintained a ferrous ion activity in the soil solution sufficient to allow increasing formation of iron‐rich montmorillonite clays.
New Concepts in Soil Survey Interpretations for On‐Site Disposal of Septic Tank Effluent
Authors: Bouma J. 
Published: July 2010

AbstractSoil survey interpretations for on‐site disposal of septic tank effluent are made in terms of soil limitations using existing technology. New technology, based on a detailed analysis of liquid movement and associated purification, can be used to overcome severe and very severe limitations and to reduce slight and moderate limitations. Experimental data obtained and technology derived from single experimental innovative disposal systems are relevant only if extrapolations can be made to other soils shown to be identical. Three procedures of extrapolation are discussed: (i) detailed on‐site spot checks of key properties; (ii) on‐site taxonomic soil classifications and (iii) taxonomic soil classifications at the experimental site followed by extrapolation to mapping units named after the same soil series. Largely unknown variability of key properties for liquid waste disposal in soil series or in mapping units may reduce the practical value of the latter two procedures but potential advantages are (i) reductions of expensive on‐site inspections and (ii) use of soil maps for showing potential changes in land‐use patterns following introduction of innovative technology. This approach emphasizes soil potential rather than soil limitations.
Feedlot Waste Effects on Soil Conditions and Water Evaporation
Authors: Unger Paul W. , Stewart B. A. 
Published: July 2010

AbstractFeedlot wastes were applied to field plots at 0, 22, 67, 134, or 268 metric tons/ha for 4 successive years. Core and bulk soil samples from the plots were used to evaluate treatment effects on soil water retention, bulk density, strength, porosity, organic matter content, and water‐stable aggregates. Evaporation was determined from laboratory columns containing feedlot‐wastetreated soil at the surface and untreated soil below the treated soil. For soils treated with feedlot wastes at high rates, water contents at saturation and at −0.2 and −1.5 bars matric potential were significantly higher, and bulk densities were significantly lower, than for untreated soils or those treated at low rates. Soil strength, porosity index values, and water contents at −15 bars matric potential were not significantly affected by waste applications. Soil organic matter and aggregation increased and evaporation decreased as waste application rates increased.