bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil Moisture and Soil Temperature Changes with the Use of Black Vapor‐Barrier Mulch and Their Influence on Pineapple (Ananas comosus (L.) Merr.) Growth in Hawaii
Authors: Ekern Paul C. 
Published: July 2010

AbstractAs the mulching practice in pineapple culture in Hawaii has developed over the last 50 years, a number of functions have been assigned to the action of the mulch. This study gives primary consideration to the effect of soil moisture and soil temperature changes upon pineapple growth. Soil moisture changes were determined from field samplings and lysimeter studies at Wahiawa, Oahu. Changes in the soil moisture budget with the mulch were so slight that the variability of field sampling precluded assessment without excessive replication. Coefficients of variability for samples taken at the plant butt were 3 to 5% of a moisture constant (e.g., 15‐bar point) for a soil series or within a single field. Moisture use, measured by semicontained hydraulic lysimeters, was reduced by the mulch when the soil was very wet but changed little when the soil moisture ranged from field capacity (0.15‐bar) to the 15‐bar point.The mulch raised the average soil temperature about 1.6C during the winter. The measured one‐third increase in the plant growth was nearly identical with the increase calculated from the growth‐response of pineapple to temperature.
Differential Responses of Slash Pine Progeny Lines to Some Cultural Practices
Authors: Pritchett W. L. , Goddard R. E. 
Published: July 2010

AbstractIn three experiments involving intensities of management' slash pine (Pinus elliottii Engelm. var. elliottii) progenies of selected lines and crosses varied greatly in their growth rates on unaltered sites and in growth responses to environmental improvements. In three tests, some selections made poor growth in unfertilized soil, but responded well to fertilizer applications, while others made good growth in unfertilized soil, but were little affected by fertilizers. Of greater importance, some progeny lines made good growth in unfertilized soil and at the same time responded to fertilizer treatments.There were greater growth differences within progeny lines due to variations in the immediate environment than there were among lines of different geographic origin.These results emphasize the importance of testing progenies of plus trees on soils as productive and similarly managed as under plantation conditions.
Culture‐Table Air‐Ducts for Glasshouse Cooling
Authors: Reisenauer H. M. , Arkley T. H. 
Published: July 2010

AbstractA modification of glasshouse culture tables into a cooled air distribution system is described. Conditioned air is passed upward around the pots and plants. This modification provides a uniform air temperature environment over the table surface, and, as compared to conventional systems, greatly reduces the maximum root media temperatures attained.
Comparison of Water Content‐Pressure Head Data Obtained by Equilibrium, Steady‐State, and Unsteady‐State Methods
Authors: Topp G. C. , Klute A. , Peters D. B. 
Published: July 2010

AbstractThe water content‐pressure head relationship for a small, well‐confined, rectangular sample of fine sand was obtained under different water flow conditions. Water contents were measured by a gamma system and pressure heads were measured by a tensiometer‐pressure transducer combination. During drying, more water was retained in the sand at a given pressure head in the unsteady flow case than in the static equilibrium and steady‐state cases, which agreed with each other.
Potassium and Ammonium Fixation by Vermiculitic Soils
Authors: Page A. L. , Burge W. D. , Ganje T. J. , Garber M. J. 
Published: July 2010

AbstractThe fixation of potassium (K) and ammonium (NH4) against removal by unbuffered salts under wet and air‐ and oven‐dry (110C) conditions by vermiculitic soils is reported. Under wet conditions, the soils exhibited a rather definite capacity to fix NH4 and K; amounts of NH4 and K fixed were essentially equal. Exchange capacity reductions accompanying wet fixation demonstrated that an irreversible exchange adsorption mechanism would account for practically all of the NH4 and K fixed. The amount of NH4 and K fixed under air‐ or oven‐dry conditions was comparable to the amount fixed under wet conditions where the amount of NH4 and K added did not exceed the fixing capacity observed under wet conditions. However, when the amount added to soils to be subjected to oven drying exceeded the fixing capacity established for soils under wet conditions, NH4 and K were fixed without a further reduction in the cation exchange capacity, indicating the occurrence of a fixation process or processes not associated with the cation exchange capacity.
Clay Mineralogy and Mica‐Vermiculite Layer Charge Density Distribution in the Switzerland Soils of Indiana
Authors: Post Donald F. , White Joe L. 
Published: July 2010

AbstractA study was made of the weathering of mica inherited from Ordovician limestone and calcareous shales in two (I and II) Switzerland soils, which belong to the Typic Normudalf, fine, mixed mesic family. X‐ray and physico‐chemical studies of the clay fraction showed that the solum of Switzerland I had an average of 24% mica and 35% vermiculite and the solum of Switzerland II was 40% mica and 24% vermiculite.Layer charge density calculated from the ratio Σ(CEC + total K)/m2 clearly showed the decrease in charge density moving from the parent material upward in the soil profiles. The degree of swelling of the vermiculite on solvation was a function of this charge density. Magnesium‐saturated, glycerol‐solvated samples remained at 14.2A; Mg‐saturation and ethylene glycolation expanded some vermiculite to 16 to 16.5A; Ca‐saturated and glycerol treatment resulted in expansion of vermiculite to 17A; and K‐saturation and air drying readily collapsed most of the vermiculite to 10 to 10.3A.
Miscible Displacement of Nitrate through Soil Columns
Authors: Corey John C. , Nielsen Donald R. , Kirkham Don 
Published: July 2010

AbstractOne hundred milliliters of an aqueous solution containing 0.55 g of CaCl2 and 0.35 g of Ca(NO3)2 · 4H2O was displaced through 30‐cm long acrylic plastic columns containing soil. Velocity of water flow, sucrose concentration of the solution, and water content of the columns affected the loss of nitrate. Nitrate loss was determined by comparing breakthrough curves of nitrate with chloride. No nitrate was lost at a flow velocity of 1.32 cm/hr, but 21% was lost at 0.11 cm/hr. At a flow velocity of 0.11 cm/hr and sucrose concentrations of 0, 50, and 200 ppm, the losses of nitrate amounted to 21, 21, and 67%, respectively, of the total added. A net gain of nitrate was observed under unsaturated flow conditions.
Characterization of Differential Aluminum Tolerance among Varieties of Wheat and Barley
Authors: Foy C. D. , Fleming A. L. , Burns G. R. , Armiger W. H. 
Published: July 2010

AbstractAluminum‐sensitive ‘Monon’ wheat (Triticum aestivum, spp vulgare (Vill. Host) Mac Key and ‘Kearney barley (Hordeum vulgare) (L. emend. Lam) varieties had higher root cation exchange capacities and induced lower pH levels in nutrient solutions than did Al‐tolerant ‘Atlas 66’ wheat and ‘Dayton’ barley varieties. Sensitive varieties contained higher concentrations of Al (and usually P) in their roots and lower concentrations of Ca in their tops than tolerant varieties, when grown in solutions containing Al. Furthermore, roots of Al‐sensitive varieties made less growth and contained higher concentrations of Al than those of tolerant varieties, even when the two were grown in the same container of vigorously aerated nutrient solution. This suggests either that zones of differential pH still exist around the roots of different varieties or that sensitive varieties absorb more Al at the same pH or both. Whether the lower Al tolerance of certain varieties is simply the result of greater accumulation of Al by roots, greater sensitivity to the same concentration of Al already absorbed, or both, cannot be determined from the present study. Differential Al tolerance of varieties was not closely related to differences in the Al or P contents of plant tops.
Soil Losses and Crust Formation as Related to Some Soil Physical Properties
Authors: Epstein E. , Grant W. J. 
Published: July 2010

AbstractSoil loss curves of six soil types were obtained using a laboratory rainfall simulator. During the first 10 min of rainfall, soil losses increased to a maximum and then decreased sharply for the Marshall silty clay loam, Dunkirk silt loam, Caribou loam, and Nicholville silt loam soils. There was no peaking effect with the Hartland sandy loam and Winooski silt loam soils and the rate of soil loss was constant after 10 min. A linear relationship was obtained between clay content and soil loss during the 5‐ to 10‐min period. Detailed studies on the Dunkirk and Winooski soils suggest that the peaking effect may be due to the rate and extent of crust formation in the early stages of rainfall wetting. Bulk density of the 0‐ to 5‐mm layer increased from 1.15 to 1.65 g/cc for the Dunkirk soil and from 0.83 to 1.14 g/cc for the Winooski. The amount and distance of splash from a Caribou soil was measured using two drop sizes, 5.1 mm and 3.2 mm. Splash soil losses from the soil pans for the six soils was as much as three to four times those found in the runoff water.
The Establishment and Growth of Loblolly Pine Seedlings on Compacted Soils
Authors: Foil R. Rodney , Ralston C. W. 
Published: July 2010

AbstractLoblolly pine (Pinus taeda L.) seedlings were grown from seed on core samples collected from surface soils of Lakeland loamy sand, Coxville loam, and Bayboro clay that had been compacted, puddled, or loosened. Seed germination was not affected by soil type or treatment, but seedlings became established with difficulty on clay cores and on heavily compacted cores of lighter texture. Top height and root length were not related to soil type, but seedlings grown on clay were significantly lighter than the other groups. Loosening the soil from its normal structure reduced growth on light‐textured soils, but stimulated it on clay soils. Compaction, whether at 3.5 or 10.5 kg cm‐2 of surface pressure, greatly reduced seedling size and weight. Small growth differences between compaction treatments indicated that even the smallest pressure applied reduced soil aeration and increased mechanical impedance to root growth to infavorable levels. There were negative linear relationships between root weight and penetration and densities ranging from 0.8 to 1.4 g cm‐3.
Fractionation of Soil Inorganic Phosphate by a Modification of Chang and Jackson's Procedure
Authors: Williams J. D. H. , Syers J. K. , Walker T. W. 
Published: July 2010

AbstractA modified version of the phosphate fractionation procedure of Chang and Jackson (1957) included the determination of “residual inorg. P” and introduced a revised nomenclature for the other fractions. Added phosphate sorbed during the fluoride extraction was usually completely recovered in the succeeding sodium hydroxide extraction; this enabled mutually compensating corrections to be applied to NH4F‐P and 1st NaOH‐P values. A second acid treatment increased the amount of Ca‐P extracted. Further modifications simplified the colorimetric determinations of inorganic phosphate in several of the extracts. A measure of the reproducibility of fractionation results was also obtained.
Patterns Observed for the Oxidation of Ammonium to Nitrate by Soil Organisms
Authors: Morrill L. G. , Dawson J. E. 
Published: July 2010

AbstractAmmonium sulfate solutions were percolated for 28 days through samples from the top two horizons of 55 soils derived from several classes of glacial tills and through six calcareous horizons influenced by sodium. Four general nitrification patterns were observed:(I) Ammonium rapidly oxidized to nitrite which accumulated over a long period before being oxidized to nitrate. (II) Ammonium and the produced nitrite both rapidly oxidized. (III) Ammonium slowly oxidized to nitrate without nitrite appearing. (IV) Ammonium oxidation not detectable by either nitrite or nitrate formation.The occurrence of the four patterns was correlated with soil reaction and other acidity related properties. Nitrosomonas spp. and Nitrobacter spp. organism numbers and proliferation characteristics influenced by soil environment accounted for the four nitrification patterns observed except insufficient Nitrobacter spp. organisms were detected to produce the nitrate formed in type III soils.Nitrification patterns were modified by altering the soil properties and the number of nitrifying organisms consistent with the above interpretations. Ammonia, nitrite, nitrate, and pH affected Nitrobacter spp. lag in type I soils.
Mica Genesis in Hawaiian Soils
Authors: Juang T. C. , Uehara G. 
Published: July 2010

AbstractA soil mica having a formula Na0.11 NH40.06 K1–24 (Al, Si) (Al, Fe, Mg) O20 (OH)4 has been identified in soils of the wet uplands in the Hawaiian Islands. It contains 7.2% potash and is predominantly a mixer‐layered mica with vermiculite‐montmorillonite and chlorite. The mica is concentrated in the surface horizons, and its concentration increases with soils formed under increasing rainfall and elevation. Biological recycling of potash is proposed as a mechanism for its formation.
Phosphorus‐Zinc Interaction in Two Soybean Varieties Differing in Sensitivity to Phosphorus Nutrition
Authors: Paulsen Gary M. , Rotimi Olusegun A. 
Published: July 2010

AbstractTwo soybean varieties (Glycine max (L.) Merr.) differing in sensitivity to phosphorus nutrition were grown in nutrient solutions containing various levels of P and Zn. Low P levels decreased growth and P concentration in leaves more than in other plant parts. High P levels decreased growth of the P‐sensitive variety more than the P‐tolerant variety but decreased Zn concentration in both varieties equally. Added Zn overcame the effect of P on the tolerant variety but not on the sensitive variety, indicating two different detrimental effects of P. Zinc deficiency affected growth of all plant parts similarly but had little effect on P content of plants except that when Zn was added to deficient plants P concentration in leaves decreased.Interaction of P with Zn decreased Zn concentration of leaves most and roots least. The effect of P on Zn appeared to originate in the roots, however, and to occur on translocation of Zn to the upper plant parts.
Potassium Exchange Equilibria and Yield Responses of Oats, Barley, and Corn on Selected Quebec Soils
Authors: Zandstra H. G. , MacKenzie A. F. 
Published: July 2010

AbstractPotassium:calcium + magnesium activity ratios were used to calculate availability indices on eight Quebec soils. These were compared to available potassium measurements and related to yield responses of oats (Avena sativa L.), barley (Hordeum vulgare L.), and corn (Zea mays L.) to potassium fertilizers in field experiments. Crop growth did not change the potential buffering capacities (PBCK) of two selected soils, which indicated that the quantity‐intensity relation regulated the release of potassium although the activity ratio was greatly reduced. The potassium potential was obtained by multiplying the total amount of exchangeable potassium (−ΔK°) with the potential buffering capacity to place soils on a comparative basis. The potassium potential fully defined the quantity‐intensity relation and correlated more closely to crop responses than the activity ratio measurement, the PBCK, or the available potassium determination.
Bulk Density Measurements on Certain Soils High in Coarse Fragments
Authors: Cunningham R. L. , Matelski R. P. 
Published: July 2010

AbstractBulk density methods were employed in repetitious sampling of Millheim silt loam containing high amounts of soft shale coarse fragments. The bulk density of a 377,560 cm3 soil volume was also determined as a reference for evaluating the samples collected. Statistical analyses of the data indicate that the 347.5 cm3 core sample best evaluates bulk density. However, in soils containing fragments harder than shale, cores are impossible to collect. Clod samples closely approximate 347.5 cm3 core samples in evaluating bulk density and can be taken in almost any soil. Thus, they are a useful sample for the determination of bulk density with the advantage that it can be used for moisture retention measurements.
Oxidation‐Reduction Potential of Saturated Forest Soils
Authors: Bonner F. T. , Ralston C. W. 
Published: July 2010

AbstractLarge decreases in redox potentials of saturated soil over a 25‐day incubation period were favored by high temperature and the addition of sucrose, loblolly pine needles (Pinus taeda L.), or yellow‐poplar leaves (Liriodendron tulipifera L.). The addition of a complete nutrient solution had no effect in soils incubated with sucrose, but it reduced the drop in potential in soils incubated with tree litter at 21–27C. The data suggest the need for care when evaluating soil aeration by means of redox potentials and the dominant role of soil microorganisms in activating redox systems.
Bulk Volume and Hydraulic Conductivity Changes during Sodium Saturation Tests
Authors: Waldron L. J. , Constantin G. K. 
Published: July 2010

AbstractFragmented samples of 1 organic and 5 mineral California soils were permeated with salt solutions while confined in cylinders under a constant axial stress of 0.05 bar. Continuous and precise measurement of bulk volume changes during sodium saturation with 1M NaCl followed by 0.25M NaCl showed that while hydraulic conductivity always decreased upon changing to the more dilute solution, the bulk volume increased with some soils and decreased with others. Such bulk decreases occurred only in the first passage of 0.25M NaCl following sodium saturation and were attributed to aggregate failure. If 1M NaCl was re‐introduced, hydraulic conductivity increased with all soils so tested and bulk volume decreased. Further successive permeations with 1M and 0.25M solutions produced hydraulic conductivity increases with bulk volume decreases on changing from 0.25M to 1M, and hydraulic conductivity decreases with bulk volume increases on changing from 1M to .025M NaCl. A mechanical explanation is given which is based on a bimodal pore model of the soil and on the way in which variation of stress from point to point within the soil affects volume changes of the swelling material and the soil pore‐size distribution.
Factors Influencing Hydraulic Conductivity of Soils in the Presence of Mixed‐Salt Solutions
Authors: McNeal B. L. , Layfield D. A. , Norvell W. A. , Rhoades J. D. 
Published: July 2010

AbstractFor a group of soils having variable clay content but nearly uniform clay‐fraction mineralogy, relative hydraulic conductivity in the presence of mixed‐salt solutions decreased markedly with increasing clay content, particularly at the lowest salt concentrations employed. The stability of a group of Hawaiian soils under high‐sodium, low‐salt conditions was greatly reduced by partial removal of the free iron‐oxides. Replacing the Ca in percolating NaCl‐CaCl2 solutions with Mg measurably decreased soil hydraulic conductivity, although the effect was often negligible when comparisons were made at equivalent exchangeable‐sodium‐percentages.
Prediction of the Effect of Mixed‐Salt Solutions on Soil Hydraulic Conductivity
Authors: McNeal B. L. 
Published: July 2010

AbstractA procedure is described for predicting the hydraulic conductivity of soils in the presence of mixed‐salt solutions, after first measuring the absolute hydraulic conductivity of the soil with a single high‐salt, high‐sodium solution, and then measuring the relative hydraulic conductivity of the same sample with a low‐salt solution. Calculated interlayer swelling values for soil montmorillonite serve as a frame of reference for the predictions. Swelling values are obtained using a simplified domain model for characterizing the exchangeable‐cation distribution on Na‐Ca montmorillonites. Reliability of the procedure is established with a group of soils having variable clay content but constant clay‐fraction mineralogy. The effect of soil texture on relative hydraulic conductivity to mixed‐salt solutions appears to be adequately accounted for through the interlayer swelling values used for the predictions.
Chemical and Physical Properties of Iron and Aluminum Phosphates and Their Relation to Phosphorus Availability
Authors: Juo Anthony S. R. , Ellis Boyd G. 
Published: July 2010

AbstractSynthetic, colloidal ferric and aluminum phosphates were crystallized in aqueous medium to form variscite, AlPO4 · 2H2O and strengite, FePO4 · 2H2O. The compounds were identified and characterized by X‐ray, infrared analysis, and electron microscopy. Iron phosphate crystallized at a much faster rate than aluminum phosphate under the same temperature and pressure conditions. Variscite and strengite which were crystallized at 105C for 40 days had specific surface areas of 24.9 m2g‐1 and 1.98 m2g‐1, respectively. The strengite consisted of single spherical crystals with an average diameter of 6 microns and the variscite consisted of reniform crystalline aggregates with an average diameter of 1.5 micron. In quartz sand cultures, with sudan‐grass (Sorghum vulgare sudanese) as the indicator crop, the relative availability of P from the synthetic compounds was: strengite < variscite ⋘ colloidal Fe‐P ⋍ colloidal Al‐P.
Iron Deficiency in Cotton in Relation to Growth and Nutrient Balance
Authors: Vretta‐Kouskoleka Helen , Kallinis Thomas L. 
Published: July 2010

AbstractIron deficiency symptoms were developed in cotton (Gossypium spp.) growing in nutrient solutions. The first symptoms appeared when the plants were 15 days old, while a general chlorosis developed by the time the plants were 8 weeks old. The deficiency was first observed on the upper young leaves. These leaves became chlorotic and progressively their margin turned necrotic and curled upwards. Addition of Fe in the nutrient solution of the deficient plants corrected all deficiency symptoms within 1 week. Two ranges of Fe concentration, 85–112 ppm for the young cotton blades, and 57–88 ppm for the old cotton blades were found to be the critical concentrations of Fe for cotton.
Parent Material Uniformity and Origin of Silty Soils in Northwest Arkansas Based on Zirconium‐Titanium Contents
Authors: Chapman S. L. , Horn M. E. 
Published: July 2010

AbstractUniformity of parent material studies were made of 15 soils overlying various geologic materials, utilizing petrographic and X‐ray spectographic techniques. Zr and Ti contents were used as tests for a “loess” versus a “residual silt” hypothesis for the origin of silty soils in northwestern Arkansas. The lack of significant deviations with depth in Zr and Ti contents and ratios points to an absence of lithologic discontinuities in soils suspected of having an upper loess parent material. It is concluded that these soils are formed in local materials and not from extra‐regional loess. It is proposed that prolonged weathering of local rocks together with reworking by mass movements, water, and wind on a local basis has resulted in a rather homogeneous regolith on the older gently sloping landscapes over cherty limestones and siltstones. The local nature of the soil parent materials is also indicated by the fact that Zr and Ti contents in the very fine sands were found to be related to underlying rocks being highest (ZrO2, 0.30%; TiO2, 0.26%) in soils over sandstone and lowest (ZrO2, 0.03% TiO2, 0.10%) in soils over cherty limestone. Zr was most abundant in coarse silts except for two soils over sandstone in which it was most abundant in the very fine sands. Ti increased as particle size decreased. In several soils Ti was present as leucoxene coatings on quartz and chert grains of very fine sand size. This indicates the probable translocation of Ti in soils and its general unsuitability as a stable constituent in soil genesis studies.