bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of the Osmotic Stress Regulatory Pathway in Morphogenesis and Secondary Metabolism in Filamentous Fungi
Authors: Duran Rocio , Cary Jeffrey W. , Calvo Ana M.
Published: March 2010

Environmental stimuli trigger an adaptative cellular response to optimize the probability of survival and proliferation. In eukaryotic organisms from mammals to fungi osmotic stress, mainly through the action of the high osmolarity glycerol (HOG) pathway, leads to a response necessary for adapting and surviving hyperosmotic environments. In this review we show that the osmoadaptative response is conserved but not identical in different fungi. The osmoadaptative response system is also intimately linked to morphogenesis in filamentous fungi, including mycotoxin producers. Previous studies indicate that the response to osmotic stress is also coupled to the biosynthesis of natural products, including mycotoxins.
Development of an Electrochemical Immunosensor for Fumonisins Detection in Foods
Authors: Abdul Kadir Mohamad Kamal , Tothill Ibtisam E.
Published: March 2010

An electrochemical affinity sensor for the determination of fumonisins mycotoxins (Fms) using monoclonal antibody modified screen-printed gold electrode with carbon counter and silver-silver chloride pseudo-reference electrode is reported in this work. A direct competitive enzyme-linked immunosorbent assay (ELISA) was initially developed, exhibiting a detection limit of 100 µg·L-1for fumonisins. This was then transferred to the surface of a bare gold screen-printed electrode (SPGE) and detection was performed by chronoamperometry, monitoring the reaction of 3,3’,5,5’-Tetramethylbenzidine dihydrochloride (TMB) and hydrogen peroxide (H2O2) catalysed by HRP at −100 mV potential vs. onboard Ag-AgCl pseudo-reference electrode. The immunosensor exhibited detection limit of 5 µg·L−1 fumonisins with a dynamic range from 1 µg·L−1–1000 µg·L−1. The sensor also performed well in extracted corn samples.
The effect of fissures on the strength of structural timber
Authors: Esteban Miguel , Arriaga Francisco , Íñiguez Guillermo , Bobadilla Ignacio , Mateo Raquel
Published: March 2010

Detailed measurements of drying fissures were carried out on 28 pieces of gross cross-section structural Scots pine timber. Different parameters have been proposed to measure their magnitude: length, depth, thickness and slope of grain, as well as an index of area in the neutral axis plane (ratio of effective to total surface). The parameters of fissures have been related to bending strength, shear strength, modulus of elasticity and rupture energy obtained from mechanical tests, considering whether rupture is due to bending or shear. All of the fissures observed allows to classify the pieces as MEG according to the UNE 56544 standard. To quantify the magnitude of fissures the index of areas is proposed, while mechanical properties can be quantified by rupture energy. Analysis of the results does not show any relation between the fissures analyzed and the mode of failure, their magnitude and mechanical properties..
The willingness of private-sector doctors to manage public-sector HIV/AIDS patients in the eThekwini metropolitan region of KwaZulu-Natal
Authors: Naidoo Panjasaram , Jinabhai Champaklal C. , Taylor Myra
Published: March 2010

Background: South Africa is severely affected by the AIDS pandemic and this has resulted in an already under-resourced public sector being placed under further stress, while there remains a vibrant private sector. To address some of the resource and personnel shortages facing the public sector in South Africa, partnerships between the public and private sectors are slowly being forged. However, little is known about the willingness of private-sector doctors in the eThekwini Metropolitan (Metro) region of KwaZulu-Natal, South Africa to manage public-sector HIV and AIDS patients.Objectives: To gauge the willingness of private-sector doctor to manage public-sector HIV and AIDS patients and to describe factors that may infuence their responses.Method: A descriptive cross-sectional study was undertaken among private-sector doctors, both general practitioners (GPs) and specialists, working in the eThekwini Metro, using an anonymous, structured questionnaire to investigate their willingness to manage public-sector HIV and AIDS patients and the factors associated with their responses. Chi-square and independent t-tests were used to evaluate associations. Odds ratios were determined using a binary logistic regression model. A p value < 0.05 was considered statistically significant.Results: Most of the doctors were male GPs aged 30–50 years who had been in practice for more than 10 years. Of these, 133 (77.8%) were willing to manage public-sector HIV and AIDS patients, with 105 (78.9%) reporting adequate knowledge, 99 (74.4%) adequate time, and 83 (62.4%) adequate infrastructure. Of the 38 (22.2%) that were unwilling to manage these patients, more than 80% cited a lack of time, knowledge and infrastructure to manage them. Another reason cited by five doctors (3.8%) who were unwilling, was the distance from public-sector facilities. Of the 33 specialist doctors, 14 (42.4%) indicated that they would not be willing to manage public-sector HIV and AIDS patients, compared with only 24 (17.4%) of the 138 GPs (p < 0.01).Conclusion: Many private-sector doctors are willing to manage public-sector HIV and AIDS patients in the eThekwini Metro, potentially removing some of the current burden on the public health sector.
AN INCUBATION STUDY OF NITROGEN ADDED AS UREA TO SEVERAL MANITOBA SOILS WITH PARTICULAR REFERENCE TO RETENTION OF NITROGEN
Authors: TOMAR J.S. , SOPER R.J.
Published: March 2010

The objective of this study was to determine the magnitude of biologically immobilized and/or chemically fixed N (N retained) resulting from N addition to soils under laboratory conditions. Urea (200 μg N/g of soil) tagged with 21.0 atom % 15N was added to 11 Manitoba soils. The relationship between microbial immobilization and/or chemical fixation of added N and soil characteristics was determined using forward stepwise and multiple linear regression analyses. Three to 32 ppm of added N was immediately retained by the soils after urea was added. Biological immobilization and/or chemical fixation was virtually completed within the first 4 wk of incubation with only one soil showing continuous increase in the retention of applied N during the remainder of the experiment. Amounts of urea N retained in soils during the 12-wk incubation period ranged from 16 to 91 ppm. The initial retention of N was positively correlated with sand + silt fraction and negatively correlated the pH of the soil, the R2 value being 0.86**. Correlations between, 15N retained and organic matter (OM) content for 4 and 8 wk of incubation were positive (R2 = 0.40* and 0.53*, respectively). After the 12 wk of incubation, the retention of added N by soils was positively correlated with OM and negatively correlated with soil pH (R2 = 0.74**). The retention of N with pooled data of 4, 8 and 12 wk of incubation was positively correlated with OM and negatively correlated with both pH and CEC of the soils (R2 = 0.73**). Mineralization of soil N and retention of added N for 4, 8 and 12 wk of incubation were found to be positively correlated, the r2 values being 0.42*, 0.52* and 0.42*, respectively. Gaseous losses of applied N appeared to be appreciable in only one soil. Ten of the eleven soils showed no or little N interchange, suggesting that a significant proportion of the applied urea N appeared to be truly immobilized and/or fixed in soils.
INFLUENCE OF TERBACIL ON MICROBIOTA IN SOIL AND CULTURES
Authors: ROSLYCKY E.B.
Published: March 2010

Terbacil in concentrations up to 500 μg∙g−1 of sandy loam soil had little effect on populations of actinomycetes, bacteria, and fungi under laboratory and field conditions during a period of 5 mo. Concentrations up to 700 μg of terbacil∙mL−1 did not affect the in vitro growth of 111 strains of agriculturally important microorganisms, including effective, parasitic, and lysogenic rhizobia from seven cross-inoculation groups, pathogenic, attenuated, and saprophytic agrobacteria, azotobacters, and other bacteria, actinomycetes, and fungi. Terbacil inhibited the respiration of total soil microbiota, of bacteria, and of fungi at all concentrations tested. By contrast, it stimulated the respiration of actinomycetes at concentrations up to 500 μg∙mL−1 and partially inhibited it at 700 μg∙mL−1. Replication of bacterial and actinomycete isolates showed minimal inhibition by the extreme concentrations.
DEFINITION OF FABRIC DISTRIBUTIONS TO CHARACTERIZE THE REARRANGEMENT OF SOIL PARTICLES IN THE TURBIC CRYOSOLS
Authors: FOX C. A. , PROTZ R.
Published: March 2010

Micromorphological study of Turbic Cryosols (permafrost soils) from the MacKenzie River Valley and Yukon Coastal Plain resulted in the observations of distinct unnamed fabric distributions that implied rearrangement of the skeleton grains and f-members. It was noted that the skeleton grains or f-members were capable of independent reorganization in relation to the plasma or f-matrix. Three modal fabric types were defined as follows: 1. Orbiculic fabric — The skeleton grains or f-members are reorganized into circular or ellipsoidal patterns. 2. Suscitic fabric — The skeleton grains or f-members are vertically aligned and often show an accumulation of finer matrix material at the base. 3. Conglomeric fabric — A compound distribution in which individual f-members are enclosed by finer matrix material into a secondary fabric such as fragmic or granoidic. The interpretation of the genesis of these fabrics may aid in understanding the developmental history of the soil, especially those soils that have been subjected to cryogenic processes.
THE EFFECTS OF CONTINUOUS FERTILIZATION ON NUTRIENT BALANCE AND CROP YIELD IN THE NORTHERN NIGERIAN SAVANNAH: A PRELIMINARY ASSESSMENT
Authors: LOMBIN GANYIR
Published: March 2010

Crop uptake of the major cations from the soil solution depends not only on their absolute amounts but also on their quantitative relationships. The risk of accentuating nutrient deficiencies through unbalanced cation ratios arising from injudicious fertilization practices is particularly high in the poorly buffered, continuously cropped/fertilized savannah soils of Nigeria. This paper evaluates the preliminary results of a long-term investigation of the effects of continuous fertilization on soil cation ratios, crop nutrition and yield in northern Nigeria. The effects of nine factorial combinations of three levels (0, 25 and 50 kg∙ha−1) each of K and Mg (applied in 1976) are being monitored on two soils — Dystric Nitosol or Oxisol (at Mokwa) and Ferric Luvisol or Ultisol (at Yandev) using maize (Zea mays L.) as a test crop. Soil and index leaf K, Ca and Mg concentrations were related to yield by means of correlation and regression analyses. Maize yields were strongly and negatively related to soil exchangeable K, and percent in plant tissue, and highly significantly and positively correlated with percent Ca in plant tissue, soil Ca:K and (Ca + Mg):K ratios. It is thus evident that K depressed yields by creating unfavorable soil Ca:K, (Ca + Mg):K ratios, and to a lesser degree, Mg:K ratios through its repressive action on these two other cations. The results have demonstrated the practical significance of the inverse Ca-K relationship in crop nutrition with respect to the Nigerian savannah soils and have also shown the fragile nature of the balance between the major cations and how easily the balance can be upset by injudicious fertilizer use and management. This calls for caution in the development of fertilizer programs for the area. Use of fertilizers containing a high Ca concentration is suggested.
MAPPING SALINITY USING RESISTIVITY AND ELECTROMAGNETIC INDUCTIVE TECHNIQUES
Authors: CAMERON D.R. , READ D.W.L. , JONG E. DE , OOSTERVELD M.
Published: March 2010

The Wenner array and two terrain conductivity meters (EM31 and EM38) were used to demonstrate their potential for mapping field scale salinity. The Wenner configuration of electrodes (four probes) measured soil resistivity (inverse of conductivity) while the two terrain meters used electromagnetic inductive currents to measure conductivity directly. All instruments gave a clear delineation between areas of high and low salt content; this distinction could not be obtained from aerial photographs. The continuous recording EM31 conductivity meter proved to be the most rapid method for mapping saline areas, but could not be used to obtain detail on salt distribution with respect to depth. The shallower sensing EM38 gave a rapid response, but the prototype used was sensitive and required frequent scale adjustment. The assembled Wenner four-probe array was a bulky piece of equipment to handle and poor soil contact was experienced occasionally in drier soils. Resistance readings with the Wenner array were time-consuming, but the technique did offer the attractive advantage of measuring salt distribution with depth.
A QUESTIONNAIRE TO USERS OF SOIL MAPS IN BRITISH COLUMBIA: RESULTS AND IMPLICATIONS FOR DESIGN AND CONTENT
Authors: VALENTINE K. W. G. , NAUGHTON W. C. , NAVAI MARTHA
Published: March 2010

A total of 70 people (30%) replied to a questionnaire about the design and content of soil maps from British Columbia. Most people are using their maps in the office. The most common scale used is between 1:40 000 and 1:80 000 as a result of the general availability of 1:50 000 maps, but maps of a larger scale would be preferred. Thirty-two percent of the respondents usually wanted soil information about a site, whereas 23% wanted pattern information about a large area (46% wanted both). This has an implication on the way the legend should be constructed. Texture, slope and soil water content were the properties ranked of highest importance by respondents regardless of their occupation. There was a slight preference for a complex connotative map symbol as opposed to a simple one. This preference was expressed more by those with experience in using soil maps. Those will less experience preferred a simple symbol. A colored soil map with a topographic base map was what most respondents wanted. Fully 51% of the respondents had some difficulties in getting the information they needed from a soil map. They either found the information inaccurate, they could not understand the legend or the symbol, or they had difficulty locating themselves on the map. These difficulties most often arose from the lack of any statements about mapping procedures and reliability, complicated and non-standard legends and symbols and unfamiliar terminology (usually soil taxonomic names). As a result of these responses, a number of suggestions are offered for the improvement of soil maps.
TEMPERATURE PROFILES IN A RAPE FIELD BEFORE AND AFTER HARVEST
Authors: BUCHER G. E. , LAMB R. J. , BRACKEN G. K.
Published: March 2010

Temperature was recorded at replicate locations in a rape field, both in the soil and in the crop canopy. Sources of variability in these records are examined, and the temperatures are compared with standard records from nearby meteorological stations. Variability within replicates depends on elevation, reaching a maximum at a soil depth of 5 cm. Temperatures in the soil of the rape field were more extreme than those recorded under sod at a nearby meteorological station, though the differences were small when a full rape canopy was present. Removal of the canopy at harvest caused wide diurnal fluctuations and an increase in the average daily maximum at all crop elevations, though temperatures recorded at a nearby meteorological station were similar before and after harvest. Linear regression equations are provided that estimate daily maximum and minimum temperatures in the soil of the rape field to a depth of 20 cm from standard meteorological records.
PHOSPHATE ADSORPTION BY SOIL AMENDED WITH CHEMICALLY TREATED SEWAGE SLUDGES
Authors: LEE C. CHOW , SOON Y. K. , BATES T. E.
Published: March 2010

A loamy soil amended with sewage sludges chemically treated with Ca(OH)2, Al2(SO4)3 or FeCl3 was used for P adsorption studies. Phosphate adsorption was increased by sludge application in the order: Ca-sludge >> Al-sludge = Fe-sludge > untreated soil, and was associated wtih the increase in CaCO3 and hydrous iron and aluminum oxide countents resulting from sludge application.
ASSOCIATION OF TOTAL CaCO3 AND ACTIVE CaCO3 WITH GROWTH OF FIVE TREE SPECIES ON CHERNOZEMIC SOILS
Authors: CARTER M. R.
Published: March 2010

In Chernozemic soils, active CaCO3, an estimate of the CaCO3 in the clay and fine silt particles, proved to be a more effective site index for several tree species than total CaCO3. In general, active CaCO3 exceeding 7–9% caused incidences of stunted growth and chlorosis. High levels of active CaCO3 within the 0–30 cm soil depth were related to enrichment of CaCO3 in the clay fraction.
DETERMINATION OF SOIL CLIMATE CLASSES AND SOIL FAMILIES FOR A LEVEL 3 SURVEY IN THE CORDILLERA
Authors: VOLD T. , MARSH R. D.
Published: March 2010

The soil family was used to describe soil map units in an intermediate level survey of British Columbia. The main obstacle to its application was determination of soil climate. Soil climate (soil temperature classes and soil moisture subclasses) was derived from atmospheric climate data. It was then related to climax forest vegetation which was used to locate map unit boundaries. By linking biological characteristics to the soil survey, interpretations for wildlife and forestry were enhanced. At the level in which the survey was conducted, the soil family usefully reflected the soil variation in the landscape while providing ample information for most land use interpretations.
PERSISTENCE AND MOVEMENT OF CYANAZINE AND PROCYAZINE IN SOIL UNDER FIELD CONDITIONS
Authors: YOO J. Y. , MUIR D. C. G. , BAKER B. E.
Published: March 2010

The herbicides cyanazine (2-chloro-4-(1-cyano-1-methyl ethylamino) -6-ethylamino-s-triazine) and procyazine (2-chloro-4-cyclopropylamino-6-(1-cyano-1-methyl ethylamino)-s-triazine) were applied (post-emergence) to two corn fields that were drained by separate tile drains. Soil (0- to 20-, 20- to 40-, and 40- to 60-cm depths) and tile-drain water samples were collected before application and at frequent intervals for 6 mo following application. Cyanazine and procyazine showed similar, relatively short persistence in soil with half-lives of 6 and 13 days, respectively. The major portion (greater than 95%) of the residues of both herbicides was detected in the 0- to 20-cm depth. The herbicides were detected in tile-drain water at concentrations ranging from 2 to 111 ng/L. Overall losses of cyanazine and procyazine residues via tile-drain water represented less than 0.01% of the quantity applied.
A MICROMORPHOLOGICAL STUDY OF CALCAREOUS SOIL HORIZONS IN SASKATCHEWAN SOILS
Authors: MERMUT A. R. , ST. ARNAUD R. J.
Published: March 2010

The nature and distribution of carbonates in calcareous horizons from several Saskatchewan soils were examined micromorphologically. Carbonate minerals were found to occur in several distinct forms which included skeletal grains and plasma, cutanic accumulation, glaebular separations and crystallaria. Carbonates which occurred as individual grains consisted of calcite and dolomite, inherited from the original parent materials. However, finer crystallites of secondary origin within the plasma were also observed. Maximal accumulations of secondary carbonates within the plasma, as evidenced in a Turkish soil, imparted a crystic plasmic fabric to the horizon. Cutanic accumulations were observed as cutans (calcans, carbonatic argillans), neocutans (neocalcitans) and as quasicutans, the latter occurring subcutanically to natural ped surfaces or void walls. The cutanic accumulation forms were most pronounced in Cca horizons of well-drained soils. Three types of carbonatic glaebules were observed in the soils studied. Those with sharp boundaries were associated with dry environments whereas those with diffuse boundaries appeared to be related to soils developed under more humid conditions. A third form, sesquioxidic carbonatic glaebules, were evident in soil horizons affected by poor drainage. Biorelicts, in the form of individual shell fragments, lithorelicts as original calcareous rock fragments, and crystallaria in the form of intercalary crystals and acicular crystals within tubes were other types of carbonates found in the soils studied.
A KEY FOR CLASSIFYING SOILS TO THE SUBGROUP LEVEL OF THE CANADIAN SYSTEM OF SOIL CLASSIFICATION
Authors: STRONG W. L. , LIMBIRD A.
Published: March 2010

A dichotomus key is presented to identify the soils of Canada to the subgroup level of the Canadian System of Soil Classification. The key is designed to assist environmental analysts who infrequently classify soils in Canada.
THE EFFECTS OF SURFACE-APPLIED CALCIUM ON SOIL AND MATURE SPARTAN APPLE TREES
Authors: NEILSEN G. H. , HOGUE E. , DROUGHT B. G.
Published: March 2010

In 1975, hydrated lime and calcium sulfate were applied to a Rutland gravelly sandy loam under the canopy of mature apple trees (Malus domestica Borkh. ’Spartan’) on M16 at 3000, 6000, 3 × 2000 and at 3000, 6000, 3 × 4000 kg/ha, respectively, pH and exchangeable Ca, Mg and Mn were measured in the soil sampled in 1979 at 10-cm intervals to a 60-cm depth for each of the check, 6000 kg/ha Ca(OH)2 and 12 000 kg/ha gypsum treatments. The acidity of the surface soil was decreased significantly in the 6000 kg/ha Ca(OH)2 treatment. Negligible soil Ca accumulation occurred below the surface 10-cm depth for any treatment. Soil Mn was decreased from the surface to the 20-cm level in the Ca(OH)2 treatment while soil Mg was decreased from the surface to the 30-cm level in the gypsum treatment. Fruit Ca concentration at harvest, 1975–1979 was not increased by soil Ca treatments. Leaf Mg was often reduced by soil gpysum applications in excess of 3000 kg/ha. Leaf Mn reduction did not occur until the 4th and 5th yr of the experiment in the 6000 and the 3 × 2000 kg/ha Ca(OH)2 treatments.
EFFECT OF VARIOUS PRETREATMENTS ON X-RAY DIFFRACTION PATTERNS OF CLAY FRACTIONS OF PODZOLIC B HORIZONS
Authors: WANG C. , KODAMA H. , MILES N. M.
Published: March 2010

The objective of this study was to compare the effects of various pretreatments on the X-ray identification and quantification of clay-sized minerals from some podzolic B horizons. After soil samples were treated with H2O2 to remove organic matter, clay fractions were dispersed, separated, and freeze-dried. A portion of each clay sample was subjected to the following pretreatments: ultrasonic bath, extraction by citrate-dithionite, extraction by 0.5 N NaOH, and extraction by Tiron. Oriented slides were used for identification and quantification of clay minerals after each pretreatment. The X-ray patterns for ultrasonically dispersed samples were used as a basis for evaluating the effectiveness of the three chemical pretreatments. Tiron pretreatment was found to be the most suitable method for removal of amorphous material from clay separates of podzolic B horizons. The traditional citrate-dithionite method was not effective in removing amorphous Si from clays. The 0.5 N NaOH method is not recommended because it resulted in significant destruction of phyllosilicates and it was not effective in removing amorphous Fe.
POSSIBLE USES OF FREEZE-PURIFICATION IN THE RECLAMATION OF SALINE SOILS
Authors: JONG E. DE
Published: March 2010

Twenty-four, 15-cm-long soil columns were leached with a solution containing 2100 ppm Na and 2000 ppm Ca as NaCl and CaCl2, respectively. Half the columns were gravity-drained, the other half were drained under a pressure of 0.36 kg/cm2. The columns were frozen in a deep freeze, the equivalent to 6 cm of the original leaching solution was frozen on top of the columns, and the columns were then allowed to thaw. The initial 30% of the meltwater had a higher salt content and a higher SAR than the original solution, while the reverse was true for the last 70% of the melt. The infiltrating meltwater lowered EC and SAR of the top half of the soil columns. Differences were relatively small between four treatments in which the ice melted while the soil thawed, but these four treatments gave better leaching than the treatment in which the ice melted on a pre-thawed soil column. The results suggest that freeze-purification of saline drain water can be used in two ways for the reclamation of saline soils: (a) the initial melt could be collected and disposed of, while the later meltwater is used for leaching; or (b) all meltwater could be allowed to infiltrate into the soil resulting in a procedure similar to the high-salt-water dilution method of reclaiming saline soils.
PODZOLIC SOILS WITH LUVISOLIC-LIKE MORPHOLOGIES IN THE UPPER SUBALPINE SUBZONE OF THE CANADIAN ROCKIES 2. GENESIS
Authors: SMITH C. A. S. , COEN G. M. , PLUTH D. J.
Published: March 2010

Clay mineralogy and soil fabric were used to determine processes responsible for development of Luvisolic-like characteristics in some soils of the upper subalpine subzone in the central Rocky Mountains of Alberta. Evaluation by particle size distribution through the profile was complicated by the presence of a silty surficial deposit overlying a texturally heterogenous calcareous till of the study area. Direct observation, in thin section, of apparent illuvial clay revealed its abundance to be relatively low and its distribution to be unlike that found within illuvial horizons of Gray Luvisols elsewhere in Canada. Both pedogenesis and nature of parent material influenced the mineralogy of the clay-sized fraction. Comparison of the clay suites of the argillic-like horizons with those of the significantly different overlying material provided further evidence that contemporary lessivage was largely inconsequential. A combination of processes is hypothesized to have contributed to the anomalous morphologies of these soils. These include the dissolution and removal of primary carbonate from the solum, geomorphic influences and the in situ reorganization of plasmic material within the till.
EFFECTS OF SULPHUR AND PHOSPHORUS FERTILIZATION ON THE YIELD AND QUALITY OF BARLEY (Hordeum vulgare L.) IN THREE SOUTHWESTERN QUEBEC SOILS
Authors: MNKENI P. N. S. , MACKENZIE A. F.
Published: March 2010

Field studies were conducted on three southwestern Quebec soils for 2 yr to provide information on effects of S fertilization on barley growth, to examine any S-P interaction, and to assess contributions of S from rain during the growing season. The treatments were arranged in a factorial combination of four levels of S (0, 15.6 or 31.2, 62.4 and 93.6 kg S/ha) with three levels of P (0, 117 and 234 kg P2O5/ha) added as gypsum and triple superphosphate, respectively. The results showed that added S either had an inconsistent effect or no effect on barley yield on the experimental soils. The lack of response was attributed to annual S additions from rain estimated to be in excess of 10 kg S∙ha−1∙yr−1, as well as high levels of available S in the soils. No S-P interaction was observed, indicating that high P fertilization should not result in S deficiencies for barley in southwestern Quebec.
A SOIL WATER BUDGET MODEL WITH A NEARLY IMPERMEABLE LAYER
Authors: JONG R. DE , SHAYKEWICH C. F.
Published: March 2010

A soil water budget model which accounted for a nearly impermeable layer in the profile was developed to describe the water content in a non-homogeneous soil-root system. Water uptake by the roots was represented by a sink term which was dependent upon the root distribution, the soil water content and the potential transpiration. The chosen boundary conditions, precipitation, evapotranspiration and a nearly impermeable layer at the bottom of the soil profile approximated those existing in the field. A submodel to calculate interception was included in the model. Data obtained from a field experiment on a clay soil were compared with calculated results for the period 1 May to 30 Sept. 1975. The overall agreement between daily measured and calculated soil water contents was excellent; all calculated values fell within 10% of the measured data. The model also yielded acceptable results in predicting the distribution of soil water through the profile.
EFFECT OF LABILE INORGANIC PHOSPHATE STATUS AND ORGANIC CARBON ADDITIONS ON THE MICROBIAL UPTAKE OF PHOSPHORUS IN SOILS
Authors: CHAUHAN B. S. , STEWART J. W. B. , PAUL E. A.
Published: March 2010

The effect of labile inorganic phosphate (Pi) status of the soil on the decomposition of added cellulose and on the immobilization, mineralization, and redistribution of native and added P in soils was studied in a greenhouse incubation experiment. Cellulose was added at 765 μg C∙g−1 soil with and without P (9 μg∙g−1 soil) every 30 days under adequate N, H2O, and constant tempreature to two soils of different available P status. Lack of P eventually slowed down decomposition of added C, but this effect was partially compensated for by increased mineralization of organic P (Po) forms. Added P was redistributed to both P, (58–69%) and Po (42–31%) forms; higher amounts of Po were found in the soil with the highest Pi status. The correlation between microbial P uptake and solution P values was significant, and microbial C:P ratios ranged from 12:1 under high available P conditions to 45:1 where P was in low supply.
MAGNESIUM AVAILABILITY AND PLANT UPTAKE FROM DIFFERENT MAGNESIUM SOURCES IN A GREENHOUSE EXPERIMENT
Authors: WHITE R. P. , MUNRO D. C.
Published: March 2010

Because different sources were being utilized to meet fertilizer Mg guarantees in the Atlantic Area, the availability of Mg to ryegrass (Lolium perenne L.) and the effect on soil test levels of four Mg sources were evaluated at two soil pH levels over five harvests in a greenhouse experiment. At equivalent rates of applied Mg (50 ppm) the availability ranked as follows based on total Mg uptake: MgSO4 > Sul-Po-Mag > ground dolomitic limestone > coarse dolomitic grits = check soil. Soil pH had no apparent effect on relative availabilities of the sources. Limestone applied at a rate to equal 240 ppm Mg supplied more plant-available Mg than any other source and, as well, maintained the highest soil test level over all five harvests. Coarse dolomitic grits exhibited no value as a plant-available Mg source.
POTASSIUM STATUS OF A DARK BROWN CHERNOZEM SOIL AFTER SIXTY-SIX YEARS OF CROPPING UNDER IRRIGATION
Authors: DUBETZ S. , DUDAS M. J.
Published: March 2010

An irrigated rotation has supported high crop yields for 66 yr without the benefit of K fertilizer because of the relatively high total K status (14 392 ppm in the 0- to 15-cm layer and 11 183 ppm in the 15-to 30-cm layer) of the soil. This K status, under native conditions, was due to the nature of the parent material, biocycling and minimal leaching. After two-thirds of a century of intensive cropping, the exchangeable K was reduced by 28% in the 0- to 15-cm layer. Extractable K (NaTPB method) decreased progressively from 2023 ppm in the 0- to 15-cm layer to 1368 ppm in the 45- to 60-cm layer in the native sod soil but there was no appreciable change in levels of NaTPB-K in the cropped soil. Apparently, some of the readily extractable K. from micaceous minerals or feldspars, or both, was converted to exchangeable K as the latter pool was depleted through continued cropping. Critical levels of exchangeable and extractable K have not yet been reached.
THE COUPLED TRANSPORT OF WATER AND HEAT IN FREEZING SOILS: A FIELD STUDY
Authors: SHEPPARD M. I. , KAY B. D. , LOCH J. P. G.
Published: March 2010

Progressive changes in soil moisture profiles and temperature profiles have been monitored during the seasonal freezing of a gray-brown luvisol. Calculations accounting for deformation of the coordinate system have been performed to permit accurate estimates of the vertical displacement of the ground surface and the penetration of the 0 °C isotherm. Problems associated with collecting an appropriate data set in order to test numerical models of coupled transport of water and heat under field conditions are discussed.
THE EFFECT OF RESIDUAL FERTILIZER COPPER ON AMMONIFICATION, NITRIFICATION AND PROTEOLYTIC POPULATION IN SOME ORGANIC SOILS
Authors: MATHUR S. P. , PRESTON C. M.
Published: March 2010

As a part of attempts at examining the suitability of using moderate amounts of Cu for mitigating the undesirably fast decomposition and subsidence of some organic soils, this investigation revealed that both total and DTPA-TEA-extractable Cu contents of 14 samples of cultivated organic soils correlated negatively with the total microbial population counted on soil extract-acitidione-gelatin agar plates and positively with the percentage of that population capable of extracellular proteolysis. On the other hand, the concentrations of both total and extractable Cu did not correlate with either the total number of proteolytic organisms counted, or the capacities of the soils for ammonification and nitrification. The results are, therefore, in accord with the belief that Cu curtails the decomposition of organic soils primarily through inactivation of accumulated soil enzymes, but not through direct toxic effects on the general soil microbial population.
SOIL MOISTURE AND TEMPERATURE RESPONSE TO SHALLOW TILLAGE IN THE EARLY SPRING
Authors: DARWENT A. L. , BAILEY W. G.
Published: March 2010

Surface soil moisture was conserved in a loam to clay loam soil receiving a single shallow cultivation in the early spring, while in an unfilled soil it declined markedly. Tillage effects were less marked at deeper depths. Soil temperatures were found to differ only slightly between tilled and untilled soils.
THE COMPATIBILITY OF THE NITRIFICATION INHIBITOR DICYANDIAMIDE WITH INJECTED ANHYDROUS AMMONIA
Authors: ASHWORTU J. , RODGERS G. A.
Published: March 2010

Dicyandiamide has physical, chemical and biological properties that render it suitable for use as an inhibitor of nitrification of injected anhydrous ammonia (NH3). It is readily soluble and stable in NH3 and, when applied at 15 kg/ha, it effectively inhibited nitrification of injected urea for 3 mo in soil at ca. 5 °C. These properties are relevant to the practice of fall application of NH3, with its attendant risk of loss of some of the applied nitrogen before spring sowing, as a result of nitrification.
THE FLUORESCENCE AND VISIBLE ABSORBANCE OF Cu(II) AND Mn(II) COMPLEXES OF FULVIC ACID: THE EFFECT OF METAL ION LOADING
Authors: UNDERDOWN ALAN W. , LANGFORD COOPER. H. , GAMBLE DONALD S.
Published: March 2010

The fluorescence of a well-characterized fulvic acid is found to be quenched by the binding of Cu(II), Mn(II) or H+. Below 40% protonation of the 5.0 mmole/g most strongly acidic carboxyl groups, the results indicate weak collisional quenching by OH−. Metal ion complexing becomes weaker with increasing amounts bound.
LABORATORY DETERMINATION OF FIELD BULK DENSITY FOR IMPROVING FERTILIZER RECOMMENDATIONS OF ORGANIC SOILS
Authors: LIEROP W. VAN
Published: March 2010

The objectives of this study were to find ways to improve the accuracy of soil fertilizer recommendations by taking into account the variation in bulk density (BD) of organic soils. To achieve this end, field BD values of 30 organic soils (0.100–0.504 g/mL) were used to evaluate methods of measuring the BD in the laboratory by means of correlation and regression techniques. A simple and rapid procedure using the reconstituted BD of field-moist soils was the most accurate means of determining the average field BD in the laboratory, as indicated by the correlation coefficient obtained between the BD values obtained by this method and those in the field (r = 0.975**). The second most accurate method relied upon the exponential relationship between the water content of soils and their BD (R2 = 91.1 %). The least exact method of correcting for BD variations was to scoop a volume of dried (65 °C) and sieved (2-mm) soils, as is done in some soil test laboratories. Although the values obtained by this method were related (r = 0.502**) to the field data, drying caused shrinkage of soils, thereby increasing their BD about twofold. Soil pH (r = 0.716**) and percentage ash contents (r = 0.851**) were also related to the field BD of soils. These tests could be used to estimate the BD of soils when the preferred method cannot be used. Regression equations are provided for relating appropriate test values to the BD of organic soils.
A PROCEDURE FOR THE CHARACTERIZATION OF SOIL ORGANIC MATTER
Authors: SCHNITZER M. , LOWE L. E. , DORMAAR J. F. , MARTEL Y.
Published: March 2010

In a recent cooperative study, in which four laboratories participated, organic matter in a large number of Canadian soil samples was characterized by relatively simple methods. As result of this work we are proposing a procedure for the extraction, separation and characterization of soil organic matter. The procedure includes determinations of organic C and total N in initial soils, followed by the isolation from the soils of humic and fulvic acids. Total C and N and E4/E6 ratios are then determined in the latter fractions. From these data, proportions of extractable soil-C and soil-N and HA/FA ratios are computed.
INEXPENSIVE THERMISTOR SENSORS FOR TEMPERATURE MEASUREMENTS IN ORGANIC SOILS
Authors: CAMPBELL JAMES A. , FRASCARELLI LOUISE
Published: March 2010

Thermistors were incorporated in stainless steel tubular probes and in CPVC epoxy-filled pioe for accurate periodic and continuous in situ measurements of temperature in organic soil. Temperature can be measured with ± 0.1 °C with portable analog meters and ± 0.01 °C with digital meters.
DISTRIBUTION OF MERCURY RESIDUES FROM THE USE OF MERCURIAL FUNGICIDES ON GOLF COURSE GREENS
Authors: FUSHTEY S. G. , FRANK R.
Published: March 2010

Soil samples taken from two golf courses with a long history of mercurial fungicide use for disease control showed mercury residues in excess of background levels to a maximum depth of 30 cm at one site and 60 cm at the other. Laterally, residues were found up to 30 m from the treated areas at both sides.
HOW SOIL MAP UNITS AND DELINEATIONS CHANGE WITH SURVEY INTENSITY AND MAP SCALE
Authors: VALENTINE K. W. G.
Published: March 2010

It is becoming common for soil surveys to be made of the same area at different intensities and published at different scales. The principles of cartographic generalization are discussed that control the relationships between the map units and delineations on maps made from such surveys. A study of two sets of maps showed that almost no lines were coincident. Up to 20% of the small scale delinations could be ’inliers’ of different soils and about 15% of the large scale delineations would be outside their small scale equivalents. The same discrepancies are to be expected between large scale soil maps and the smaller scale maps of physiography or vegetation that are often used to stratify soils. Reasons for these discrepancies are discussed under the headings of simplification and classification. Recommendations arc made to guide the preparation of maps and legends for different intensities and scales of survey in the same area. These recommendations have practical implications for the planning of surveys and the designs of computer-based autocartography systems.
EVOLUTION DE L’UREE PLACEE EN BANDES DANS DEUX SOLS ACIDES DU QUEBEC
Authors: GIROUX M. , CARRIER D.
Published: March 2010

The objectives of this experiment were to determine the power of Morin (sand) and Achigan (sandy-loam) soils to hydrolyze urea and to nitrify ammonium. The urea was applied at a rate of 1500 mg N/kg soil in a drill 6 cm below the soil surface. The soils were incubated for 63 days at 20 °C and 25% moisture content (vol/wt) in 2-L containers. The band-applied urea hydrolysis was directly proportional to the logarithm of its remaining concentration in the soil (i.e. first-order reaction). Calculated reaction rate constants were −0.112 and −0.143 per day for the sand and the sandy loam, respectively. The unequal reaction rates were, presumably, related to the different chemical and physical properties of these soils. The rate of urea ammonification was significantly more rapid than the ammonium nitrification. One week after starting the incubation, only 18.3% and 11.5% of the applied urea remained in the Morin and Achigan soils, respectively. However, no nitrification was detected until about the 20th day and it was more active in the sandy soil. Soil pH increased and decreased significantly as ammonification or nitrification progressed, respectively.
BIO-CYCLING OF PHOSPHORUS IN SOIL BY PLANT ROOTS
Authors: READ D. W. L. , CAMPBELL C. A.
Published: March 2010

Plants cycle nutrients in soil by bringing minerals from the subsurface to the surface soil. This paper presents evidence that phosphorus, a relatively immobile nutrient, can be moved to the subsoil by the roots under cereals that have received high rates of P. Residual effects of phosphatic fertilizer have been studied at Swift Current, Saskatchewan since 1966. Single applications of 0, 100, 200 and 400 kg P/ha were applied in 1966. Soil samples taken in the fall of 1967, 1974 and 1979 showed that there is more NaHCO3-extractable P under the plots that received 100, 200 or 400 kg of P than under the unfertilized plots. At depths below 30 cm the differences were greater in 1979 than in 1974, particularly under the 400 kg P/ha treatment. This indicates a gradual downward movement of P, probably in the tissue of the plant roots.
AMMONIA VOLATILIZATION FROM LIQUID DAIRY CATTLE MANURE IN THE FIELD
Authors: BEAUCHAMP E. G. , KIDD G. E. , THURTELL G.
Published: March 2010

The volatilization of ammonia from applied liquid dairy cattle manure was measured in the field during 6- to 7- day periods in early May of 4 yr. An "open" system involving an aerodynamic diffusion method was employed for these measurements. Ammonia flux followed a diurnal pattern with maxima occurring shortly after midday and minima occurring during the early morning hours. The magnitude of daily flux values tended to decrease with time. However, both temperature and rainfall influenced the magnitude of ammonia flux. Generally, ammonia flux values increased with temperature but were suppressed by rainfall. Over periods of 6 or 7 days following the time of manure application, between 24 and 33% of the ammoniacal N applied in the manure was lost by volatilization. Samples of manure taken immediately following application and 5 days later showed a decrease in ammoniacal N concentration during this period. Although some ammonium moved into the 0- to 2- cm soil layer, immediately following application, most appeared to remain in the manure layer in spite of rainfalls which occurred during the experimental periods. Five days following manure application, the relatively large quantities of ammoniacal N remaining in the manure layer were subject to potential volatilization.
N FERTILIZATION OF FIELD-GROWN FABA BEANS IN MANITOBA
Authors: RICHARDS JOHN E. , SOPER R. J.
Published: March 2010

The effect of fertilizer N on yield, protein content and symbiotic N2 fixation in faba beans (Vicia faba L.) was studied with nine field trials during 3 yr. Forage and seed yields of nodulated faba beans were infrequently and unpredictably affected by rate of application at seeding (up to 300 kg N/ha), type of application (34 and 67 kg N/ha surface-broadcast or placed with the seed), and time of application (at full bloom or at mid pod-fill). Protein content of faba bean forage material was variably affected by applied N; in one-half of the harvests conducted, at least one of the N application treatments resulted in significantly higher forage protein contents. No logical pattern or reason for the forage protein response was found. Seed protein content was unaffected by applied N up to 150 kg N/ha, but was significantly increased by 300 kg N/ha in two out of three trials. Maximum rate of dry matter accumulation and N uptake commenced at blooming and continued up to the mid pod-fill growth stage. In seven trials monitored, the proportion of faba bean shoot N derived by symbiotic N2 fixation was 54%, with values of five out of the seven trials ranging from 63 to 71%. This amounted to 54–111 kg N/ha. Applied N decreased faba bean symbiotic fixation at all trials but one where available soil N was very high and symbiotic N2 was not occurring.
INOSITOL PHOSPHATE AND ORGANIC PHOSPHORUS CONTENTS AND PHOSPHATASE ACTIVITY OF SOME CANADIAN AND GHANAIAN SOILS
Authors: APPIAH M. R. , THOMAS R. L.
Published: March 2010

Total organic phosphorus, inositol phosphates and phosphatase activity of some selected Canadian and Ghanaian soils were compared. The lower organic phosphorus content of Ghanaian soils compared to the Canadian soils may be the result of either the faster rate of mineralization of organic phosphorus in the tropical Ghanaian soils or differences in the nature of organic residues returned to the soils. Wide variations in the amounts of inositol phosphate were observed in both groups of soils. The low activity of phosphatases in the Ghanaian soils may be due to the lower content of organic matter, a lower microbial biomass and consequently a lower phosphatase production. The effect of rotation and fertilizer application on the total organic P, inositol P and phosphatase activity indicated that alfalfa grown in rotation with corn and oats contributed significantly to the total soil organic phosphorus content with no apparent increase in inositol phosphate content. No consistent trends were observed in either the total amount of inositol phosphates or the proportion of the total phosphorus that existed as inositol phosphates for either the fertilized or unfertilized soils. The activity of phosphatase was generally higher in the corn-oat-alfalfa rotation than in the systems of corn-oat and continuous corn. Fertilization decreased the phosphatase activity in all cropping systems.
PROPRIETES PHYSICO-CHIMIQUES ET MINERALOGIQUES DES SOLS DES FORETS DE CHENES DE L’OUEST DE L’IRAN
Authors: RAFAHI H.
Published: March 2010

Most of the soils studied are non-evolved. The other soils of the area that can be distinguished are calcareous brown soils, sierozems and erosion soils. The soils are low in organic matter. The carbonate, varying from 0.4 to 46.3%, tends to increase with depth. Horizon of accumulation of carbonate (in the sierozems) is found between 30 and 100 cm from the soil surface. Sulfate exceeds chlorine ions in the soil extract. The salinity does not exist in these soils. The exchange capacity varies from 4.7 to 29.4 meq/100 g of soil. The dominant clay mineral in some of these soils is vermiculite. In the forests of western Iran, Quercus persica and Quercus saii generally occupy calcareous, poor and rather deep soils, whereas Quercus infectoria is usually grown on the less calcareous, rich and deep soils.
REEVALUATION OF THE OCCURRENCE OF INTERSTRATIFIED CLAYS AND OTHER PHYLLOSILICATES IN SOUTHERN ALBERTA SOILS
Authors: DUDAS M. J. , PAWLUK S.
Published: March 2010

Clay fractions of subsoils from Southern Alberta were characterized by X-ray diffraction using improved methods of sample preparation and pretreatment control and recently reported criteria for identification of interstratified mica-smectite. Diffraction behavior of fine clays was indicative of admixtures of discrete smectite, mica and kaolinite. High angle diffraction characteristics suggested that clay fractions did not contain interstratified mica-montmorillonite. Smectite, mica, kaolinite and chlorite, in decreasing order of abundance, comprised total clay fractions. Use of the complete set of specimen pretreatments and criteria allowed identification of two smectite species and indicated that vermiculite and mixed-layer clays, previously reported to occur in these soils, are not constituents of clay separates.