bluuebunny/crossref_metadata_2025 huggingface dataset:
SIMULATED DEW FORMATION AND MICROBIAL GROWTH IN SOIL OF A SEMIARID REGION OF WESTERN CANADA
Authors: BIEDERBECK V. O. , CAMPBELL C. A. , NICHOLAICHUK W.
Published: March 2010

To simulate the effect of dew formation on microbial growth in semiarid soils, air-dry loam was exposed to moisture condensation by incubating soil in a sine wave temperature incubator in which the diurnal temperature was 27.5 and 4 C and the relative humidity was 45% at 27.5 C. In an open system, condensation increased the soil moisture from about 1.4 to 4% (by weight) which is equivalent to a moisture suction of −1,930 and −200 bars, respectively. Even at such high suctions, condensation caused marked increases in bacteria and actinomycetes as assessed by plate and direct counts. A pure culture of Arthrobacter oxidans, a typical nonsporeforming soil bacterium, responded in a manner similar to the natural bacterial flora. Neither temperature per se, spore germination, nor contamination by airborne microorganisms was responsible for these increases. It was hypothesized that at such high suctions, moisture distribution in the soil must be heterogenous in order to permit bacterial growth.
RESPONSE OF SOIL MICROFLORA AND CERTAIN CROPS TO VORLEX AND LINURON
Authors: ROSLYCKY E. B.
Published: March 2010

Vorlex and linuron combination treatments of muck drastically reduced the population of molds, while those of the bacteria and actinomycetes remained practically unaffected. The reduction was due to Vorlex; linuron alone exerted an insignificant influence on the populations. Recovered fungi were not pathogenic and the population change had no detrimental effect on Lactuca sativa L. and Avena sativa L.
AMELIORATION OF A BROWN SOLODIZED SOLONETZ SOIL BY A SURFACE APPLICATION OF GYPSUM PLUS AMMONIUM NITRATE
Authors: CARTER M. R. , WEBSTER G. R. , CAIRNS R. R.
Published: March 2010

Combined applications of ammonium nitrate (449 kg/ha) and gypsum (4.48 tonnes/ha) were added annually to a bromegrass sod for 4 yr. The soil was a Brown Solodized Solonetz with an exchangeable sodium percentage (ESP) of 17 and 33 in the Ap and Bnt horizons, respectively. The significant effects of the combined applications were to reduce exchangeable Na, increase water infiltration and depth of Ca penetration, and provide small increased yields over that of ammonium nitrate alone. Analysis of columnar peds from the Bnt horizon showed that inped penetration of Ca had occurred at the expense of Na. These studies indicate a synergistic effect, whereby the solubility and penetration of gypsum are enhanced by ammonium nitrate.
ETUDE PAR L’ANALYSE EN COMPOSANTES PRINCIPALES DES PROPRIETES CHIMIQUES D’UN SOL FORESTIER 10 ANS APRES ECLAIRCIE
Authors: GONZALEZ A. , BOUDOUX M. , HUBERT G.
Published: March 2010

Principal component analysis was used to illustrate the evolution of chemical properties of a soil under sugar maple–beech forest, following two levels of thinning (30 and 50% of basal area). This multivariate analysis technique clearly showed that there were no significant differences between treated and untreated soils 10 yr after thinning.
PROPERTIES OF FOUR QUEBEC SOILS AFTER INCUBATION WITH FIVE SPECIES OF EARTHWORMS
Authors: LEGER R. G. , MILLETTE GERARD J. F.
Published: March 2010

Undisturbed soil profiles from the middle of the B horizon topped with leaf litters and inoculated with earthworms were kept under laboratory conditions for 100 days. The soil properties examined were pH at three depths, and exchangeable calcium, exchangeable magnesium, nitrate nitrogen, available phosphorus, exchangeable potassium, organic matter and aggregate stability of a mixed soil profile. The effects of the earthworm treatments were to change the pH conditions of the soil, the amount of change varying with the species of earthworm present in a particular soil series. A decrease in exchangeable calcium and exchangeable magnesium in Uplands soil and available phosphorus in Dalhousie soil was also shown. The only effect of leaf litter treatments was to change nitrate nitrogen in Uplands and Dalhousie soils. We estimate that three- or fourfold the experimental time would be required for earthworms to sufficiently work the soil and significantly influence properties of an undisturbed soil core.
EFFECTS OF SOIL ACIDITY ON RHIZOBIA NUMBERS, NODULATION AND NITROGEN FIXATION BY ALFALFA AND RED CLOVER
Authors: RICE W. A. , PENNEY D. C. , NYBORG M.
Published: March 2010

The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse experiments using soils from these locations. The pH of the soils (limed and unlimed) varied from 4.5 to 7.2. Rhizobia populations in the soil, nodulation, and relative forage yields (yield without N/yield with N) were measured in both the field and greenhouse experiments. Rhizobium meliloti numbers, nodulation scores, and relative yields of alfalfa decreased sharply as the pH of the soils decreased below 6.0. For soils with pH 6.0 or greater, there was very little effect of pH on any of the above factors for alfalfa. Soil pH in the range studied had no effect on nodulation scores and relative yields of red clover. However, R. trifolii numbers were reduced when the pH of the soil was less than 4.9. These results demonstrate that hydrogen ion concentration is an important factor limiting alfalfa growth on acid soils of Alberta and northeastern British Columbia, but it is less important for red clover. This supports the continued use of measurements of soil pH, as well as plant-available Al and Mn for predicting crop response to lime.
EFFECTS OF ORGANIC MATTER CONTENT ON EXCHANGEABLE Al AND pH-DEPENDENT ACIDITY OF VERY ACID SOILS
Authors: HOYT P. B.
Published: March 2010

Twenty-nine soil samples were selected within a field for similar pH (4.60–4.72) but with widely varying organic matter contents (3.5–20.5%). Exchangeable Al decreased while pH-dependent acidity increased with increasing organic matter content. The implication of these relationships for liming practices is discussed.
ORGANIC COMPOUNDS FORMED BY THE HYDROGEN PEROXIDE XIDATION OF SOILS
Authors: GRIFFITH S. M. , SCHNITZER M.
Published: March 2010

Two samples taken from tropical volcanic surface soils and one sample from a Canadian Podzol subsurface soil were oxidized with H2O2 under conditions usually employed for the removal of organic matter from soils prior to mineralogical analyses. Between 65 and 82% of the C but only between 23 and 36% of the N in the initial organic matter in the three soils was oxidized to volatile and water-soluble products. Among the latter, small amounts of about 40 different aliphatic and aromatic compounds were identified, most of which were phenolic. Extraction with organic solvents removed n-alkanes and n-fatty acids from H2O2-resistant organic matter, but most of the latter consisted of humic substances strongly bonded to or absorbed on inorganic soil constituents. H2O2-resistant fractions accounted in the case of two soils, initially rich in organic matter, for 12.0 and 7.5% of the air-dry weights of peroxidized soils. The presence of such substantial amounts of H2O2-resistant organic matter may interfere with the dispersion and mineralogical analysis of peroxidized soils, especially those with high initial organic matter contents.
ETUDE SUR LA VALEUR DES CRITERES CHIMIQUES PROPOSES PAR LA COMMISSION PEDOLOGIQUE DU CANADA POUR LA CLASSIFICATION TAXONOMIQUE DES SOLS DU QUEBEC
Authors: BARIL ROGER W. , TRAN THI SEN
Published: March 2010

Correlations were made among chemical criteria used for taxonomic soil classificaton. The compared tests were: oxalate Δ (Fe + Al), pyrophosphate-extractable (Fe + Al), oxalate-extractable Al, pH-dependent cation exchange capacity (ΔCEC), ratios of pyrophosphate-extractable (Fe + Al) over clay or over dithionite-extractable (Fe + Al), and finally soil pH measured in 1 M NaF. Significant correlations were found among various measured parameters. However, no single test was found to be reliable as a single criterion when applied to the taxonomic classification of Quebec soils. The two chemical tests, pyrophosphate-extractable (Fe + Al) and its ratio over clay, combined with morphologic criteria appeared useful for classifying Quebec Podzols. A few soils, which presented discrepancies from chemical criteria were found difficult to classify, thus suggesting the possibility of establishing new sub-groups in the Canadain soil taxonomic classification system.
RESIDUAL EFFECTS OF PHOSPHORUS FERTILIZER. I. FOR WHEAT GROWN ON FOUR CHERNOZEMIC SOIL TYPES IN SASKATCHEWAN AND MANITOBA
Authors: READ D. W. L. , WARDER F. G. , SPRATT E. D. , BAILEY L. D.
Published: March 2010

The effects of single applications of 100, 200, and 400 kg/ha of P were measured under field conditions on Chernozemic soils in Manitoba and Saskatchewan for 8 yr. All applications of P increased the yield of wheat and increased the amount of available P in the soil. The addition of P with the seed did not increase the yield on plots that had received 100 kg/ha of P or more, except in 2 yr at one of the four test locations. On extremely P-deficient soils in Manitoba, 21% of the broadcast P (applied at 100 kg P/ha) was recovered by grain in 8 yr; the percent recovered was lower from the 200 and 400 kg P/ha at all sites (15 and 9%, respectively) but the amount of available P remaining in the soil was greater. Single large applications of 100 kg/ha of P were shown to be effective over the 8-yr period. Higher rates of application showed little advantage over 100 kg P/ha in the 8 yr but would probably remain effective for longer periods.
EFFECTS OF TEMPERATURE AND PHOSPHATE CONCENTRATION ON RATE OF SODIUM PYROPHOSPHATE AND SODIUM TRIPOLYPHOSPHATE HYDROLYSIS IN SOIL
Authors: CHANG C. , RACZ G. J.
Published: March 2010

Rates of hydrolysis of water-soluble sodium pyrophosphate and sodium tripolyphosphate, applied to soil at 200 ppm P, were extremely rapid (about 2–7%/h) during the 0 to 24- or 0- to 48-h period following phosphate application but decreased with time of incubation. Rates of hydrolysis increased linearly and increased about two- to threefold as temperatures were increased from 5 to 35 C or from 5 to 50 C. Inconsistent results were obtained at temperatures above 50 C. Increases in incubation temperature increased the total amount of added polyphosphate hydrolyzed by the soil in 120 h from about 40 to 70% at 5 C to about 80 to 95% at 35 C and 50 C. Water-soluble polyphosphate hydrolyzed at a greater rate than 0.5 N H2SO4-soluble polyphosphate. However, the effects of temperature on rate of hydrolysis of acid-soluble polyphosphate and water-soluble polyphosphate were similar. Polyphosphate hydrolyzed at a greater rate in the noncalcareous Newdale soil than in the calcareous Lakeland soil. Rate of tripolyphosphate hydrolysis was usually greater than rate of pyrophosphate hydrolysis. Rate of hydrolysis of water-soluble polyphosphate, expressed as %/h, decreased exponentially as concentration of applied polyphosphate increased from 200 to 1,600 ppm. However, rate of orthophosphate production per unit time increased exponentially with increased substrate concentration.
FACTORS CONTRIBUTING TO CROP RESPONSE ON A DEEP-PLOWED SOLONETZ SOIL
Authors: HARKER D. BROOK , WEBSTER G. R. , CAIRNS R. R.
Published: March 2010

Deep plowing was evaluated in the field and simulated in a greenhouse study in an attempt to isolate soil factors responsible for yield effects on a Duagh Solonetz soil. Generally, fertilization provided a more significant yield response than deep plowing in the field or horizon mixing in the greenhouse. In the field, however, deep plowing in combination with fertilization produced an additional 542 kg/ha of alfalfa-bromegrass forage over fertilization alone [Formula: see text]. Also, in fertilized greenhouse treatments, retaining the A horizon on the surface while mixing sub-horizons proved significantly beneficial over mixing all three horizons [Formula: see text]. The main factor responsible for yield effects appeared to be the Ca enrichment of surface and B horizon areas. An increase in the Ca:Na ratio improved water intake rates and reduced water-logging of the soil, thereby providing a more suitable medium for root development and a more efficient use of indigenous and applied N.
EFFECTS OF FERTILIZER N AND SOIL MOISTURE ON YIELD, YIELD COMPONENTS, PROTEIN CONTENT AND N ACCUMULATION IN THE ABOVEGROUND PARTS OF SPRING WHEAT
Authors: CAMPBELL C. A. , DAVIDSON H. R. , WARDER F. G.
Published: March 2010

The accumulation of aboveground dry matter (DM) and nitrogen (N) by spring wheat (T. aestivum L. cv. Manitou) grown on stubble land in lysimeters at two moisture levels (irrigation and natural rainfall) and seven rates of N was measured at five sampling dates. With irrigation, DM increased exponentially with time and N fertilization. This also occurred on dryland except between shot blade and anthesis when DM accumulated more slowly and plants lost 20% of their N at application rates > 61.5 kg N/ha. Rainfall after anthesis increased grain yields of dryland crops fertilized with > 61.5 kg N/ha more than those receiving less N because the former plants still had residual fertilizer N available to them. Grain yield response to N fertility followed the law of diminishing returns on irrigated land, but on dryland the relationship fitted a logarithmic growth curve. Grain yield when neither water nor N was added was 1,600 kg/ha; it increased by 71, 47 and 300% when water, 164 kg N/ha, and water plus 164 kg N/ha, respectively, were applied. On dryland, grain protein was 15.4% with no N applied and 17.0% at rates > 61.5 kg/ha; on irrigation, it increased from 14.1 to 15.7% with increasing N levels. Number of heads and kernels and kernel weight were increased by irrigation but only the two former parameters were increased by N. Dry matter accumulation was related to N concentration in plants by: DM = (%N)−k where k was < 1. N accumulated in plants at a faster rate than DM. The maximum rate of N accumulation was not affected by moisture; it was highest (4.7 kg N/ha/day) at a fertilizer rate of 123 kg N/ha. Irrigated plants recovered one-half or more of the fertilizer N, and dryland plants recovered one-quarter to one-third. Fertilizer recovery decreased with increasing fertilizer N. At maturity more than 70% of the N in the aboveground plant parts was located in the grain; N fertilizer had little effect on this porportion but drought during flowering retarded translocation of assimilates to the grain.
RELATIONSHIPS OF YIELD DATA TO AGROCLIMATES, SOIL CAPABILITY CLASSIFICATION AND SOILS OF ALBERTA
Authors: PETERS T. W.
Published: March 2010

A method has been devised to relate the yields of wheat, oats and barley to the agroclimatic subregions of Alberta, the soil capability for agriculture and the soils of Alberta, using yield data supplied by the Alberta Hail and Crop Insurance Corporation. Four management practices are included: crops grown on stubble, fallow, stubble-fertilized and fallow-fertilized. Duncan’s multiple range test was used to test the validity of the differences in yields between the agroclimatic subregions, soil capability classes for agriculture, soil series and management practices. This information allowed for the development of economic assessment of a land resource which could be utilized for land evaluation and land use planning.
CHARACTERISTICS OF THE MINERAL CONSTITUENTS OF SOME ALBIC AND SPODIC HORIZONS AS RELATED TO THEIR CHARGE PROPERTIES
Authors: LAVERDIÈRE M. R. , WEAVER R. M. , D’AVIGNON A.
Published: March 2010

Some physical, chemical and mineralogical properties of five albic and six spodic horizons were studied in an attempt to relate their composition to their charge properties. The samples investigated contained less than 3% clay and had specific surface areas less than 30 m2/g. pH values measured in M NaF were lower than 9.5 for the A2 horizons but higher than 10.5 for all the Bir horizons studied. Mineralogy of the clay fraction was studied by using X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis along with selective chemical dissolution analyses. Chloritized vermiculite was the dominant phyllosilicate in the Bir samples, while montmorillonite dominated in the clay fraction of most of the A2 samples. Amorphous constituents, as determined by acid ammonium oxalate and 0.5 N NaOH extractions, represented up to 40% of the clay-sized fraction of some of the samples. Primary minerals such as quartz, feldspars and to a lesser extent hornblende and magnetite were the major constituents of the coarser fractions. The change in chemical and mineralogical compositions of the A2 and Bir horizons sharply reflected the variation that existed in their overall electrochemical behavior as shown by the potentiometric titration curves. A2 horizons usually behaved like a constant surface charge system, while the Bir samples reacted like a constant surface potential system with PZC values varying between pH 4.1 and 4.9.
RADIOCARBON DATING OF ORGANIC MATTER FROM A CULTIVATED TOPSOIL IN EASTERN CANADA
Authors: MARTEL Y. A. , LASALLE P.
Published: March 2010

Radiocarbon dating was used to determine the mean residence time of the organic matter from a Gleysolic Ap horizon of eastern Canada. The total soil organic matter and the fulvic acids dated modern, the humic acids as 1,220 ± 150 yr B.P. and the humin as 180 ± 100 yr B.P. Acid hydrolysis of the total soil organic matter yielded a soluble fraction dating modern and an unhydrolyzed material dating 1,530 ± 110 yr B.P. Acid hydrolysis of this topsoil appears practical to separate the soil organic matter into two fractions of different stability. Fractionation into fulvic, humic acids and humin may help to give information on the dynamics of the soil organic matter by separating the soil into at least three fractions of varying stability.
THE REACTION OF TWO LUVISOLIC FOREST SOILS TO PHOSPHATE FERTILIZATION
Authors: BAKER J.
Published: March 2010

Response of two forested Luvisolic soils to phosphorus fertilization was compared using chemical extractants known to be effective in removing certain soil phosphorus compounds. Fifteen months following fertilization application, the Mercoal series (Bisequa Luvisol) showed total phosphorus decreases in each of the soil horizons or layers sampled. To sampling depth, phosphorus concentrations in all but the NH4F extract (mainly aluminum phosphate) were lower in fertilized than in control samples. Vegetative uptake was considered to be mainly responsible for phosphorus decreases and movement, especially noticeable in the deeper mineral horizons. The Coalspur series (Orthic Luvisol) showed an appreciable phosphorus increase in the litter layer although both mineral horizons, Ae and Bt, exhibited losses. The Coalspur soil exhibited increases in soil phosphorus susceptible to all but the NH4F extractant. The data suggest a greater mobility and movement of soil phosphorus in these Luvisolic forest soils than usually observed in cultivated soils. Following fertilization, Mercoal probably had a greater number of phosphorus compounds (reaction products perhaps) more readily available than did the Coalspur.
EFFECTS OF DATE OF SOD BREAKING ON NITROGEN REQUIREMENTS AND YIELD OF BARLEY FOLLOWING FESCUE IN ROTATION
Authors: HENNIG A. M. F. , RICE W. A.
Published: March 2010

Yield of barley (Hordeum vulgare L.) on land broken out of fescue (Festuca rubra) sod decreased with delay in time of breaking. Without nitrogen, but with phosphorus and potassium, the 4-yr (1969–72) mean yields were 2.89, 1.97, 1.61 and 1.24 tonnes/ha for plots broken in July, August, September and May, respectively. Increasing rates of nitrogen up to 90 kg N/ha resulted in yield increases which were nearly linear and similar for all breaking dates. With 90 kg N/ha yields were 4.09, 3.90, 3.28 and 2.96 tonnes/ha for plots broken in July, August, September and May, respectively. In a second experiment conducted for 2 yr, (1972 and 1974) an application of more than 90 kg N/ha did not result in further increases in yield of barley except in the plots broken in September. Uptake of N by barley (grain and straw) as with yield of barley grain was essentially linear and increased with increasing rates of N fertilizer. A delay in breaking from July to the following May resulted in a decrease of around 20 kg/ha of soil NO3-N in the top 60 cm of soil. Between September and May, the difference was only 1.2 kg/ha. This difference in soil NO3-N would not account for the yield differences obtained, since without fertilizer N the plots that were broken in September yielded about as much as those broken in May and fertilized with 22 kg N/ha. Soil moisture measurements in spring prior to seeding generally showed a decrease with delay in breaking. The differences were small and alone would not account for the wide variations in yields. It was observed that the seedbed condition was better with early than late breaking and that regrowth of fescue was markedly less on the plots broken in July than on the plots broken in September or May. The combined effect of these factors apparently limits the production of barley on recently broken grass sod.
MICROORGANISMS AND OCHRE DEPOSITS IN FIELD DRAINS OF ONTARIO
Authors: IVARSON K. C. , SOJAK M.
Published: March 2010

The effluents and ochreous deposits in several partly blocked field drains in Ontario were microbiologically and chemically assayed. The effluents contained several million per milliliter of the iron-oxidizing bacterium Gallionella. Sphaerotilus, a sheath-forming bacterium, was also numerous. Both microorganisms were generally encrusted with amorphous ferric iron oxides. They were also found in the ochreous deposits inside the tiles and also in the deposits adjacent to plugged filters surrounding the tiles. The iron-oxidizing bacterium Thiobacillus ferrooxidans was not found. Filamentous structures resembling the iron-oxidizing bacterium Metallogenium were frequently observed but the experimental evidence indicated them to be aggregates of colloidal Fe(OH)3. Calcite, dolomite, quartz and feldspar were common constituents of the effluents and the ochreous deposits. In some cases, one or more of gypsum, plagioclase, chlorite and illite were present. The ochreous deposits were generally high in iron and contained elements normally found in soil. Occasionally the materials were found to contain traces of magnetite. Except for the iron in the silicates the remaining iron was non-crystalline, present as amorphous ferric oxyhydroxide. Amorphous manganese oxide was also found. It was recognized that chemical oxidation might be an important agent in oxidizing the FE+2; however, the results and a literature survey indicated that Gallionella plays a major role. It is theorized that following oxidation, a ferric hydroxide sol is produced, which in the presence of electrolytes forms aggregates of colloidal Fe(OH)3 that combine with microbes and ions in the tile water to produce an amorphous precipitate. In association with carbonates, quartz and clay minerals, the precipitate forms ochreous substances. The paucity of dissolved ferrous and ferric iron, the presence of organic matter and adsorbed anions inhibits crystallization of the amorphous ferric oxyhydroxide. Roots in conjunction with large numbers of Sphaerotilus formed effective plugs.
NITROGEN ISOTOPE FRACTIONATION DURING AMMONIUM EXCHANGE REACTIONS WITH SOIL CLAY
Authors: KARAMANOS R. E. , RENNIE D. A.
Published: March 2010

Nitrogen isotopic fractionation during ammonium adsorption by clay colloids was shown to occur in two time-dependent stages. A rapid 15N enrichment of the NH4+ in solution was followed by a gradual depletion until, after an 8- to 10-h equilibrium period, the δa15N of the NH4+ in solution was approximately 1; this value was significantly lower than the initial value of 2.3 for the NH4Cl used in these experiments. The isotopic equilibrium constant (ke) for the ammonium adsorption reaction was greater than unity, and higher for the Ca2+- than K+-saturated clay colloids.
ASSOCIATION OF ZINC WITH OXIDES OF IRON AND ALUMINUM IN SOME MANITOBA SOILS
Authors: KALBASI M. , RACZ G. J.
Published: March 2010

Eight soils in Manitoba, varying in texture, Great Soil Group and Subgroup, and amount of clay movement were analyzed for concentration of HNO3 + HClO4-extractable Zn, Fe, Al and Mn and percent sand, silt and clay. Soils were categorized into three textural groups, coarse, medium to fine and very fine. Statistical analyses were conducted to investigate the inherent associations between concentration of native Zn and concentrations of Fe, Al and Mn as well as sand, silt and clay contents for each textural group independently. Native soil Zn concentration was highly correlated with HNO3 + HClO4-extractable concentrations of Fe (r = 0.80, 0.89 and 0.90 for coarse, medium to fine and very fine-textured soils, respectively) and Al (r = 0.68, 0.79 and 0.81 for coarse, medium to fine and very fine-textured soils, respectively) and with clay content (r = 0.69, 0.64 and 0.82 for coarse, medium to fine and very fine-textured soils, respectively). Significant correlation between Zn concentration and clay content likely resulted from Fe and Al oxides coatings on silicate clays and from a large proportion of free Fe and Al oxides being clay-size. Correlation between Zn and Mn concentration was not significant for medium to fine and very fine-textured soils and was significant at only 5% level for coarse-textured soils. Large quantities of Zn (45–71% of HNO3 + HClO4-extractable Zn) were extracted along with the amorphous and organic complexed Fe and Al from four other Manitoba soils indicating, once again, that Zn was in some manner associated with oxides of Fe and Al in Manitoba soils.
NITROGEN TRANSFORMATIONS AND TRANSPORT OVER 17 MONTHS IN FIELD FALLOW MICROPLOTS USING 15N
Authors: KOWALENKO C. G.
Published: March 2010

A field experiment with an Ottawa area clay loam soil utilizing open-ended microplots and 15N-labelled fertilizer showed the relative importance of seasons on transformation and transport of nitrogen. Denitrification appeared to be appreciable during the growing season; about 39% of the fertilizer N was denitrified in 86 days (May–Sept.) and 65% was lost after 511 days but leaching losses were included in the latter period. Nitrification of fertilizer N was very rapid with extractable NH4+-N approximating background level within the first 43 days. Immobilization of fertilizer N was negligible in the first 159 days and only a small amount was immobilized during the remainder of the experiment. Mineralization of soil N averaged 0.77 and 1.10 kg N/ha/day in the first two sampling periods. Clay fixation of NH4+-N was significant in this soil with 59% of the 152 kg N/ha applied being immediately fixed. Over one-half (66%) of this recently fixed NH4+-N was released in the first 86 days of the experiment with the remainder held tightly through the sampling period. Movement of fertilizer N was greatest in the late fall and early spring, i.e. periods of high precipitation and low evaporation.
BARLEY RESPONSE TO PHOSPHORUS FROM PHOSPHOLIPIDS AND NUCLEIC ACIDS
Authors: McKERCHER R. B. , TOLLEFSON T. S.
Published: March 2010

Barley responses in a phosphate-deficient soil to 50 μg P/g soil showed DNA and KH2PO4 similarly efficient at increasing dry matter and P content per unit biomass. Phosphatidylcholine increased P content but not dry matter. DNA and phosphatidylcholine induced unusual but dissimilar plant morphological effects.
SALINE SOILS IN SASKATCHEWAN DUE TO WIND DEPOSITION
Authors: BALLANTYNE A. K.
Published: March 2010

Wind is one of the mechanisms causing saline soil in Saskatchewan. This type of salinity is always adjacent to intermittant saline ponds or lakes.
MICROBIOLOGICAL FEATURES OF TERRESTRIAL SITES ON THE DEVON ISLAND LOWLAND, CANADIAN ARCTIC
Authors: JORDAN D. C. , MARSHALL MARGARET R. , McNICOL PATRICIA J.
Published: March 2010

Bacterial populations of the Devon Island Lowland consist mainly of psychrotrophic aerobes and facultative types, with counts falling within temperate zone limits. Nitrification and sulphate reduction appear restricted but denitrification potential is considerable. Peat polygon and mesic meadow areas have the highest microbial activities, the polar desert the least.
WATER-SOLUBLE CONSTITUENTS IN DEFROST WATER OF BLACK CHERNOZEMIC A HORIZONS DURING SPRING THAW
Authors: DORMAAR J. F.
Published: March 2010

The water-soluble constituents present in defrost water of Black Chernozemic Ah and Ap horizons during spring thaw and water extracts prepared in the laboratory were examined and their possible genetic significance discussed. The defrost period lasted about 40 days in 1975 and about 20 days in 1976; as a result, pronounced anaerobicity could not be implied. The period of actual post-frost leaching amounted to only a few days. C, Ca, and PO4-P increased until just before post-frost leaching. Little Fe and no measurable Al were present in the defrost water. The C, Ca, Mg, Na, and NO3-N concentrations were higher, while K, Si, and PO4-P concentrations were lower in the Ap than in the Ah horizon solutions studied.
CALCULATION OF HYDRAULIC CONDUCTIVITY DECREASES IN THE PRESENCE OF MIXED NaCl-CaCl2 SOLUTIONS
Authors: DANE J. H.
Published: March 2010

A model was developed to calculate hydraulic conductivity decreases in swelling soils in the presence of mixed NaCl-CaCl2 solutions. A calculated swelling factor, based on a demixed-ion clay swelling model, was used to compute an effective soil porosity corresponding to each electrolyte solution. The procedure required knowledge of the total electrolyte concentration (C) and sodium adsorption ratio (SAR) of the solution phase, and of the fraction of expansible minerals, the bulk density, and the particle density of the solid phase. The calculated effective soil porosities were used to predict hydraulic conductivity values corresponding to solutions of decreasing C or increasing SAR values. A hydraulic conductivity value, corresponding to a solution which suppressed all swelling, had to be experimentally determined in order to make the prediction. Good agreement was found between predicted and experimental hydraulic conductivity values for two soils containing different amounts of expansible minerals and subjected to salt solutions of varying compositions.
MICROMORPHOLOGICAL EVIDENCE OF ILLUVIAL CLAY IN HORIZONS DESIGNATED Bt IN THE FIELD
Authors: McKEAGUE J. A. , GUERTIN R. K. , PAGE F. , VALENTINE K. W. G.
Published: March 2010

Semi-quantitative counts of areas of oriented, apparently illuvial clay in thin sections of B horizons showed that less than half of the 44 horizons designated Bt in the field had at least 1% apparently illuvial clay, and the counts for more than 1/3 was 0.2% or less. Many of the horizons that did not meet the micromorphological criteria of a Bt (at least 1% illuvial clay) contained much more clay than the associated Ae horizon and a higher proportion of fine clay than the associated C. Most of the soils having Bt horizons with more than 1% apparently illuvial clay were soils of humid to sub-humid regions, Luvisolic soils and Black or Dark Gray subgroups of Chernozemic or Solonetzic soils; none were Brown or Dark Brown Chernozemic or Solonetzic soils. Comparisons of counts of apparently illuvial clay in thin sections by four operators showed that compatibility of results varied among samples and that prior consultation resulted in an increased degree of agreement. Problems of distinguishing illuvial clay in thin sections are discussed and illustrated.
CHEMICAL AND PHYSICAL PROPERTIES OF THE PARENT MATERIAL OF A SOLONETZ SOIL AFTER INCUBATION WITH PLANT MATERIAL
Authors: DORMAAR J. F. , CAIRNS R. R.
Published: March 2010

Parent material of the Black Solonetz Duagh silt loam was incubated after mixing with the equivalent of 20 yr production of bromegrass (Bromus inermis Leyss) that had been grown on unfertilized Duagh silt loam, fertilized Duagh silt loam, and unfertilized Eluviated Black Chernozemic Malmo silt loam. The impact of the amendments on soil properties was measured by suitable laboratory analyses and by growing barley seedlings (Hordeum vulgare L.). The unfertilized Duagh bromegrass had minimal effect on the chemical and physical properties of the parent material. Unfertilized Malmo and fertilized Duagh bromegrass generally had similar effects and imparted similar organic matter (OM) characteristics to the Duagh parent material. They lowered the breaking strength of the soil and enhanced the yields of the barley seedlings and the N, Na, Ca, and K uptake by the barley seedlings. The incorporation of the unfertilized Malmo and the fertilized Duagh bromegrass caused an 8- to 14-fold increase in the infiltration rate and caused a mobilization of alkaline earth cations. With leaching in the presence of certain forms of OM, the solubilized cations displaced Na from the exchange complex and lowered the exchangeable sodium percentage (ESP) to the level found in Chernozemic soils. Thus, the composition and amount of the plant material added to the soil may influence the development of a Solonetzic or Chernozemic soil profile from the same parent material.
NITROGEN TRANSFORMATIONS IN SOIL-PLANT SYSTEMS IN THREE YEARS OF FIELD EXPERIMENTS USING TRACER AND NON-TRACER METHODS ON AN AMMONIUM-FIXING SOIL
Authors: KOWALENKO C. G. , CAMERON D. R.
Published: March 2010

Three years of field experiments showed the interplay of plant uptake of N, N movement, denitrification, fixation of fertilizer NH4+ and its release, and N mineralization in soil–plant systems. The N uptake by barley (Hordeum vulgare L.), averaged over the growing season, ranged between 0.97 and 2.02 kg N/ha/day and the rate depended on initial extractable inorganic N in the soil, and form and timing of N fertilization. The net mineralization rate of this soil, averaged over the growing season, ranged between 0.16 and 1.80 kg N/ha/day and varied with year and N fertilization practices. However, detailed monitoring of plant uptake showed that a maximum rate of uptake occurred early in its growth, decreasing to a negligible rate later in the season. The N mineralization rate was more uniform over the growing season. A pool of inorganic N in the soil at seeding or within the first half of the growing season overcame the seasonal deficit in N supply and resulted in increased crop growth and/or N uptake. Fertilizer N movement was small and never beyond the maximum (75-cm) sampling depth. This supported the assumption that unrecovered fertilizer N in this study was largely due to denitrification. Denitrification was shown to be greatly influenced by the season, with a maximum rate occurring in the spring or early summer, and concurred with the period of maximum rate of plant uptake of N. Denitrifiers were capable of competing with high rates of plant uptake since the rate of denitrification was similar in fallow and cropped systems. The form of N application (NO3−, NH4+, NH4+ plus N-serve) did not significantly affect the denitrification rate. The soil used in this study fixed 34–60% of the 150 kg NH4+/ha fertilizer immediately upon application. The fixed fertilizer N was available to barley, with 71–96% of the recently fixed NH4+ being released over the growth period. The presence of N-serve resulted in less fixed fertilizer NH4+ being released during crop growth.
A FIELD COMPARISON STUDY OF AMMONIUM PHOSPHATES AND SUPERPHOSPHATE–UREA OR AMMONIUM NITRATE ON CORN (ZEA MAYS L.) GROWTH IN FIVE QUEBEC SOILS
Authors: OKALEBO J. R. , MacKENZIE A. F.
Published: March 2010

Effects of mono-, diammonium, and superphosphate with added urea or ammonium nitrate on corn (Zea mays L.) growth were studied in the field in 1971 and 1972. At the rate of 100 kg P2O5/ha, none of the carriers affected emergence of seedlings in five Quebec soils. Leaf P content at silking time was of little benefit in predicting P status of the plants, or in differentiating among the carriers. Phosphorous applications gave significant corn yield increases, with carriers performing alike when averaged over all sites. However, some yield differences among carriers occurred on some soil types and seasons. These carrier differences were not consistent and remain to be clarified. The ammonium phosphates compared with the check generally hastened maturity but reduced potassium levels in leaf tissue of corn.
ANALYSE PAR DILUTION ISOTOPIQUE DE LA FERTILITE ET DE LA FERTILISATION PHOSPHORIQUE DE QUELQUES SOLS DU QUEBEC
Authors: FARDEAU JEAN-CLAUDE , JAPPE JOCELYNE
Published: March 2010

Analysis of available soil phosphate by isotopic dilution method, observed as kinetics between 1 and 100 min after the injection of 32PO43− in the soil–solution system, allows the measure of three kinetics parameters: r1/R, r1 is the radioactivity remaining in the solution after 1 min of isotopic exchange and R the total radioactivity injected in the system, n the slope of the straight line which, in logarithmic coordinates, gives the decrease of the radioactivity remaining in the solution versus time, and p the phosphate-ions concentration in the solution. Analysis performed in this manner on some Canadian typical agricultural soils shows that localization of phosphatic fertilizers is absolutely necessary in some cases, the soil fixation capacity for phosphate ions being too large. In these soils a homogeneous increase of available soil phosphate is economically impossible.
INFLUENCE OF SOIL DENSITY ON LEAF WATER POTENTIAL OF CORN
Authors: MORRIS D. T. , DAYNARD T. B.
Published: March 2010

Corn plants were grown in growth rooms at 1.2 and 1.4 g cm−3 soil bulk density. Leaf water potentials (LWP) of paired plants of similar leaf area were monitored during 3-day drying cycles. With denser soil, LWP declined more rapidly during light, and increased more slowly during dark intervals because of restricted root growth.
EFFECTS OF NITROGEN SOURCE, METHOD OF PLACEMENT AND SOIL TYPE ON SEEDLING EMERGENCE AND BARLEY CROP YIELDS
Authors: TOEWS W. H. , SOPER R. J.
Published: March 2010

An inverse correlation between seedling damage caused by urea drilled with the seed and soil cation exchange capacity was determined in eight field trials conducted on soils with a wide range in cation exchange capacity and pH. Seedling damage increased with increasing rates of urea nitrogen and seriously affected potential grain yields of Conquest barley (Hordeum vulgare L.). Drilled NH4NO3 caused greater grain yield increases than drilled urea in a manner inversely related to the seedling damage caused by urea. Drilled NH4NO3 caused greater yield increases than broadcast and incorporated NH4NO3 at 22.4 and 44.8 kg/ha over the 2-yr period. The NH4NO3 broadcast and incorporated in the soil caused greater yield increases than urea similarly applied. The magnitude of the difference was related to soil cation exchange capacity and pH which jointly influenced the quantity of NH3 volatilized.
EFFECTS OF VARIOUS SOIL SUPPLEMENTS AND WATER STRESS ON THE YIELD AND YIELD COMPONENTS OF WHEAT
Authors: BOLE J. B. , DUBETZ S.
Published: March 2010

Seven soil supplement products did not affect grain or straw yields, or any of the measured yield components of unstressed wheat or of wheat subjected to an 8-bar soil water stress at early heading. Soil water stress reduced yields by reducing the number of spikes per plant and, to a lesser but significant degree, the number of kernels per spike and the average kernel weight.
DEGRADATION OF HYDROCARBON SLUDGES IN THE SOIL
Authors: CANSFIELD P. E. , RACZ G. J.
Published: March 2010

Hydrocarbon residues from crude oil storage tanks were incorporated into field plots of a Red River Clay soil. The oil content immediately after application was 1.45% based on the weight of air-dried soil. The plots were sampled after application and after 106, 476 and 833 days. Hydrocarbons were extracted from samples with tetrahydrofuran at room temperature and fractionated by a combination of solvent extraction and column chromatography into the following fractions: (1) saturates, (2) monoaromatics, (3) diaromatics, (4) polyaromatics and polar compounds and (5) high molecular weight material such as asphaltenes. Fractions (1) to (4) were examined by gas–liquid chromatography. The results showed that 50.4% of the total applied residues were degraded within 833 days. The individual fractions were degraded to varying extents: (1) 54.6%, (2) 50.0%, (3) 57.1%, (4) 44.4% and (5) 11.1%. The alkanes in fraction (1) degraded to low levels during the first 106 day s.
GROWTH AND YIELD OF BARLEY IN FLOODED SOIL: ETHYLENE GENERATION AND Eh RELATIONSHIPS
Authors: LEYSHON A. J. , SHEARD R. W.
Published: March 2010

Barley growing on a Gleysolic soil was subjected to short-term periods of flooding (2–10 days) at four stages of development. The treatments resulted in a reduction in dry matter accumulation proportional to the duration of flooding. Furthermore, plants 14 and 21 days old at flooding were most affected immediately following inundation whereas, at maturity, plants flooded at 28 and 35 days old were the most affected in that head emergence was delayed and grain yield was reduced by as much as 55%. Flooding increased the soil-produced ethylene from 0.15 to 3.78 ppm after 10 days. Ethylene production was related to a lowering of the soil Eh below 340 mV. It is suggested that the poor growth of barley, while in part due to an O2 deficiency, may also be a result of ethylene formation during flooding.
THE "INTERPRETER EFFECT" IN MAPPING TERRAIN IN NORTHERN BRITISH COLUMBIA USING COLOR AERIAL PHOTOGRAPHY AND LANDSAT IMAGERY
Authors: VALENTINE K. W. G.
Published: March 2010

Thirteen professional soil surveyors and sixteen university students produced a terrain map of a 2,000-km2 area just east of Telegraph Creek in northern British Columbia. The mapping was done on three adjacent color photographs (scale 1:120,000) and a LANDSAT image (enlarged to 1:250,000). Results were compared to a previous biophysical survey and expressed as percentage agreement with the previous map. These results were analyzed for three types of consistency; between all interpreters on one image; between images for each interpreter; and between valleys and mountains. The professionals’ and students’ results were analyzed separately. There was nearly 60% agreement with the previous map using photographs and about 50% using the LANDSAT image. The professionals obtained slightly higher agreement than the students. Mapping variability between interpreters was satisfactorily low: the standard deviation was 6.0% or less in 8 out of 12 image comparisons. Interpreter consistence from image to image was less than satisfactory; r values between images were positive and high in only 3 out of 12 comparisons. More interpreters mapped a greater proportion of the mountains than the valleys in agreement with the previous map. The thick vegetation in the valleys may mask the terrain more. Groups of interpreters could be consistent on one image but there appears to be a significant amount of interpreter bias from image to image and area to area.
EFFETS DES DOSES DE BORE, DES REGIMES HYDRIQUES ET DU pH DES SOLS SUR LES RENDEMENTS DE LA LUZERNE ET DU LOTIER ET SUR L’ASSIMILABILITE DU BORE
Authors: DIONNE J. L. , PESANT A. R.
Published: March 2010

Alfalfa (Medicago sativa L. cv. Vernal) and birdsfoot trefoil (Lotus corniculatus L. cv. Leo) were grown under greenhouse conditions in order to determine changes in boron response and availability following variations in soil pH and soil moisture regimes. Three rates of boron applications were selected: 0, 1.5, and 3.0 ppm of B. Soil pH was adjusted to 5.0, 6.5 and 7.5, respectively. The soil moisture regimes were fixed as following: (1) very dry (H1) with soil moisture between 50% of field capacity and wilting point, (2) dry (H2), with soil moisture between field capacity and wilting point. (3) optimum (H3), with soil moisture between field capacity and 70% of this value. Boron fertilization was more useful to alfalfa than to birdsfoot trefoil. Optimum rate was found to be 1.5 ppm of B. On Ste-Rosalie clay, the yield increase due to boron was 22% on soils under the dry regime (H2) but was almost non-existant at the very dry (H1) and optimum water regime (H3). Boron application on Greensboro loam was more efficient on soils undergoing dry (H2) and very dry soil moisture regime (H1) than on soils where moisture conditions were optimum (H3). Dry matter yields were increased by a factor of 10 under dry (H2) and very dry (H1) soil moisture regimes compared to a factor of 4 under optimum soil moisture regime (H3). Under acid soil conditions, no yield increase was obtained following boron applications. Boron availability and response of the two legumes to B was also decreased by overliming soils to pH 7.4. The cyclic drought periods that happened under dry (H2) and very dry (H1) soil moisture regime produced similar effects. Boron availability and efficiency as plant nutrient was greatly reduced, if not annihilated, by the combined effect of repeated drought cycles and by either excessive soil acidity or overliming.
AVAILABILITY OF THE HERBICIDE TRIFLURALIN FOR CONTROL OF WILD OATS AS INFLUENCED BY SOIL CHARACTERISTICS IN FOUR MANITOBA SOILS
Authors: WEBSTER G. R. B. , SHAYKEWICH C. F. , KANHAI S. , REIMER G. J.
Published: March 2010

The effects of soil properties on available phytotoxic residues and total extractable residues of the herbicide trifluralin were investigated in four Manitoba soils. The four soils, Red River heavy clay, Gladstone clay loam, Newdale loam, and Almasippi loamy sand, were treated with trifluralin at levels in the range 0.2–3.0 ppmw (dry weight soil), and the soils maintained at or near field capacity in the growth chamber. Available residues were determined at 0, 2, and 5 wk using a wild oat (Avena fatua) bioassay. Total residues were measured at regular intervals to 16 wk using ultrasonic extraction and gas–liquid chromatography analysis. Biological results showed that wild oat control expressed as ED50 required much less applied or residual trifluralin in Almasippi loamy sand than in Red River heavy clay, with the other two soils being intermediate. Total residues, on the other hand, remained highest in Red River heavy clay, although the differences between soil types were not great. Net loss of trifluralin was best explained by a first-order kinetic expression. Availability of phytotoxic residues was related mathematically to clay content of the soils in combination with time from application. It was further shown that bioassay is inadequate for determination of total residues in soils unless time from application is held constant.
TRANSFORMATIONS IN THE Feo/Fed RATIO OF PEDOGENIC IRON OXIDES AFFECTED BY IRON-REDUCING BACTERIA
Authors: MUNCH J. C. , HILLEBRAND Th. , OTTOW J. C. G.
Published: March 2010

In model experiments under controlled conditions of pH, particle size and amount of glucose, changes in the free Fe oxides (Fed) and acid oxalate soluble Fe (Feo) of six soils were studied after inoculation with iron-reducing, nitrogen-fixing Clostridia. In all soils, the total amount of Fed as well as crystalline Fe (Fed-Feo) decreased immediately and significantly, while Fe(II) in solution increased sigmoidally and was inversely proportional to changes in pH. Feo remained relatively constant throughout the incubation period. As a consequence, the Feo/Fed ratio increased in all samples. At the end of the reduction process, total dissolved Fe(II) correlated with the original Feo content and showed a negative correlation to Fed-Feo. These results are explained by a mechanism in which active non-crystalline iron oxides are reduced in preference to the crystalline forms. The latter are probably transformed and reduced to non-crystalline forms but not until all available active non-crystalline oxides have been exhausted. In the discussion, the reliability of acid oxalate-soluble Fe as a measure of the non-crystalline, active pedogenic iron forms is outlined. Further, the significance of a lowered redox potential (Eh or rH) in reductive transformations of flooded soils is analyzed.