bluuebunny/crossref_metadata_2025 huggingface dataset:
SOIL pH VARIATION IN BRITISH COLUMBIA APPLE ORCHARDS
Authors: NEILSEN G. H. , HOYT P. B.
Published: March 2010

Soil pH variation was examined in British Columbia apple orchards. Soil pH tended to increase as distance from the tree trunk and depth from the soil surface increased. However, pH variation from tree to tree was frequently significant both for widely separated trees in orchards where pH was expected to be variable and for adjacent trees in orchards expected to have uniform soil pH. To represent orchard blocks adequately, emphasis should, therefore, be placed upon collecting samples from many rather than a few trees. Nonetheless, the possibility of decreased soil pH near trees can not be ignored in sampling individual trees.
SOIL TRAFFICABILITY IN SPRING 1. SIMULATION OF THE DRAINAGE PROCESS
Authors: PAUL C. L. , VRIES J. DE
Published: March 2010

A mathematical-physical model developed in the Netherlands for the simulation on nonsteady flow of water in subsurface-drained soils was tested by comparing its output with data collected in spring from two farmers’ fields in the Lower Fraser Valley of British Columbia. The ultimate objective of the tests was the prediction of soil strength and trafficability. The model was found to be useful for predicting depth to the water table and, to a lesser extent, soil water matric potential in the top 15 cm in fields drained by drains spaced at 30.5 m and 15.2 m. However, there were problems in evaluating input data. One problem was that of obtaining the drainage intensity, which was found to have a great effect on model output. A solution of the modified Glover-Dumm transient-state drainage equation provided a means of obtaining the drainage intensity directly from measured water table recession. A second problem was related to the use in the model of soil water flow parameters obtained from the water flow characteristic measured on undisturbed columns in the laboratory. Key words: Drainage model, matric potential, water table depth, trafficability, drainage intensity
VESICULAR ARBUSCULAR MYCORRHIZAL SPORE POPULATIONS IN VARIOUS SASKATCHEWAN SOILS AND THE EFFECT OF INOCULATION WITH Glomus mosseae ON FABA BEAN GROWTH IN GREENHOUSE AND FIELD TRIALS
Authors: KUCEY R. M. N. , PAUL E. A.
Published: March 2010

The numbers of vesicular arbuscular mycorrhizal spores in various Saskatchewan soils, and the effect of Glomus mosseae inoculation on the growth of faba beans (Vicia faba) were studied. The size of the mycorrhizal spore population varied from site to site, but in general, more spores were found in undisturbed soils than in adjacent cultivated soils. Practices which reduced the density of potential host roots also reduced the numbers of spores found in the soil. Inoculation of faba beans with G. mosseae spores resulted in increased dry matter production both in growth chamber and field studies in the presence of indigenous mycorrhizal spores. Inoculation also resulted in higher levels of root colonization and increased total phosphorus uptake. Key words: Mycorrhizae, faba bean, phosphorus, spore, colonization, soil
PREDICTION DES BESOINS EN ENGRAIS N, P et K DES LEGUMES CULTIVES EN SOL MINERAL: LES CHOUX
Authors: CHAMBERLAND EMILE
Published: March 2010

The objective of this study was to verify and improve the accuracy of fertilizer recommendations for growing cole crops on mineral soils. To achieve this end, 21 field trials were conducted on 12 soils during 1978–1981; of these trials, 13 were performed with late cabbage and Brussels sprouts and eight early cabbage and brocoli. The test crops were fertilized at four rates of N, P and K, and yield responses were related to soil test values. The Cate-Nelson iteration method was used to partition soils into three different classes according to their yield response to fertilization. Furthermore, polynomial and Mitscherlich equations were fitted to yield versus soil K and P data. These procedures suggested that fertilizer recommendations would be more precise by classifying these crops into early- and late-maturing groups. Accordingly, the recommended fertilization rates for soils containing a deficient or medium P supply were 70 and 80 kg P/ha for early and late crops, respectively. A clear yield response by early cabbage to K fertilization was indicated for soils containing a medium K supply; on these soils maximum yields would be achieved with an application of about 180 kg K/ha. On the other hand late cabbage and Brussels sprouts apparently only needed about 120 kg K/ha to achieve maximum yields on the same class of soils. While an increase in yields attributable to K fertilization is unlikely on soils containing a low and high K supply, a rate of 120 kg K/ha is nonetheless recommended to ensure maximum yield and maintain soil fertility levels. As regards N-fertilization, maximum yields early and late crop were produced with 160 and 180 kg N/ha, respectively. Key words: Fertilizer, N, P, K, vegetables, cabbages
EFFECTS OF FORAGE LEGUME SPECIES ON SOIL MOISTURE, NITROGEN, AND YIELD OF SUCCEEDING BARLEY CROPS
Authors: HOYT P. B. , LEITCH R. H.
Published: March 2010

Effects of five legume species grown for hay on yield of succeeding barley crops and on moisture and N status of five soils were measured. When N fertilizer was applied, yields of barley following alfalfa, birdsfoot trefoil, alsike clover, red clover and sweet clover were the same as those following barley grown on fallow (control). Also, soil moisture in spring and soil moisture used by barley were about the same following legumes and the control. However, without N fertilizer, the legumes caused large yield increases to barley grown on two Gray Luvisolic soils (Beryl, Davis) and a Black Solodic soil (Landry); the legumes caused little change in barley yields on another Gray Luvisolic soil (Alcan) and caused large decreases on another Black Solodic soil (Rycroft). Residual soil N contributed by the legumes, calculated from N in the succeeding barley crops, was greater for the Beryl and Landry soils than for the Alcan and Davis soils. This corresponded closely to yields of the previous hay crops on those soils. The legumes caused a decrease in residual N for the Rycroft soil. Mineral-N and Δ mineral-N in the soil were well correlated with N uptake in barley for the Alcan, Landry and Rycroft soils but were poorly correlated for the other two soils. Key words: Forage legumes, barley yields, soil nitrogen and moisture
MEASUREMENT OF EVAPORATION FROM SOIL BENEATH CROP CANOPIES
Authors: WALKER G. K.
Published: March 2010

Evaporation rates beneath maize canopies were measured using an intact soil core technique. Early in the growing season evaporation rates were periodically high (4.0 mm∙day−1) following rain, but declined rapidly. At full crop cover, when energy supply normally limits evaporation, significant differences in evaporation were detected between canopies with leaf area indices of 3.0 and 4.0. Key words: Evaporation measurement, energy supply, Zea mays L., leaf area, soil evaporimeter, lysimeter
FIVE YEARS OF SOIL ANALYSES AND YIELD DATA ON DEEP-PLOWED SOLONETZIC SOIL
Authors: BALLANTYNE A. K.
Published: March 2010

Crop yields and soil data were obtained for 5 yr on 12, 1-ha plots of slight to moderately saline Solonetzic soil which had been plowed to a depth of 61 cm. Wheat, durum wheat, oats and flax were grown. Wheat yields range from a decrease of 0.25 t/ha to an increase of 0.74 t/ha. An average increase of 0.34–0.40 t/ha should be expected from deep plowing this type of soil. The surface soil following deep plowing increased in clay, fine clay, pH, CaCO3 and H2O-soluble Ca. It decreased in H2O-soluble Na. Water-soluble Mg remained relatively constant. With moderate fluctuations, these changes have persisted for 5 yr. Key words: Deep plowing, Solonetzic, sodium, calcium carbonate
EFFECTS OF POTASSIUM FERTILIZER AND FALL HARVESTS ON ALFALFA GROWN ON THE EASTERN CANADIAN PRAIRIES
Authors: BAILEY L. D.
Published: March 2010

The objectives of the study were to determine the effect of soil and fertilizer potassium (K) on the yield and chemical composition of alfalfa (Medicago sativa L.), and whether fall harvesting (October) had detrimental effects on alfalfa grown under the relatively cool and short growing season of the Eastern Canadian Prairies. Vernal alfalfa was sown on five soils, two high and three low in amounts of exchangeable K. Three harvests were taken each year in June, July, and October at the full bud stage. The soils were rated on their potential potassium supplying power (PKSP). The effect of fertilizer K on increasing the availability of soil K and on the K and N composition of the forage were measured. The PKSP of the soils was not related to initial levels of exchangeable K. However, soils with low exchangeable K and low PKSP required an annual application of 200 kg K/ha to produce maximum yield. There was response to K fertilizer on only one of the soils with high exchangeable K, and then only to the first increment. At maximum yield on all soils, the K and N contents of the forage at full bud were greater than 2.0% and 3.0%, respectively. When the K content of the forage was less than 1%, severe winter injury occurred and yields decreased. With adequate K fertilizer fall harvesting had no detrimental effects on alfalfa production. Comparisons of the K and N contents of the forage indicates that increasing the concentration of K available to the crop may have a beneficial effect on N-fixation. Key words: Medicago sativa L. ’Vernal’, potential potassium supplying power, nitrogen fixation
EFFECT OF LIMING ON THE YIELD, NUTRITION AND COPPER STATUS OF POTATOES, CARROTS AND ONIONS GROWN SEQUENTIALLY IN TWO PEAT SOILS
Authors: MATHUR S. P. , LEVESQUE M. P.
Published: March 2010

In a greenhouse study, two Mesisols, a woody and a sedge peat, were enriched with calcitic agricultural limestone at rates of 0.5–30 t/ha to increase their pH from 3.0 to 5.8. The general fertilization included 50 ppm (20 kg/ha) of Cu (wt/wt). Maximum yields of potatoes were obtained at a soil pH of 3.4–3.6 (4–6 t lime/ha rate) but harvest index of potato tubers (mass of tubers as percent of total dry matter produced) indicated that the 10-t/ha rate would be more suitable. The Cu concentration of potato leaves and tubers did not exceed 16 ppm, and was thus less than phytotoxic level (20 or 30 ppm), even at soil pH lower than 3.4. After further addition of other fertilizers and 25 ppm of Cu, carrots gave maximum yields at the 30-t/ha rate. Copper concentrations in carrot tops and roots were below 16 ppm even at the 10-t-lime/ha rate (soil pH 3.8 or 4.0). Onions, grown after repetition of the fertilization for carrots, gave highest yield, particularly of bulbs, at the 30-t-lime/ha rate but this corresponded to an undesirably high soil pH of 5.7 or 5.8. The Cu concentration in bulbs exceeded 16 ppm only when yields were unacceptably low at the 6-t/ha and lower rates of liming. In all crops, Cu concentrations generally decreased sharply as soil pH rose above 4.0. The Ca:Mg ratio in plants usually increased with liming but, within the range observed here, did not closely parallel increases in yield. Plant concentrations of N, P and K generally decreased with liming at the highest rates (20 or 30 t/ha). Key words: Liming, peat, potatoes, onions, carrots, copper
CARBONATE MINERALOGY OF LAKE SEDIMENTS AND SURROUNDING SOILS. 2. THE QU’APPELLE LAKES
Authors: GHEBRE-EGZIABHIER K. , ST. ARNAUD R. J.
Published: March 2010

The nature and distribution of carbonate minerals in the upper Qu’Appelle basin in south-central Saskatchewan were investigated. The equivalent carbonate content and calcite:dolomite ratios of the deposits reflect the mechanisms of glacial deposition and some differences in the sources of the original parent material. The particle size analysis shows that the Qu’Appelle Lake sediments are more clayey than the surrounding soils and till deposits. Mg-bearing calcites occur only in the fine-sized fraction of the carbonate accumulation horizons. However, most of the upper Qu’Appelle Lake sediments contain appreciable amounts of sand-sized Mg-bearing calcites. The marked increase in carbonate content of the sediments relative to the adjacent soils and deposits is partially due to direct precipitation of calcite from the supersaturated lake waters. In this respect, a good correlation exists between the lake water ionic activity products for CaCO3 and the relative equivalent carbonatic mineral contents of the sediments. Key words: Mg-bearing calcite, dolomite, IAP, erosion
MICROBIAL ACTIVITY AND MYCORRHIZAL POTENTIAL OF FOUR OVERBURDEN TYPES USED IN THE RECLAMATION OF EXTRACTED OIL SANDS
Authors: DANIELSON R. M. , VISSER S. , PARKINSON D.
Published: March 2010

Slender wheatgrass and jack pine were grown in the greenhouse in cores containing a bottom layer of extracted oil sands with four overburdens individually layered over the sand. The overburdens included a muskeg peat, two shallow mineral overburdens and a deep overburden. Mycorrhizal development, microbial respiration and biomass and the degree of decomposition of slender wheatgrass roots in litter bags were determined in each plant species-overburden combination. Both ecto- and vesicular-arbuscular (VA) mycorrhizal inoculum was present in all four overburdens. The symbionts of slender wheatgrass were the "fine endophyte" and Glomus aggregatum. VA development was very low in peat whereas plants in the shallow overburdens became heavily mycorrhizal. Infection did not spread from the overburden layer to roots in the tailing sand. Jack pine roots in the peat and two shallow overburdens were heavily infected after 4 months. The most common symbiont was an ascomycete known as the E-strain. Microbial respiration was highest in the peat and was not influenced by plant species. Microbial biomass was also highest in the peat and much lower in the mineral overburdens. Only in the peat was the amount of microbial biomass larger with slender wheatgrass than with jack pine. Slender wheatgrass roots decomposed most rapidly in the peat overburden and least rapidly in the deep overburden. Key words: Microbial activity, jack pine, slender wheatgrass, mycorrhizae, reclamation, oil sands
USE OF PLANT ANALYSIS TO PREDICT SULFUR DEFICIENCY IN RAPESEED (Brassica napus and B. campestris)
Authors: MAYNARD D. G. , STEWART J. W. B. , BETTANY J. R.
Published: March 2010

The sulfur status of rapeseed (Brassica napus and Brassica campestris) plants grown in field studies was assessed using a variety of plant indices; percent sulfur, percent hydriodic acid reducible sulfur (HI-S in plant dry matter), HI-S:total S ratio, and total N:total S ratios. Of these, HI-S:total S determined at the rosette growth stage was the most accurate and consistent index of seed yield. A growth chamber study indicated that the HI-S:total S ratio would not be affected by nitrogen fertilizer application at normal field rates. Key words: Sulfur, deficiency, rapeseed (Brassica spp.), plant analysis
WATER REPELLENCY OF DEGRADED LIGNITE IN A RECLAIMED SOIL
Authors: RICHARDSON J. L. , WOLLENHAUPT N. C.
Published: March 2010

Lignitic material located in a reshaped mine spoil at a depth of 35–53 cm was extremely water-repellent and no root growth was observed in or below this layer. The material is black (10YR 2/1) when dry and is easily identifiable. It is postulated that this layer may influence water movement and nutrient uptake because of the water repellency. Key words: Lignite, reclamation, strip mining, water repellency
COMPOSITION DU MATERIEL LIANT DANS DES HORIZONS A ORTSTEIN, DURIQUES, FRAGIQUES ET CIMENTES INTERGRADES DU QUEBEC
Authors: PAGE F. , BERRIER J.
Published: March 2010

Cemented, fragic and intergrade-cemented horizons of five soil series of Quebec were studied using submicroscopic, micromorphological and chemical processes. The quantities of bonding agents present in the bonding material were expressed as a relative percentage. These bonding agents consist of organic matters, Fe, Al and Si hydroxides assumed to be present as FeO(OH), AlO(OH) and SiO(OH)2, and clays (< 2 μm). The Fe, Al and Si hydroxides were extracted by dithionite-citrate-bicarbonate, ammonium oxalate and NaOH, respectively. The clays were obtained by sedimentation after treating soils with dithionite and H2O2. The sub-microstructure of the bonding material varied with the horizons as indicated by the relative percentages of bonding agents. In the Bhc ortstein horizon, the coatings consist of discrete four-sided polyhedric units, these in turn are subdivided into spheroids of 0.2- to -1 μm diameter and contain 68% organic bonding agents, 20% hydroxide bonding agents and 12% particulate bonding agents (clays < 2 μm). In the Bhfc ortstein horizon, the grain coatings are subdivided into partly joined polyhedric units having a smooth or fluffy surface, these coatings contain 39% organic bonding agents, 32% hydroxide-bonding agents and 29% particulate-bonding agents. In the Bfc ortstein horizon, the grain coatings are continuous and appear as a smooth surface covered by many microplanes. These coatings contain 21% organic matter, 33% hydroxide-bonding agents and 46% particulate-bonding agents. In the BCcgj duric horizon, the grain coatings are also continuous with a smooth surface but crossed by few microplanes. These coatings contain 2% organic bonding agents, 36% hydroxide-bonding agents and 62% particulate-bonding agents. In the BCcjgj and BCcj intergrade-cemented horizons, the bonding material consists of various ultramicrostructures and concentration of bonding agents. In the Btjx fragic horizon, the particulate bonding agents are largely dominant (92%) and form an ultramicrostructure having simple packing. Microanalysis of bonding materials found in cemented and cemented-intergrade horizons confirmed earlier proportion reported for these coatings. It appears that coating strength is a result of the interaction between the bonding agents present. On the other hand, the brittleness of humid fragic horizons is probably caused by stress forces generated by the packing of soil mineral grains. Two principal factors have been described as responsible for this packing. The attractive clay (< 2 μm) forces on larger soil grains during soil dessications and the compaction of soil grains by glaciers during the Ice age. Key words: Binders, ultramicroscopy, Ortstein, Duric and Fragic A horizons
EFFECT OF FOLIAR-APPLIED SELENIUM ON YIELDS AND SELENIUM CONCENTRATION OF ALFALFA, TIMOTHY AND BARLEY
Authors: GUPTA UMESH C. , KUNELIUS H. T. , WINTER K. A.
Published: March 2010

In a field study, the residual effects of 1, 2, and 4 kg Se/ha applied as a foliar spray and of 1 kg Se/ha applied to the soil were measured for up to five cropping seasons on yields and Se concentration of alfalfa (Medicago sativa L.), timothy (Phleum pratense L. and barley (Hordeum vulgare L.). Selenium applied as foliar spray reduced yields by 16–37% for the three species in the first year but had no effect in the second and subsequent years. Foliar applications of Se at 1–4 kg/ha in the first year produced alfalfa and timothy containing 27–142 ppm Se, which, when fed to livestock, would cause Se toxicity. Barley grain at these rates contained 4.3–8.4 ppm Se. The tissue Se concentrations of the three species did not exceed 0.6 ppm in the second and subsequent years. The residual effect of 1 kg Se/ha applied to the soil lasted longer on the three species than 1 kg Se/ha applied as foliar spray. Selenium applied to soil or as a foliar spray at 1 kg/ha resulted in tissue concentrations greater than 0.1 ppm Se in forages for two to four cropping seasons, and in barley grain for one to two cropping seasons. At 2 and 4 kg Se/ha, applied as a foliar spray, the tissue Se levels greater than 0.1 ppm were maintained for two to four cropping seasons in barley, alfalfa, and timothy. Tissue Se concentrations were generally higher in timothy than in alfalfa and barley grain. Key words: Forages, barley, selenium, yields, foliar application, podzol soil
RELATIONSHIP BETWEEN EXCHANGEABLE SODIUM AND SODIUM ADSORPTION RATIO IN A SOLONETZIC SOIL ASSOCIATION
Authors: HARRON W. R. A. , WEBSTER G. R. , CAIRNS R. R.
Published: March 2010

The relationship between the sodium adsorption ratio (SAR) and exchangeable sodium ratio (ESR) in a Solonetzic soil association of the Black soil zone of East-Central Alberta was examined. Highly significant correlations between ESR and SAR were determined for the A and B horizons of this soil association, although the regression equations were different for each horizon. The slope of the regression line indicated that Na was adsorbed three times more strongly, relative to Ca, in the B horizon than in the A horizon. The difference in adsorption was attributed to differences in soil properties, particularly clay and organic matter content, between the two horizons. Equations to calculate exchangeable sodium percentage (ESP) from SAR were also determined for the two horizons studied. To relate the soluble Na levels to exchangeable Na in the Duagh-Malmo soil association, appropriate equations should be used for each horizon. Also, data showed that an SAR of 3 in the B horizon corresponds to an exchangeable Ca:Na ratio of 10 that is used to differentiate Solonetzic from Chernozemic soils in the Canadian Classification System. Key words: Solonetzic soil association, soluble-exchangeable cation ratios
NITROGEN FERTILIZATION OF LAND CONTINUOUSLY CROPPED TO CORN (Zea mays L.)
Authors: RICHARDS JOHN E. , SHEPPARD S. C. , BATES T. E.
Published: March 2010

Three field trials were conducted to determine if and how response of corn (Zea mays L.) to applied N changes during continuous production. Nitrogen was broadcast at rates of 0, 56, 112, 168, 224 and 336 kg/ha each year for 10 yr. Rates of N in excess of 168 kg/ha significantly reduced emergence at the Fox site; no effect occurred elsewhere. Applied N had no effect upon seedling weight, decreased the interval from seeding to silking, and increased grain and stover yields at all sites. The most profitable rates of N for grain production throughout the study were 85 and 110 kg/ha at the Conestogo and Fox sites, respectively. At the Chinguacousy site, there was a significant year by N rate interaction with grain yield declining by 5600 kg/ha over 10 yr in the 0-kg-N/ha treatment. A model developed by multiple regression analysis (R2 = 0.71) for this site predicted that the most profitable rates of N application were 38, 178, and 213 kg/ha in years 1, 5, and 10, respectively. Applied N decreased ear moisture content at harvest and increased lodging at all sites. Key words: Zea mays L., N fertilization, year by N interaction
IMPACT OF RIGHT-OF-WAY CONSTRUCTION ON ORGANIC SOIL BULK DENSITY IN THE RED LAKE PEATLAND
Authors: GRIGAL D. F.
Published: March 2010

The objective of this study was to evaluate changes in soil bulk density associated with construction of a 500-kV transmission right-of-way (ROW) across a peatland in northwestern Minnesota. Immediately before (1979), and for 2 yr following construction (1980, 1981), bulk density of the organic soil within the ROW and in undisturbed control areas was monitored. Soils were primarily Typic Mesisols (Borohemists), with some Mesic Fibrisols (Sphagnofibrists). Monitoring was carried out in five vegetation types, ranging from graminoid fen to treed bog. Soil bulk density was determined in 25-cm increments to 1 m. There were no significant differences in density between the ROW and the control before construction. When data for the 2 yr following construction were combined, results showed significantly higher density in the surface of the ROW than in the surface of the controls. Absolute differences were small, however. The density in the ROW was 5% higher and that in the controls 5% lower than the overall mean of 0.052 g∙cm−3. Largest differences were in a vegetation type with a fibric surface, the treed fen, where, in 1981, the surface in the control had a bulk density of 0.033 g∙cm3, and in the ROW, 0.049 g∙cm−3. Because of high hydraulic conductivity at both densities, any present restriction of water flow across the peatland is unlikely. Key words: Transmission lines, water flow, histosols, Minnesota
CHLORITE AND BIOTITE WEATHERING BY FULVIC ACID SOLUTIONS IN CLOSED AND OPEN SYSTEMS
Authors: KODAMA H. , SCHNITZER M. , JAAKKIMAINEN M.
Published: March 2010

The dissolution by dilute fulvic acid (FA) solutions of elements constituting two chlorites and biotite was investigated in closed and open systems. In closed systems, dilute FA solution rapidly dissolved substantial amounts of Si, Al, Fe, Mg, and K (in the case of biotite only) from chamosite and biotite during the first 100 h of contact. Thereafter, the rate of dissolution decreased exponentially with increasing time. Maximal concentrations of elements dissolved were approximately proportional to FA concentrations when these were 0.1% (wt/vol) and lower. In the open systems, relatively fast dissolution rates of Fe-clinochlore and biotite were observed initially (up to 30≈35 days). Following this, the rates slowed to near constancy. If the dissolutions had continued at the constant rates, it would have taken a 0.025% FA solution about 22 yr to dissolve 1 g of Fe-clinochlore and 7.2 yr to dissolve 1 g of biotite. Increases in flow rate from 1 to 3 mL/h increased the rates of dissolution of the elements by 2.5–3 times. Ratios of elements dissolved by FA in both systems differed from the elemental ratios of the minerals in being enriched in Fe and Mg, which indicates the preferential dissolution of elements in octahedral coordination. Key words: Fe-clinochlore, Mn-Mg-chamosite, dissolution rate
PHOSPHATE-SOLUBILIZING BACTERIA AND FUNGI IN VARIOUS CULTIVATED AND VIRGIN ALBERTA SOILS
Authors: KUCEY R. M. N.
Published: March 2010

Seventeen sites throughout southern Alberta were sampled in the spring of 1981. Total and NaHCO3-extractable phosphorus and soil texture were determined for each soil sampled. Phosphate-solubilizing and total bacterial and fungal populations were determined by serial dilution and plate counting. Available P constituted an average of 1% of the total P present in the soils. Phosphate-solubilizing bacteria and fungi made up 0.5 and 0.1%, respectively, of the total bacterial and fungal populations. A highly significant correlation was found between the numbers of total and phosphate-solubilizing fungi and the levels of total P in the soil. As a group, the fungi were superior to bacteria in solubilizing both freshly precipitated calcium phosphate and Idaho rock phosphate. Fungi also retained this ability over many subculturing transfers. A high percentage of the bacterial isolates lost their solubilizing ability when subcultured. A significant correlation was found between an organism’s ability to solubilize freshly precipitated calcium phosphate in agar plates and Idaho rock phosphate in solution culture. Key words: Fungi imperfecti, Penicillium sp., phosphate-solubilizing microorganisms
RESPONSE OF AN ORCHARDGRASS-PERENNIAL RYEGRASS SWARD TO RATE AND METHOD OF UREA AND AMMONIUM NITRATE APPLICATION
Authors: BOMKE A. A. , BERTRAND R. A.
Published: March 2010

Urea and ammonium nitrate were applied at rates of 75, 150 and 300 kg N/ha as either a single application in April or split into three equal increments, one applied in April and the second and third following cuts one and two. The orchardgrass-perennial ryegrass sward responded significantly to applied N in each year; however, the yield produced by the two sources differed in only one of the three years. In that year split applied ammonium nitrate gave 8% higher yields than similarly applied urea. The sources were found to be equivalent when applied in the spring. Split application of the N rates increased total annual dry matter yields in one of the three years regardless of N source. In all three years split application of N shifted forage production from cut one to cuts two and three. Key words: N uptake, split N application, orchardgrass-perennial ryegrass sward
ESTIMATION OF SOIL EROSION AND DEPOSITION BY A LANDSCAPE ANALYSIS TECHNIQUE ON CLAY SOILS IN SOUTHWESTERN SASKATCHEWAN
Authors: MERMUT A. R. , ACTON D. F. , EILERS W. D.
Published: March 2010

The thicknesses of self-mulching A horizons were studied in native grassland and cultivated glaciolacustrine clay soils in southwestern Saskatchewan to estimate the extent of erosion and evaluate the relationship between slope characteristics, erosion and sedimentation. It has been shown that under similar gradient, the thickness of the A horizon, in the erosional portion of slopes, is less under cultivated than native grassland conditions; whereas, in the depositional portion the thickness of the A horizon is greater under cultivation. Erosion equations were developed which indicated 7.4 kg∙m−2∙yr−1 or 0.57 cm/yr for a 7.5% backslope and 2.1 kg∙m−2∙yr−1 or 0.16 cm/yr for 2% backslope. Calculated losses of organic matter from the most severely eroded slopes amounted to 650 kg∙ha−1∙yr−1. Comparable losses of nitrogen were 65 kg∙ha−1∙yr−1. This represents a 41% and 35% loss in organic matter and nitrogen, respectively, under nearly 70 yr of cultivation. The very close relationship shown in this study between various slope attributes and erosion clearly indicates the importance of slope considerations in all erosion studies. Key words: Erosion, deposition, swelling clay soils, landscape analysis, organic matter loss
THE MINERALIZATION OF NITROGEN AND SULPHUR FROM PARTICLE-SIZE SEPARATES OF GLEYSOLIC SOILS
Authors: LOWE L. E. , HINDS A. A.
Published: March 2010

An aerobic incubation procedure was used to evaluate the susceptibility to mineralization of N and S in five Gleysolic soils and their particle-size fractions (2–50 μm, 1–2 μm, 0.2–1 μm and < 0.2μm). During an 8-wk incubation, the release of mineral N and S increased with decreasing particle size. The N:S ratio of the mineralization products was generally narrower than that of the starting materials. Total N mineralized from size fractions after 8 wk accounted for 4.5–25.4% of fraction N. For S the corresponding range was 2.7–43.3% of fraction S. The proportions of N and S released after 8 weeks showed no consistent relationship to particle size, although, in a number of cases, the proportions of N and S released were greater for the finer size fractions. It was concluded that complexing of organic fractions with clays did not, in itself, confer increased resistence to mineralization of N and S. Key words: Nitrogen mineralization, sulphur mineralization, particle-size separates, Gleysolic soils
LABORATORY STUDIES OF FACTORS AFFECTING MICROBIAL DEGRADATION OF WHEAT STRAW RESIDUES IN SOIL
Authors: PUIG-GIMENEZ M. H. , CHASE F. E.
Published: March 2010

A simple laboratory method for measuring CO2 evolution from soil was developed using 580-mL plastic containers. Rate of CO2 evolution was measured by exposing 0.1 N NaOH in the closed containers for 4 h and determining the altered conductivity of the absorbent. With 400 g of soil per unit plus 0.172% straw, a coefficient of variation < 2% (total CO2 evolved, 6 wk) was typical with three replicates. Tests with two low-fertility Ontario soils showed that rate of straw decomposition was not affected significantly by fertilizer amendment or length of straw cuttings, but it did increase when soil depth was reduced; also the amount of CO2 evolved increased with duration of soil storage. The method was applied to problems relating to the Mediterranean climate, burning of crop residues, and consequent depletion of soil organic matter. Simulation studies directed towards increasing soil organic matter showed that straw decomposition rates would (1) decrease as crop residues added to soil were increased two- to fivefold, (2) recover markedly over the winter from delayed decomposition caused by the late arrival of autumn rains, and (3) be unaffected by depth of straw placement in soil. Key words: Straw decomposition, chemical fertilizer, CO2 evolution, moisture, temperature, straw placement
DISSIMILATORY REDUCTION OF 15N-LABELED NITRATE IN THE PRESENCE OF NONLABELED NO OR N2O
Authors: NÔMMIK H. , MELIN J. , PLUTH D. J.
Published: March 2010

Dissimilatory reduction of labeled nitrate in the presence of nonlabeled N2O, or NO, was studied in forest mor humus during anaerobic incubation. Data on the isotopic composition of the N2O and N2 pools suggested that all of the N2 formed had passed the N2O pool. This finding supported the earlier suggestion that N2O is an obligatory intermediate in the dissimilatory reduction of nitrate to N2. Due to a likely occurrence of nonenzymatic isotopic exchange between NO and nitrate, the technique used was considered unreliable to study the nature of NO as a possible intermediate in the sequence of nitrate reduction. However, qualitative observations indicated that NO was not a free, obligatory intermediate. Reduction of nitrate was strongly inhibited by the presence of NO. Reduction of N2O to N2 was significantly retarded by the presence of nitrate. The length of the lag period increased as the initial nitrate concentration was increased. Key words: Dissimilatory nitrate reduction, denitrification, nitrous oxide, nitric oxide
POTASSIUM STATUS OF SOME QUEBEC SOILS: K RELEASED BY NITRIC ACID AND SODIUM TETRAPHENYLBORON AS RELATED TO PARTICLE SIZE AND MINERALOGY
Authors: AL-KANANI T. , MacKENZIE A. F. , ROSS G. J.
Published: March 2010

The K release characteristics of surface samples from five Quebec soils were investigated. Each soil was fractionated by size into six separates. Each separate was extracted with 1 M ammonium acetate (NH4OAc), with 1 M nitric acid (HNO3) and with sodium tetraphenylboron (NaTPB) and the K extracted was determined. The clay separates contained most of the HNO3 and NaTPB-extractable K. The average amounts of K removed by 1 M HNO3 and NaTPB from the clay was up to 16 times more than that released from silt or sand fractions. The strong relationship between extractable K and clay content was probably due to the similarity in mineralogical composition and degree of weathering of these soils. Clay-sized chlorite and vermiculite were destroyed by the HNO3 extraction but not by the NaTPB extraction. Crop response to K fertilizer was generally reduced as clay content and extractable K increased. Key words: Extractable K, NaTPB-K, HNO3-K
FIRST 12 YEARS OF A LONG-TERM CROP ROTATION STUDY IN SOUTH WESTERN SASKATCHEWAN — BICARBONATE-P DISTRIBUTION IN SOIL AND P UPTAKE BY THE PLANT
Authors: CAMPBELL C. A. , READ D. W. L. , WINKLEMAN G. E. , McANDREW D. W.
Published: March 2010

The first 12 yr (1967–1978) of an ongoing crop rotation study being conducted on a Brown Chernozemic loam soil at Swift Current, Saskatchewan, has already been assessed for yield, economics and soil N changes. In this paper the effect of crop rotation, N and P fertilizer and environmental factors on NaHCO3-extractable in-organic P (bicarbonate-P) and plant P were assessed. The soil had a high level of bicarbonate-P at the initiation of the experiment. Withholding P fertilizer for 12 yr did not reduce the level of bicarbonate-P but, frequent P application, using generally recommended rates of P, increased the bicarbonate-P in the top 15 cm of soil; the bicarbonate-P levels below 15-cm depth were unchanged. Bicarbonate-P changes during fallowing were significantly related to changes occurring in cropped treatments (r = 0.62** to 0.85**). There was no evidence of net P mineralization. Between spring and fall 66–88% of the variability in bicarbonate-P occurring in the top 15 cm of soil was related to soil moisture, air temperature, and their interaction. Invariably, bicarbonate-P increased between late fall and spring thaw. P uptake by plants was linearly related to time through to shot blade stage; the rate slowed thereafter, but uptake continued to maturity. The amount of P uptake was directly related to dry matter yield and positively influenced by N fertilizer. It was concluded that bicarbonate-P might not be the best indication of P availability and that a more detailed study of the cycling of P in these rotations would be invaluable. Key words: Bicarbonate-P, uptake, temperature effects, moisture effects
INCREASE IN NEUTRAL SALT EXTRACTABLE CATION EXCHANGE CAPACITY OF SOME ACID SOILS AS AFFECTED BY CaSO4 APPLICATIONS
Authors: SINGH S. SHAH
Published: March 2010

The equilibration of acid soils, a Sombric Ferro-Humic Podzol (CSSC-2) from British Columbia, an Orthic Ferro-Humic Podzol (CSSC-19) from Quebec and two horizons of a Dystric Brunisol (SSD-330, SSD-331) from British Columbia, with CaSO4 solution demonstrated that SO4 ions reacted with components of these soils. These reactions increased soil pH, ion activity product (Al)(OH)3 and neutral salt extractable exchangeable cations. The increase in pH and ionic activity product (Al)(OH)3 were noticeable on a single equilibration; however, increase in neutral salt extractable cations was only observed after subsequent equilibrations. After three equilibrations, the sums of NaCl extractable cations were 6.56, 11.99, 5.62 and 4.31 meq/100 g for soil samples CSSC-2, CSSC-19, SSD-330 and SSD-331, respectively. The corresponding values for the unequilibrated soils were 5.20, 7.49, 4.30 and 2.50 meq/100 g. On further equilibration there was no increase in total extractable cations for sample CSSC-2; however, for the other three samples there were increases which became progressively smaller. The reaction of SO4 ions with aluminum hydroxy clay complexes seems to be the mechanism for the increase of negative sites. Key words: Cation exchange capacity, CaSO4, acid soils
NITROUS OXIDE EMISSIONS FROM SOILS DURING THAWING
Authors: GOODROAD L. L. , KEENEY D. R.
Published: March 2010

We, as well as others, have observed that nitrous oxide (N2O) fluxes increased markedly during soil thaw in early spring. This phenomenon was examined further by determining nitrous oxide concentrations in the soil profile and N2O fluxes from the soil surface during the winter-spring period and evaluating physical release and microbial production of N2O on thawing of frozen soil cores in the laboratory. In mid-winter, soil profile N2O concentrations were close to ambient and surface N2O fluxes were low. At thawing, high N2O concentrations (ranging from 1082 to 2066 mg∙m−3) were found at 10–30 cm in the soil profiles of a coniferous forest, and in manure- and straw-treated plots. Concurrently, N2O flux increased markedly and reached some of the highest values observed during the entire season. When thawing was complete, soil profile N2O concentrations and N2O flux declined. Soil cores were taken from frozen soil, warmed in the laboratory, and N2O release measured. Nitrous oxide was released on warming, and cores treated with CHCl3 had a slower release rate. The results indicate that some of the N2O flux occurring at thawing is due in part to physical release of N2O, and that additional N2O is likely produced by denitrification. Key words: Nitrous oxide, denitrification, frozen soils, nitrogen loss
INFLUENCE OF TREE WINDTHROW ON THE PROPERTIES AND CLASSIFICATION OF SELECTED FORESTED SOILS FROM NOVA SCOTIA
Authors: BEKE G. J. , McKEAGUE J. A.
Published: March 2010

Soils affected by tree-throw (arbroturbation) at three sites in Nova Scotia varied in development and microrelief characteristics. Soil horizonation was strongly developed and continuous through the mound-and-pit sequence at one site but was intermittent and irregular at the other two sites. Analytical data, particularly those for oxalate- and pyrophosphate-extractable Fe and Al reflected the morphological variations observed in the pedons. Classification of the arbroturbated soils according to the Canadian system is not a problem though it is necessary to indicate turbation by appending a phase to the soil class name at levels above the series. Mapping areas of such soils involves no change from regular procedures except in the description of the soil units. Hummocky microrelief due to arbroturbation presents some limitations in the use of land. Key words: Physical disturbance, classification, mapping, land use
USE OF TEMPE CELL, MODIFIED TO RESTRAIN SWELLING, FOR DETERMINATION OF HYDRAULIC CONDUCTIVITY AND SOIL WATER CONTENT
Authors: SOMMERFELDT T. G. , SCHAALJE G. B. , HULSTEIN W.
Published: March 2010

The Tempe cell, modified by others to determine saturated hydraulic conductivity (K), was further modified to restrain swelling of the soil and to facilitate air and water movement across the top and bottom of the sample. An apparatus was developed whereby K and water content (θ) could be determined for several soil samples concurrently and suction levels could be varied without disturbing the sample. K and θ were determined for several prepared soil samples by the constant head permeameter method and by the Tempe cell with and without swelling restrained, and for soil cores by the Tempe cell with swelling restrained. With swelling restrained, the K results from the prepared samples did not differ significantly from those of the core samples. For the sandy to silty loam soils at suction levels 0, 10, and 20 kPa, θ of the core sample was less than that from the other samples, whereas for the clay loam soils, θ of the core sample was less than that from the others at suction levels of 0 and 10 kPa. For all methods, θ was correlated to clay content of the soil. These results indicate that the Tempe cell, as finally modified with swelling restraints, can be used to determine K and θ for characterizing the drainability of a nonstructured to weakly structured soil, using either prepared samples or cores. Key words: Hydraulic conductivity, pore volume, soil water content, Tempe cell
AVAILABILITY OF SUBSOIL SULPHATES TO BARLEY AND RAPESEED
Authors: BOLE J. B. , PITTMAN U. J.
Published: March 2010

Increased use of sulphur (S) fertilizers in southern Alberta led to a series of field and phytotron experiments to investigate the importance of S fertilizers and the role of subsoil reserves of sulphate sulphur (SO4-S) for barley (Hordeum vulgare) and rapeseed (Brassica napus). Two types of experiments were conducted. In the field-plot studies, barley was grown on dryland soils low in surface SO4-S but underlain by subsoil high in SO4-S. Neither elemental nor SO4 forms of S significantly increased barley yields in a series of 10 experiments on those soils. The comparisons were made at three levels of N fertilizers. In a series of lysimeter studies, three successive crops were grown in soil low in inorganic S (2.0 μg SO4-S∙g−1), or soil supplemented with 25 μg 35SO4-S∙g−1 soil at specified depths in the lysimeters. Barley was adequately supplied with S from SO4-S at a depth of 54–72 cm. It obtained 55% of its S from a high SO4-S (25 μg∙g−1) layer of soil at that depth, although 40 days growth were required before the S was effectively utilized. Five times as much S was taken up by the barley when the entire soil received an additional 25 μg SO4-S∙g−1 as when only the 54- to 72-cm depth was supplemented; however, the yields were unaffected. Most of the excess S was retained in the straw. Rapeseed took up an increasing amount of SO4-S as the proportion of the lysimeters that initially contained SO4-S was increased. Rapeseed was also able to utilize SO4-S from a depth of 54–72 cm. Rapeseed showed deficiency symptoms when most of the added and soil reserves of S had been depleted by previous crops; its growth habit became indeterminate and seeds did not develop. Although total dry matter yield was not greatly affected, seed yield was markedly reduced in S-deficient rapeseed. Rapeseed took up 10 times as much S as did barley when the S supply was just adequate for seed production. Although rapeseed had a much higher S requirement than barley, both crops were adequately supplied by subsoil reserves of SO4-S under the field and controlled environment conditions studied. The studies suggest that fertilizer recommendations should be based on soil analysis to a depth of at least 60 cm. Key words: Sulphur fertilizer, sulphates, 35S, barley, rapeseed, nutrient uptake
EFFECT OF VARIOUS SOURCES OF SULFUR ON YIELD AND SULFUR CONCENTRATION OF CEREALS AND FORAGES
Authors: GUPTA UMESH C. , MacLEOD J. A.
Published: March 2010

Field experiments were conducted at three locations in Prince Edward Island to determine the effects of various sources of S (Agri-Sul, gypsum, and Urea-Sul) on S concentration of tissue and yields of forages and cereals. Gypsum was effective in increasing the S concentration in plant tissues. Agri-Sul at 10–80 kg S∙ha−1 was generally ineffective in increasing the S concentration of forages and cereals. In the absence of added S (check treatments), the plant tissue S concentrations in alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.) ranged from 0.18 to 0.39 and from 0.14 to 0.27%, respectively. In wheat (Triticum aestivum L.) and barley (Hordeum distichon L.), the S concentrations varied from 0.12 to 0.26 and from 0.13 to 0.20% in the boot stage tissue and grain, respectively, in the check treatments. In general, the S concentration was higher in the boot stage tissue than in the grain. Pea (Pisum sativum L.) seeds and vegetative material from the check treatments contained 0.19–0.24% and 0.17–0.36% S, respectively. Gypsum or Urea-Sul did not increase the yields of forages or cereals. In one instance Agri-Sul slightly increased the alfalfa yield (5–8.5%), but this was not associated with tissue S increases. Plant tissue S levels as low as 0.12–0.18% appeared to be adequate for barley, wheat, timothy, peas, and alfalfa. Key words: Sources of sulfur, tissue S, yields, cereals, forages
FOREST FLOOR VARIABILITY AND FACTOR ANALYSIS: A CASE STUDY
Authors: ARP P. A.
Published: March 2010

A case study is presented to illustrate how factor analysis can be used to quantify probable causes of physical and chemical forest-floor variability. Twenty forest-floor variables were examined for a 30 × 30-m sampling plot located within a mature, naturally regenerated conifer stand. "Slough" (the degree of accumulation of decayed stumps, logs, branches, etc.), litter (hardwood- vs. softwood-type in terms of base-status) and insolation (degree of canopy closure) factors appeared to underlie the observed variability pattern. Factor identification was facilitated by the following variable association pattern: (i) total C with total Fe, Al, N, P, K; (ii) total C with LFH-mass and thickness; (iii) water-extractable P with 2 N potassium-chloride-extractable NH4-H; (iv) total and 1 N ammonium-acetate-extractable Ca with pH; and (v) ground cover vegetation density with forest floor moisture content and thickness. Key words: Forest floor, lateral variability, factor analysis
COSTS OF UNDERGROUND SERVICE INSTALLATIONS IN RELATION TO SOIL QUALITY AND SOIL SURVEY INTERPRETATIONS
Authors: CRESSMAN D. R. , DUMANSKI J.
Published: March 2010

This study examines the development costs of underground service installation in relation to various land factor constraints. Records from municipal development projects were found to be inadequate for apportioning development costs. Professional judgment from full-time cost estimators was found to be more useful. Although development costs on marginal agricultural lands are somewhat higher than on good quality lands, these additional costs are minimal when compared to the total investment in a development project. Key words: Soil interpretations, capability, land preservation, development costs