bluuebunny/crossref_metadata_2025 huggingface dataset:
THE ROLE OF SEASONAL SALT AND WATER FLUXES IN THE GENESIS OF SOLONETZIC B HORIZONS
Authors: FULLERTON (nee Landsburg) S. , PAWLUK S.
Published: March 2010

Seasonal salt and water fluxes into Black Solonetz soils were evaluated at two sites in east-central Alberta. The dominant mode of moisture movement into the soil pedon was by capillary movement of water upwards from the water table. Solonization occurred in the Bntj horizons as a consequence of salt transport; the salts responsible were NaHCO3 and Na2SO4. Seasonal salt and water fluxes were identified at both research sites. From May to November when soil temperatures were above 0 °C, capillary movement and evaporation were the major mechanisms responsible for salt transport, concentration and deposition. From December to March when soil temperatures were below 0 °C water moved upwards from the water table towards the freezing zone depositing salts upon freezing. Key words: Genesis, solonetzic; season, groundwater, salt flux, water flux
CLASSIFICATION, MACROMORPHOLOGY AND CHEMICAL CHARACTERISTICS OF FOLISOLS FROM BRITISH COLUMBIA
Authors: FOX C. A. , TARNOCAI C. , TROWBRIDGE R.
Published: March 2010

The Folisol great group within the Organic soil order was expanded by the Expert Committee on Soil Survey to include the subgroups Hemic, Humic, Lignic and Histic Folisols. Representative Folisols from the Coastal Western Hemlock biogeoclimatic zone in British Columbia were studied to document the macromorphology and chemical characteristics of these subgroups. A proposal for improving F and H horizon designations is also presented. This documentation and improvements to the classification system provide a better basis for the soil surveyor to recognize and account for thick accumulations (> 40 cm) of folic materials overlying mineral or peat materials as well as accumulations (> 10 cm) over rock or fragmental material. Key words: Folisols, organic material, soil classification, Organic soil order
15N ANALYSIS OF HIGHLY ENRICHED SAMPLES ON A MASS SPECTROMETER
Authors: DRURY C. F. , TEL D. A. , BEAUCHAMP E. G.
Published: March 2010

Mass spectrometer analysis of highly enriched 15N samples underestimated the 15N enrichment. Conventional 15N analysis utilizes a ratiometer procedure in which the ratio of 29N2 to 28N2 ions is determined. Samples containing high enrichments had a low quantity of 28N2 ions and it appeared background contamination of 28N2 produced erroneous results with this procedure. Therefore, results obtained with the ratiometer procedure were compared to those obtained with a scanning procedure which measured the 28N2, 29N2 and 30N2 peak heights. The 15N enrichment was determined by the scanning procedure by using all three N2 peaks (28/29/30 method), the 28N2 and 29N2 peaks (28/29 method), and 29N2 and 30N2 peaks (29/30 method). These four methods were compared over a range of enrichments from 0.366 to 99 atom % 15N in samples containing 0.5, 1.0 and 1.5 mg N. Samples with enrichments less than 10 atom % 15N were best estimated by the ratiometer method. Enrichments greater or equal to 10 atom % 15N were most accurately determined by the 29/30 method. Background contamination during sample preparation produced 28N2 peaks which had a negligible effect on samples containing low enrichments, but was a source of error in highly enriched samples. Since natural levels of 29N2 and 30N2 in air are very low, the 29/30 method was found to closely estimate the expected 15N enrichment in standard samples greater than 10 atom % and had the lowest standard deviation. Key words: High 15N enrichment, mass spectrometer, ratiometer procedure, peak scanning procedure
EFFETS DE LA FUMURE POTASSIQUE ET DES RÉGIMES HYDRIQUES SUR LA RÉPONSE AU POTASSIUM DE LA LUZERNE ET DE LA FLÉOLE DES PRÉS
Authors: DIONNE J. L. , PESANT A. R. , BARNETT G. M.
Published: March 2010

The objectives of this study were to determine the changes in yield response and water use efficiency of alfalfa (Medicago sativa L. 'Saranac') and timothy (Phleum pratense L. 'Climax') to potassium applications and variations in soil moisture regimes. For each of the two test crops the factorial combination of the following treatments were replicated three times: three soils (Ste Rosalie clay, Greensboro loam, and Danby sandy loam), potassium (0, 25, 50 and 100 mg K kg−1 of dry soil) and three moisture levels: (1) optimal, 70–100% of available water (AW); (2) semi-dry, 0–100% AW; and (3) dry, 0–50% AW. Yield increases of 68% for alfalfa and 40% for timothy were produced by potassium applied to soil under the optimal moisture regime with almost no yield increase under dry soil moisture conditions. Water use efficiency was higher for alfalfa than for timothy, and increased with rates of potassium on Greensboro loam and Danby sandy loam but not on Ste Rosalie clay. Potassium content of alfalfa was lower when grown at optimal soil moisture than in the dry regime. Differences in potassium content between moisture regimes were small for timothy. Due to higher yields, potassium uptake by alfalfa was greater when soils were cropped at optimal moisture. However, less exchangeable potassium was found after the experiment in soils cropped to alfalfa in the optimal moisture regime than in soils under the dry moisture regime. Therefore potassium fertilizer was most effective at the optimal moisture level (near field capacity). Key words: Potassium fertilization, exchangeable potassium, soil moisture regime, potassium uptake, alfalfa, timothy
SOIL ORGANIC MATTER CHARACTERISTICS AFTER LONG-TERM CROPPING TO VARIOUS SPRING WHEAT ROTATIONS
Authors: JANZEN H. H.
Published: March 2010

Soil from a long-term crop rotation study conducted at Lethbridge, Alberta was analyzed to determine the influence of various spring wheat rotations with and without perennial forages on total and mineralizable soil organic matter contents. Crop rotations considered included: continuous wheat (W), fallow-wheat (FW), fallow-wheat-wheat (FWW), and fallow-wheat-wheat-forage-forage-forage (FWWAAA) in which the forage was a mixture of alfalfa and crested wheat grass. The organic C and N contents of soil after 33 yr of cropping were highest in treatments W and FWWAAA, and decreased with increasing frequency of fallow in the rotation. The inclusion of the perennial forage in the rotation did not increase organic C and N levels above those observed in the continuous wheat treatment (W). Differences in levels of mineralizable organic matter among treatments, as measured in laboratory incubations, were much greater than differences in total organic matter content among treatments. In the surface soil layer (0–15 cm), N mineralization was significantly higher in treatment W than in treatments FWW and FWWAAA, and was more than twice that observed in treatment FW. In the subsurface soil layer (15–30 cm), N mineralization was greatest in treatment FWWAAA when sampled just after the plowdown of forage. Effects of crop rotation on C mineralization were similar to those observed for N. Levels of mineralized organic matter were closely related to levels of "light fraction" material (specific gravity < 1.59 g cm−3), which is believed to consist primarily of incompletely decomposed organic matter of plant origin. Differences in amounts of mineralizable organic matter among treatments were attributed to varying frequencies and patterns of crop residue additions. The pronounced effects of crop rotation on the distribution of organic matter among labile and humified organic matter will have a strong impact on soil fertility and may need to be taken into consideration in the development of fertilizer recommendations. It was concluded that inclusion of perennial forages in spring wheat rotations for the purpose of enhancing soil fertility and organic matter levels was not justified under semiarid conditions. Key words: Carbon, nitrogen, mineralization
HEAVY METAL CONCENTRATIONS IN HALTON REGION SOILS: AN ASSESSMENT FOR FUTURE MUNICIPAL SLUDGE UTILIZATION
Authors: WEBBER M. D. , SHAMESS A.
Published: March 2010

Studies were conducted to determine: (a) the heavy metal concentrations in Halton Region agricultural soils; and (b) whether a 1984 estimate of at least 39 yr for practicing land application of sludge in the Region was valid. Soil samples were taken on a regular grid pattern from the agricultural area of the Region. In a very large proportion of the samples, heavy metal concentrations were less than the maximum permissible values for sludge application to land in Ontario and in most of the samples, they were less than or approximately equal to the mean values for uncontaminated soils in Ontario. In a small proportion of the samples, heavy metal concentrations exceeded the maximum permissible values for sludge application to land in Ontario. These samples were obtained mainly west of the Niagara Escarpment in the southwest corner of the Region and the offending metals were primarily Pb and Zn. High Pb and Zn concentrations in these soils were not related to sludge application but were naturally occurring and probably were derived from Pb and Zn sulfides in the soil parent material. It was concluded that sludge may be applied on a very large proportion of the agricultural land in Halton Region and that the 1984 estimate of at least 39 yr for continuing this practice was valid. Moreover, in view of recent reductions in annual sludge quantity for land application in the Region and in sludge Cd concentration, the 39-yr estimate was considered to be conservative. Key words: Heavy metals, cadmium, Halton Region, municipal sludge, land application
CORN RESPONSE TO RESIDUAL N FROM UREA AND MANURES APPLIED IN PREVIOUS YEARS
Authors: BEAUCHAMP E. G.
Published: March 2010

The response of corn (Zea mays L.) to residual N from several manures and urea was determined in the first and second years following application. Grain yields were obtained from six field trials conducted over a 12-yr period at the Elora Research Station. Manures or urea were applied at several rates during 1 or more years followed by 2 yr (3 yr for one trial) of yield measurements when N treatments were not applied. During the years when corn grain yield response to residual N was determined, one-half of each plot received 120 kg N ha−1 as anhydrous ammonia. This provided a potential yield which was used to evaluate a residual "organic manure" effect or the effect of manure in increasing yields over those obtained only with chemical fertilizers including N. The results indicated that yield responses from residual N from liquid dairy cattle manure and solid beef manure were considerably lower than that from liquid poultry manure and urea in the first year. In the second year there was only a small response from residual N from any of the sources. These results were used to formulate a "decay series" which agreed generally with several published decay series in that response to residual N decreased in a curvilinear manner. Residual N appeared to be less available than predicted by published decay series especially after the second year. There was no clear evidence in this study that manures provided an additional "organic manuring" effect of increasing yields over those obtained only with chemical fertilizers. Key words: Residual manure N, organic manuring effects, decay series
IDENTIFICATION OF PEDOGENIC CARBONATE MINERALS USING STABLE CARBON AND OXYGEN ISOTOPES, X-RAY DIFFRACTION AND SEM ANALYSES
Authors: MILLER J. J. , DUDAS M. J. , LONGSTAFFE F. J.
Published: March 2010

A Cca and Ck horizon of an Orthic Regosol in Alberta were investigated using 13C/12C and 18O/16O isotope ratios, X-ray diffraction and the scanning electron microscope as a possible basis for differentiating pedogenic and lithogenic carbonate minerals Using the stable carbon-isotope method, the abundance of newly-formed pedogenic carbonate minerals in bulk soil samples of the Cca and Ck horizon was estimated to be 48 and 33% respectively. The δ18O values of carbonate minerals in bulk soil samples of the Cca and Ck horizon were −13.1 and −12.0‰, respectively. The presence of Mg-bearing pedogenic calcite in the sand and fine silt (2–10 μm) fractions of the Cca horizon were associated with soluble Mg2+/Ca2+ ratios of about two. Pedogenic carbonate minerals were visible as tiny equidimensional crystals about 0.1–0.6 μm in diameter, and as surface coatings on the sand-size, primary carbonate minerals in both horizons. These results may have a practical application in the use of ca and k suffixes in horizon designation. Key words: Pedogenic carbonate minerals, stable isotopes, Mg-bearing calcite, surface morphology
TILLAGE SYSTEMS AND ATRAZINE AND ALACHLOR RESIDUES ON A POORLY DRAINED SOIL
Authors: GAYNOR J. D. , STONE J. A. , VYN T. J.
Published: March 2010

Seasonal residues of an acetanilide and triazine herbicide were monitored in ridge, conventional, and zero tillage systems. Alachlor (2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide), and atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) residues were less than 8% of the spring application concentration at the end of the growing season. Moldboard plowing in the fall reduced herbicide residues in spring because of soil dilution by plowing to greater than the sampling depth. Ridge tillage systems had higher spring residues apparently because of reduced herbicide dissipation on the drier ridge tops. The higher residues of the triazines on ridge tops may be injurious to triazine sensitive crops. Key words: Herbicide, till-plant, ridge tillage, des-ethyl atrazine
THE SCANNING ELECTRON MICROSCOPIC MORPHOLOGY OF QUARTZ IN SELECTED SOILS FROM ALBERTA
Authors: BLACK J. M. W. , DUDAS M. J.
Published: March 2010

This study compared the surface morphology of quartz grains from A and C horizons of a Chernozem, Luvisol and a Solonetz. Observations and chemical determinations were based on scanning electron microscopy and energy dispersive X-ray analysis of fine sand separates. Features indicative of glacial and eolian transport, physical weathering by low energy subaqueous impact, and chemical dissolution and silica precipitation dominated surface characteristics. Most surface morphological features were of an inherited origin since they were common to solum and parent material samples. Quartz dissolution features were not uniquely associated with solum samples and apparently not of pedogenic origin. Key words: Scanning electron microscopy, quartz, pedogenesis, surface morphology, weathering classification
EFFECT OF ZINC APPLICATIONS ON CORN AT TWO SITES EXHIBITING LOW PLANT TISSUE ZINC CONCENTRATIONS IN PRINCE EDWARD ISLAND
Authors: WHITE R. P. , GUPTA UMESH C. , PRIDHAM E. , SANDERSON J. B.
Published: March 2010

No yield responses to applied Zn occurred on corn (Zea mays L.) at two Prince Edward Island sites where untreated leaf Zn concentrations were 11 to 14 μg g−1. Both soil- and foliar-applied Zn increased leaf and whole-plant Zn concentrations. Key words: Banded Zn, foliar-applied Zn, corn yield
COMPARISON OF TWO SOIL-WATER MODELS UNDER SEMI-ARID GROWING CONDITIONS
Authors: JONG R. DE
Published: March 2010

The Versatile Soil Moisture Budget (VSMB) and the Soil-Plant-Air-Water (SPAW) model were compared and tested against soil-water content data from a long-term experiment in which wheat was grown on fallow land in the semi-arid zone of Saskatchewan. Both models were driven by daily air temperatures and precipitation data. At the expense of requiring more detailed soil and crop information, the SPAW model simulated the water balance and its components in greater detail than the VSMB. Predictions of soil-water contents throughout the growing season with either model corresponded very well with the measured data. The overall mean absolute difference in total soil-water content to a depth of 120 cm was 1.5 cm for the VSMB and 1.2 cm for the SPAW model. Predictions of water distribution in the profile were also satisfactory. A choice between the two models, to be used under semi-arid growing conditions, will depend on the availability of input data and the required level of output. Key words: Soil-water movement, modelling, evapotranspiration
STUDIES ON THE POTASSIUM-SUPPLYING CAPACITIES OF SOUTHERN ONTARIO SOILS. II. NITRIC ACID EXTRACTION OF NONEXCHANGEABLE K AND ITS AVAILABILITY TO CROPS
Authors: RICHARDS JOHN E. , BATES THOMAS E.
Published: March 2010

A previous study showed that large differences in K uptake by alfalfa (Medicago sativa L.) grown in the greenhouse occurred on soils which had similar ammonium-acetate-extractable K (NH4OAc-K) concentrations at seeding. Differences in total K uptake appeared to be closely related to the uptake of nonexchangeable K (NEK). The objective of this study was to determine what fractions or forms of NEK in the soils were responsible for the large differences in total K uptake noted in the greenhouse experiment. The total amount of NEK extracted in seven sequential extractions with boiling 1 M HNO3 (Mactotal) varied widely among soils and was significantly related to the total amount of K (r = 0.69; P < 0.05) and NEK (r = 0.75; P < 0.05) taken up by eight crops of alfalfa. Mactotal was separated into two fractions of differing solubility and the most soluble fraction, StepK, was highly correlated with NEK uptake (r = 0.85; P < 0.01) and total K uptake (r = 0.86; P < 0.01). The least soluble fraction, CRK, was not significantly correlated with either NEK or total K uptake. A multiple regression equation with NH4OAc-K and StepK as independent variables explained 86% of the variation in total K uptake among soils. The coarse clay fraction (0.2–2.0 μm) was the main source of NEK taken up by alfalfa. It was concluded that differences in the K-supplying capacity of southern Ontario soils were due not only to differences in NH4OAc-K concentrations but also to the amount of the StepK fraction of NEK present in the soils. The quantity of StepK present appeared, from a field experiment, to be influenced by the amount of fertilizer applied over a period of years. If a simple method of measuring StepK can be found, soil tests for plant available K in Ontario soils might be greatly improved. Key words: HNO3 extractable K, nonexchangeable K, NH4OAc-K, alfalfa, coarse clay, fine clay
SHRINK-SWELL POTENTIAL AND CRACKING IN CLAY SOILS OF SASKATCHEWAN
Authors: DASOG G. S. , ACTON D. F. , MERMUT A. R. , JONG E. DE
Published: March 2010

Clay soils in Saskatchewan were studied to understand their shrink-swell potential, to identify soil properties that predict the coefficient of linear extensibility (COLE), and to assess the extent of cracking during the growing season. The soils have medium to very high shrink-swell potential, which is related to the specific surface area associated with expandable clays. Because expandable clays in these soils are predominantly of fine clay size, COLE is reasonably well predicted from percent fine clay. The extent of cracking is estimated for some sites using an improved method of measurement. Limited data suggest that cracking intensity in native grassland is less than in cultivated sites and that, under wheat, it is more pronounced in subarid than in subhumid sites. The magnitude of cracking in clay soils of Saskatchewan is much lower than in warmer regions of the world. It is suggested that COLE values and the extent of cracking could be used in improving the classification of clay soils. Key words: Clay soils, COLE, shrink-swell potential, shrinkage, cracking, Saskatchewan
EFFECT OF Penicillium bilaji ON THE SOLUBILITY AND UPTAKE OF P AND MICRONUTRIENTS FROM SOIL BY WHEAT
Authors: KUCEY R. M. N.
Published: March 2010

Penicillium bilaji has previously been shown to increase wheat growth and P uptake by solubilizing phosphates under soil conditions. Laboratory experiments were conducted to determine if P. bilaji was able to solubilize inorganic compounds of copper, iron and zinc. Greenhouse and field experiments were also conducted to determine if P. bilaji had an effect on uptake of copper, iron and zinc by wheat. Under pure culture conditions, P. bilaji was able to solubilize cuprous and cupric oxide, cupric carbonate and zinc metal and, to a lesser extent, ferrous and ferric oxides and pyrite. The soil studies showed increased wheat dry matter production and seed and P yields in response to P. bilaji inoculation, which was related to increased incidence of P-solubilizing fungi in the wheat rhizospheres. Penicillium-inoculated plants contained greater quantities of Cu and Zn under greenhouse conditions and more Cu and Fe under field conditions than treatments not receiving Penicillium inoculum. Cu and Fe concentrations in the plants, in most cases, were not affected; however, Zn concentrations were increased by P. bilaji under greenhouse conditions. It was concluded that P. bilaji is able to cause solubilization of relatively insoluble forms of Cu, Fe and Zn. It did not directly affect the uptake of Fe and Cu by wheat in the soils used in these experiments, but may increase the uptake of Zn by plants. Key words: Penicillium bilaji, rock phosphate, copper, zinc, iron, wheat
PROBABILITY OF RESPONSE OF FLAX TO NITROGEN FERTILIZER DEPENDENT UPON PLANTING DATE AND WEATHER
Authors: SHEPPARD S. C. , BATES T. E.
Published: March 2010

Profitability in agricultural crop production is largely dependent on weather, and specifically on the probabilities associated with weather. Experiments designed to assess the profitability of fertilization account for this by spanning several years and, thus, sampling weather over several years. We measured the response of flax (Linum usitatissimum 'Dufferin') to N fertilization on three planting dates in each of 3 years. Weather patterns and yields differed more among planting dates than among years. The degree of response to N was also dependent on weather, especially during the logarithmic phase of vegetative growth and during the ripening phase. Through several statistical methods, equations were developed that accounted for over 95% of the variability in yield based on meteorological data. These equations were applied in a stochastic simulation of 100 yr of flax trials. The probabilities of response to N and the dollar-return to cost ratios were computed. The sensitivity of these probabilities to the meteorological data was discussed. The estimates suggested that a profitable response of flax to N would occur in about 58% of the years in southern Ontario. Key words: Stochastic, flax, net radiation, degree-day, Linum usitatissimum
QUANTIFYING THE INFLUENCE OF CROPPING HISTORY ON SOIL STRUCTURE
Authors: KAY B. D. , GROENEVELT P. H. , ANGERS D. A. , BALDOCK J. A.
Published: March 2010

Information on rates of change of the structure of different soils under different cropping systems is vital to research in soil conservation. Much data on soil structure cannot be used to provide information on rates of change because of an inability to relate measurements at a given time to cropping history. A conceptual model is presented which facilitates quantification of cropping history in relation to soil structure. The model relates structural form, structural stability, stabilizing materials, biological factors and forces which may be exerted on the soil. Soil and crop management practices influence the nature and magnitude of forces involved, biological factors, and the level of stabilizing materials. The model is applied, for illustrative purposes, to five different cropping treatments involving the production of corn and bromegrass grown for different lengths of time over a 15–yr period. Functions to describe the accumulation or loss of stabilizing material under the two different cropping systems are assumed and functions describing the relations between calculated levels of stabilizing materials and structural stability, and between structural stability and structural form are then presented. The model provides a framework for expressing the impact of soil and crop management practices on soil structure and includes variables which could be used for assessing the "quality" of soil under current conditions. It also provides a method for characterizing the susceptibility of soils to structural change arising from soil and crop management practices. Extensive research is required to evaluate the model, however potential applications justify the effort which will be required. Key words: Tensile strength, wet aggregate stability, compaction index, corn, bromegrass, soil conservation
A COMPARISON OF THREE METHODS FOR DETERMINING CALCIUM ION ACTIVITY IN SOIL SOLUTIONS
Authors: LUTWICK GERALD W. , WEBSTER GORDON R. , KRATOCHVIL BYRON
Published: March 2010

Calcium ion activity, (Ca2+), in 37 soil solutions was determined using species calculation, potentiometric (ion selective electrode), and colorimetric (tetramethylmurexide) methods. Agreement among the three estimates of (Ca2+) was tested by comparing the potentiometric and colorimetric methods to the species calculation method. Good agreement was observed between (Ca2+) estimates using the potentiometric and species calculation methods. Percent relative error between the two methods was less than 5% for 76% of the soil extracts and less than 10% for 85% of the soil extracts. Differences are thought to be related to interference from H+, Na+, K+, and Mg2+ above certain concentrations. The colorimetric and species calculation methods agreed poorly in their estimates of (Ca2+) in soil solutions. Relative error was less than 20% for only 39% of the estimates. Sodium interference is thought to be a major contributor to error in estimating (Ca2+) using the colorimetric method. Key words: Calcium ion activity, methods comparison, aqueous species distribution, selective ion electrode, tetramethylmurexide
ALLOCATION AND MICROBIAL UTILIZATION OF C IN TWO SOILS CROPPED TO BARLEY
Authors: DINWOODIE G. D. , JUMA N. G.
Published: March 2010

This study was undertaken to compare some aspects of carbon cycling in a Gray Luvisol at Breton and a Black soil at Ellerslie, Alberta cropped to barley. Comparisons of the above and below-ground allocation of carbon, distribution of carbon in soil, and microbial use of carbon were made between sites. Shoot C, root C, microbial biomass C, soil organic C, water soluble organic C, and polysaccharide C were measured on four dates between 31 July and 20 Oct. 1986. The total quantity of carbon in the soil-plant system at Ellerslie (17.2 kg C m−2) was greater than at Breton (6.6 kg C m−2). On average shoot C at Ellerslie (247 g C m−2) was greater than at Breton (147 g m−2). The quantity of root C (avg. 21 g C m−2) was the same at both sites resulting in higher shoot C:root C ratios at Ellerslie than Breton. Microbial biomass (expressed as g C m−2 or g C g−1 root C) was one to two times lower at Breton than at Ellerslie but respiration (g CO2-C g−1 microbial biomass C) during a 10-d laboratory incubation was two to four times greater. Microbial biomass C, soluble C and polysaccharide C expressed as mg C g−1 of soil were less at Breton than Ellerslie. However when these data were compared on a relative basis in terms of soil C (g C g−1 soil C), microbial biomass C and soluble C were higher at Breton than Ellerslie. Polysaccharide C was the same at both sites. Although the microbial biomass was smaller at Breton than at Ellerslie, more carbon was lost from the system by microbial respiration and a greater proportion of the carbon in the soil was in microbial and soluble C pools. Soil characteristics, and cropping history affected the amount of carbon stabilized in soil. Key words: Chernozemic, Luvisolic, microbial C, soluble C, polysaccharide C, soil organic matter, barley
SELENIUM ENRICHMENT OF CROPS THROUGH FOLIAR APPLICATIONS
Authors: GUPTA UMESH C. , WINTER K. A. , McRAE K. B.
Published: March 2010

A field study was conducted, at two locations on Prince Edward Island, over a 5-yr period to determine the effects of foliar applications of sodium selenite on the Se concentration in barley (Hordeum vulgare L.) grain and in alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.) foliage. Applications of 10–20 g Se ha−1 resulted in barley kernels and forage plant Se levels that would be adequate to prevent Se deficiency in most livestock. The highest rate of Se, at 80 g ha−1, resulted in plant Se concentrations of 706 μg kg−1 in timothy. The measured plant Se concentrations, to the same applications, varied from year to year but the responses to applied Se levels were generally in the same proportions. For similar application rates Se concentrations were lower in barley grain than in the forages. Tissue Se levels in the second cuts of alfalfa and timothy were lower than in the first cut. High levels of foliar-applied Se did not result in a carryover effect the following crop year. Annual foliar applications of Se would be required to raise the Se levels in crops into the sufficiency range for livestock feeds. Key words: Selenium content, foliar spray, cereals, forages, Podzol soils
RELEASE OF THE HORMONE-LIKE ACTIVITIES FROM Allolobophora rosea (Sav.) AND Allolobophora caliginosa (Sav.) FECES
Authors: NARDI S. , ARNOLDI G. , DELL'AGNOLA G.
Published: March 2010

The effects of humus on plant metabolism are conditioned by the release of the hormone-like activities contained in HEf bound to HSp. HEf and HSp are both humic fractions that can be separated from each other by acidification with acetic acid or other organic acids. HEf is composed of small molecules and shows hormone-like activities; HSp possesses higher molecular weight and works as a support for HEf. The molecular sizes of the separated HEf and HSp are both low enough to permit root absorption. The dispersion and solubilization of humic molecules are essential to the release of cytokinin-like activity from HSp, but are only preliminary to the release of auxin- and gibberellin-like activities. These can be released by a partial acidification of the humic extracts that do not result in complete depolycondensation. The process appears to regulate the delivery of the hormone-like substances and is influenced by their particular arrangement in the humic aggregate. Key words: Humus fractions, biological effect, nitrate uptake, hormone-like activity
SIGNIFICANCE OF CORRENSITE IN SOILS OF SOUTHEASTERN ONTARIO
Authors: MILES N. M. , KIMPE C. R. De
Published: March 2010

Samples were collected from Ap/Ah and Bm horizons of 10 soils from southeastern Ontario. The soil reaction ranged from medium acid to mildly alkaline. Mineralogical analysis of the various particle-size fractions showed the presence of corrensite, talc and graphite in the assemblage. These three minerals were also present in large amounts in marble outcrops, where they were formed by hydrothermal alteration and metamorphism. The significance of inherited interstratified minerals in the soils was considered from the analytical aspect: the first-order basal reflection should be confirmed because higher orders could be confounded with other mineral reflections; and from the pedogenetic aspect: failing to recognize an inherited interstratified mineral would be misleading in the interpretation of soil evolution. Key words: Grenville province, interstratified mineral, corrensite, talc, graphite, inherited minerals
INFLUENCE OF ACID SULFATE WEATHERING ON CHEMICAL AND MINERALOGICAL PROPERTIES OF AN ACID SULFATE SOIL OF MANITOBA
Authors: ROSS G. J. , IVARSON K. C. , EILERS R. G.
Published: March 2010

The chemical and mineralogical characteristics of a Gleyed Sombric Brunisol (Keld Series) of the Grandview area of Manitoba were analyzed in detail to determine the influence of acid sulfate weathering. The Keld soil has developed in till derived from underlying soft Cretaceous pyrite-containing shale of the Ashville Formation. The major chemical features of this soil are low pH (3.3) and high amounts of exchangeable Al (15 cmol(+) kg−1) of the Cg and Bg horizons. In addition, amounts of As are high (18–25 mg kg−1) throughout the profile. This element seems to be associated with iron oxides but not with jarosite-type minerals. Pyrite and gypsum were found in the IICkg horizon but jarosite-type minerals, consisting mainly of natrojarosite with ≈ 40% jarosite, were detected in the Cg horizon only. Aluminium-substituted goethite is present in the Bmgj horizon. Smectite, which is partly beidellitic and has an average layer charge density of 0.32 equivalents per formula unit, is the dominant clay mineral in the soil profile and is inherited from the underlying shale along with associated kaolinite and mica. The oxidation and decomposition of pyrite and the formation of sulfuric acid, jarosite-type minerals and aluminum substituted goethite are typical of acid sulfate weathering reactions. The dominant effect of acid sulfate weathering on the clay minerals is their extensive structural breakdown towards the surface of the profile. This is also indicated by the high amounts of Si and Al extracted from weathered mineral residues in the surface horizons. The IICkg horizon of the keld profile is in the pre-sulfuricization stage, the Cg horizon expresses the active sulfuricization stage, and the Bg, Bmgj, and Ah horizons represent the postsulfuricization stage. Key words: Keld series, acid sulfate weathering, natrojarosite, As levels
USE OF HIGH GRADIENT MAGNETIC SEPARATION IN DETAILED CLAY MINERAL STUDIES
Authors: GHABRU S. K. , ST. ARNAUD R. J. , MERMUT A. R.
Published: March 2010

High gradient magnetic separation is a simple, inexpensive, nondestructive and rapid means of concentrating iron-bearing minerals to nearly monomineralic levels, particularly those present in undetectable proportions in soil clays. The use of variable magnetic flux density further allows subfractionation of the iron-bearing minerals. Besides iron content, the efficiency of high gradient magnetic separation is highly dependent on the particle size. The stability of suspension, suitable flow rates, contact time and the packing of steel wool are significant factors. The experimental setup used in this study was effective for 2–0.2 μm clays but modifications are necessary to adapt the technique to finer (< 0.2 μm) particle sizes. This resulted in the separation of three distinct mineral groups: (a) smectite, kaolinite, quartz and feldspars, which were entirely associated with the > 1.38 Tesla (T) fraction, suggesting that the smectite and kaolinite present in these soils contain little or no iron; (b) vermiculite, mixed-layer minerals and mica, which were present in all the high gradient magnetic separation fractions; and (c) amphiboles and hydroxy interlayered minerals concentrated only in the < 1.38 T fractions. The contents of hydroxy interlayered minerals and amphiboles increased with decreasing levels of magnetic flux density and concentrated in the < 0.20 T fraction, from which they were further separated into monomineralic separates. A very small proportion of the interlayered mineral present in the total clay had a non-iron-bearing (probably Al-Mg interlayered) counterpart. The iron-bearing vermiculite, mixed-layer minerals (weathering products of biotite) and mica showed different iron contents. Key words: Magnetic separation, iron-bearing minerals, clay mineralogy, X-ray diffraction, scanning electron microscopy
MINERALIZATION AND REDISTRIBUTION OF CARBON FROM SURFICIAL AND BURIED CORN STALKS
Authors: MOTT S. C. , DAVENPORT J. R. , THOMAS R. L.
Published: March 2010

Although corn (Zea mays L.) stalks contribute to the total quantity of organic material in soil, their direct influence on soil structural stabilization may be small. In a laboratory study 14C-labelled corn stalks were placed on the surface of, or buried at, a 5-cm depth in a sandy loam soil. The soils were incubated at 25 °C for 119 d to determine the extent of organic carbon redistribution. Approximately 70% of the buried stalk carbon and 90% of the surface stalk carbon remained in the soil after incubation. Most of the residual carbon was identifiable as stalk tissue. Less than 5% of the added carbon was intermixed with the soil. Both the lack of C redistribution in the soil and the high loss of the mineralized 14C as CO2 stress the importance of the initial distribution of added organic materials in soils. The results imply that corn stover is a poor source of soil C and that it would be best used as a surface protectant against raindrop impact. Key words: Carbon mineralization, carbon redistribution, corn stalks, soil structure
CARBON PARTITIONING AND RHIZODEPOSITION IN CORN AND BROMEGRASS
Authors: DAVENPORT J. R. , THOMAS R. L.
Published: March 2010

Carbon partitioning and rhizodeposition by corn (Zea mays L.) and bromegrass (Bromus inermis Leyss.) were evaluated after 1 and 2 yr of cropping. 14C-labelled CO2 was used as a tracer of assimilated C. Most of the 14C assimilated by corn was translocated to the aboveground plant (nearly 90%), whereas the amounts located above and below ground in bromegrasss were approximately 60 and 40%, respectively. The total amount of rhizodeposition by bromegrass was twice that of corn after both 1 and 2 yr of cropping. A model was developed to predict the amount of carbon input by the below-ground systems of both crops on a field scale. The model indicates that the annual carbon rhizodeposition by bromegrass would be nearly five times higher than the below-ground carbon input under corn. Key words: Carbon partitioning, rhizodeposition, soil structure, root exudates
SOIL CHEMICAL CRITERIA FOR IRRIGATION SUITABILITY CLASSIFICATION OF BROWN SOLONETZIC SOILS
Authors: BENNETT D. R.
Published: March 2010

A good statistical relationship was obtained between the exchangeable-sodium ratio and the sodium adsorption ratio (SAR) in Brown Solonetzic and associated soils in southern Alberta. Reliable estimates of the exchangeable-sodium status of these sulfate-rich soils may be anticipated when SAR values are less than 20. Prediction of the exchangeable-sodium status of soils on the basis of SAR values is preferable for both Solonetzic soil and irrigation suitability classification. A saturation extract SAR value of five in the B horizon generally corresponds to an exchangeable calcium to sodium ratio of 10. Saturation extract SAR values of five and 12 are recommended as revised soil chemical criteria for Brown Solonetzic soil and irrigation suitability classification, respectively. Key words: Solonetzic soils, exchangeable cations, sodium adsorption ratio, selectivity coefficient, irrigation suitability
ESTIMATING SPATIAL VARIATIONS OF SOIL WATER CONTENT USING NONCONTACTING ELECTROMAGNETIC INDUCTIVE METHODS
Authors: KACHANOSKI R. G. , WESENBEECK I. J. VAN , GREGORICH E. G.
Published: March 2010

The relationships among the spatial variations of soil water content, soil texture, soil solution electrical conductivity, and bulk soil electrical conductivity were examined for a field characterized by net drainage and low concentrations of dissolved electrolytes. Bulk soil electrical conductivity was measured over various depths at 52 locations within a 1.8-ha field using noncontacting electromagnetic inductive meters. Soil water content (0–0.5 m depth) was measured at the same locations using the time domain reflectometry method. Measurements of soil texture and soil solution conductivity were obtained from core samples from 37 of the sampling locations. Soil water content at the site ranged from 0.06 to 0.36 m3 m−3. Clay content ranged from 2.5 to 44% percent and bulk soil electrical conductivity ranged from 0.0 to 0.21 S m−1. Significant correlation existed among almost all of the measured variables. Regression analysis indicated soil solution conductivity had no effect on measured bulk soil electrical conductivity for soil water contents less than 0.25 m3 m−3. Bulk soil electrical conductivity explained 96% of the spatial variation of soil water content independent of a wide range of soil texture. Autocorrelations of soil water content were similar to autocorrelations for bulk soil electrical conductivity. Under conditions similar to those in the study area, it should be possible to infer spatial variations in soil water content quickly by measuring bulk electrical conductivity using noncontacting electromagnetic inductive meters. Key words: Spatial variability, soil water, electrical conductivity, soil texture
STABILIZATION OF RESIDUAL C AND N IN SOIL
Authors: JANZEN R. A. , SHAYKEWICH C. F. , GOH TEE BOON
Published: March 2010

Three Manitoba soils varying in clay and organic matter content were mixed with each of four plant residue amendments: (1) a control where no plant or fertilizer materials were added; (2) 14C- and 15N-labelled wheat straw; (3) 14C- and 15N-labelled wheat straw plus 15N-labelled KNO3; and (4) 14C- and 15N-labelled prebloom alfalfa residue. The soils were incubated at 20 °C and 75% field capacity for 90 d. Soil samples were collected at 0, 7, 30, and 90 d of incubation. Two humic acid fractions were obtained from the amended soils. Fraction A was obtained by Na4P2O7 extraction and Fraction B was recovered from the remaining residue by sonication. Significant (P < 0.05) differences were observed in the incorporation of 14C and 15N into both fractions. The effect of clay content on C and N incorporation was most marked in Fraction B: C incorporation in all treatments tended to be higher in the Red River Clay soil than in the Newdale (bottom of the knoll) soil; N incorporation in the straw and alfalfa treatments tended to be higher in the Red River Clay soil but, in the straw-plus-fertilizer treatment, N incorporation tended to be higher in the Newdale (bottom of the knoll) soil. The effect of the form of C and N in the residue was most apparent in the incorporation of N into Fraction B: in all soils the level of 15N in the alfalfa treatment was significantly (P < 0.05) higher than that in the straw plus fertilizer treatment. Key words: Plant residue management, incorporation, incubation, C and N turnover, KNO3 fertilizer
IRRIGATION TREATMENT AND ALFALFA YIELD ON A LAYERED ALLUVIAL SOIL
Authors: RYSWYK A. L. VAN , STEVENSON D. S. , WILLIAMS R. J.
Published: March 2010

Alfalfa yields were increased 1.5 t ha−1 during the mid-June through August growth period, when irrigation treatments increased the percent of days with greater than 50% available soil water storage capacity from 25 to 100. Data are discussed in relation to current irrigation recommendations for southern interior British Columbia. Key words: Irrigation interval, alfalfa, layered alluvial soil, available soil water storage, growing degree days, climatic moisture balance
CLASSIFICATION OF CULTIVATED ESTUARINE ACID SULFATE SOILS IN QUEBEC
Authors: KIMPE C. R. DE , LAVERDIÈRE M. R. , BARIL R. W.
Published: March 2010

When drained and cultivated, acid sulfate soils developed on coastal marsh sediments lose some of their specific properties because large amounts of lime are applied before cultivation and sulfate ions are leached out of the profiles. However, these soils still contrast strongly with other Gleysolic soils and their special characteristics should be given more emphasis in the soil classification system, especially for the benefit of soil fertility specialists. Key words: de l'Anse soils, jarosite, Gleysolic soils, sulfur
PERSISTENCE AND CARRY-OVER OF METRIBUZIN AND TRIALLATE IN SUBARCTIC SOILS
Authors: CONN JEFFERY S. , CAMERON JILL S.
Published: March 2010

Persistence of metribuzin and triallate in soil was studied near Delta Junction, Alaska from 1982 to 1985. Metribuzin was applied at 0.3, 0.6 and 1.3 kg ha−1 and triallate was applied at 0.7, 1.4 or 2.8 kg ha−1 in 1982. Spring barley, oats, spring wheat and rapeseed were planted in the plots in 1983 and 1985 to determine whether herbicide residues would decrease populations or yield of rotational crops. Application rate had no effect on degradation rate of metribuzin or triallate. Twelve percent of the metribuzin and 61% of the triallate applied still remained after 115 d. Three years after application, 2% of the metribuzin and 14% of the triallate applied still remained. In 1983, oat stands and yields in plots where triallate was applied at 2.8 kg ha−1 were lower than control plots. In 1985, there were no carry-over effects. Key words: Herbicide persistence, metribuzin, triallate, subarctic soils
CHARACTERIZATION AND CLASSIFICATION OF ROOT MAT HORIZONS IN SOME COASTAL BRITISH COLUMBIA PODZOLS
Authors: MARTIN DALE E. , LOWE L. E.
Published: March 2010

Podzols formed in high-rainfall areas of south coastal B.C. often have layers of highly organic material at depth in the profile, and in many cases, “pipes” of similar material angling down through the profile. These materials have a greasy feel, few discernible mineral grains, occasional remnants of wood structure and a cellular nature. The horizontal layers, termed "root mats", range in thickness from 1 cm to > 30 cm, and are overlain by coarse-textured material of low organic matter content. Chemically this material is similar to surficial H horizons with respect to C:N and N:S ratios, but closely resembles Podzolic B horizons with respect to Fe content and humus fraction ratios. In contrast oxalate-extractable Al values are remarkably high, sometimes exceeding 10%. The majority of the root mats can be classified as organic (> 17% organic C), either as H or O horizons. Those containing < 17% C meet the criteria for Bhf horizons. Key words: Root mat, root channel, oxalate-extractable Al, organic horizons
EFFECT OF LONG-TERM PIG SLURRY AND SOLID CATTLE MANURE APPLICATION ON SOIL CHEMICAL AND BIOLOGICAL PROPERTIES
Authors: NDAYEGAMIYE A. , CÔTÉ D.
Published: March 2010

Chemical and biological properties were evaluated in 1987 on an acidic silty loam soil following a long-term field study established in 1978 and cultivated with silage corn. Treatments included a control, solid cattle manure (20, 40 and 60 Mg ha−1 FYM) and pig slurry (60, 120 m3 ha−1 SLU) applied every 2 yr and annually, respectively. No fertilizer was applied. The results of this study have shown that neither treatment significantly affected soil pH values, total-N contents and C:N ratios compared to the control. The cation exchange capacity (CEC) of the soil was significantly higher with FYM treatment than with control or SLU application. The highest rates of FYM and SLU have also increased (P < 0.05) soil organic carbon, microbial activity and potentially mineralizable nitrogen. The soil microflora populations (bacteria, fungi, actinomycetes, ammonifiers and nitrifiers) were greatly improved by both treatments. There were no significant differences in organic matter content or the relative amount of humic and fulvic acids between FYM and SLU plots. In spite of these results, FYM application (40 and 60 Mg ha−1) did affect more significantly the distribution of organic carbon in HA and the E4/E6 quotients than SLU additions. Humic acids extracted from SLU amended soils had a lower C content and lower E4/E6 ratios than humic acids from FYM soils. Long-term SLU application did not contribute to decreased organic matter content, CEC and humic acids yield, probably because of optimal organic residues returned to the soil by the corn crops. The FYM application generally improved soil chemical and biological properties. For a sustainable soil productivity, long-term SLU application should then be avoided in rotation in which small amounts of plant residues are returned, especially on soils with low organic matter contents. Key words: Organic matter, microbial activity, nitrogen mineralization potential, CEC, solid cattle manure, pig slurry