British Columbia Soils Research Articles

Degradation of hydrocarbons in crude oil by the ascomycete Pseudallescheria boydii (Microascaceae).

Four unique strains of Pseudallescheria boydii were isolated from oil-soaked soils in British Columbia and Alberta and compared to strains from cattle dung and raw sewage. Considerable variability in morphology, colony appearance, colony diameter, and temperature tolerance occurred among the strains. They also varied in the sporogenous states produced in culture; all strains had a Scedosporium anamorph and either the Graphium anamorph or cleistothecial teleomorph. Conspecificity of the six isolates was inferred from their morphology and supported by restriction fragment length polymorphism profiles of the internally transcribed spacer region of rDNA and comparing these to Petriella sordida, a similar taxon in the Microascaceae. Three of the strains isolated from oil-contaminated soil and the strain from sewage were tested for their ability to utilize hydrocarbons by incubation with Prudhoe Bay Crude oil as the sole carbon source. Gas chromatographic analysis of the residual oil revealed that the strains isolated from oil-contaminated soil degraded the linear aliphatics. The strain from sewage, previously shown by others to utilize the volatile n-alkanes (i.e., ethane, propane, and butane), did not utilize the liquid saturate compounds. None of the strains was observed to degrade compounds in the aromatic fraction. Pseudallescheria boydii may be an important agent for in situ bioremediation of saturates in oil-contaminated sites.

Biocontrol of Phytophthora cactorum in vitro with Enterobacter aerogenes

Phytophthora cactorum causes significant mortality of mature trees in New Zealand pipfruit orchards. Replants of infected sites often succumb to this pathogen within 3 years. Enterobacter aerogenes, strain B8 was reported to control P. cactorum infection of apples in nursery soils in British Columbia. This strain was imported to New Zealand in 1991 and compared with indigenous isolates of E. aerogenes. The Canadian isolate differed from New Zealand isolates in utilisation of tartrate, tolerance of NaCl (5 cf. 7%), and inhibition of P. cactorum in vitro. Strain B8 was fungicidal whereas New Zealand isolates were fungistatic. Electron microscopy of mycelium exposed to strain B8 on agar revealed extensive disruption of cell membranes, intermixing and aggregation of organelles, necrosis, vacuolation, breakdown of the cell wall, and hyphal death. Hyphae exposed to New Zealand isolates of E. aerogenes exhibited vacuolation of the outer cytoplasm and degradation of the cell wall and plasmalemma but not cell degradation and death.

Growing season nitrogen dynamics in manured soils in south coastal British Columbia: Implications for a soil nitrate test for silage corn

Spring soil nitrate and ammonium dynamics in south coastal British Columbia soils were examined with respect to the potential to develop a soil nitrate test for silage corn (Zea mays, L.). Soil nitrate and ammonium contents were measured to 90 cm depth in two soils from April to July of two growing seasons. Treatments included a control, spring application of either 300 or 600 kg total N ha−1 as liquid dairy manure, or 200 kg N ha−1 as inorganic fertilizer. Significant amounts of ammonium were present until late May following manure and until mid-June following fertilizer application, requiring simultaneous determination of both nitrate and ammonium concentrations to assess soil inorganic N contents during this period. Most of the changes in soil nitrate over time occurred in the top 30 cm, suggesting that sampling to 30 cm depth would be sufficient in most cases for a soil nitrate test in this region. Most of the increase in soil inorganic N associated with the spring application of manure occurred by 1 June. A soil nitrate test in early to mid-June when the corn is at the six leaf stage appeared to be most suitable for use in south coastal British Columbia to determine if additional fertilizer N is required. A sample taken at this time will measure soil nitrate contents just before the period of rapid corn N uptake, after most of the additional inorganic N associated with spring manure application is already present in the soil as nitrate, and after nitrification of the manure ammonium has occurred. Key words: N recovery, preplant nitrate test, pre-sidedress soil nitrate test

Solution, exchangeable and clay-fixed ammonium in south coast British Columbia soils

Solution, exchangeable and clay-fixed ammonium were measured in a variety of south coast British Columbia soils in the laboratory using extraction, equilibration and leaching procedures, and with and without ammonium amendments in order to evaluate the relative significance of adsorption and fixation processes on nitrogen behavior. Non-amended soils contained from 59 to 224 g N g−1 of fixed ammonium and these amounts were correlated with clay (positive) and sand (negative) contents. The amount of native fixed ammonium in the soils was influenced by management history. Recovery of ammonium added to eight selected samples by a small volume of solution followed by air drying was the same with 1 and 2 M KCl extractions, but less was extracted by 0.1 M KCl and even less by water. This showed that both 1 and 2 M KCl had sufficient K+ to displace the NH4+ present (inherent and added) on the exchange sites without an apparent effect on fixed ammonium. Up to 68% of the ammonium added was not extracted by 2 M KCl and assumed to have been fixed in the clay lattice. The proportion of the added ammonium that was adsorbed onto the exchange sites was linear up to 200 μg N g−1 application, but the amount fixed by the clays was linear to only about 100 μg N g−1 application rate. Data from studies where soil columns were leached with NH4NO3 provided only limited information on the relative importance of exchange versus fixation processes to the adsorption of ammonium. Leaching columns with a limited number of batches of NH4NO3 followed by water (short cycle) were useful for comparing the ability of different soils to adsorb and retain ammonium, but the relative importance of exchange versus fixation could not be determined. In the 18 samples of this study, the amount of NH4+ adsorbed ranged from 84 to 25% during short cycle column leachings. Different patterns of adsorption occurred among the four soil samples that were leached with a large number of batches of ammonium (long cycle), but it could not be determined whether or not these patterns were related to differences in proportions of fixation relative to exchange. Measurements showed that ammonium was fixed in the soils during the long cycle leachings but that the amounts of fixed ammonium measured were influenced by air drying the sample before analysis. Several studies with and without toluene additions showed that microbial activity must be controlled during these measurements. It was concluded that south coastal soils contained significant amounts of fixed ammonium and can fix additional ammonium. The amount of ammonium in the clay fixed pool and the potential to fix added ammonium was different in relation to the soil type, their previous management, and wetting and drying cycles. The biological significance of fixed ammonium and the fixation process must not be discounted in any nitrogen studies of these soils for proper interpretation of data. Key words: Ammonium fixation, equilibration, column leaching, microbial/enzyme inhibition, extractant concentration

Nitrogen induced potassium deficiency in white spruce (Piceaglauca) and Engelmann spruce (Piceaengelmannii) seedlings

White spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (Piceaengelmannii Parry ex Engelm.) seedlings grown for 2 or more years in sandy loam nursery soils in British Columbia often show yellow and necrotic shoot-tip symptoms. Chemical analysis of a white spruce and a white × Engelmann hybrid spruce provenance showed that the symptoms were associated with low needle K concentrations. After nursery growth was complete, growth tests showed that seedlings with symptoms took longer to flush and had 43% less shoot extension than normal green seedlings. To see why K fertilizer alone did not always cure the symptoms, 1.5-year-old Engelmann spruce seedlings were transplanted and grown for a further 1.5 years in a 4 × 3 × 3 factorial experiment (K level × N source × N level). Nitrogen fertilization increased growth and symptom occurrence, with sources resulting in more symptoms in the order (NH4)2SO4 < NH4NO3 < Ca(NO3)2. Potassium fertilization decreased symptoms, although not completely, but had no effect on growth. Shoot-tip NH4+ was positively correlated with symptoms, while higher levels of soil and shoot-tip K, as well as soil and shoot-tip Mg, were associated with reduction in symptoms. It was concluded that heavy N fertilization created requirements for K, and probably Mg, above the tissue concentrations normally regarded as adequate, and that K fertilization did not always eliminate symptoms because of a Mg requirement.

Tillage Effects on Thermal Conductivity of Two Soils in Northern British Columbia

AbstractTillage management practices may affect crop growth, in part by altering soil thermal properties. Effects of long‐term conventional (CT), no tillage (NT), and modified no tillage (NTR: NT with surface residue pushed away from a 7.5‐cm zone over the seed rows) systems on soil thermal conductivity (K) and water content (θ) were evaluated on Donnelly silt loam and sandy loam (Typic Cryoboralfs). Measured K (M1) was compared with calculated K using the McInnes equation (M2) and a modified McInnes equation (M3, which included additional soil properties). The K in both soils increased with an increase in soil θ; the differences among the tillage systems decreased as the soil dried. Soil K for the silt loam was 0.81 (θ = 0.13 m3 m−3), 0.83 (θ = 0.14 m3 m−3), and 0.84 W m−1 K−1 (θ = 0.15 m3 m−3) in CT, NTR, and NT, respectively, at 25 d after planting in 1992 (a dry year). It was 1.13 (θ = 0.42 m3 m−3), 1.53 (θ = 0.50 m3 m−3) and 1.55 W m−1 K−1 (θ = 0.57 m3 m−3) in CT, NTR, and NT, respectively, at 47 d after planting in 1993 (a wet year). Soil K for sandy loam was significantly lower than for silt loam. Soil K measured by M1 and calculated by both the M2 and M3 methods were highly correlated. However, the calculated K values were somewhat improved, although not significantly, with the M3. Mean K was lower by 0.133 W m−1 K−1 in M2 and by 0.045 W m−1 K−1 in M3 than in M1 under CT on silt loam. Increased soil water storage under long‐term NT produced a greater thermal contact area and, consequently, a significantly greater K under NT and NTR than CT.

Seed banks of forested and disturbed soils in southwestern British Columbia

The species composition and density of seed banks in the forest floors and mineral soils of several undisturbed (immature, midseral forests) and disturbed (transmission line rights-of-way) ecosystems in southwestern British Columbia were estimated using the seedling-emergence method. The total soil surface area sampled was 9.4 m2. Germination behaviour of seven dominant species in response to depth of burial and substrate was also studied in a greenhouse experiment. A total of 16 289 seedlings germinated, representing 62 native and naturalized vascular plant species and several unidentified grass species. Most seedlings emerged from the forest floor, and the number of germinants generally decreased with increasing sample depth. Drier ecosystems had the lowest number and density of germinants. Burial depth significantly affected germination of all species tested. Mineral soil was equal, or superior, to forest floor as a germination substrate for all species tested. Depth–substrate interactions for several species indicated that the pattern of influence of burial depth in relation to substrate varied with species. Caution is urged extrapolating greenhouse seed-bank studies to potential weed populations in the field. Establishment of species from the seed bank will be a function of the depth to which the soil is disturbed and the kind of disturbance (burning, scarification) imposed. Key words: British Columbia, Coastal Western Hemlock zone, seed bank, seed germination, seed diversity, seed density.

Oxidation of elemental sulphur and acidulation of calcareous orchard soils in southern British Columbia

The capacity of soils to oxidize S was measured by incubation with finely divided elemental S in 13 calcareous orchard soils from the southern interior of British Columbia. Sulphur oxidation rates ranged from 3.4 to 26 μg S cm−2 d−1. The magnitude of pH decrease in response to added S varied inversely with initial CaCO3 content (r = − 0.58, P = 0.04) and silt content (r = − 0.64, P = 0.02) and directly with sand content (r = 0.64, P = 0.02). Incubation studies with one calcareous orchard soil indicated that finely divided S was more effective over time than other acidulants (FeSO4, Al2 (SO4)3 and H2SO4). A field study was carried out on the same soil. Finely divided and bentonitic granulated S were applied at 4.5 t ha−1 on the grass surface or incorporated to a depth of 15 cm. Incorporated fine S was oxidized to a much greater extent during a 2-yr period than was incorporated grandulated S. However, when surface applied, they were oxidized equally but slowly. Key words: S incubation, acidulating materials, S oxidation, soil pH, electrical conductivity

EXISTING AND POSSIBLE NEW GLEYSOLIC ORDER CRITERIA APPLIED TO FIVE PEDONS FROM BRITISH COLUMBIA

Use of the current criteria for distinguishing Gleysolic soils from gleyed intergrades to other soil classes resulted in the apparent misclassification of some soils in British Columbia. Pedologists of the area selected five pedons encompassing several degrees of expression of gley features. Current classification criteria based on soil color and possible new differentiating features based on chemical and micromorphological analyses were applied in considering the classification of the soils. Application of the current specific color criteria involving low chromas and prominent mottling result in the classification of three pedons in the Gleysolic order and two in gleyed subgroups of other orders. This classification was appropriate in the view of B.C. pedologists except for one Gleysolic pedon in which the water table is rarely within 1 m of the surface. Prior to drainage, however, the soil was probably saturated to the surface and under reducing conditions for prolonged periods each year. Thus, classification as a Gleysolic soil is appropriate as it probably reflects the prevailing conditions and processes during most of the period of soil genesis.Segregation of iron and manganese as nodules and coatings was most marked in the Gleysolic pedons. Walls of some voids were bleached due to depletion of iron oxides. Though study of thin sections, bulk chemical analysis and analysis of specific features by scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDXRA) were useful in providing information on soil properties, they did not indicate an improved basis for differentiating Gleysolic soils from others. The color criteria used to distinguish soils of the Gleysolic order do not necessarily reflect the current soil water regime, and they are not intended to do so. The current criteria resulted in the appropriate classification of the five soils. Key words: Gleying, reduction, iron, manganese, micromorphology, SEM-EDXRA

Responses of apple seedlings to biocides and phosphate fertilizers in orchard soils in British Columbia

(1985). Responses of apple seedlings to biocides and phosphate fertilizers in orchard soils in British Columbia. Canadian Journal of Plant Pathology: Vol. 7, No. 3, pp. 294-301.

Imogolite in cemented horizons of some British Columbia soils

Imogolite was detected in clay fractions dispersed at pH 4 from four of seven samples of horizons below the podzolic B horizons of some soils from coastal British Columbia. The presence of imogolite was indicated by morphology as shown by electron micrographs, and by infrared spectra and X-ray diffraction. Imogolite might account, in part, for the anomalously high oxalate-extractable Al values of the horizons tested. Associated amorphous aluminosilicates and imogolite may act as as cementing agents of the cemented subsoils studied.

Persistence of carbofuran residues in some British Columbia soils.

Although a number of studies have been reported on the degradation of this insecticide (GETZIN 1973; CARO et al. 1973; READ 1969) detailed knowledge of its behavior under local conditions has been lacking. As a preliminary to a more complete study, soils which had been treated with carbofuran one and/or two years previously were sampled and analysed. Surprisingly high residues were found and there was evidence of build-up where treatments were repeated for two successive years.

Mercury in soils of British Columbia, a mercuriferous region

Mercury concentrations in various horizons of British Columbia soils were determined to estimate natural background levels in soils from various geographical areas of the province. Highly enriched concentrations near the Pinchi Lake cinnibar deposit declined to background levels ranging from 10 to 310 ppb Hg in the district. In six other regions, concentrations in surface mineral horizons averaged 85 ppb and ranged to 490 ppb but surface horizons of peaty muck soils and those predominated by vegetative litter contained 164 ppb Hg on the average and as much as 741 ppb. Concentrations in subsurface horizons were lower than at the surface. A significant relationship between Hg concentration and organic matter content was observed. Comparison with soils from outside British Columbia indicated its location within a generalized mercuriferous belt accounted for the relatively high concentrations observed.

A Study of Tree Root Strength Deterioration Following Clearfelling

The tensile strengths of Douglas fir and western red cedar roots growing in landslide-susceptible mountain soils in coastal British Columbia were measured in the laboratory. Tests on small roots, between 1 and 12 mm in diameter, sampled from living trees and from dead stumps cut at various times in the past, showed that Douglas fir and cedar roots rapidly lose their tensile strength after death of the parent tree. Within 3–5 years after felling of the parent tree small roots may lose over half their original tensile strength.

PERSISTENCE AND MOVEMENT OF α- AND γ-CHLORDANE IN SOILS FOLLOWING TREATMENT WITH HIGH-PURITY CHLORDANE (VELSICOL HCS-3260)

Residues from high-purity chlordane (Velsicol HCS-3260) were determined in British Columbia soils for 16 mo following applications in June 1971 at two rates of 5.6 and 11.2 kg active ingredients (a.i.)/ha. Residues from a cool, moist location declined rapidly during the 1st mo following application, with greater percentage loss from the lower application rate. From the 2nd mo until 16 mo after application, decay rates were linear with time. Although 225 cm rain fell during this period, less than 2% of the total residues reached the 15–23-cm horizon. Calculated half-lives were 4 and 11 mo, respectively. Residues from a semiarid location were more persistent and did not decline rapidly within the 1st mo after application. Possible reasons for these differences are discussed. Leaching experiments with five different soil types in the laboratory confirmed the limited movement of chlordane observed in field soil.

The Morphology and Genesis of Some Alpine Soils in British Columbia, Canada: I. Morphology, Classification, and Genesis

AbstractFive soils occurring in alpine regions of British Columbia, Canada, were described. The soils were found to have silt loam to loamy sand textures. Four of the soils met the morphological requirements of the Spodosol order. Dark surface mineral horizons occurred at four sites; two of these qualified as umbric epipedons. Volcanic ash was found in the vicinity of some sites. The soils were classified into the USDA Comprehensive System and the System of Soil Classification for Canada.

The Morphology and Genesis of Some Alpine Soils in British Columbia, Canada: II. Physical, Chemical, and Mineralogical Determinations and Genesis

AbstractThe results of selected physical, chemical, and mineralogical analyses, carried out on five soils occurring in three alpine regions in British Columbia, Canada, are presented and discussed. An evaluation of the genesis of these soils is made in relation to the analytical results and to the literature.The soils have developed on relatively young post‐Pleistocene parent materials and are gravelly and have loamy sand to silt loam textures, in the fine earth fractions, the slight accumulations of silt and clay at the surface, are due primarily to more intense physical weathering and partly to surface additions of eolian material. Volcanic ash was found in the surface horizons at three of the sites.Physical weathering is significant in these soils and chemical weathering is taking place as evidenced by the presence of spodic horizons, abundant amorphous iron and aluminum in all horizons, and the content of secondary minerals.Several properties of these soils were correlated with total carbon contents and hence organic matter contents. Volcanic ash was believed to have had an influence, to a minor degree, on the soil properties where it occurred.With sufficient leaching, soils with spodic characteristics develop. Under a coniferous or ericaceous vegetative cover Spodosols occur; however, under a cover of grasses, sedges, and forbs the spodic characteristics may be masked by organic matter accumulations in the surface mineral horizons.

EFFECT OF SOIL ORDER, pH, TEXTURE AND ORGANIC MATTER ON THE CORRELATION BETWEEN PHOSPHORUS IN ALFALFA AND SOIL-TEST VALUES

Soil and tissue samples were collected from 192 alfalfa fields representing a wide variety of cultivated soils in British Columbia. The phosphorus content of the alfalfa was correlated with the amounts of available P extracted by eight soil-test methods. The Olsen method, Bray's P1 method, and a modification of Bray's P1 method showed high correlation with plant phosphorus over a wide range of soils; the other five methods showed lower correlation. The relationship observed between soil phosphorus and plant phosphorus differed with soil pH and soil order for the various available-phosphorus methods used. None of the methods gave significant correlations with the Solonetzic and Podzolic soils. Multiple correlation studies indicated that soil pH and texture were required to explain the contribution of available phosphorus in soil, as measured by any soil-test method, to phosphorus in alfalfa.

THE DETERMINATION OF EXCHANGEABLE CATIONS AND CATION-EXCHANGE CAPACITY OF SOILS USING DILUTE NICKEL CHLORIDE

The use of nickel as a displacing ion in the determination of exchangeable cations and cation-exchange capacity was evaluated using several British Columbia soils. The values for exchangeable cations and cation-exchange capacity for the soils examined, using 0.25 normal neutral nickel chloride, were higher than those obtained by the ammonium acetate extraction method. For the most part, in samples examined, values were found to be more readily and consistently reproduced with the nickel chloride extractant. Dispersion of soil organic matter and silicate clay minerals was negligible, and the washing step involving ethanol has been eliminated.

The Influence of Soil Moisture Regime and Phosphorus Source on the Response of Alfalfa to Phosphorus

AbstractThe influence of soil moisture regimes and P sources on the response of alfalfa to P was studied in the growth chamber. Surface samples of two calcareous British Columbia soils, Machete stony sandy loam and the Nisconlith clay loam were used. Alfalfa yield and P uptake were highest when soil moisture tension was allowed to reach a maximum of 2.0 bars and subsequently reduced to 0.2 bars. The P sources were almost equally available with this regime.Calcium metaphosphate and anhydrous dicalcium phosphate produced the highest yields. P content of alfalfa was highest with monoammonium phosphate on the Machete soil. Monocalcium phosphate resulted in the highest tissue P with the Nisconlith soil. Amount of P removed from the soil, with the exception of hydroxyapatitc, was not markedly influenced by P source. Hydroxyapatitetreated soil released the lowest amount of NaHCO3‐extractable P.