bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF MEFLUIDIDE ON YIELD AND CHEMICAL COMPOSITION OF CRESTED WHEATGRASS IN EAST-CENTRAL SASKATCHEWAN
Authors: McCAUGHEY W. P. , COHEN R. D. H.
Published: March 2010

Two experiments, each of two years duration, were conducted to examine the effect of the plant growth regulator, mefluidide (N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide), on yield and chemical composition of crested wheatgrass (Agropyron cristatum) (L.) Gaertn.). In exp. 1, 1986, high rates of mefluidide resulted in reduced (P < 0.05) dry matter yield (DMY) and growth was inhibited for longer periods of time at higher application rates. Mefluidide treatment reduced (P < 0.05) neutral detergent fiber (NDF) content, increased (P < 0.05) crude protein (CP), ash and in vitro digestible organic matter (IVDOM) contents and had no effect on acid detergent fiber (ADF) or lignin contents. In 1987, neither DMY nor chemical composition were affected by mefluidide treatment. There were no effects of mefluidide treatment on DMY of regrowth in either year. However, regrowth CP content in 1986 and IVDOM content in 1987 were increased (P < 0.05) by mefluidide treatment while other chemical fractions were unaffected. In exp. 2, conducted in both 1987 and 1988, mefluidide application reduced (P < 0.05) reproductive shoot densities (RS) and DMY in both years. However, in 1987, the reduction in DMY only became apparent at late harvest dates. There were no effects of mefluidide treatment on CP content in either year. The regrowth DMY was reduced (P < 0.01) by mefluidide treatment in 1988 but not 1987 and CP content was not affected in either year. In these experiments, mefluidide enhanced forage quality when environmental conditions were favorable but was not effective during periods of drought stress. The high probability of drought occurring on the Canadian prairies would appear to limit application of this technology to more mesic locations. Under dry growing conditions, improvements in forage quality appear to be obtained at the expense of reduced forage yields.Key words: Agropyron cristatum, plant growth regulators, forage quality, mefluidide, nutritional value
ALKALOID CONTENT OF REED CANARYGRASS (Phalaris arundinaceae L.) AS DETERMINED BY GAS-LIQUID CHROMATOGRAPHY
Authors: DUYNISVELD G. W. , SLOMINSKI B. A. , WITTENBERG K. M. , CAMPBELL L. D.
Published: March 2010

A technique was developed for the quantification of gramine, hordenine and 5-methoxy-N,N-dimethyl tryptamine (5MeO-DMT) in reed canarygrass (RCG) using gas–liquid chromatography. One gram of freeze-dried, ground RCG sample was extracted with methanol containing 1% ammonium hydroxide. Following solvent evaporation, the residue was extracted with dilute hydrochloric acid (0.01 N). The pH of the extract was then raised and stabilized by adding 0.5 M sodium tetraborate-boric acid buffer pH 9. The internal standard solution (0.25 mg mL−1) n-nonadecane was added and the extract was purified by partitioning with chloroform. The chloroform was then evaporated and the alkaloids were derivatized with bis(trimethylsilyl)-trifluoroacetamide and effectively separated on a gas chromatographic column packed with 2% OV-7 on Chromosorb W. Derivatization was effective at 100 °C (20 min). Extraction of the sample with methanol was maximal at 30-minute extraction time and the recovery of all the alkaloids studied was shown to average 90%. Development of this procedure provides a means to measure RCG gramine, hordenine and 5MeO-DMT concentrations in the presence or absence of tryptamines or β-carbolines. Initial growth and regrowth of five cultivars of RCG from two locations were evaluated for gramine, hordenine and 5MeO-DMT content using this technique. No differences were detected in hordenine content. Gramine content was higher (P < 0.05) in Rival than Venture, with Castor, Palaton and Vantage being intermediate. None of the cultivars contained detectable levels of 5MeO-DMT. There were no differences (P > 0.05) in hordenine content between initial growth and regrowth; however, gramine content of regrowth was higher (P < 0.05) than initial growth.Key words: Gramine, hordenine, 5-methoxy-N,N-dimethyl tryptamine, reed canarygrass, Phalaris arundinaceae L.
EFFECTS OF VOLUNTEER WHEAT AND BARLEY ON THE GROWTH AND YIELD OF FLAX
Authors: FRIESEN LYLE , MORRISON IAN N. , MARSHALL GEORGE , ROTHER WESLEY
Published: March 2010

Field experiments were conducted in 1982 and 1983 to determine the effects of increasing densities (0–70 plants m−2) of volunteer wheat (Triticum aestivum L. Neepawa) and barley (Hordeum vulgare L. Bonanza) on the growth and seed yield of flax (Linum usitatissimum L. Dufferin). Rectangular hyperbolic models were fitted to data using nonlinear regression analysis. Results indicated that both volunteer cereals severely reduced flax biomass and yield, with volunteer barley interference causing greater losses than volunteer wheat at equivalent densities. From the regression equations it was calculated that an intermediate density of 30 volunteer wheat plants m−2 reduced the yield of flax by 49% in 1982 and 53% in 1983, whereas an equivalent density of volunteer barley plants reduced flax yields by 56% in 1982 and 67% in 1983.Key words: Competition, flax, volunteer wheat, volunteer barley, rectangular hyperbola, yield loss
THE BIOLOGY OF CANADIAN WEEDS.: 95. Ranunculus repens
Authors: LOVETT-DOUST J. , LOVETT-DOUST L. , GROTH A. T.
Published: March 2010

Ranunculus repens L. (creeping buttercup) is a common weed in the Maritimes, Ontario and Quebec, as well as British Columbia. A review of the literature on the biology of the species is presented. Ranunculus repens can develop large spreading clones as it produces ramets on stolons, and readily regenerates from root fragments. It is therefore particularly resistant to cultivation as a weed control strategy. It is, in addition, partially, or fully resistant to many herbicides, and its seeds show dormancy and sustained viability in the seed bank. Several investigations have been carried out on the population dynamics of this species, and its responses to light and nutrient treatments have been described.Key words: Weed biology, Ranunculus repens, creeping buttercup
THE EFFECT OF A SEAWEED EXTRACT CONTAINING CYTOKININ ON THE GROWTH AND YIELD OF BARLEY
Authors: TAYLOR J. S. , HARKER K. N. , ROBERTSON J. M. , FOSTER K. R.
Published: March 2010

A cytokinin-containing seaweed extract, Nitrozyme™ (Nitrozyme1), was tested under field conditions over 4 yr for its effects on the growth and yield of barley (Hordeum vulgare L.). In 1986 and 1987, Nitrozyme did not increase yield and had no beneficial effects on growth of Harrington and Bonanza barley. In 1988 and 1989, the effects of Nitrozyme on barley (cv. Leduc) were compared against those of kinetin, a synthetic cytokinin. Neither Nitrozyme nor kinetin had an effect on growth or yield.Key words: Nitrozyme, seaweed extracts, cytokinins, kinetin, plant growth regulator, Hordeum vulgare L.
SUPERCOOLING AND ICE NUCLEATION EVENTS IN THE CROWN OF WINTER WHEAT SEEDLINGS
Authors: PUKACKI PAWEL M. , McKERSIE BRYAN D.
Published: March 2010

Differential thermal analysis (DTA) was used to investigate the freezing of tissue water in crowns of two cultivars of winter wheat (Triticum aestivum L.), Frederick and Norstar, which differ in their winterhardiness. Crown tissue from 7-day-old nonacclimated seedlings had an LT50 (lethal temperature at which survival was 50%) of −6 or −8 °C for Frederick and Norstar, respectively, and showed a single freezing exotherm. In contrast, crown tissue from seedlings, acclimated for 5 weeks at 2 °C, had an LT50 of −14 or −18 °C, respectively, and exhibited a double freezing exotherm. The basal region of the crown has been shown to be more sensitive to freezing injury than the apical meristem and its ice nucleation point was at a higher temperature in all samples. The ability of crowns to supercool decreased slightly as the cooling rate was increased from 2 °C h−1 to 120 °C h−1, but the water in the less hardy cultivar Frederick, consistently froze at a higher temperature than the more hardy Norstar. Slow cooling rates, such as 2° or 10 °C h−1, improved the ability of DTA to discriminate the differences in freezing resistance among the cultivars. However, because of the large plant to plant variability this method has no practical value in the identification of more freezing tolerant plants.Key words: Differential Thermal Analysis, Triticum aestivum, freezing, winterhardiness
EFFETS DE LA FERTILISATION AZOTÉE SUR LA CROISSANCE DE TRANSPLANTS DE TOMATE ET DE LAITUE CULTIVÉS EN PLATEAUX MULTICELLULAIRES AVEC OU SANS ÉCLAIRAGE D’APPOINT
Authors: MASSON JEAN , GOSSELIN ANDRÉ , TREMBLAY NICOLAS
Published: March 2010

Tomato (Lycopersicon esculentum Mill. ’Springset’) and lettuce (Lactuca sativa L. ’Ithaca’) transplants were grown under natural and supplemental light (100 μmol m−2 s−1 PAR) and fertilized with four nitrogen doses (100, 200, 300, and 400 mg L−1 N). Supplemental light increased tomato shoot dry weight, shoot percent dry matter, leaf area, root dry weight, and root-to-shoot ratio. Lettuce transplants showed increased shoot and root dry weight as well as leaf area when supplemental light was present. For both species, nitrogen increased shoot dry weight and leaf area, but decreased shoot percent dry matter and root-to-shoot ratio. High nitrogen doses increased tomato and lettuce shoot dry weight and leaf area chiefly under supplemental light.Key words: Lycopersicon esculentum, Lactuca sativa, pretransplanting nutritional conditioning, seedling
THE EFFECT OF FLOWER REMOVAL ON POTATO TUBER YIELD
Authors: JANSKY S. H. , THOMPSON D. M.
Published: March 2010

Relationships between fruit and vegetative growth may influence tuber yield. In 1987, flower removal significantly increased yield at irrigated and dryland sites for the potato clone ND860-2. In 1988, flower removal did not significantly increase yield in Norchip, ND2008-2 or ND860-2 planted under dryland conditions. Response to flower removal appears to be dependent on environmental conditions.Key words: Solarium tuberosum, tuber yield, flower removal, potato, ND860-2, partitioning
PITFALLS IN INTERPRETATION OF SOIL DRAINAGE FROM SOIL SURVEY INFORMATION
Authors: McKEAGUE J. A. , TOPP G. C.
Published: March 2010

Soil drainage groups assigned on the basis of soil survey information were evaluated against measured saturated hydraulic conductivity (Ksat) data for nine soils in Ontario. The drainage groups used in the drainage guide for Ontario, are based mainly on assumed relationships between soil texture and the capacity of the soil to transmit water.Measured Ksat values were incompatible with the drainage groups assigned to at least four of the nine soils. For the soils tested, there was very little relationship between texture and Ksat. Structure, including porosity, had a major influence on Ksat, and near-surface structure is influenced greatly by land use. Thus, general interpretations of the drainage characteristics of soil series have serious limitations. The usefulness of soil survey information for interpretation of soil drainage could be increased by improved description of soil morphology and by reliable estimates of Ksat during mapping. Such estimates can be based on morphology if they are regularly recalibrated by measurement. Key words: Hydraulic conductivity, tile drainage, texture, soil morphology
EFFECT OF SOIL WATER AND TEMPERATURE ON CORN (Zea mays L.) ROOT GROWTH DURING EMERGENCE
Authors: CUTFORTH H. W. , SHAYKEWICH C. F. , CHO C. M.
Published: March 2010

Root growth between germination and emergence for the corn hybrids Pioneer 3995, Northrup King 403 and Pride 1108 was studied. Soil temperatures of 15, 19, 25 and 30.5 °C and a range of soil water contents were used. Decreases in soil temperature and water content both decreased root growth rate. Sensitivity to water content decreased with decreasing soil temperature. All three hybrids responded to soil temperature in the same way. By contrast, Pioneer 3995 was less sensitive to soil water stress than was Northrup King 403, while Pride 1108 was the most sensitive. Key words: Soil water, soil temperature, root growth (early), corn
BORON AND ZINC NUTRITION OF TOBACCO GROWN IN PRINCE EDWARD ISLAND
Authors: GUPTA UMESH C. , ARSENAULT W. J.
Published: March 2010

Field experiments were conducted at various locations in Prince Edward Island to determine the effect of applied Zn and B on tobacco (Nicotiana tabacum L.) yield, grade index, and tissue B and Zn concentrations. Addition of B at 1.1 kg ha−1 did not increase tobacco yield. Rates of B at 8.8 kg ha−1 and higher proved toxic and resulted in yield reductions. At these higher rates there was more than 3 μg g−1 hot-water-soluble (HWS) B in the soil and 113–169 μg B g−1 in the various primings. Tissue B levels as low as 31 μg g−1 in the third priming and the HWS B as low as 0.3 μg g−1 soil did not give B deficiency symptoms. Additions of Zn tended to increase yields but not significantly. Tissue Zn levels as low as 17 μg g−1 in the 3rd priming did not result in Zn deficiency symptoms. No yield reductions occurred when the tissue Zn levels were as high as 115 in the first and 57 μg g−1 in the fourth priming. The grade index of tobacco was not affected by Zn applications but B applications of 8.8 kg ha−1 significantly decreased the index. Tissue Zn and B were higher in the 1st and 2nd than in the 3rd, 4th, or 5th primings. Key words: Tobacco yields, tissue boron, tissue zinc, boron toxicity
VEGETATION AND MANAGEMENT EFFECTS UPON SOME PROPERTIES OF BLACK CHERNOZEMIC SOILS OF THE EDMONTON REGION
Authors: PAWLUK S.
Published: March 2010

Characteristics and properties of Black Chernozemic soils were assessed after 17 yr of continuous forest, grass and grain cover as well as summerfallowing in order to determine the influence of habitat upon soil development. Of major interest were morphological and micromorphological changes although physical chemical and biological aspects are also included. Variations observed in many of the soil characteristics and properties within five different habitats were minor, reflecting a great deal of resiliency to changes imposed by new sets of pedogenic forces. The most notable changes in morphological features were associated with fabric rearrangement as reflected in increased compaction and decreased porosity under cropping and fallowing and development of banded fabric and breakdown of basic mullgranic fabric units under forest cover. Characteristics of surface soils within the grass plot closely resembled uncultivated grassland soils. Only slight variability was observed among chemical parameters. Soils were slightly more acidic and base unsaturated under forest canopy. Total percent O.C. values showed little variation among plots and were very close to values reported for Ah horizons of uncultivated Black Chernozemic soils in the region. H2SO4-hydrolyzable sugar content was markedly lower in the fallowed plot. Soil collembola and mites showed considerable variability with habitat. Their overall contribution to the pedogenic process is yet uncertain. Key words: Black Chernozemic; soil degradation; soil development; soil fauna
CHANGES WITH TIME IN THE FORM AND AVAILABILITY OF RESIDUAL FERTILIZER PHOSPHORUS ON CHERNOZEMIC SOILS
Authors: WAGAR B. I. , STEWART J. W. B. , MOIR J. O.
Published: March 2010

A sequential phosphorus (P) fractionation procedure was used to measure the changes in the labile and stable forms of inorganic and organic P following single broadcast P applications to Canadian Chernozemic soils under cereal cropping. Approximately half of the fertilizer residues remained in plant-available forms (resin, NaHCO3). In a Black Waskada clay loam 8 yr after the application of 200 and 400 kg P ha−1, residual fertilizer P consisted of resin-P, 30–40%; HCl-P, 25–30%; residue-P, 10–15%; NaOH-P, 10–15%, NaHCO3-P, 10%; and aggregate protected P, 3%. The residues in a Dark Brown Sutherland clay 5 yr after the application of 160 kg P ha−1 were: resin-P, 35%; NaOH-P, 30–40%; NaHCO3-P, 15%; HCl-P, 0–5%; H2SO4-P, 5%; and aggregate protected P, 5%. The soils differed in the quantity of fertilizer recovered in inorganic HCl-extractable forms. In the Sutherland soil the change from wheat-fallow to continuous wheat cropping produced a build-up of organic P which occurred with and without the addition of P fertilizer. Key words: Residual P, P transformations, Labile Pi; labile Po, stable Pi stable Po
PEDOGENIC IMOGOLITE IN SANDY BRUNISOLS OF EASTERN ONTARIO
Authors: WANG C. , KODAMA H.
Published: March 2010

Imogolite that appears to have formed by weathering in the present soil (pedogenic imogolite) occurred in two well-drained Dystric Brunisols on fine sand materials in eastern Ontario. Imogolite was detected by electron microscopy and was most abundant in the fine clay fraction of the lower B horizons. Several characteristics of these two pedons considered to be favorable for the occurrence of imogolite are: low organic matter content in the sola; high ratio of (Alo-Alp)/Alp in the B horizons; the strong but not extremely acid soil reaction in the B horizons and the porous nature of the soils. The finding is consistent with the hypothesis that the downward movement and precipitation of inorganic amorphous forms of Al and Si is a major process in podzolization. It also demonstrates that the occurrence of imogolite is not restricted to Spodosols or Podzolic soils. Key words: Pedogenic imogolite, proto-imogolite allophane, Dystric Brunisols, Spodosols
SELECTION FOR CAPTAN TOLERANCE IN THE Rhizobium phaseoli-Phaseolus vulgaris L. N2-FIXING SYMBIOSIS
Authors: RENNIE R. J.
Published: March 2010

Application of the seed-applied fungicides captan, DL-Plus, Evershield, thiram and Metalaxyl reduced nodulation in the field bean cultivar Lancer (Phaseolus vulgaris L.) in the field. Captan, Evershield, B3 and Thiram also lowered the acetylene reducing activity under the same conditions. Captan, DL-Plus, and B3 resulted in significant yield reductions of field bean inoculated with commercial multi-strain rhizobial inoculant. Since captan or captan-containing fungicides were the most potent inhibitors of symbiotic N2 fixation in field bean, spontaneous mutants of Rhizobium phaseoli strains 3644 and 8215 were selected on the basis of ability to grow in microbial medium containing 100 ppm of Captan 50 W. Controlled environment chamber and field evaluations indicated that all mutants were less sensitive to commercial rates of Captan 50 W (2.0 g per kilogram seed) than either parent strain or commercial multi-strain inoculant. Inoculation of captan-treated seed with these mutants 24 h prior to seeding did not affect nitrogenase activity or yield. Assessment of the effect of captan on the N2-fixing symbiosis and the captan tolerance of R. phaseoli strains by the acetylene reduction assay or 15N isotope dilution at levels of 15N natural abundance gave similar results. The existence of mutants of R. phaseoli tolerant to seed-applied captan but unaltered in symbiotic properties makes the combined use of captan as a seed protectant and seed-applied rhizobial inoculation fully compatible. Key words: Phaseolus vulgaris L., Rhizobium phaseoli, captan, N2 fixation, 15N isotope dilution, acetylene reduction
A COMPARISON OF HPLC ANALYSIS OF NITRATE IN SOILS WITH THE PHENOLDISULFONIC ACID AND HYDRAZINE SULFATE METHODS
Authors: KUCHNICKI T. C. , WEBSTER G. R. B.
Published: March 2010

Six Manitoba soils of varying physical and chemical compositions were used to determine the efficiency of nitrate analysis by high-performance liquid chromatography (HPLC). The nitrate was extracted with distilled water and the extract was analyzed with a reverse phase column using a mobile phase of 1:1 methanol-water, pH 3.0. In five soils, the HPLC method of nitrate analysis resulted in near 100% recovery of added nitrate. An average 90.2% recovery was obtained with the hydrazine sulfate method using sodium bicarbonate, pH 8.5, as the soil extractant. Variable recoveries were obtained with the phenoldisulfonic acid method using a silver sulfate-copper sulfate extractant. Key words: HPLC, nitrate analysis, soil
CROP RESIDUE MANAGEMENT PRACTICES, AND N AND P FERTILIZER EFFECTS ON CROP RESPONSE AND ON SOME PHYSICAL AND CHEMICAL PROPERTIES OF A BLACK CHERNOZEM OVER 25 YEARS IN A CONTINUOUS WHEAT ROTATION
Authors: NUTTALL W. F. , BOWREN K. E. , CAMPBELL C. A.
Published: March 2010

In the Black soil zone of the Canadian Prairies seedbed preparation is important for handling crop residues from high yields and for incorporating herbicides and fertilizers into soil in the fall or prior to seeding in spring. There are numerous tillage implements available to the producer for this operation. The question often arises as to the relative merits and demerits of using these implements, especially with respect to their effect on yield and on soil quality. A 25-yr (1959–1983) continuous spring wheat study was carried out at Melfort, Saskatchewan, in a split-plot design. The main plots were: four fall tillage implement treatments (plow, heavy duty cultivator, one-way disc and double disc), chopped straw in the fall and spring burn of straw. Four rates of fertilizer (0/0, 5/10, 22.5/10 and 45/10 kg ha−1 N/kg−1 ha−1 P) were subplots from 1959 to 1977; the fertilizer rates were doubled for 1978 to 1983. The results showed that there was no significant effect of tillage on yield but there was a significant fertilizer by tillage interaction. The spring burn treatment gave the highest yield (2073 kg ha−1) and the plow treatment the lowest yield (1963 kg ha−1). Fertilizer increased yields when moisture was adequate and either had no effect or depressed yields when precipitation was low. Only the plow treatment caused a loss of organic C and N. All tillage treatments increased the erosive fraction of the soil (fraction < 0.83 mm) compared to the chopped straw and spring burn treatment. The application of the 90/20 kg ha−1 rate of N and P fertilizer decreased the proportion of soil aggregates < 0.83 mm. There was no significant effect of tillage treatment on soil moisture conserved over the winter. There also was no tillage effect on NO3-N in the soil measured in the spring, but burning caused a significant increase in sodium bicarbonate-soluble P. The chopped straw treatment was concluded to be the best choice because the unincorporated residues will protect the soil best through the fall and winter and it is the easiest to implement. Where herbicides or fertilizers need to be fall-incorporated, any of the mechanical tillage implements except the plow should be equally suitable. Key words: Organic matter change, tillage, soil moisture, erodible aggregates, grain protein
CLASSIFICATION OF SOILS DEVELOPED ON BASIC PARENT MATERIALS IN THE CANADIAN AND FRENCH SYSTEMS OF SOIL CLASSIFICATION
Authors: KIMPE C. R. DE , DEJOU J.
Published: March 2010

Six profiles of soils developed on parent materials poor in SiO2 but rich in total Fe (> 10% Fe2O3), were sampled in Canada and France. In the French system of soil classification, the soils were classified as Andosols or Andic and Andic Brown soils because of their large amounts of < 50 μm particles and amorphous material, and their low bulk density related to large percentages of organic matter. All profiles contained one or more horizons that met the criteria of a Podzolic B horizon in the Canadian system of soil classification. The absence of a class for Andosols makes an appropriate classification of these soils difficult in the Canadian system. Key words: Andosols, Andic soils, Andic brown soils, podzols, soil classification
COMPARISON OF TILLAGE AND DIRECT DRILLING FOR ITALIAN RYEGRASS ON THE PROPERTIES OF A FINE SANDY LOAM SOIL
Authors: CARTER M. R. , KUNELIUS H. T.
Published: March 2010

The soil physical, biological, and chemical condition was assessed under cultivated and direct-drilled systems for the annual establishment of Italian ryegrass (Lolium multiflorum Lam.) on Prince Edward Island. After 3 yr, the degree of tillage-induced soil compaction and change in soil biological and chemical properties were determined over the 0- to 24-cm soil depth, and compared with the soil structure under a permanent timothy (Phleum pratense L.) pasture. The study was conducted at two sites on a Charlottetown fine sandy loam, an Orthic Humo-Ferric Podzol (Haplorthod). Although the tillage comparisons produced significant changes in soil porosity, pore-size distribution, pore continuity, aggregation and soil strength, the range in physical properties was within the range considered optimum for soil structure. Soil strength was shown to exhibit marked temporal variation over the growing season. Changes in the distribution of soil microbial biomass C and N, percent organic C, pH and plant nutrients were evident between the establishment methods. Generally, soil chemical and biological conditions under direct-drilling were similar to those under permanent pasture. Comparison of the actual with the estimated maximum bulk density down the soil profile indicated that the propensity for soil consolidation or compaction was the same under the direct-drilling and cultivated systems and similar to that measured under permanent pasture. The annual establishment of Italian ryegrass, for 3 yr, by direct-drilling did not adversely affect soil structure or increase soil compaction. Key words: Direct-drilling, Italian ryegrass, soil structure, soil biological properties, tillage
TEMPERATURE-SENSITIVE NODULATION AND N2 FIXATION OF Rhizobium leguminosarum BIOVAR Phaseoli STRAINS
Authors: RENNIE R. J. , KEMP G. A.
Published: March 2010

Two strains of Rhizobium leguminosarum biovar phaseoli, both previously Nod+Fix+ and efficient in N2 fixation, now have altered symbiotic properties presumably through spontaneous mutation. Rhizobium leguminosarum biovar phaseoli strain RCR 3605 was Nod−Fix− in a cool growth temperature regime (14–23 °C) and Nod+Fix− in a warm regime (17–23 °C) on seven of nine bean cultivars studied. Rhizobium leguminosarum biovar phaseoli strain CIAT 57 was Nod+Fix− in both temperature regimes. CIAT 57 and RCR 3605 are synonyms for strains derived from the same parent strain but housed in different culture collections. The nodulation deficiency in CIAT 57 is presumably genetically predetermined in the bacterium rather than in the plant because no Nod+Fix+ phenotype was identified on nine bean cultivars tested. A control R. leguminosarum biovar phaseoli strain, RCR 3644, was efficient on all cultivars. In the warm temperature regime, the Nod+Fix− phenotype was observed with strain RCR 3605 only on some cultivars, suggesting that the host plant genome played a role in this ineffective symbiosis. It is likely that deleterious genetic mutations during prolonged storage may be altering the N2-fixing ability of these rhizobial strains and that commercial inoculants must be continually monitored for symbiotic performance of strains with a variety of host plant cultivars. Key words: Field bean, Rhizobium leguminosarum biovar phaseoli, N2 fixation
COMPARISON OF FALL AND SPRING APPLICATION OF NITROGEN FERTILIZERS IN NORTHERN AND CENTRAL ALBERTA
Authors: NYBORG M. , MALHI S. S.
Published: March 2010

Fall and spring applications of N fertilizers (56 kg N ha−1) were compared for yield, and for N uptake, of spring-sown barley in 41 experiments in central and northern Alberta and three in north-central Saskatchewan. In addition, loss of fertilizer N from fall to spring was measured by determining mineral N in the soil samples taken before seeding. The N fertilizers were incorporated into the soil, to a depth of 10–12 cm for 42 experiments and to a depth of 4–5 cm for two experiments. The mineral N contents of soils, sampled in May to 60- or 90-cm depths in 22 experiments, indicated an average of 41% of the fall-applied urea N disappeared from the mineral N pool. The losses tended to be greater with fall-applied calcium nitrate than with fall-applied urea. The average increase in yield of barley grain was only 55% as great from fall application compared with spring application. The effect was slightly greater for N uptake in grain. Of the 44 experiments, the lower yield increase, and the lower N uptake from fall application was significant in 40 and 41 cases, respectively. The N uptake by grain tended to be less with calcium nitrate than with urea when the fertilizers were fall-applied. In multiple regression analyses, the ratios of fall:spring for yield increase from urea and for the recovery of urea N in grain were regressed upon date of fall application, soil drainage, fall soil moisture content, soil texture, and soil organic matter content. Of the independent variables, only date of fall application was statistically significant, with more effectiveness of the urea with later date of application. Key words: Fall application of N, mineral N losses, N fertilizers, N uptake, spring application of N, urea fertilizer
RESTORING PRODUCTIVITY TO AN ARTIFICIALLY ERODED DARK BROWN CHERNOZEMIC SOIL UNDER DRYLAND CONDITIONS
Authors: DORMAAR J. F. , LINDWALL C. W. , KOZUB G. C.
Published: March 2010

A field was artificially eroded by levelling in 1957 and then continuously cropped to barley for 7 yr. Subsequently, a wheat-fallow experiment was conducted from 1965 to 1979 to determine the effects of four fertilizer treatments and green manure (yellow sweet clover) on restoring the productivity to soil that had been "eroded" to various depths. After 22 yr and 14 crops, the productivity of the land from which soil was removed has been improved but not fully restored. Although green manuring with yellow sweet clover improved soil structure, wheat yields were not improved because of competition for soil moisture and poorer in-crop weed control in this part of the rotation. The addition of 45 kg N plus 90 kg P2O5 per hectare in each crop year to sites from which 8–10, 10–20, or 46 + cm of soil had been removed resulted in yield increases of 18, 46, and 70%, respectively, over the unfertilized check of each treatment; the average yields were 104, 91, and 70%, respectively, of the undisturbed, unfertilized (check) treatment. On "erosion" treatments where only 8–10 cm of soil were removed, 45 kg N plus 22 kg P2O5 per hectare were sufficient to restore the productivity. Precipitation apparently had a greater effect than fertilizer application on wheat yields. The loss of organic matter and associated soil structure characteristics seemed to be critical factors contributing to yield losses associated with soil erosion. These results show that it is more practical to use management practices that prevent soil erosion than to adopt the practices required to restore eroded soil. Key words: Soil erosion, topsoil loss, water-stable aggregates, soil organic matter, green manure, precipitation
A RAPID METHOD FOR ESTIMATING WEIGHTED SOIL SALINITY FROM APPARENT SOIL ELECTRICAL CONDUCTIVITY MEASURED WITH AN ABOVEGROUND ELECTROMAGNETIC INDUCTION METER
Authors: WOLLENHAUPT N. C. , RICHARDSON J. L. , FOSS J. E. , DOLL E. C.
Published: March 2010

This study presents a method for calibrating electromagnetic induction instrument readings with saturated paste electrical conductivity (ECe) for field mapping purposes. Each meter reading represents an integration of the apparent soil electrical conductivity (ECa) over the meter’s response depth. To correlate the meter readings with measured ECe within soil depth increments, several pedons representing a range of soil salinity for the survey area were sampled in 30-cm increments to a depth corresponding to the meter response. A weighting procedure based on the meter response-depth function was developed to condense the multiple ECe by depth measurements into a single weighted area specific value. These values were correlated with the apparent soil electric conductivity from the electromagnetic induction instrument by simple linear regression. This technique is designed for soil association of similar parent materials. The resulting regression equation yields a quick reliable equation that avoids complex mathematics and converts the instrument readings into weighted forms of commonly used saturated paste electrical conductivity values. Key words: Soil survey, electrical resistance
APPLICATION OF A SEQUENTIAL EXTRACTION PROCEDURE TO THE DETERMINATION OF THE DISTRIBUTION OF SULPHUR FORMS IN SELECTED PEAT MATERIALS
Authors: LOWE L. E.
Published: March 2010

Total S (St), soluble sulphate, pyritic S, elemental S, carbon-bonded S (C-S) and organic sulphate S were determined on four peat samples and three sedimentary gyttja samples, one of which (Ginc.) had been subjected to aerobic incubation. A sequential extraction procedure was used to assess the distribution of St and of organic S forms in a series of peat fractions. Total S varied from 0.42 to 3.67%, with values below 1% associated only with freshwater-derived peats. The S content of brackish peat and of gyttja was consistently high and in some cases, organic S exceeded 6% of the organic matter. With the exception of Ginc., organic S accounted for a very high proportion of St (mean 94%), with C-S the dominant organic S form. Ginc. showed a very different S form distribution from the unincubated gyttja samples, with organic S accounting for only 44.5% of St, and organic sulphate-S exceeding C-S. Ginc. also had a lower pH, suggesting acidification resulting from oxidation of the organic C-S fraction during incubation. The recovery of St in seven peat (or gyttja) fractions averaged 99%, and indicated that humic acid and residue ("humin") fractions together generally accounted for most of the organic S (73.3–90.4%), with the notable exception of Ginc., for which these fractions only accounted for 42–47% of organic S. The proportion of humic acid-S increased with increase in degree of peat decomposition. The fulvic acid fraction contained variable proportions of St and had relatively more oxidized S forms than humic acid or residue fractions. Some oxidation of C-S occurred during alkaline extraction. Minor amounts of organic S were extracted with water, chloroform and ethanol-benzene. Key words: Sulphur forms, peat sulphur, gyttja, peat fractions
COMPARISON OF ALUMINUM SPECIATION IN SOIL SOLUTIONS EXTRACTED BY BATCH AND COLUMN METHODS
Authors: DUFRESNE A. , HENDERSHOT W. H.
Published: March 2010

Soil solutions from an Orthic Ferro-Humic Podzol and a Typic Humisol were extracted using a soil to solution ratio of 1:10 by the batch and column procedures. The aluminum speciation in the extracts was determined by measuring three forms of dissolved aluminum (uncomplexed monomeric, total monomeric and total reactive). The two methods of extraction gave different results. For most of the mineral horizons and the moderately to well-decomposed organic horizons the batch method tended to extract more dissolved aluminum, particularly in uncomplexed monomeric form. The greatest differences between the two methods were for the lowest bulk density materials, the L and F horizons of the Podzol and the Of of the Humisol. The variations were due to channelling in the column and the inability of the shaker to assure good mixing between the soil and solution. It is concluded that the batch method is best suited for routine laboratory analyses. Key words: Soil solution chemistry, Podzols, Humisols
ACKNOWLEDGMENT OF REVIEWERS
Authors: Author Delete
Published: March 2010

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TILLAGE PRACTICES ON A NORTHERN CLAY SOIL: EFFECTS OF SOD BREAKING METHODS ON CROP PRODUCTION AND SOIL PHYSICAL PROPERTIES
Authors: GREVERS M. C. J. , BOMKE A. A.
Published: March 2010

Crop production in northern regions is mainly affected by a short growing season, and can also be further limited on heavy-textured soils by cool, wet spring conditions. Selected sod breaking practices were carried out resulting in maximum differences with respect to sod burial and soil physical properties. Soil physical properties measured included bulk density, air-filled porosity, aggregate size distribution, surface roughness and soil temperature. The main effects of the different tillage systems were: (1) differences in soil structure in terms of density and air-filled porosity, and (2) differences in the degree of residue incorporation. Moldboard plowing resulted in more favorable aeration porosity and soil temperature in spring than chisel plowing or discing. Rotovating prior to either moldboard plowing or chisel plowing had only a minor effect on soil physical conditions. In general the more effective the tillage was in incorporating crop residue and thatch, the higher was the subsequent soil temperature during the first 5 wk of the growing season. The differences in crop production followed the same trend as did differences in soil structure. This effect persisted through the third cropping season. Increasing levels of fertilizer N increased barley yields in all tillage treatments but did not offset the effect of physical differences caused by the tillage implements. Key words: Northern soils, tillage, soil temperature, soil structure, fertilizer nitrogen, barley
EFFECT OF SUBSOILING ON WHEAT YIELD AND SALT DISTRIBUTION OF A SOLONETZIC SOIL
Authors: CHANG C. , SOMMERFELDT T. G. , SCHAALJE G. B. , PALMER C. J.
Published: March 2010

The effects of subsoiling, deep ripping to 52 cm depth, in the amelioration of a Solonetzic soil under irrigated and nonirrigated conditions were examined at the Vauxhall Research Substation in Alberta. All plots were fertilized by broadcasting N and P2O5 at rates of 80 and 42 kg ha−1, respectively. Hard spring wheat (Triticum aestivum L. ’Neepawa’) was grown annually from 1980 to 1984. The plot area had a high degree of spatial variability in both physical and chemical properties of the soil. Subsoiling in the fall of 1979 and 1980 had no significant effects on soil salinity and sodicity or on wheat yield under nonirrigated conditions. However, under irrigated conditions, subsoiling enhanced the downward movement of salts and had a significant overall profile (to 90 cm) effect on soil salinity and sodicity, but it had no significant effect among depths within the profile. Subsoiling also had no significant effect on wheat yield under irrigated conditions. Irrigation alone improved the soil salinity and sodicity conditions, increased wheat yields, and reduced yield variability. Key words: Amelioration, irrigation, salinity, sodicity, spatial variability
DISTRIBUTION OF SOIL Zn FRACTIONS IN BRITISH COLUMBIA INTERIOR ORCHARD SOILS
Authors: HOYT P. B. , MacKENZIE A. F. , NEILSEN D.
Published: March 2010

The distribution of Zn in soil fractions was determined for 20 representative orchard soils from the British Columbia Interior. This was part of a larger study to examine Zn availability to fruit trees. Medium to high levels of total soil Zn were measured (51.5–226.3 mg kg−1) with an average of 89.7 mg kg−1. A sequential fractionation showed that 0.3–23.2% of total soil Zn was exchangeable, 0.5–29.7% was associated with organic matter, 1.3–15% was associated with Fe + Al oxides and 45.6–92% was residual. A separate determination indicated that 6.4–24% soil Zn was associated with Mn oxides. Except for the Fe + Al oxide fraction for which no correlations were made, amounts of Zn in the fractions were significantly positively correlated with total Zn, and also, with Bray P1 extractable P and organic matter content. Zinc in the exchangeable and organic fractions was negatively correlated with both pH and residual Zn. This suggested a redistribution of soil Zn from the residual fraction into the exchangeable and organic fractions with acidification. For exchangeable Zn this was further evidenced in the much smaller amounts of Zn extracted by M NH4OAc (pH 7.0) than by M MgCl2 from acid soils. The observed range of total Zn and exchangeable Zn suggests that a wide range of Zn availability could exist in B.C. Interior orchard soils. Key words: Soil Zn, Zn fractionation, orchard soils, pH × exchangeable Zn interaction
COMPUTER-ASSISTED MAPPING OF IRRIGATION WATER REQUIREMENTS FOR VANCOUVER ISLAND BASED ON SOIL AND AGRICULTURAL CAPABILITY SURVEY DATA
Authors: NAGPAL N. K. , SONDHEIM M. W. , WALLIS C. H.
Published: March 2010

The methodology is presented for computer assisted mapping of volumetric irrigation water requirement, as applied to the east coast of Vancouver Island, British Columbia. Soil and agricultural capability maps at 1:20 000 scale were digitized and the corresponding field and laboratory data were stored in a computer mapping system. An algorithm generates the volume of water required for each polygon by multiplying an area by a depth. The area is the number of arable hectares in the polygon. The depth is calculated as a weighted average of the individual irrigation depths for the arable soils within the polygon, where arability is tied to the attributes of each soil as compared to agricultural capability criteria. Using a water requirement model, the irrigation depth for a given soil is defined as a function of available water storage capacity, estimated to an assumed rooting depth for various crops, or to a root restricting layer; level of risk; and depth to the water table. On the resulting maps, polygons needing water are displayed, with a label depicting the required volume. Tabular summaries are provided on a polygon and mapsheet basis. The relative effects of using different definitions of arability (either agricultural capability classes 1 through 4 or agricultural capability classes 1 through 5), different rooting depths (0.5 or 1.0 m, depending upon proposed crops), and different levels of risk (one of 10, 20, or 50%) can be assessd by developing a set of scenarios. Key words: Irrigation, computer mapping
A GEOGRAPHIC ANALYSIS OF GRAIN CORN YIELD TRENDS IN ONTARIO USING A COMPUTERIZED LAND INFORMATION BASE
Authors: DUMANSKI J. , BOOTSMA A. , KIRKWOOD V.
Published: March 2010

The geographic variability of grain corn yield trends in Ontario for the period 1961–1982, and the relative importance of nitrogen fertilizer, weather variability, technology and cropland expansion on these trends was investigated. Of particular interest was the difference in yield response among regions to the increased weather variability in the 1970s. After the effects of weather on yield were removed, linear and nonlinear as well as positive and negative technology (time) trends were observed, depending on the suitability of soils and climate for corn in each area. Yield increases resulting from technology improvements (assuming normal weather) averaged 2, 1 and 0.3% per year in the most suitable, intermediate and marginal areas, respectively. Grain corn yields were more closely related to weather variability than to nitrogen fertilizer sales or cropland expansion. Although N fertilizer increased coincidentally with yield in the 1960s, a low correlation (r = 0.16) over the whole 1965–1982 period indicated the likely importance of other factors on yield. Weather parameters related to temperature and precipitation explained 21–64% of the variation in yield in multiple linear regression analyses. Including time parameters (technology) in the regression improved the explained variance for most map units (R2 = 0.36–0.79). A decrease in yields and an increase in yield fluctuations observed in many areas in the mid-1970s appeared to be related to increased weather variability, the greatest effect of which was in the areas least suited to corn. Grain corn yields have continued to increase in some areas of Ontario while in other areas yields have plateaued or decreased marginally. This pattern is distributed geographically north and eastward from the most suited regions. Key words: Corn yield, weather variability, nitrogen fertilizer, cropland expansion, land information, data bases
THE INFLUENCE OF DRAIN DEPTH ON THE RATE OF SOIL RECLAMATION IN IRRIGATED AREAS OF SOUTHERN ALBERTA
Authors: BUCKLAND G. D. , HARKER D. B. , SOMMERFELDT T. G.
Published: March 2010

Leaching trials were conducted for 2 yr on two irrigated saline-sodic soils with subsurface drains installed at depths of 0.76, 1.22 and 1.68 m. At one site, after 2 yr of leaching, average salinity levels in the 0- to 2.0-m soil depth were reduced to 91, 88 and 74% of original levels with drain depths of 0.76, 1.22 and 1.68 m, respectively. At the other site, where less water was applied, respective salinity levels were 114, 86 and 99% of original levels. Resalinization and resodification of the surface 0.2 m of soil occurred at both sites in the second year, which was a drought year, and were most pronounced with a drain depth of 0.76 m. Relative reductions in salinity, and efficiency of leaching, were lowest for the 0.76-m-depth drains at both sites. Key words: Subsurface drainage, reclamation, soil salinity, leaching
NUTRIENT CYCLING AND AVAILABILITY IN FOREST SOILS
Authors: MAHENDRAPPA M.K. , FOSTER N.W. , WEETMAN G.F. , KRAUSE H.H.
Published: March 2010

Nutrient availability in different forest soils must be known before increased wood production can be sustained either by adding supplemental nutrients or by judicious silvicultural operations to optimize the linkage between the variable nutrient requirements of forest crops. This is complicated by the variable availability of nutrients on forest sites during crop development. Forest crops unlike agricultural crops have long rotation periods which make it difficult to apply agricultural methods of estimating potentially available nutrients directly to forest soils. Presented in this review are (i) various approaches used in forestry to estimate the nutrient supplying potential of different sites, (ii) factors affecting nutrient availability, and (iii) evidence to suggest that nutrient cycling processes in forest ecosystems are important factors affecting tree growth. It is suggested that data from chemical analyses of soil samples collected at specific times and sites should be used with caution for both practical decision making and simulation modelling purposes. Key words: Nitrogen, phosphorus, litterfall, throughfall, stemflow, mineralization
IMPROVEMENT OF SOIL PROPERTIES AND PLANT GROWTH ON A BROWN SOLONETZIC SOIL USING IRRIGATION, CALCIUM AMENDMENTS AND NITROGEN
Authors: CARTER M. R. , PEAREN J. R. , CAIRNS R. R. , McANDREW D. W. , KARKANIS P. G.
Published: March 2010

A 4-yr study was conducted on an irrigated Brown Solonetzic soil in southern Alberta to determine the effects of relatively low rates (4.2 Mg Ca ha−1) of surface-applied gypsum (CaSO4·2H2O) and lime (CaCO3) on soil chemical properties, water penetration and growth of bromegrass (Bromus inermis Leyss). Annual applications (155 kg N ha−1) of ammonium nitrate (NH4NO3) and ammonium bisulphite (NH4HSO3) were applied alone and in combination with the Ca amendments. Gypsum improved the chemical condition of the Bnt horizon by decreasing soluble Na and the electrical conductivity, and increasing levels of exchangeable Ca. The exchangeable Ca to Na ratio was increased from 5.5 to 16.9, while the sodium adsorption ratio was reduced from 18.1 to 7.6. Gypsum also decreased the EC of the Csk horizon from 12.7 to 5.2 dS m−1. In contrast, the lime amendment only increased the exchangeable Ca level of the Bnt horizon. Ammonium bisulphite decreased the soil pH of the soil profile, especially the Ap horizon (7.3–6.3), and increased the initial rate of water penetration into the Bnt horizon. Gypsum increased by threefold the rate of water infiltration into the Bnt horizon compared with the control soil. Plant yields were increased over the control by ammonium bisulphite (46%), ammonium nitrate (66%), gypsum (77%) and gypsum plus ammonium nitrate (111%). The study indicates that a combination of irrigation with gypsum was capable of moving Ca into a relatively high sodic Bnt horizon, causing an improvement in both the soil condition and plant productivity. Key words: Solonetzic soil, irrigation, gypsum, lime, sodic soil, ammonium nitrate