Canadian Prairie Region Research Articles

New bioactive natural products from Coprinus micaceus

Chemical studies on the crude methanolic extract of Coprinus micaceus, collected from the Canadian Prairie region, have resulted in the isolation of two new natural products, micaceol (1), a sterol and (Z,Z)-4-oxo-2,5-hetpadienedioic acid (2). Compound 2 was isolated for the first time as a natural product. Structures of these new compounds were established with the aid of extensive NMR spectroscopic studies. Compound 1 has shown anti-bacterial activity against Corynebacterium xerosis and Staphylococcus aureus, whereas compound 2 exhibited glutathione S-transferase inhibition.

Correlates of Canadian Prairie summer rainfall: implications for crop yields

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 32:25-33 (2006) - doi:10.3354/cr032025 Correlates of Canadian Prairie summer rainfall: implications for crop yields Ray Garnett1,*, Niru Nirupama2, C. Emdad Haque3, T. S. Murty4 1Agro Climatic Consulting, 1340 Aikins Street, Winnipeg, Manitoba R2V 2C7, Canada 2School of Administrative Studies, Rm. 210A, Atkinson College, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada 3Natural Resource Institute, University of Manitoba, 70 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada 4Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur Room A106, Ottawa, Ontario K1N 6N5, Canada *Email: ergarnett@shaw.ca ABSTRACT: Large-scale atmospheric circulations and anomalies have significant influence upon seasonal weather over many parts of the world. We examined the impact of sunspot activity and large-scale atmospheric features on regional seasonal weather, as well as implications for crop yield and agronomy. The atmospheric variables analyzed included the stratospheric quasi-biennial wind oscillation (QBO), El Niño/Southern Oscillation (ENSO), and North American snow cover (NAS) on Canadian summer rainfall, regarded as a key variable for establishing grain yield. Because the study is an exploratory one, we focused on correlation coefficients between selected variables. The analysis is based on 55 yr of atmospheric, crop yield and climatic data for >50 weather stations over the Canadian Prairie region. Our study reveals that high (low) sunspot activity, an easterly (westerly) phase of the QBO, persistent La Niña (El Niño) conditions and heavier (lighter) than normal NAS in seasons leading up to the summer months are associated with low (high) summer rainfall. KEY WORDS: Summer rainfall · Snow cover · Sunspots · ENSO · QBO · Canadian Prairie · North America Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 32, No. 1. Online publication date: August 10, 2006 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2006 Inter-Research.

Management of Canadian prairie region grazed grasslands: Soil C sequestration, livestock productivity and profitability

The GrassGro model (a computer simulation of management-induced changes in range and pasture forage and livestock productivity) was combined with spreadsheet analyses to estimate the influence of improved grazing practices on soil organic carbon (SOC), and farm profitability, across native rangelands and tame pastures of the southern Canadian Prairies. Improved practices included complementary grazing (CG) and reduced stocking density (RSD) on rangeland; and N fertilization (FERT), seeded grass/legumes grazed continuously (GLGC) or rotationally (GLGR), and RSD on tame pastures. The analysis was stratified into three ecoregions on the basis of similarities in climate and soil type. Averaged over 30 yr and ecoregions, SOC rates of gain through improved management were 5 (RSD) to 26 (CG) kg C ha-1yr-1 for rangelands, and 86 (RSD), 75 (GLGC), 62 (GLGR) and 222 (FERT) kg C ha-1yr-1 for tame pastures. Gains with FERT were considered largely negated by associated energy (C) costs, N2O emissions, and shifts in grassland species. The CG system alone improved net returns to the producer. The estimated potential combined SOC gain on prairie grazinglands (11.5 Mha) was 1.63 MMT CO2 yr-1 (or 0.465 MMT C yr-1), slightly less than the 1.70 MMT CO2 yr-1 currently emitted from agricultural soils in Canada. Key words: Soil carbon, GrassGro model, grazing management, rangeland, tame pasture

Crop rotation and tillage impact on carbon sequestration in Canadian prairie soils

Carbon sequestration was determined for different tillage systems in semiarid to sub-humid climates and coarse to fine-soil texture in Saskatchewan, Canada. Annually cropped rotations sequestered 27–430 kg C ha −1 per year more than crop rotations containing bare fallow. The potential for sequestering soil organic C (SOC) with crop rotations without bare fallow was greater in the sub-humid than in the drier climates. No-tillage (NT) sequestered 67–512 kg C ha −1 per year more than tilled systems. With elimination of both tillage and bare fallow, the SOC increase was approximately 300 kg C ha −1 per year in the semiarid climate regardless of soil texture, and approximately 800 kg C ha −1 per year in the sub-humid climate. Relative annual increase in SOC under no-till was approximately a linear function of clay content across locations. Fine-textured soils have a greater potential for gains in SOC under no-till in Canadian prairie region.

TREE RING RECONSTRUCTIONS OF STREAMFLOW FOR THREE CANADIAN PRAIRIE RIVERS1

ABSTRACT: Information regarding long term hydrological variability is critical for the effective management of surface water resources. In the Canadian Prairie region, growing dependence on major river systems for irrigation and other consumptive uses has resulted in an increasing vulnerability to hydrological drought and growing interprovincial tension. This study presents the first dendrochronological records of streamflow for Canadian Prairie rivers. We present 1,113‐year, 522‐year, and 325‐year reconstructions of total water year (October to September) streamflow for the North Saskatchewan, South Saskatchewan, and Saskatchewan Rivers, respectively. The reconstructions indicate relatively high flows during the 20th Century and provide evidence of past prolonged droughts. Low flows during the 1840s correspond with aridity that extended over much of the western United States. Similarly, an exceptional period of prolonged low flow conditions, approximately 900 A.D. to 1300 A.D., is coincident with evidence of sustained drought across central and western North America. The 16th Century megadrought of the western United States and Mexico, however, does not appear to have had a major impact on the Canadian rivers. The dendrohydrological records illustrate the risks involved if future water policy and infrastructure development in the Canadian Prairies are based solely on records of streamflow variability over the historical record.

Global snow cover monitoring with spaceborne K/sub u/-band scatterometer

This paper presents a study to demonstrate the potential of a spaceborne K/sub u/-band scatterometer to monitor global snow cover. Global Ku-band data were acquired by the NASA Scatterometer (NSCAT) operated on the Advanced Earth Observing Satellite (ADEOS) from September 1996 to June 1997. NSCAT backscatter patterns aver the northern hemisphere reveals boundaries between different snow classes, defined by the Cold Regions Research and Engineering Laboratory (CRREL), Hanover, NH, snow classification system at different times of the snow season. They show the evolution of the backscatter signature throughout the entire seasonal snow cycle. Within the snow extent determined by the National Oceanic and Atmospheric Administration (NOAA), Washington, DC, and Climate Prediction Center (CPC), operational snow product, Ku-band backscatter data expose detailed features and rapid changes as observed in in-situ snow depth data from surface weather stations in U.S., Canada, and Russia. Sensitivity of Ku-band backscatter to snow conditions is illustrated with the dramatic change over the U.S. northern plains and the Canadian prairie region corresponding to the snow event leading to the 1997 Flood of the Century. They discuss snow field experiments and data analysis plan to understand snow scattering mechanisms, to interpret snow backscatter, and to derive its relationship with snow physical parameters.

Predator size and distance to edge: is bigger better?

I investigated the use of edge by soil arthropods by testing whether mesoarthropod predators were closer to edge than expected and whether large predators were closer to edge than small predators. The experimental design consisted of 120 boxes, each covering 200 cm2 of soil, that were randomly distributed within a 0.13-km2 aspen stand located in the Canadian prairie region. Each 2-kg box depressed the leaf litter, creating a microhabitat island for soil arthropods consisting of 61 cm of edge. During 20 weekly surveys from May to September in 1997 and 1998, numbers and distribution of arthropods located immediately beneath the boxes were recorded. Mesoarthropod predators were found closer to edge than expected. Centipedes, beetle larvae, and predatory mites (Acari) were found at intermediate distances to edge, whereas beetles, ants, adult flies, bugs, and spiders were distributed adjacent to edge. Generally, larger mesoarthropod predators were found closer to edge than smaller individuals, within each taxonomic group. Collembola, the major mesofauna prey, were distributed randomly with respect to edge during wet periods of high density. During the subsequent dry periods, reduced densities of Collembola occurred and distribution became skewed, with greater numbers in interior areas and reduced densities near edges. Temperature and moisture under the boxes did not vary with distance to edge, although the microclimate was cooler and more humid under the experimental boxes relative to beyond the boxes. These results support the hypotheses that mesoarthropod predators forage along box edges (i.e., linear corridors) and that larger individuals may gain access to edge owing to their larger size, although alternative explanations are possible, depending on the particular taxonomic group.

Experience with alkali-aggregate reaction in the Canadian prairie region

This paper summarizes alkali-aggregate reaction (AAR) experience in the prairie region to date. Information is presented on reactive rock types and their geological significance, laboratory test data, field evidence of affected structures, and industry practices for preventive measures and management of affected structures. The frequency and severity of documented AAR-affected structures in Manitoba, Saskatchewan, and Alberta is low, Alberta having the highest incidence. A significant number of aggregate sources in the region show potential for excessive expansion when subjected to laboratory testing. The lack of field evidence is generally attributed to the lower alkali contents of cements that have historically been produced and used in the region. Limited number and extent of searches for affected structures, inadequate diagnosis of the phenomenon, and client confidentiality are also factors. It is imperative that specifiers, owners, researchers, suppliers, and producers be aware of the potential reactivity of local aggregates. The occurrences of AAR-related deterioration in the field demonstrates that the phenomenon is not limited to the laboratory. The effectiveness of low to moderate alkali contents of concrete mixtures in controlling the AAR phenomenon demonstrates the need to specify low-alkali cement and the importance of measuring the effectiveness of supplementary cementing materials in preventing AAR. There is a need to conduct extensive field searches for affected structures and it is important that suspected cases of AAR be properly diagnosed.Key words: alkali-aggregate reaction, concrete, Manitoba, Saskatchewan, Alberta, laboratory testing, field evidence, pattern cracking, prisms, mortar bars, prevention, management.

Experience with alkali-aggregate reaction in the Canadian prairie region

This paper summarizes alkali-aggregate reaction (AAR) experience in the prairie region to date. Information is presented on reactive rock types and their geological significance, laboratory test data, field evidence of affected structures, and industry practices for preventive measures and management of affected structures. The frequency and severity of documented AAR-affected structures in Manitoba, Saskatchewan, and Alberta is low, Alberta having the highest incidence. A significant number of aggregate sources in the region show potential for excessive expansion when subjected to laboratory testing. The lack of field evidence is generally attributed to the lower alkali contents of cements that have historically been produced and used in the region. Limited number and extent of searches for affected structures, inadequate diagnosis of the phenomenon, and client confidentiality are also factors. It is imperative that specifiers, owners, researchers, suppliers, and producers be aware of the potential reactivity of local aggregates. The occurrences of AAR-related deterioration in the field demonstrates that the phenomenon is not limited to the laboratory. The effectiveness of low to moderate alkali contents of concrete mixtures in controlling the AAR phenomenon demonstrates the need to specify low-alkali cement and the importance of measuring the effectiveness of supplementary cementing materials in preventing AAR. There is a need to conduct extensive field searches for affected structures and it is important that suspected cases of AAR be properly diagnosed.Key words: alkali-aggregate reaction, concrete, Manitoba, Saskatchewan, Alberta, laboratory testing, field evidence, pattern cracking, prisms, mortar bars, prevention, management.

Freeze-drying processes and wind erodibility of a clay loam soil in southern Alberta

Freeze-drying has been implicated as a factor causing soil aggregate breakdown on the Canadian Prairies and northern Great Plains. Aggregates of a Dark Brown Chernozemic clay loam soil sampled in October 1993 and January and April 1994 were subjected to repeated cycles of wetting (to 0.1, 0.2 and 0.3 kg kg−1 water contents) freezing, and freeze-drying under laboratory conditions. The October 1993 samples showed less disruption when initially exposed to freeze-drying cycles compared to samples taken in January and April 1994. Using regression analysis, we predicted that 31 freeze-dry cycles were required for the 0.1 kg kg−1 water content aggregates to reach 60% erodible fraction (EF, % aggregates <0.86 mm), 9 cycles for the 0.2 kg kg−1 aggregates and 2 for 0.3 kg kg−1 aggregates. In a field study, conducted over the 1994–1995 winter on a similar clay loam soil, we estimated the number of freeze-drying cycles using large vapour pressure (VPL) and small vapour pressure (VPS) gradients between the soil surface (which had a mean winter water content of ~0.1 kg kg−1) and the atmosphere. With solar energy adjustments, we predicted that the number of freeze-dry cycles required for the soil to reach 60% EF was 60 for VPL and 37 for VPS conditions. The latter number was similar to the 31 cycles predicted in the laboratory study of aggregates at 0.1 water content. Our results demonstrate that freeze-drying is an important overwinter process in the breakdown of soil aggregates and hence wind erosion risk in the Canadian prairie region. Key words: Freeze-drying, wind erosion, erodible fraction

Monitoring soil moisture over the Canadian Prairies with the ERS scatterometer

The capability of the scatterometers onboard the European Remote Sensing Satellites (ERS-1 and ERS-2) for soil moisture retrieval is investigated. The ERS scatterometer consists of three antennas that illuminate the Earth's surface from three different viewing directions. This allows the authors to study the dependence of the backscattering coefficient /spl sigma//sup 0/ on the azimuth and the incidence angle. An analysis of ERS scatterometer data over the Canadian Prairie region shows that land surfaces are slightly anisotropic with respect to the azimuth angle. It is proposed to consider the azimuthal anisotropy as an additional error source to /spl sigma//sup 0/. The variation of /spl sigma//sup 0/ with the incidence angle was found to be linked to vegetation, but independent of soil moisture. Based on these observations, a method for the normalization of the backscattering coefficient with respect to the incidence angle is proposed. The normalized backscattering coefficient at an incidence angle of 40/spl deg/, /spl sigma//sup 0/(40), is sensitive to vegetation and, in the case of moderate vegetation (grassland to sparsely forested areas), to the soil moisture content. Soil moisture maps derived from ERS-1 scatterometer measurements are compared to maps representing conditions on annually cropped land showing agreement. Results suggest that, over the Canadian Prairies, estimates of the total water content in the soil profile might be possible with an accuracy of about 10% of field capacity if little or no rainfall has occurred for three days before radar image acquisition.

Review of recent developments in soil water simulation models

Soil water is of great importance to agricultural and hydrological systems, affecting crop yields, agricultural management practices and a wide range of physical and chemical processes in soils. Many models have been developed over the years to simulate soil water, ranging from simple water balance procedures to complex deterministic models. In this paper, some of the basic concepts, strengths, weaknesses and input requirements of soil water models are reviewed. Simple budget models which require only available water-holding capacity, based on the concepts of field capacity and wilting point, and monthly average values of precipitation and potential evapotranspiration (PET) are often adequate for climatic characterizations. However, detailed deterministic models are useful for investigating more complex processes such as solute movement, soil degradation and crop growth. These models are based on Richards’ equation, with an added term for root water extraction. They generally require daily or hourly meteorological data and detailed hydraulic conductivity and water potential functions for various soil layers.Meteorological data for input into models are widely available in Canada from a network of climate stations. However, the network density is sparse for those models which use the most accurate procedures for estimating PET, requiring parameters such as wind, solar radiation and/or humidity. Moreover, pedotransfer functions generally need to be used to estimate, from existing soil databases, the required soil inputs for sophisticated models.To demonstrate a practical application, a soil water model was used in conjunction with simple crop yield/water use relationships to characterize soil water regimes and crop production risks. The probability of obtaining break-even yields (PBEY) for continuous spring wheat was calculated and mapped for the Canadian prairie region. PBEY ranged from less than 20% in the most arid region of the prairies to between 60 and 100% in most humid areas. An estimate of PBEY based on modelled yields was in close agreement with that based on long-term measured yields in the sub-arid region. With increasing availability of integrated multi-process based models, this technique has potential for studying the effects of soil characteristics and crop management techniques on PBEY. Key words: Soil water, simulation models, review, spring wheat, break-even yield, Canadian prairies

An Evaluation of Heating and Ventilation Control Strategies for Livestock Buildings

Thermal responses and supplemental heat consumption of a livestock building airspace were investigated using a simulation program and Typical Meterological Year weather data for a cold (-23 to -32°C) and a warm day (-4 to 7°C) in the Canadian Prairie Region. Three different control strategies using different sizes of heating/ventilating equipment and different controller time constants were evaluated. In an either-or-temperature (EOT) control, stage 1 ventilation was provided continuously by fan 1; stage 2 ventilation and the heater were controlled by the same temperature actuated switch such that either the heater was on or stage 2 ventilation fan 2 was on, but not both. In an either-or-neither temperature (EONT) control, stage 1 ventilation was provided continuously and the heater and stage 2 ventilation were controlled by separate actuated switches with a fixed interstage differential. In a temperature-humidity control (THC), all stages of ventilation were controlled thermostatically and the heater was controlled by a humidistat. THC control strategy provided the best thermal response and used the least supplemental heat. EOT control could achieve a variable ventilation rate for moisture control when fans and heater were correctly designed. EONT control provided good temperature control but failed to control humidity. Oversizing of heating/ventilating equipment resulted in poorer thermal response and higher energy consumption for EOT and EONT systems but had little effect on the THC system. Controllers with large time constants economized the use of supplemental heat but introduced poor thermal responses for all three control strategies.

Variability of soil water deficiencies for perennial forages in the Canadian prairie region

Variability in soil water deficiencies on the Canadian prairies was assessed by calculating forage aridity indices (FAI). These indices integrate climatic and soil parameters with water requirements for optimal forage growth. The model calculated a daily soil water balance by rain entering the soil until full capacity was reached, and evapotranspiration occurring at the potential rate. Supplemental water was added when the available soil water was reduced to 50% of the soil available water-holding capacity (AWC). The summation of these supplements constituted the forage aridity index for the growing season. Daily weather data from 1956–1985, derived for 250 agroecological resource areas (ARA) and 4 different AWCs were input to the model. The results were summarized in terms of fixed probability levels ranging from 5 to 95%. The 50 and 10% probability levels were mapped for the dominant AWC within each ARA. Regression equations were developed to account for local variability in AWC. The FAI during a “normal” year (50% probability) ranged from 66 to 496 mm, while during an ‘abnormally dry’ year (10% probability) it ranged from 180 to 579 mm. Within similar climatic regions, the 50% probability FAI of 100 mm AWC soils was approximately equal to what might be expected once every ten years (10% probability) on a 250 mm AWC soil. Relationships among FAIs at different AWCs and fixed probability levels were developed in order to estimate probability levels between 5 and 95%.

Non-Metropolitan Population Growth and the Evolution of Rural Service Centres in the Canadian Prairie Region

STABLER J. C. (1987) Non-Metropolitan population growth and the evolution of rural service centres in the Canadian Prairie region, Reg. Studies 21, 43–53. The growth of non-metropolitan population in the Canadian Prairie region during the 1970s did not produce a counterpart revival of the trade centre status of rural communities. Analysis of 1,027 small communities in this region reveals that more than one-half declined in trade centre status between 1961 and 1981. Further, each functional category provided fewer consumers' and producers' services in 1981 than in 1961. These observations imply that, while an increasing number of people prefer to live in non-metropolitan areas, their shopping patterns, nevertheless, reflect a preference for the options provided by larger urban places. Their presence has not revived the trade centre status of the small communities they have chosen to live in. STABLER J. C. (1987) La croissance de la population non-metropolitaine et l'evolution des noyaux tertiaires ruraux d...

Segregation in feeding behaviour of four diving ducks in southern Manitoba

The canvasback, Aythya valisinaria; redhead, A. americana; scaup, A. affinis; and ruddy duck, Oxyura jamaicensis, are sympatric on the small wetlands of the Canadian prairie region. The four species did not occur randomly and each species tended to occur by itself more often than with any other species. Each species tended to forage in a particular part of a pond. Selection for different foraging sites appears to be important in segregating those species whose diets overlap most.

Oil and protein content, and oil composition of the seeds of some plants of the Canadian prairies

AbstractThe oil and protein content are reported for the seeds of 19 plant species selected for their possible crop potential for the Canadian prairie region. Data on seed oil composition are reported for the 12 species which contained greater than 15% seed oil.