Acesulfame and other artificial sweeteners in a wastewater treatment plant in Alberta, Canada: Occurrence, degradation, and emission.

Acesulfame (ACE), sucralose (SUC), cyclamate (CYC), and saccharin (SAC) are widely used artificial sweeteners that undergo negligible metabolism in the human body, and thus ubiquitously exist in wastewater treatment plants (WWTPs). Due to their persistence in WWTPs, ACE and SUC are found in natural waters globally. Wastewater samples were collected from the primary influent, primary effluent, secondary effluent, and final effluent of a WWTP in Alberta, Canada between August 2022 and February 2023, and the artificial sweeteners concentrations were measured by LC-MS/MS. Using wastewater-based epidemiology, the daily per capita consumption of ACE in the studied wastewater treatment plant catchment was estimated to be the highest in the world. Similar to other studies, the removal efficiency in WWTP was high for SAC and CYC, but low or even negative for SUC. However, ACE removal remained surprisingly high (>96%), even in the cold Canadian winter months. This result may indicate a further adaptation of microorganisms capable of biodegrading ACE in WWTP. The estimated per capita discharge into the environment of ACE, CYC, and SAC is low in Alberta due to the prevalent utilization of secondary treatment throughout the province, but is 17.4-18.8 times higher in Canada, since only 70.3% of total discharged wastewater in Canada undergoes secondary treatment.

Evaluation of Standardized Bait Trapping Approaches and Climatic Factors That Influence Wireworm Catch in the Canadian Prairies.

Wireworms are significant pests of a variety of economically important crops grown in the Canadian Prairies. These soil-dwelling larvae of click beetles feed on and burrow into the accessible underground plant tissues, which can result in cosmetic injury, stunting, wilting, and plant death. Successful management of wireworms relies on accurate estimations of their abundance and activity in infested fields. Bait trapping is the most commonly used method for sampling wireworms and standardized approaches have been developed; however, little work has been done to optimize trapping efficacy in different geographical regions. In this study, we evaluated the effect of bait trapping duration, seed formulation, and the causal relationship with CO2 production and soil temperature on the wireworm catch in three fields located in Manitoba, Canada. As expected, wireworm catch increased with trapping duration and placing traps in ground for 8 d is adequate in most cases. Both barley and wheat were more effective baits than soybean; however, barley released more CO2 (i.e., an attractant for wireworms) and performed better at elevated soil temperatures. Overall, the results of this study will serve as valuable guidelines to improve current wireworm sampling methods, and can be integrated into strategies aimed at managing these important pests to crop production.

Three years of surveillance associates agro-environmental factors with wireworm infestations in Manitoba, Canada.

BACKGROUND: Wireworms, the soil-dwelling larvae of click beetles, are a major threat to global agricultural production. This is largely due to their generalist polyphagous feeding capabilities, extended and cryptic life cycles, and limited management options available. Although wireworms are well-documented as economically important pests in the Canadian Prairies, including Manitoba, there are gaps in knowledge on species distributions, subterranean behaviour and life cycles, feeding ecology and damage capacity, and economic thresholds for crop yield loss. RESULTS: We carried out 3 years (2018-2020) of intensive surveillance of larval populations across Manitoba. A total of 31 fields (24 in ≥ 2 consecutive years) were surveyed in early spring using standardized bait trapping approaches. Wireworms were present in 94% of surveyed sites, but the catch within fields varied year to year. While Hypnoidus bicolor predominated (94% of larvae), several other pest species were identified. We then explored the relationships between wireworm trap numbers and agro-environmental factors. The larval catch tended to decrease under conditions of low soil temperatures and increased clay content, coupled with high soil moisture and precipitation during the trapping period. Treatment and cultural methods appeared less influential; however, wheat production in either of the previous two growing seasons was associated with increased wireworm catch. Our models failed to predict a relationship between wireworm catch and crop yields, although infestations were rare in our region. CONCLUSION: Our findings better infer the risks posed by wireworms to crop production in the Canadian Prairies, and the agro-environmental factors that represent the greatest contributors to these risks. This information should be incorporated into future integrated pest management (IPM) strategies for wireworms. © 2021 Her Majesty the Queen in Right of Canada Pest Management Science © 2021 Society of Chemical Industry Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Phosphorus runoff from Canadian agricultural land: A dataset for 30 experimental fields.

Phosphorus (P) runoff from agricultural land plays a critical role in downstream water quality. This article summarizes P and sediment runoff data for both snowmelt and rainfall runoff from 30 arable fields in the Canadian provinces of Saskatchewan, Manitoba and Ontario. The data were collected from 216 site-years of field experiments, with climates ranging from semi-arid to humid and a wide range of field management practices. In the article, mean annual and seasonal (in terms of snowmelt and rain) precipitation inputs, runoff depths, and P and sediment concentrations and loads are presented, along with ranges of yearly values. In addition, information of field management and soil characteristics (e.g. soil type and soil Olsen P) is also presented for each field. The data have potential to be reused for national and international cross-region comparisons of P and sediment losses, constructing and validating decision-support models and tools for assessing and managing P losses in both snowmelt and rainfall runoff, and informing beneficial management practices to improve agricultural water quality. Interpretation of the data is found in "Phosphorus runoff from Canadian agricultural land: A cross-region synthesis of edge-of-field results" [1].

A new approach for generating optimal GLDAS hydrological products and uncertainties.

This study proposes a new approach that can be used to generate the optimal surface state information and associated uncertainties from the estimates provided by the six land surface models used by the Global Land Data Assimilation System (GLDAS). The Förstner and best quadratic unbiased variance component estimators are used simultaneously with the least-squares method to calculate optimal values and the associated uncertainties. To demonstrate the concept, the research focused on three GLDAS hydrological products, namely soil moisture (SM), snow water equivalent (SWE), and canopy water (CAN) over the Canadian Prairies. When the Förstner estimator is applied, the estimated SM and SWE differ from their corresponding mean values by 26 mm and 9 mm respectively. Almost similar result was found with the best quadratic estimator. The estimated maximum uncertainties of each component including SM, SWE and CAN vary from year to year (e.g. 35 mm in 2006, 12 mm in 2007 and 2009 and 0.1 mm in 2001, respectively). The uncertainties of the total water storage (TWS) are almost similar to that of SM, which contributes more importantly to TWS in the area considered. The results obtained by the two proposed estimators were compared to the waterGAP hydrological models (WGHM), and to the Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage anomalies. The optimal SWE anomalies generated from GLDAS using the proposed approach show a maximum correlation of r = 0.97 with the WGHM SWE anomalies. The optimal TWS anomalies have a correlation of r = 0.91 with WGHM, and r = 0.71 with GRACE. However, the correlation jumps to r = 0.81 when GRACE TWS is corrected for groundwater signals (with a mean RMSE of 8.5 mm). The RMSE and mean absolute error between our proposed methods and WGHM and GRACE are better than those obtained with each individual LSM or their average value. No significant mean bias error is observed in each case. Finally, the analysis of the time-lag characteristics of the resonance period between the results and their coherence was done by using a cross wavelet transform and a wavelet coherence analysis.

Technoeconomic analysis of biojet fuel production from camelina at commercial scale: Case of Canadian Prairies.

This study undertakes technoeconomic analysis of commercial production of hydro-processed renewable jet (HRJ) fuel from camelina oil in the Canadian Prairies. An engineering economic model designed in SuperPro Designer® investigated capital investment, scale, and profitability of producing HRJ and co-products (biodiesel, naphtha, LPG, and propane) based on biorefinery plant sizes of 112.5-675 million L annum-1. Under base case scenario, the minimum selling price (MSP) of HRJ was $1.06 L-1 for a biorefinery plant with size of 225 million L. However, it could range from $0.40 to $1.71 L-1 given variations in plant capacity, feedstock cost, and co-product credits. MSP is highly sensitive to camelina feedstock cost and co-product credits, with little sensitivity to capital cost, discount rate, plant capacity, and hydrogen cost. Marginal and average cost curves suggest the region could support an HRJ plant capacity of up to 675 million L annum-1 (capital investment of $167 million).

Reduced abundance and earlier collection of bumble bee workers under intensive cultivation of a mass-flowering prairie crop.

One of the most commonly seeded crops in Canada is canola, a cultivar of oilseed rape (Brassica napus). As a mass-flowering crop grown intensively throughout the Canadian Prairies, canola has the potential to influence pollinator success across tens of thousands of square kilometers of cropland. Bumble bees (Bombus sp.) are efficient pollinators of many types of native and crop plants. We measured the influence of this mass-flowering crop on the abundance and phenology of bumble bees, and on another species of social bee (a sweat bee; Halictus rubicundus), by continuously deploying traps at different levels of canola cultivation intensity, spanning the start and end of canola bloom. Queen bumble bees were more abundant in areas with more canola cover, indicating that this crop is attractive to queens. However, bumble bee workers were significantly fewer in these locations later in the season, suggesting reduced colony success. The median collection dates of workers of three bumble bee species were earlier near canola fields, suggesting a dynamic response of colonies to the increased floral resources. Different species experienced this shift to different extents. The sweat bee was not affected by canola cultivation intensity. Our findings suggest that mass-flowering crops such as canola are attractive to bumble bee queens and therefore may lead to higher rates of colony establishment, but also that colonies established near this crop may be less successful. We propose that the effect on bumble bees can be mitigated by spacing the crop more evenly with respect to alternate floral resources.

Occurrence of Ditylenchus weischeri and Not D. dipsaci in Field Pea Harvest Samples and Cirsium arvense in the Canadian Prairies.

The stem nematode, a parasite of the herbaceous perennial weed, Cirsium arvense (L.) Scop. and identified as Ditylenchus dipsaci (Kühn) Filipjev, was reported in the Canadian prairies in 1979. Recently, D. weischeri Chizhov parasitizing Cirsium arvense was described in Russia, and it has been shown that this species is not an agricultural pest. In this study, we examined Ditylenchus species found in field pea (Pisum sativum L.) grain harvest samples in 2009 and 2010 and from C. arvense shoots in pea fields in the Saskatchewan, Alberta, and Manitoba provinces. Samples from 538 fields (mainly yellow pea) were provided by 151 growers throughout the main pea-growing area of the Canadian prairies. Of the samples collected, 2% were positive for Ditylenchus. The population density of the nematode ranged between 4 and 1,500 nematodes kg(-1) pea harvest sample and related to presence of C. arvense seeds. Positive samples occurred in 2009 but not in 2010 and were from throughout the pea-growing area of the Canadian prairies and not related to cropping history. C. arvense collected from yellow pea fields in Saskatchewan and Manitoba, but not Alberta, were infested with Ditylenchus. Morphological and molecular (ITS-PCR-RFLP) traits indicated that this species belongs to D. weischeri. The results indicated the stem nematode found in yellow pea grain is D. weischeri which resided with C. arvense seeds and debris to pea samples. Unlike D. dipsaci, D. weischeri is not a nematode pest of economic importance; therefore, its presence in the pea harvest samples was not a concern.