Agri-Food Canada Research Articles

AAC Planet field pea

AAC Planet is a semi-leafless and powdery mildew (caused by Erysiphe pisi Syd.) resistant field pea ( Pisum sativum L.) variety developed at Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, Alberta, Canada. It has high yielding potential, late maturity, tall plant height with good lodging resistance, medium seed size, round seed shape, and low seed coat breakage. It has maturity of 100 days, and thousand-seed weight of 221 g with seed protein content of 24.6%. AAC Planet has a lodging score of 3.2 on the scale of 1–9. It is moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and fusarium root rot (caused by Fusarium avenaceum and F. solani).

AAC McMurphy field pea

AAC McMurphy is a semi-leafless, yellow cotyledonary field pea ( Pisum sativum L.) cultivar developed at Agriculture and Agri-Food Canada Lacombe Research and Development Centre, Lacombe, Alberta, Canada. It has a maturity of 90 days, one-thousand-seed weight of 246 g, and a lodging score of 2.9 on the scale of 1–9. The seed crude protein content of AAC McMurphy is 24.2%. AAC McMurphy is resistant to powdery mildew (caused by Erysiphe pisi) and moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and fusarium root rot (caused by Fusarium avenaceum).

69 The Holos model for estimating greenhouse gases and soil carbon: Characterizing regionalized beef farm model systems

Abstract The objective of this work is to characterize regionally representative beef farm systems that represent dominant or typical surveyed management practices for 11 beef-producing regions across Canada. This work fulfills two further purposes 1) to improve and expand the Holos model interface; and 2) to facilitate the estimation of greenhouse gas (GHG) emissions and soil carbon (C) changes on beef farms in different regions of Canada. Holos version 4 is the whole-farm model of Agriculture and Agri-Food Canada’s to estimate GHG emissions and changes in soil C on Canadian farms in response to shifts in management practices. Holos can be implemented in all 10 Canadian provinces and accounts for GHG emissions from crop and livestock production [enteric and manure methane (CH4), manure and soil N2O emissions], farm machines and infrastructure [on-farm energy carbon dioxide (CO2) emissions], as well as from the upstream production of some farm inputs (synthetic fertilizer and pesticides). The model is designed to utilize data readily available on the farm to answer, ‘What if?’ scenarios, whereby the user can test the effect of changing management practices on their whole-farm GHG budget. To reduce the data input burden on the user, Holos V4 has built-in model livestock systems for beef, dairy, swine and poultry production that characterize the dominant features of these operations in Canada at the national scale based on relevant literature/data and expert opinion. Regarding beef production, we have characterized regionally specific model beef farms for incorporation into Holos, one for each of 11 Canadian beef-producing regions. General characteristics and management practices for each farm were based on the 2011 Beef Farm Survey (Sheppard et al., 2015), which summarizes management information from 1,009 Canadian beef farms, combined with data from the Canadian Cow-Calf Cost of Production Network (Canfax 2023). Each regional farm includes cow-calf, backgrounding in confinement, backgrounding on pasture and finishing components, and considers all the specific feed (e.g., forage, grains, by-products) required for each stage of the beef cycle. These 11 model farms are simulated within the current Holos V4 model to explore the impacts of variation in beef management practices on farm GHG emissions across Canada and on soil C stocks on lands used to produce feed and graze cattle. An overview of the national-level dairy, swine and poultry components in Holos will be presented along with a more detailed perspective of whole-farm GHG budget and multi-decadal soil C dynamics in regionalized beef farms. The impact of management and environmental factors that lead to differences in GHG emissions and soil C stocks in beef farms will also be explored.

Effect of carnosine on nitrosamine formation in gastric-simulated aqueous and lipid environments.

Nitrite salts are frequently utilized as meat additives to improve the quality and safety of processed meat products. However, these salts are associated with the formation of carcinogenic nitrosamines. Given its potential regulating effect on the formation of intermediate molecules, such as nitric oxide, it is hypothesized that carnosine, a meat constituent possessing antioxidant activity and other multiple health benefits, could dampen the formation of nitrosamines. The current study therefore assessed the effect of carnosine on nitrosamine formation in both a monophasic aqueous system and a biphasic water-lipid system simulating a gastric environment. In the monophasic system, relatively high levels of carnosine were required to significantly reduce the formation of different species of nitrosamine compared with the control (no carnosine). While higher levels of some nitrosamines were generated in both phases of the biphasic system, low carnosine concentrations significantly suppressed nitrosamine formation in the aqueous phase, while in the lipid phase, intermediate levels of carnosine were required. At higher carnosine levels, further reduction in nitrosamines was observed in the lipid phase. This study demonstrates the capacity of carnosine to reduce nitrosamine formation in aqueous and lipid environments and suggests the potential of dietary carnosine to lower the risks associated with the consumption of processed meat products. © 2024 His Majesty the King in Right of Canada and The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Wild Oat ( Avena fatua ): Crop Mimicry and Herbicide Resistance

Abstract Wild oat ( Avena fatua ) is a weed species that through crop mimicry survive in conventional managed farmlands, particularly in cereal crops such as wheat and barley. Adaptation of wild oat likely dates back around 9000 years when domestication of cereal species began in the Fertile Crescent and around the Mediterranean Sea. So far, wild oat has been described as a troublesome weed in 44 countries across temperate parts of the world. Wild oat reduces crop yields due to its competition for nutrients, water and light. Variable seed dormancy results in early maturing plants that add to the soil’s seed bank, and later maturing plants that contaminate the harvested grain. Since wild oat seeds resembles cereal grain, they are difficult to remove by mechanical seed cleaning. Seed lots contaminated with wild oat seeds are downgraded since it reduces the suitability as food and feed. Contaminated seedlots used for planting is a source of long distance spread of the weed. Herbicide application is an important part of wild oat control in areas with intensive wheat and barley production. Herbicide labels typically recommend the optimal size of wild oat seedlings and crop plants for best control. However, timing of an application can be difficult when wild oat plants are at different growth stages. The majority of herbicides are grouped according to the mode-of-action in cells of weed plants either inhibiting specific enzymes or entire metabolic pathways. Repeated use of herbicides with the same mode-of-action creates a selection pressure that can result in development of wild oat populations resistant to these herbicides. There is a direct relationship between the number of wild oat plants treated with herbicides and the risk of selecting for resistant plants. Thus, best management practices (BMP) aim to reduce the number of wild oat seed in the field, and include rotating between herbicides with different mode-of-action, and following recommendations on herbicide labels regarding plant growth stages and dosage. Cultural practices include rotating crop species and optimizing crop health, planting of weed-free seed, and cleaning of machinery between fields. Wild oat’s adaptations for crop mimicry and herbicide resistance make it problematic to manage but incorporating BMPs into an integrated approach can help. Information © His Majesty the King in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada.

Development and Application of the Snow, Soil Water and Water Balance Model, an Online Model for Daily Estimation of Snowpack Processes, Soil Water Content and Soil Water Balance

SNOSWAB (Snow, Soil Water and Water Balance) is a unique online deterministic model built using tipping-bucket approaches that allows for the daily estimation of (i) snowpack processes; (ii) soil water content; and (iii) soil water budget. SNOSWAB is most suitable for modeling field-scale processes for vertically and horizontally homogeneous soils, and its applicability is not limited to specific climate zones or geographical areas. The model is freely available, and its streamlined online interface integrates powerful calibration, visualization and data export routines. In this study, SNOSWAB development and a conceptual model, as well as an example of its application using data collected during a 12-year (2008–2019) field study conducted at the Agriculture and Agri-Food Canada Harrington Experimental Farm (HEF) on Prince Edward Island (PEI), Canada, are presented. Input data consisting of daily air temperature, total precipitation, rainfall and evapotranspiration were used in conjunction with soil properties and daily soil water content, snowpack thickness, surface runoff and groundwater recharge to calibrate (2010–2014) and validate (2015–2019) the model. For both the calibration and validation simulations, the statistical indicators used for evaluating model performance indicated, in most cases, high model fitness (i.e., R2 > 0.5, NRMSE < 50% and −25% < PBIAS < 25%) for the various time intervals and parameters analyzed. SNOSWAB fills an existing gap in the online environment and, due to its ease of use, robustness and flexibility, shows promise to be adopted as an alternative for more complex, standalone models that might require extensive resources and expertise.

Yellow mustard gum: pilot-scale production and characterization.

Yellow mustard gum (YMG), which is extracted from the mucilaginous part of yellow mustard bran, has been considered an emerging natural hydrocolloid gum but lacks commercial development and production. To promote the commercial utilization of YMG, this study developed a pilot-scale YMG production protocol in an economic and environmentally friendly way to produce a clean-label YMG product. This YMG produced at pilot scale (YMW) was characterized in terms of chemical composition, rheological properties, and interaction with a commercial gum, κ-carrageenan, and was compared with purified YMG through ethanol precipitation (YME). The protocol processed up to 100 L of raw material with zero solvent and a minimal number of steps and showed strong quasi-industrial potential. The YMW showed a similar chemical composition as YME. However, the YMW contained a slightly lower amount of carbohydrate and a much larger amount of ash and potassium than the YME. The rheological results concluded that both the YMW and YME solutions exhibited shear-thinning flow behavior and a weak gel, with YME showing higher viscosity and stronger gel structure. Most interestingly, YMW could form unpourable gels when blended with native κ-carrageenan whereas YME barely achieved this despite the equivalent total gum concentration. This study demonstrated the feasibility of YMG production at a large scale with economic and green procedures and discovered its new functionality for commercial utilization. The gelling ability of YMG could provide it with wider applications as a result of a new potential synergistic combination. All this information should accelerate the process of full commercialization of YMG as a clean-label functional ingredient. © 2024 His Majesty the King in Right of Canada. Journal of The Science of Food and Agriculture © 2024 Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

C17-833 camelina

Camelina ( Camelina sativa) elite germplasm C17-833 was developed at the Agriculture and Agri-Food Canada Saskatoon Research and Development Centre. It was developed through hybridization of camelina cultivar AAC 10CS0048 and F4 line 11CS0231-24-10 and subsequent pedigree selection. C17-833 yields significantly higher (114%) than the check cultivar AAC 10CS0048. It also has significantly higher seed oil content (42.6% vs. 41.9%) and significantly larger seeds (126%). C17-833 has very good resistance to downy mildew disease caused by Hyalonospora camelinae and is adapted to all soil zones of the Canadian Prairies.

Tracing the contribution of cattle farms to methane emissions through bibliometric analyses

Methane contributes to global warming, and livestock is one of the sources of methane production. However, methane emission studies using bibliometric tools in livestock are lacking. Given the negative impact of climate change on the ecosystem and the rise in methane emissions, it is essential to conduct a bibliometrics study to provide an overview and research trends. We used the Bibliometrix package and VOSviewer to decipher bibliometric indices for methane emissions in cattle farms (MECF). Current dataset were collected from the Web of Science (Core Collection) database, and 8,998 publications were analyzed. The most co-occurring keywords scientists preferred were methane (1528), greenhouse gas (443), methane emissions (440), and cattle (369). Methane was the most frequently used keyword in the published scientific literature. Thematic evolution of research themes and trend results highlighted carbon dioxide, methane, dairy cattle, cattle, and risk factors during 1999-2017. Chinese Academy of Sciences ranked on top with 485 publications, followed by Agriculture & Agri-Food Canada, University of Colorado, National Oceanic and Atmospheric Administration, and Aarhus University. Chinese Academy of Sciences was also the most cited organization, followed by the University of Colorado, Agriculture & Agri-Food Canada, National Oceanic and Atmospheric Administration, and United States Geological Survey. Source analysis showed that the Science of the Total Environment was cited with the highest total link strength. “Science of the Total Environment” ranked first in source core 1 with 290 citation frequencies, followed by “Journal of Dairy Science” with 223 citation frequencies. Currently, no bibliometric study has been conducted on MECF, and to fill this knowledge gap, we carried out this study to highlight methane emissions in cattle farms, aiming at a climate change perspective. In this regard, we focused on the research productivity of countries authors, journals and institutions, co-occurrence of keywords, evolution of research trends, and collaborative networking. Based on relevance degree of centrality, methane emissions and greenhouse gases appeared as basic themes, cattle, and dairy cattle appeared as emerging/declining themes, whereas, methane, greenhouse gas and nitrous oxide appeared to fall amongst basic and motor themes. On the other hand, beef cattle, rumen and dairy cow seem to be between motor and niche themes, and risk factors lie in niche themes. The present bibliometric analysis provides research progress on methane emissions in cattle farms. Current findings may provide a framework for understanding research trends and themes in methane emissions in cattle farms (MECF) research.

Land use change detection and quantification of prime agricultural lands in Southern Ontario

Spatiotemporal land use change evaluation and quantification are essential for supporting and enhancing land use policies and for the sustainable management of land resources. To quantify the semi-decadal change in land use particularly prime agricultural lands in Southern Ontario, maps and matrices of spatial and temporal change of agricultural lands to other types land uses including built-up land were prepared from the Agriculture and Agri-Food Canada (AAFC) land use data. Then, the spatial and temporal changes of capable soils for agriculture and built-up land was evaluated. Finally, the amount of capable soil change in different regions and periods was calculated. The area of built-up and agricultural land has increased and decreased by 68% and 4% from 1990 to 2020, respectively. The amount of change in agricultural lands to built-up land in the period of 1990–2005 and 2005–2020 was 1179 and 1640 km2, respectively. In these periods, 920 and 1204 km2 of highly capable soils for agriculture have been converted into other land uses, respectively. The results showed that the change in agricultural lands to other types, specifically built-up areas and loss of highly capable soils for agriculture has increased over the recent years.

Bibliometric and literature review of the development of mineral fertilizers.

Mineral fertilizers are a new type of sustainable fertilizers, containing natural ores as the primary raw material with various nutrients and organic matters. This study combines two methods of bibliometric analysis to comprehensively review the progress of mineral fertilizers from 2000 to 2021. The results showed that the research on mineral fertilizers has increased in the past 21years, especially after 2014. Developed countries studied mineral fertilizers more extensively than developing countries, but some developing countries, such as China and India, are also paying attention to this area in recent years. Chinese Academic of Sciences, Agriculture and Agri-Food Canada, and Chinese Academy of Agricultural Sciences were the main publishing institutions. Nutrient elements, changes in soil properties, and the effects on promoting crop growth were the main contents of the research. Still, such issues as bioremediation, soil environment improvement, and crop resistance are becoming hot spots. The field of mineral fertilizers showed a strong interdisciplinary nature and an increasingly comprehensive research perspective. The goal is that this synthesis will be used as a starting point for a broader study on responsible environmental management and research on improving fertilizer use efficiency.

PSVII-22 Effect of Trimming External Fat Before Cooking on Palatability and Calorie Content of Beef Ribeye Steaks

Abstract Consumer concerns about excess dietary fat have increased the practice of removing external fat from beef steaks prior to cooking. This practice, however, may be detrimental to meat eating quality. The objective of this study was to determine the effects of removing the external fat before cooking on the eating quality and calorie content of ribeye steaks. Twenty longissimus thoracis muscles with Canada AAA (n = 10) and AA (n = 10) quality grades (equivalent to USDA Choice and Select, respectively) were obtained from a federally inspected commercial slaughter plant, vacuum packaged and transported under refrigerated conditions to the Lacombe Research and Development Centre (Agriculture and Agri-Food Canada). After an average of 28 d of ageing, the muscles were removed from the vacuum packaging and fabricated into four 2.54-cm steaks. One-half of the steaks were trimmed to 0.635 cm of external fat (cap on). The remaining steaks were completely trimmed of external and seam (kernel) fats (cap off), and the longissimus and spinalis dorsi muscles were combined with butcher’s twine. Steaks were cooked on an electric grill to an endpoint temperature of 74 °C. Subsequently, descriptive sensory analyses were performed by a 10-member trained meat evaluation panel and calorie analyses were conducted. Results: Compared with muscles of AA steaks cooked with cap off, the AA steaks cooked with cap on had longissimus with greater initial and sustained juiciness (P < 0.01) and a tendency towards a smaller proportion of panelists detecting livery off-flavor (P = 0.058) and mealy texture (P = 0.071), and spinalis with a tendency towards fewer panelists detecting unidentified off-flavors (P = 0.096) and spongy texture (P = 0.096). When cooking the AAA steaks with cap on, the longissimus had a decreased frequency of panelists detecting ‘other’ off-flavors (i.e., burnt, rancid, barnyard, stale; P < 0.05) and mushy texture (P < 0.05) and tended to have less off-flavor intensities (P = 0.083), whereas the spinalis had greater beef flavor intensity and desirability (P < 0.05) and fewer panelists tending to detect ‘other’ off-flavors (i.e., burnt, fatty, oily, rancid; P = 0.052), compared with steaks cooked with cap off. The more pronounced flavor effects in the spinalis compared with the longissimus of AAA steaks cooked with cap on could be due to the spinalis having greater endpoint temperatures than the longissimus muscles, which probably caused more Maillard reactions and more efficient fat melting. Regardless of the quality grade and muscle type, cooking steaks with cap on did not increase the calorie content (P > 0.10). Overall, cooking ribeye steaks with external fat had positive effects on juiciness, flavor and texture without increasing the calorie content compared with steaks cooked without external fat. Educating consumers on the benefits of maintaining the external fat while cooking will improve the eating experience of Canadian beef.

Combining Air Sampling and DNA Metabarcoding to Monitor Plant Pathogens

Monitoring the air for airborne plant pathogens is an increasingly common method for the management of economically important plant diseases. In Alberta, Canada, several commodity clusters, including dry bean, canola, potato, and wheat, currently support air monitoring research programs for airborne pathogens of interest. In this study, we assessed the feasibility of monitoring for these, and more, plant fungal pathogens simultaneously using two different sampler types (cyclone versus rotation impaction) and by metabarcoding the ITS1 region using the Illumina sequencing platform. We collected air samples from four geographically distant sites across Alberta and monitored four crop types in southern Alberta. Overall, we found weak, but statistically significant, effects of geographic location and crop type on the aeromycobiota community composition. A few common taxa, such as Ramularia, Alternaria, and Epicoccum, constituted the vast majority of reads across all samples. Nevertheless, in each sample, we identified many plant pathogens of interest and organisms that previous research has found antagonistic to those pathogens, highlighting the utility of these approaches in understanding the pathobiome. In assessing the real-world implications of read counts, we discovered that they were only weakly correlated with spore counts quantified by qPCR. The two types of samplers collected different community profiles, reinforcing the importance of carefully considering which sampler type to use in monitoring programs. Taken together, our results show promise for the future of monitoring the air pathobiome, although much more work is required to understand the relationship of airborne communities to their in-field impact on disease development. [Formula: see text] Copyright © 2023 His Majesty the King in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada. This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

A Genome Resource for 192 Verticillium dahliae Isolates Infecting Potatoes Across Canada

Verticillium dahliae is an important soilborne pathogen causing Verticillium wilt. It is also the primary causal agent of potato early dying, a disease complex involving the root-lesion nematode. Here, we report the whole-genome sequencing of 192 isolates of V. dahliae originating from the major potato production areas across Canada. Our results yielded a resource of 277,010 genetic variations that will be useful for genetic analyses and revealed the presence of two major lineages, both present in all provinces but exhibiting differences in regional prevalence. [Formula: see text] Copyright © 2023 His Majesty the King in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada. This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

An improved design for a zero-tillage experimental plot drill

Adoption of conservation farming practices such as zero tillage when planting field research plots is essential to the replication of on-farm practices. The problem is that most drill options fail to meet expectations as they are not built to the scale required, compromise the need for uniformity of plant emergence within plot areas, lack portability, or have been designed and equipped in a manner that is not relevant to farm-scale seeder technologies and practices. Agronomists and Technicians at Agriculture and Agri-Food Canada engaged with engineering expertise to design and build two prototype drills that are now in full operation.

Estimation of High-Resolution Soil Moisture in Canadian Croplands Using Deep Neural Network with Sentinel-1 and Sentinel-2 Images

Soil moisture (SM) is a crucial hydrologic factor that affects the global cycle of energy, carbon, and water, as well as plant growth and crop yield; therefore, an accurate estimate of SM is important for both the global environment and agriculture. Satellite-based SM data have been provided by the National Aeronautics and Space Administration (NASA)’s Soil Moisture Active Passive (SMAP) and the European Space Agency (ESA)’s Soil Moisture and Ocean Salinity (SMOS) satellite missions, but these data are based on passive microwave sensors, which have limited spatial resolution. Thus, detailed observations and analyses of the local distribution of SM are limited. The recent emergence of deep learning techniques, such as rectified linear unit (ReLU) and dropout, has produced effective solutions to complex problems. Deep neural networks (DNNs) have been used to accurately estimate hydrologic factors, such as SM and evapotranspiration, but studies of SM estimates derived from the joint use of DNN and high-resolution satellite data, such as Sentinel-1 and Sentinel-2, are lacking. In this study, we aim to estimate high-resolution SM at 30 m resolution, which is important for local-scale SM monitoring in croplands. We used a variety of input data, such as radar factors, optical factors, and vegetation indices, which can be extracted from Sentinel-1 and -2, terrain information (e.g., elevation), and crop information (e.g., cover type and month), and developed an integrated SM model across various crop surfaces by using these input data and DNN (which can learn the complexity and nonlinearity of the various data). The study was performed in the agricultural areas of Manitoba and Saskatchewan, Canada, and the in situ SM data for these areas were obtained from the Agriculture and Agri-Food Canada (AAFC) Real-time In Situ Soil Monitoring for Agriculture (RISMA) network. We conducted various experiments with several hyperparameters that affected the performance of the DNN-based model and ultimately obtained a high-performing SM model. The optimal SM model had a root-mean-square error (RMSE) of 0.0416 m3/m3 and a correlation coefficient (CC) of 0.9226. This model’s estimates showed better agreement with in situ SM than the SMAP 9 km SM. The accuracy of the model was high when the daily precipitation was zero or very low and also during the vegetation growth stage. However, its accuracy decreased when precipitation or the vitality of the vegetation were high. This suggests that precipitation affects surface erosion and water layer formation, and vegetation adds complexity to the SM estimate. Nevertheless, the distribution of SM estimated by our model generally reflected the local soil characteristics. This work will aid in drought and flood prevention and mitigation, and serve as a tool for assessing the potential growth of crops according to SM conditions.

Environmental Concentrations of the Type 2 Diabetes Medication Metformin and Its Transformation Product Guanylurea in Surface Water and Sediment in Ontario and Quebec, Canada.

Metformin, used to treat Type 2 diabetes, is the active ingredient of one of the most prescribed drugs in the world, with over 120 million yearly prescriptions globally. In wastewater-treatment plants (WWTPs), metformin can undergo microbial transformation to form the product guanylurea, which could have toxicological relevance in the environment. Surface water samples from 2018 to 2020 and sediment samples from 2020 were collected from six mixed-use watersheds in Quebec and Ontario, Canada, and analyzed to determine the metformin and guanylurea concentrations at each site. Metformin and guanylurea were present above their limits of quantification in 51.0% and 50.7% of all water samples and in 64% and 21% of all sediment samples, respectively. In surface water, guanylurea was often present at higher concentrations than metformin, while the inverse was true in sediment, with metformin frequently detected at higher concentrations than guanylurea. In addition, at all sites influenced solely by agriculture, concentrations of metformin and guanylurea were <1 µg/L in surface water, suggesting that agriculture is not a significant source of these compounds in the investigated watersheds. These data suggest that WWTPs and potentially septic system leaks are the most likely sources of the compounds in the environment. Guanylurea was detected at many of these sites above environmental concentrations of concern, where critical processes in fish may be affected. Due to the scarcity of available ecotoxicological data and the prominence of guanylurea across all sample sites, there is a need to perform more toxicological investigations of this transformation product and revisit regulations. The present study will help provide toxicologists with environmentally relevant concentration ranges in Canada. Environ Toxicol Chem 2023;42:1709-1720. © 2023 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Agricultural land management alters the biogeochemical cycling capacity of aquatic and sediment environments

Nutrient loading from agricultural landscapes continues to pose a threat to downstream aquatic systems, contributing to degraded water quality and eutrophication. Nutrient loading to adjacent aquatic environments is influenced by the type of applied fertilizer (chemical and manure), field management, and seasonal weather patterns. The risk these nutrients pose to downstream systems may be mitigated by the capacity of the microbial community in receiving water catchments to process those nutrients. This study evaluated the interactive effects of agricultural practices and seasonal weather patterns on nutrient cycling communities in catchment ponds within a long-term Agriculture and Agri-Food Canada research trial, located in the Lake Erie watershed in Ontario, Canada. Microbial nitrogen (N) and P (phosphorus)-cycling functions in water and sediment environments, receiving direct tile drainage and surface runoff flow, were quantified with respect to nutrient loads from liquid cow manure, solid cow manure, inorganic phosphorus, and a control fertilizer treatment, over a full year. High bacterial nitrification potential in the water column coincided with nitrogen loading, which was driven by manure/fertilizer application, tillage practices, and precipitation. The highest overall phosphorus concentrations occurred in the liquid cow manure treatment, but the availability of phosphorus in all treatments was strongly associated with microbial phosphorus mobilization capacity in both aquatic and sediment environments. Seasonality also influenced the aquatic environment, where N and P- cycling potential significantly increased during the winter months. Microbial functional potential in the water column was strongly influenced by the external environment, including season and precipitation, while the functional potential in the sediment was more resistant to environmental fluctuations, and was primarily influenced by long-term management fertilizer/manure practices. Overall, this study provides evidence that agricultural management alters the capacity of the microbial communities in adjacent aquatic environments to process nutrients.

Survey of glyphosate- and dicamba-resistant kochia (Bassia scoparia) in Saskatchewan

Kochia ( Bassia scoparia (L.) A.J. Scott) is a problematic tumbleweed, which infests row crops and ruderal areas within western Canada. Herbicide resistance makes kochia management challenging for producers. Widespread resistance to acetolactate synthase-inhibitors, evolution and spread of glyphosate resistance, and the occurrence of dicamba resistance has been previously noted in Saskatchewan. This study's objective was to evaluate the occurrence and distribution of glyphosate- and dicamba-resistant kochia in central and southern Saskatchewan. A randomized, stratified survey was conducted in the fall of 2019 at 303 sites. Rotational history was obtained using the Agriculture and Agri-Food Canada Annual Crop Inventory. Kochia samples were collected from cropped fields (78%), ditches (17%), oil well sites (2%), and railway grades (3%). Glyphosate resistance was detected in 87% of samples ( n = 275) within 137 Rural Municipalities (RMs). Dicamba resistance was detected in 45% of kochia samples ( n = 255) in 87 RMs. Crops infested with herbicide-resistant kochia included wheat ( Triticum aestivum L. and T. durum Desf.), canola ( Brassica napus L.), lentils ( Lens culinaris Medik.), barley ( Hordeum vulgare L.), flax ( Linum usitatissimum L.), and peas ( Pisum sativum L.). Reducing the soil seedbank and preventing dispersal will be critical to mitigating resistance. Good herbicide stewardship including mixing multiple modes of action is paramount. Cultural strategies to increase canopy closure and crop competitiveness to limit biomass and seed production are recommended. Kochia occupies many environments outside of cropped fields, and a community-wide management approach may be necessary to reduce dispersal potential of tumbling plants that disperse seed.

Selection of oat (Avena sativa L.) drought-tolerant genotypes based on multiple yield-associated traits.

Most plant breeding and agricultural practices are based on selecting genotypes for yield. However, this is inadequate to screen crop varieties for specific attributes, such as drought tolerance. In this study, we quantified the response of oat (Avena sativa L.) plant physiological and morphological traits to drought stress and selected some key traits to establish a genotype by yield*trait (GYT)-based method for ranking 30 oat genotypes. The effectiveness of this method was also evaluated under drought conditions. Water-deficit treatment significantly reduced leaf chlorophyll, root morphological traits, groat yield and associated components, such as mean grain weight. We observed that the genotypes 'JUSTICE' and 'BOLINA' had the smallest and largest yield loss, respectively, after exposure to drought stress, but showed opposite trends in the biomass allocation of roots and grains. This indicated that drought tolerance was highly dependent on the distribution of photoassimilates. Our results also illustrated that the GYT method is a trade-off approach and more effective in selecting oat ideotypes under drought conditions than the yield-related index method because it combines yield, yield stability, and related agronomic traits in the calculation process. Drought-tolerant genotypes had more biomass allocated to roots and grains with higher chlorophyll content and better root structure, e.g. longer root lengths than drought-sensitive lines. By integrating yield and yield-related traits, the GYT approach is more practical than traditional single-trait selection methods when assessing drought tolerance. © 2023 His Majesty the King in Right of Canada. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.