The widespread cultivation of canola, conventionally still considered a non-host plant for AM fungi, coupled with its increasing frequency in crop rotations, raises concerns about its impacts on soil microbial diversity and overall crop productivity. The main objective of this study is to assess the influence of different crop succession systems, incorporating canola, on AM fungal diversity and community structure in both the roots and in the rhizosphere, as well as on productivity of each crop present within the succession. Doubling the frequency of canola occurrence in a 4-year crop succession did not reduce the productivity of the other crops in the succession, nor did it result in a decrease in AM fungal biodiversity in the roots or rhizosphere of these crops. Interestingly, the diversity of AM fungi was higher in canola roots compared to wheat roots, indicating that canola might serve as a rudimentary host of AM fungi. The succession systems did, however, alter the AM fungal community structure in both roots and rhizosphere environments, exhibiting positive or negative correlations with crop productivity. This suggests that a simple modification of the cropping system could potentially be employed to manipulate root or rhizosphere microbiomes. Results of this study add to the growing body of evidences that plants that were thought to be non-AM fungi host, such as plants from the Brassicaceae family, could in fact interact with AM fungi.

Phytotoxic soil salinity is a global problem, and in the northern Great Plains and western Canada, salt accumulates on the surface of marine sediment soils with high water tables under annual crop cover, particularly near wetlands. Crop production can overcome saline-affected soils using crop species and cultivars with salinity tolerance along with changes in management practices. This research seeks to improve our understanding of sunflower (Helianthus annuus) genetic tolerance to high salinity soils. Genome-wide association was conducted using the Sunflower Association Mapping panel grown for two years in naturally occurring saline soils (2016 and 2017, near Indian Head, Saskatchewan, Canada), and six phenotypes were measured: days to bloom, height, leaf area, leaf mass, oil percentage, and yield. Plot level soil salinity was determined by grid sampling of soil followed by kriging. Three estimates of sunflower performance were calculated: (1) under low soil salinity (< 4 dS/m), (2) under high soil salinity (> 4 dS/m), and (3) plasticity (regression coefficient between phenotype and soil salinity). Fourteen loci were significant, with one instance of co-localization between a leaf area and a leaf mass locus. Some genomic regions identified as significant in this study were also significant in a recent greenhouse salinity experiment using the same panel. Also, some candidate genes underlying significant QTL have been identified in other plant species as having a role in salinity response. This research identifies alleles for cultivar improvement and for genetic studies to further elucidate salinity tolerance pathways.

Nitrogen transformation, either from organic amendments or synthetic fertilizers, contributes to nitrous oxide (N2O) emission, a potent greenhouse gas from agricultural soils. In grazing systems, N2O emissions can occur in both stages of production, during the forage growth phase mainly related to fertilizer use and residue transformations as well as the animal phase from animal excreta deposition and transformation. Different management practices with potential to reduce N2O emissions, including the adoption of diverse forage mixtures (poly cropping) has gained attention. Poly cropping can promote high resource use efficiency and influence edaphic-climatic conditions, major controllers for soil N2O emissions. However, information on the effect of poly cropping on soil N2O emissions in the Canadian Prairies under semiarid climate and Brown Chernozem soils is limited. The overall objective of this study was to explore the potential of using poly crop mixtures as an alternative feed source for Canadian beef cattle and its impact on soil N2O emissions. Three treatments were considered: i) control, forage oat monoculture, ii) simple mix, containing four different annual forage species (forage oat, forage pea, forage brassica, and hairy vetch), and iii) complex mix containing eight annual forage species (forage oat, forage pea, barley, forage brassica, hairy vetch, red proso millet, teff grass, and, chicory). Treatments were established in a completely randomized block design scheme with three replicates. The study was conducted at the Swift Current Research and Development Centre, the driest climatological condition in the Canadian Prairies. Following pre-seeding field preparation, treatments were established by the end of May and Urea Phosphate (34-17-0) fertilizer was split-applied at 112 kg/ha. Nitrous oxide emission was measured over the crop phase in 2023 growing season, the first year of a 3-yr trial, using the manual chamber method. Furthermore, ancillary measurements were performed. During the 2023 crop growth phase, N2O emissions ranged from 446 to 610 g Nּ ha-1, and were not affected by treatments. Soil inorganic N was greater in parts of the season for the complex mix, but that did not translate into greater cumulative N2O emissions. Overall, the treatments did not affect soil volumetric water content in the topsoil, a key factor dictating N2O emissions. This project will continue until 2026 and capture emissions from different seasons including major spring-thaw. In those years, measurements will also be extended to an on-farm sites involving farmers situated in contrasting edaphic-climatic conditions of the Canadian Prairies.

Annual canarygrass is highly responsive to chloride (Cl-) fertilizer for increasing grain yield. This responsiveness to Cl- raises the question of whether annual canarygrass is similarly responsive to other micronutrients. The effect of micronutrients, Cu, Zn, B and Mn with the basal rate of N, P, K, S, Cl-, on annual canarygrass, was studied using two application methods, soil (side-band at seeding) and foliar (3-6 leaf and flag leaf emergence). Over four years, field research was conducted at two Saskatchewan locations, Indian Head and Melfort using a randomize complete block design (RCBD). A foliar application after flag leaf emergence of either Cu, Zn or Mn provided the best method to increase the concentration of that micronutrient in the leaf tissue during seed filling. Boron concentrations in the leaf were increased during seed filling by soil or foliar treatments containing B at different site-years. Zinc, Cu, and B had no impact on grain yield. A foliar application of Mn affected grain yield at one of 6 site-years and requires further investigation. As expected, soil application of macronutrients + Cl- increased grain yield between 29 and 187% compared to unfertilized treatment in five of six site-years. Melfort in 2015 and 2016, had low levels of tissue Cl- in control treatment. The largest grain yield increases occurred at these sites, suggesting that early season tissue testing maybe use to identify Cl- responsive fields of annual canarygrass. Annual canarygrass is not responsive to Cu, Zn, and B but may be responsive to Mn.

In the Canadian prairies, pulse crops such as field pea (Pisum sativum L.) and lentil (Lens culinaris L.) are economically important and widely grown. However, in recent years, root rot, caused by a variety of fungal and oomycete pathogens, including Aphanomyces euteiches, has become a limiting factor on yield. In this study, we examined the impacts of nitrogen (N) fertilization and a commercial arbuscular mycorrhizal fungal (AMF) inoculant on pea and lentil plant health and agronomic production at three locations in Saskatchewan: Swift Current, Indian Head and Melfort. The AMF inoculation had no impact on root rot severity, and therefore is not considered a reliable method to manage root rot in pea and lentil. In contrast, N fertilization led to reductions in root rot in Swift Current, but not the other two sites. However, N fertilization did reduce nodulation. When both pea and lentil are considered, the abundance of A. euteiches in soil increased from pre-seeding to mid-bloom. A negative correlation between soil pH and disease severity was also observed. The high between-site variability highlights the importance of testing root rot mitigation strategies under multiple soil conditions to develop site-specific recommendations. Use of N fertilizer as a root rot management strategy merits further exploration, including investigation into its interactions with other management strategies, soil properties, and costs and benefits.

Soil organic carbon (SOC) is closely tied to soil health. However, additional biological indicators may also provide insight about C dynamics and microbial activity. We used SOC and the other C indicators (potential C mineralization, permanganate oxidizable C, water extractable organic C, and beta-glucosidase enzyme activity) from the North American Project to Evaluate Soil Health Measurements to examine the continental-scale drivers of these indicators, the relationships among indicators, and the effects of soil health practices on indicator values. All indicators had greater values at cooler temperatures, and most were greater with increased precipitation and clay content. The indicators were strongly correlated with each other at the site-level, with the strongest relationship between SOC and permanganate oxidizable C. The indicator values responded positively to decreased tillage, inclusion of cover crops, application of organic nutrients, and retention of crop residue, but not the number of harvested crops in a rotation. The effect of decreased tillage on the C indicators was generally greater at sites with higher precipitation. The magnitude and direction of the response to soil health practices was consistent across indicators within a site but measuring at least two indicators would provide additional confi-dence of the effects of management, especially for tillage. All C indicators responded to management, an essential criterion for evaluating soil health. Balancing the cost, sensitivity, interpretability, and availability at commercial labs, a 24-hr potential C mineralization assay could deliver the most benefit to measure in conjunction with SOC.

Canada's interest in agricultural lands has changed with time from a desire of crop yields at Confederation through to discussions in the Senate on adaptation and resilience in 2018. Long-term research experiments (LTRs) have been present and utilized by federal and university researchers to provide answers throughout. Here we highlight the importance of LTRs by identifying the historical context of LTRs and soil health research in Canada. We then briefly describe the history and key results from select LTRs and illustrate the wealth of information collected from the North American Project to Evaluate Soil Health Measurements cross-country point-in-time soil sampling from these LTRs. We discuss the LTRs, and the knowledge gained from them, with the hope that by showing the distinctive narratives associated with each of these study sites, researchers will be inspired to use them to address their research questions and make sound predictions to facilitate the adaptation of Canadian agroecosystems to climate challenges. Through identifying the value generated by these unique LTRs, we hope that the importance of these sites will inspire not only their continued maintenance but also the next generation of LTRs.

Annual canarygrass (Phalaris canariensis L.) is a specialty crop grown in Canada and the harvested grain is primarily used to feed wild and domesticated bird species. A field experiment was conducted at 5 locations in both 2012 and 2013 to study the response of annual canarygrass development and grain yield to the combined effects of fungicide (propiconazole + trifloxystrobin) and nitrogen (N) fertilizer, and to determine the minimum number of site years required to detect these effects. The experimental design was a split plot with fungicide application (none or fungicide) as the main plot and N application rate as the sub plot (10, 20, 30, 50, 70, 90 kg N·ha−1). There was a linear increase of 14.5% in grain yield as the rate of N fertilizer increased. The fungicide application increased the grain yield 8.5% by increasing kernel density from 15 197 kernels m−2 to 16 288 kernels m−2. There was no interaction between the N rate and fungicide application. The application of a fungicide did not increase the responsiveness of annual canarygrass to N fertilizer. The lack of an interaction between N and fungicide application indicates that these two practices can be managed independently by annual canarygrass producers. To optimize grain yield producers should apply 50 kg N·ha−1 and apply a fungicide to increase grain yield especially in regions where septoria leaf mottle is prevalent. The number of site years needed to consistently detect the impact of N and fungicide on the grain yield were 4 and 5 site years, respectively.

Farmers, scientists, and other soil health stakeholders require interpretable indicators of soil hydraulic function. Determining which indicators to use has been difficult because of measurement disconformity, spatial and temporal variability, recently established treatments, and the effect of site characteristics on management practice differences. The North American Project to Evaluate Soil Health Measurements includes 124 sites uniformly sampled across a range of soil health management practices in North America in 2019. We compare and recommend indicators of hydraulic function that best characterize soil health. We assessed the relationship of each indicator to a suite of soil inherent properties and climate variables, the response of each indicator to soil health management practices, the effect that soil inherent properties (clay content, sand content, and pH) and climatic variables (10-yr mean annual precipitation and temperature) had on response to management practices, and the relationship among the responses of the indicators to soil health management practices. Field capacity measured on intact cores (theta(FC_INTACT)) was the best measure of soil hydraulic function, because it responded to management, represents a direct measure of soil hydraulic function, is proximal to stakeholder values, and its response to management was not significantly influenced by inherent and climatic variables. Other suitable indicators are bulk density, soil organic carbon (SOC), and aggregate stability, which are not direct measures of soil hydraulic function but do respond to management and may be practical in situations in which measuring theta(FC_INTACT) is not. This study informs selection of soil health indicators to measure soil hydraulic function.

Annual canarygrass (Phalaris canariensis L.) has a larger response to chloride (Cl−) fertilizer than other cereal crops. This unexpected response prompted further research for unexpected interactions between Cl− and other nutrients in annual canaryseed. The objective of this study was to compare the interaction of macronutrients and micronutrients with Cl− on the development and grain yield of annual canarygrass. Thirteen fertilizer combinations were applied to determine the effect of macro- and micronutrients on annual canarygrass. A field study was conducted at six locations across Saskatchewan over a 4 yr period using a randomize complete block design. Grain yield had a strong chloride response at 7 of the 21 site years with a 70% increase in grain yield over the 7 site-years. A sideband application or surface application of Cl− were both effective. At the responsive sites without the addition of Cl−, the addition of other nutrients is not effective while at the non-responsive sites, responses to the nutrients can be achieved without the addition of Cl−. Chloride impacted canarygrass during reproductive development. Nitrogen is the major nutrient Cl− interacted with in this study. Canarygrass is not more responsive to phosphorus, potassium, sulfur, zinc, copper, manganese, and boron than other cereals. In conclusion, at Cl−-responsive sites the application of nutrients are ineffective in the absence of Cl− fertilizer. In addition, the sensitivity of annual canarygrass to Cl− indicates that it could be used to investigate the role of Cl− in cereal crop development and grain yield.

Currently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (theta(AWHC)), while some studies show the ability to substantially increase theta(AWHC) through management. The Soil Health Institute's North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (theta(FC)) and permanent wilting point (theta(PWP)). New pedotransfer functions had predictions of theta(AWHC) that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on theta(AWHC). For an increase in SOC of 10 g kg(-1) (1%) in noncalcareous soils, an average increase in theta(AWHC) of 3.0 mm 100 mm(-1) soil (0.03 m(3) m(-3)) on average across all soil texture classes was found. This SOC related increase in theta(AWHC) is about double previous estimates. Calcareous soils had an increase in theta(AWHC) of 1.2 mm 100 mm(-1) soil associated with a 10 g kg(-1) increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience.

AbstractWild oat (Avena fatua L.) and false cleavers (Galium spurium L.) are currently a challenge to manage in less competitive crops such as flax (Linum usitatissimum L.). Increasing the functional diversity in crop rotations can be an option to improve weed management. Nonetheless, this strategy had not been tested in flax in western Canada. A 5-yr (2015 to 2019) crop rotation study was carried at three locations in western Canada to determine the effect of diverse flax-based crop rotations with differences in crop species, crop life cycles, harvesting time, and reduced herbicides on managing A. fatua and G. spurium. The perennial rotation (flax–alfalfa [Medicago sativa L.]–alfalfa–alfalfa–flax) under reduced herbicide use was found to be the most consistent cropping system, providing A. fatua and G. spurium control similar to the conventional annual flax crop rotation (flax–barley [Hordeum vulgare L.]–flax–oat [Avena sativa L.]–flax) with standard herbicides. At Carman, this alfalfa rotation provided even better weed control (80% A. fatua, 75% G. spurium) than the conventional rotation. Furthermore, greater A. fatua control was identified compared with a conventional rotation in which two consecutive winter cereal crops were grown successfully in rotation (flax–barley–winter triticale [×Triticosecale Wittm. ex A. Camus (Secale × Triticum)]–winter wheat [Triticum aestivum L.]–flax). Incorporation of silage oat crops did not show consistent management benefits compared with the perennial alfalfa rotation but was generally similar to the conventional rotation with standard herbicides. The results showed that perennial alfalfa in the rotation minimized G. spurium and A. fatua in flax-cropping systems, followed by rotations with two consecutive winter cereal crops.

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity.

A black medic (Medicago lupulina L.) cover crop is able to regenerate from seed annually and produce biomass at the end of each growing season, but its long-term effectiveness on crop productivity, water use efficiency (WUE), and soil nutrient status within a no-till cropping system is unclear. A field experiment was established in 2003 in Saskatchewan in a 3-yr crop rotation [flax (Linum usitatissimum L.)-oat (Avena sativa L.)-wheat (Triticum aestivum L.)]. Treatments included cover crop (black medic or no medic), and N fertilizer (20, 60, and 100% of recommended N) arranged in a split-split plot design. Over 10 yr, medic aboveground fall biomass averaged 625 kg ha(-1) (range 0-1,868 kg ha(-1)) and was greatest at the lowest N rate, 879 kg ha(-1). Medic increased grain yield at 20% N fertilizer; no effect was observed at higher N rates. Medic increased tiller density and kernel weight at 20% N, indicating that medic positively influenced the crop throughout the entire life cycle. Medic presence did not affect grain N or P status. Medic did not affect level of available soil N in fall but consistently increased level of soil available P. This extended to the 30-60 cm soil depth in the 100% vs. lower N rates, suggesting medic roots may have influenced P cycling. In oat stubble, medic increased spring soil water and WUE. In conclusion, black medic improved crop productivity at the low N rate but improved available soil P at all N rates, warranting further research.

Aggregate stability is a commonly used indicator of soil health because improvements in aggregate stability are related to reduced erodibility and improved soil-water dynamics. During the past 80 to 90 years, numerous methods have been developed to assess aggregate stability. Limited comparisons among the methods have resulted in varied magnitudes of response to soil health management practices and varied influences of inherent soil properties and climate. It is not clear whether selection of a specific method creates any advantage to the investigator. This study assessed four commonly used methods of measuring aggregate stability using data collected as part of the North American Project to Evaluate Soil Health Measurements. The methods included water stable aggregates using the Cornell Rainfall Simulator (WSACASH), wet sieved water stable aggregates (WSAARS), slaking captured and adapted from SLAKES smart-phone image recognition software (STAB10), and the mean weight diameter of water stable aggregates (MWD). Influence of climate and inherent soil prop-erties at the continental scale were analyzed in addition to method responses to rotation diversity, cash crop count, residue management, organic nutrient amendments, cover crops, and tillage. The four methods were moderately correlated with each other. All methods were sensitive to differences in climate and inherent soil properties between sites, although to different degrees. None measured significant effects from rotation diversity or crop count, but all methods detected significant increases in aggregate stability resulting from reduced tillage. Significant increases or positive trends were observed for all methods in relation to cover cropping, increased residue retention, and organic amendments, except for STAB10, which expressed a slightly negative response to organic amendments. Considering these results, no single method was clearly superior and all four are viable options for measuring aggregate stability. Therefore, secondary considerations (e.g., cost, method availability, increased sensitivity to a specific management practice, or minimal within-treatment variability) driven by the needs of the investigator, should determine the most suitable method.

The Canadian prairies account for about 85% of Canada's arable land. Historically, cropping systems were primarily summer fallow-cereal based, which led to severe soil degradation, loss of productivity, and negative environmental consequences. Efforts were taken by all stakeholders to arrest this grave situation, and one of the key measures was retaining crop residues on the soil surface along with standing stubble to conserve soil moisture and enhance soil organic matter (SOM). This mitigation strategy led to the development of the no-till (NT) cropping system in the Canadian prairies. Adoption of NT in the early years was slow due to limitations of seeding equipment, weed control options, and lack of yield advantage over conventional tillage (CT). Since the 1980s, NT has become a routine practice on the Canadian prairie, and currently is adapted on about 65% of the arable land area. The drastic change is largely due to the development of advanced seeding and harvesting equipment and improved weed control options. Although challenges still remain, for example, the increased prevalence of herbicide resistant weeds, wet seedbed in spring, and excessive crop straw on the soil surface, NT systems have significantly contributed to enhancing economic and environmental sustainability on the prairie. In this chapter, we discuss the evolution of NT in the Canadian prairie and the impacts of the decades of NT adoption on productivity, soil health, and challenges.

Long-term field experiments are useful for determining cropping system productivity, stability, and resource use efficiency. With 12 yr (2004-2015) of data from five cropping systems on a long-term experiment (> 30 yr) under semiarid conditions in Saskatchewan, Canada, a systems-approach was used to compare grain and protein yield, stability, nitrogen (N) dynamics, N fertilizer (FUEG,P), and available N use efficiency (NUEG,P) for grain and protein. Annualized grain and protein yields for wheat (Triticum aestivum L.)-canola (Brassica napus L.)-wheat-field pea (Pisum sativum L.; W-C-W-P) were 2244 and 372 kg ha(-1), respectively, 14 to 38% and 33 to 66% higher, respectively, than continuous wheat (ContW), summer fallow-wheat-wheat-wheat (F-W-W-W), F-W-W, and lentil (Lens culinaris Medik) green manure-wheat-wheat (GM-W-W). Fallow systems were the most stable, but less productive and well-adapted to low-yielding conditions, while GM-W-W was the least stable and poorly adapted. The ContW had below-average stability and was better suited to high-yielding conditions for grain. The W-C-W-P consistently produced above-average yields, and was best suited for high-yielding conditions for grain and protein. The ContW and W-C-W-P had the highest NUEG (26.4 g kg(-1)) and NUEP (4.1 g kg(-1)), respectively, with GM-W-W having the lowest (18.1 and 2.7 g kg(-1)); FUE was the reverse of NUE. This long-term study showed that diversified cropping systems that include pulses can more consistently produce higher grain and protein yields, regardless of growing conditions, than most other systems with lower N fertilizer inputs, thereby potentially reducing the negative environmental consequences associated with N fertilizer application.

The optimal row spacing aims to maximize profitability by balancing the reduction in production costs from a wider row spacing against a potential decline in yield and increased weed pressure. A wider row spacing should increase area seeded per day, improve residue flow around seeder openers and the success of seeding between stubble rows. This study investigated the feasibility of a wider row spacing by studying the effects of row spacing (25, 30, 35, 40 cm) and N fertilizer rates (20, 40, 80, 120, 160 kg N ha(-1)) on development, yield, and quality of spring wheat (Triticum aestivum L.). The study was a two factorial in randomized complete block design. The experiment was conducted at Indian Head, SK, from 2013 to 2016. Row spacing affected plant, head, and seed density; however, the effects were generally inconsistent. One exception was biomass, which decreased as the row spacing increased in 3 of the 4 yr. Grain yield declined in 1 of the 4 yr, with the largest portion of the decrease occurring as the row spacing increased from 30 to 40 cm. As expected, increasing N rates produced greater grain yield, biomass, and grain protein. In conclusion, this study found that in most years the row spacing can be widened past 30 cm without a negative impact on grain yield in a no-till cropping system. However, to determine the probability of a grain yield decrease as row spacing is increased, a larger study over a wider geographic region is needed.

According to the UN-FAO, agricultural production must increase by 50% by 2050 to meet global demand for food. This goal can be accomplished, in part, by the development of improved cultivars coupled with modern best management practices. Overall, wheat production on farms will have to increase significantly to meet future demand, and in the face of a changing climate that poses risk to even current rates of production. Durum wheat [Triticum turgidum L. ssp. durum (Desf.)] is used largely for pasta, couscous and bulgur production. Durum producers face a range of factors spanning abiotic (frost damage, drought, and sprouting) and biotic (weed, disease, and insect pests) stresses that impact yields and quality specifications desired by export market end-users. Serious biotic threats include Fusarium head blight (FHB) and weed pest pressures, which have increased as a result of herbicide resistance. While genetic progress for yield and quality is on pace with common wheat (Triticum aestivum L.), development of resistant durum cultivars to FHB is still lagging. Thus, successful biotic and abiotic threat mitigation are ideal case studies in Genotype (G) × Environment (E) × Management (M) interactions where superior cultivars (G) are grown in at-risk regions (E) and require unique approaches to management (M) for sustainable durum production. Transformational approaches to research are needed in order for agronomists, breeders and durum producers to overcome production constraints. Designing robust agronomic systems for durum demands scientific creativity and foresight based on a deep understanding of constitutive components and their innumerable interactions with each other and the environment. This encompasses development of durum production systems that suit specific agro-ecozones and close the yield gap between genetic potential and on-farm achieved yield. Advances in individual technologies (e.g., genetic improvements, new pesticides, seeding technologies) are of little benefit until they are melded into resilient G × E × M systems that will flourish in the field under unpredictable conditions of prairie farmlands. We explore how recent genetic progress and selected management innovations can lead to a resilient and transformative durum production system.

In recent years, soybean acreage has increased significantly in western Canada. One of the challenges associated with growing soybean in western Canada is the control of volunteer glyphosate-resistant (GR) canola, because most soybean cultivars are also glyphosate resistant. The objective of this research was to determine the impact of soybean seeding rate and planting date on competition with volunteer canola. We also attempted to determine how high seeding rate could be raised while still being economically feasible for producers. Soybean was seeded at five different seeding rates (targeted 10, 20, 40, 80, and 160 plants m(-2)) and three planting dates (targeted mid-May, late May, and early June) at four sites across western Canada in 2014 and 2015. Soybean yield consistently increased with higher seeding rates, whereas volunteer canola biomass decreased. Planting date generally produced variable results across site-years. An economic analysis determined that the optimal rate was 40 to 60 plants m(-2), depending on market price, and the optimal planting date range was from May 20 to June 1.