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Forage mixtures containing legume out-yield monocultures, fix atmospheric nitrogen, and have lower carbon footprints. However, evidence-based information on creating forage mixtures by direct seeding legumes into existing pastures is limited, and information on bloat-free legumes is nonexistent. Traditionally, pastures requiring improvement in western Canada were fully replaced by breaking up the old stand and reseeding. With new and improved forage cultivars, better seeding equipment, and increased knowledge about pasture management, there is a growing interest among producers in rejuvenating pastures instead of replacing them. Pasture rejuvenation refers to the improvement in biomass productivity and (or) nutritional quality of existing pasture without removing the existing vegetation. This can be done through fertilizer application, which is generally expensive and causes negative environmental impacts. Amelioration of compacted pastureland via mechanical aeration is short-lived and can lead to weed problems. As an alternative, direct seeding of productive, nutritive and bloat-free legume species into existing pasture is an attractive option for pasture rejuvenation. For high performance grazing systems, identification of suitable bloat-free legumes and methods for direct seeding into old grass and legume stands will be essential strategies. This review includes information on the benefits of mixed pastures and seeks possible methods of introducing bloat-free forage legumes into existing pastures in western Canada for rapid improvement in productivity and quality while positively influencing animal, soil, and environmental health.

An irrigation study in southern Alberta compared spring-banded nitrogen (N) to spring-banded N plus fertigation at three plant growth stages for spring wheat (Triticum aestivum L.) and canola (Brassica napus L.). Yield and quality impacts were quantified when N fertigation was applied to (i) wheat at the early tillering, flag leaf, and anthesis stages and (ii) canola at the four-leaf rosette, bolting, and early flowering stages. For both crops, fertigation could replace some spring-banded N without an effect on yield. However, the results revealed that for canola grown with a large amount of N, applying it all in the spring often generated higher yields than if an equivalent amount of N was delivered at later stages by fertigation. Canola oil concentration declined marginally (about 1%) from no applied N to the high rate of applied N. The application of more than 60 kg N ha−1 and delayed application each increased wheat protein content. Comparing revenues to costs, fertigation did not improve profit margins for canola growers. When growers applied 90 or 120 kg N ha−1 in the spring, fertigation was financially counter-productive. In contrast, the main benefit to wheat growers from fertigation was higher grain protein, especially with N applied at later growth stages. When protein premiums increase during the growing season, fertigation would facilitate growers to obtain higher net returns than they would otherwise.

Research indicates that not all crops respond similarly to cropping diversity and the response of triticale (× Triticosecale ssp.) has not been documented. We investigated the effects of rotational diversity on cereals in cropping sequences with canola (Brassica napus L.), field pea (Pisum sativum L.), or an intercrop (triticale:field pea). Six crop rotations were established consisting of two, 2-yr low diversity rotations (LDR) (continuous triticale (T-T_LDR) and triticale-wheat (Triticum aestivum L.) (T-W_LDR)); three, 2-yr moderate diversity rotations (MDR) (triticale-field pea (T-P_MDR), triticale-canola (T-C_MDR), and a triticale: field pea intercrop (T- in P_MDR)); and one, 3-yr high diversity rotation (HDR) (canola-triticale-field pea (C-T-P_HDR)). The study was established in Lethbridge, Alberta (irrigated and rainfed); Swift Current (rainfed) and Canora (rainfed), Saskatchewan, Canada; and carried out from 2008 to 2014. Triticale grain yield for the 3-yr HDR was superior over the LDR rotations and the MDR triticale-field pea system; however, results were similar for triticale-canola, and removal of canola from the system caused a yield drag in triticale. Triticale biomass was superior for the 3-yr HDR. Moreover, along with improved triticale grain yield, the 3-yr HDR provided greater yield stability across environments. High rotational diversity (C-T-P_HDR) resulted in the highest soil microbial community and soil carbon concentration, whereas continuous triticale provided the lowest. Net economic returns were also superior for C-T-P_HDR ($670 ha–1) and the lowest for T-W_LDR ($458 ha–1). Overall, triticale responded positively to increased rotational diversity and displayed greater stability with the inclusion of field pea, leading to improved profitability and sustainability of the system.

With the increasing resistance of wild oat (Avena fatua L.) to herbicides, there is a need to evaluate the potential of alternative cropping systems based on integrated weed management principles. A 5-yr field study at eight sites across Canada was used to evaluate the profitability of alternative cropping systems that have the potential to control wild oat using cultural practices in conjunction with herbicides. Cultural practices included twice the recommended seeding rates, fall-seeded winter crops, barley (Hordeum vulgare L.) silage, fallow, and alfalfa (Medicago sativa L.). Seven of the 14 cropping systems in this study did not include wild oat herbicide for three consecutive years, controlling wild oat entirely by cultural practices. Cropping system profitability varied by location. For many locations, combinations of barley silage and fall-seeded winter crops without wild oat herbicide application were as profitable as a system of canola (Brassica napus L.) and wheat (Triticum aestivum L.) with wild oat herbicide applied every year. Unprofitable systems generally included those with fallow, alfalfa, and fall-seeded winter crops in regions with rates of high winter kill. Wild oat control can be achieved with diverse cropping systems that are as profitable as conventional annual cropping that relies on herbicide control of wild oat.

Soil organic carbon (SOC) changes slowly, and final management influences can be measured only after decades. Analysis of archived samples from a site established on grassland in 1911 showed that SOC, under wheat systems, approached steady state after several decades, and that its amount reflected the inputs of residue C.

We planted continuous wheat, with and without nitrogen fertilizer, onto a preceding long-term (44 yr) experiment with contrasting cropping systems, and measured soil organic carbon (SOC) after 6 yr. Changes in SOC were driven mostly by cumulative plant C inputs, as influenced by yield response to added nitrogen.

Recent canola acreage and production in western Canada have reached record high levels. Field experiments were conducted from 2014 to 2016 on land previously seeded to continuous canola for 6 yr at three Canadian Prairie sites. We determined that more intensive seed inputs, fertilizer, fungicide, tillage, or chaff removal could increase continuous canola yields compared with a “standard practice” (SP) treatment or match yields compared with canola in rotation. Recommended or 50% higher fertility levels alone or in combination with a higher seeding rate, tillage, chaff removal, or additional fungicide were applied to the same plots in three successive years to determine effects after 1, 2, and 3 yr of treatment imposition. In continuous canola, blackleg incidence and severity were both reduced by fungicide treatment. In rotations where canola was preceded by wheat, blackleg incidence and severity were much lower than in continuous canola. None of the treatments improved continuous canola yields compared with SP after a single year of treatment imposition. In subsequent years, canola yield increases compared with SP usually occurred as a result of additional fertilizer, seed, or fungicide. In the final year, canola yield loss due to continuous canola was largely rescued by additional seed and fertilizer. Without additional inputs, and when preceded by a different crop, canola yields averaged 11% greater than the average of all continuous canola treatments. High fertility regimes generally reduced oil content and increased protein content relative to standard fertility in continuous canola or relative to canola preceded by wheat.

Long-term field trials are ideal for characterising soil microbial communities because lasting communities in a given cropping system evolve over a long time. However, the soil microbiome has not been characterized in most long-term trials. We used a field trial established in 1911 to identify the core soil bacteria and their functioning in century-old wheat rotations, and how soil moisture deficit affected them. We collected soil samples from three wheat rotations: continuous wheat (W), fallow-wheat (FW) and fallow-wheat-wheat (FWW), all with or without N + P fertilizer, and incubated them with or without soil moisture deficit. The crop rotation effects on microbial biomass C (MBC) were in the order: W > FWW = FW. Fertilizer increased soil MBC by 21%. The activities of β-glucosidase (C cycling), N-acetyl-β-glucosaminidase (C and N cycling), and acid phosphomonoesterase (P cycling) followed similar trends, as did soil N supply measured in the field. The α-diversity of the soil bacteria was lower in continuous wheat than in the other rotations, and decreased with fertilizer application. Actinobacteria and Bacteroidetes were more abundant in continuous wheat than other rotations, and the relative abundance of Bacteroidetes increased with fertilizer application. By contrast, Acidobacteria were less abundant in continuous wheat than in other rotations. Soil moisture deficit during incubation had no effects on the soil microbiome. The core bacterial genera present in 90% of the soil samples were Bradyrhizobium, Rubrobacter, Friedmanniela and Marmoricola. β-diversity analysis revealed that the bacterial community structure in continuous wheat with fertilizer application was different from the structures in the other treatments. These and previously-published soil organic C, N and wheat yield results suggest that microbe-mediated nutrient cycling enabled sustainable continuous wheat cropping when fertilizer was applied.

Managing the land properly can help conserve the soil which is critical for sustaining our life and the global society. However, measuring the quality of the soil explicitly is still a challenge. Therefore, this study was conducted to identify suitable soil quality indicators among contrasting land managements (i.e., simple vs. complex crop rotations; manure vs. balanced fertilization) at two long-term experimental fields. The fractal structure of soils was documented by the mass-diameter relationship of soil aggregates using 3D laser scanning. Hydraulic conductivity (K), pore size fractions, and soil physical S parameter (S-index) were determined from moisture retention curves using a HYPROP system. Soil microbial community structure was characterized using phospholipid fatty acid analysis. Our results demonstrated an improved hierarchical fractal aggregation in soils under perennial legumes and grasses (Dm = 0.97) compared to nonfractal aggregation under fallow phases (Dm = 0.99). In addition, across nutrient managements, only balanced fertilization exhibited significantly enhanced fractal aggregation. Moreover, complex crop rotations and balanced fertilization also improved S-index, saturated water content (sat. WC), and plant available water (PAW) compared to their counterparts (Ps

Crop production in the semiarid Northern Great Plains has historically been limited to wheat (Triticum aestivum L.), with fallow every second or third year. In response to current prices and new production technologies, these cropping systems have been replaced with reduced frequency of fallowing and inclusion of oilseed and pulse crops in the rotation. This study examined the long-term changes that producers can expect in their production levels and economic returns for five wheat-based rotations with different fallow frequencies, use of an annual legume green manure to partially replace fallow, and a continuous diversified rotation of cereal–oilseed–cereal–pulse crops. The findings were based on the last 11 yr of a 28-yr (1987–2014) crop rotation experiment performed at Swift Current, SK, Canada. Despite the higher grain yield on fallow versus stubble, total grain production increased as fallow frequency decreased. The continuous wheat rotation produced 21% more wheat than the rotations with fallow. Wheat protein was highest for the rotation containing the legume green manure. Since its establishment in 2003, a wheat–canola (Brassica napus L.)–wheat–dry pea (Pisum sativum L.) rotation was more profitable than the traditional wheat systems. Participation in a crop insurance program reduced the financial risk from low crop yields, particularly for continuous cropping. We concluded that under current economic conditions and production practices, producers can indeed enhance production levels and farm profitability with adoption of more intensive (reduced fallow) crop rotations, particularly those that also include oilseed and pulse crops.

After 47 yr of no-till and reduced summerfallow at Lethbridge, Alberta, soil organic carbon concentration and stocks increased 2.14 g kg−1 and 2.22 Mg ha−1, respectively, in the surface 7.5 cm layer. These findings confirmed the conservation value of reducing tillage and summerfallow. The annual changes were relatively small.

Profitable malting barley (Hordeum vulgare L.) production systems are required to reverse the decline in area seeded to malting barley in western Canada. Systems that could increase the profitability of growing malting barley considered the previous crop, nitrogen (N) rate, and fungicide application. The net return (NR) and risk for these systems were computed from western Canada field data. Analysis of variance was used to evaluate the impact of systems on NR over 21 site-years of field data. Risk was evaluated with a stochastic simulation model. NR was higher and risk lower for malting barley when the preceding crop was field pea (Pisum sativum L.), when fungicide was applied at the flag leaf stage for leaf disease control, and when N was 50% of the recommended N rate. Therefore, malting barley should be grown on field pea stubble at a lower N rate, with fungicide applied when there are leaf diseases.

Field studies with two types of alfalfa (Medicago sativa L.) cultivars were conducted at Lethbridge in 2012 and 2013 and at Picture Butte in 2012 to determine the effects of irrigation on the dry matter (DM) yield and on net returns. The irrigated cultivars (Longview and Blue J) and dryland cultivars (Rangelander and Rambler) were arranged on plots in a randomized complete block design with four irrigation treatments and replicated five times. For the optimal irrigation treatment (W1), soil water content was maintained between 60 and 90% of available water in the designated root zone. Other irrigation treatments received 75% (W2), 50% (W3), and 25% (W4) of the irrigation water applied to the optimal treatment. The mean DM yields of irrigated alfalfa cultivars were greater than one of the dryland cultivars in both locations. The mean total DM yields for W2and W3at Lethbridge for Blue J, Longview and Rambler were greater than those of W1, although the differences were not always significant. The net returns, calculated by using the same price for all alfalfa harvests were similar across the cultivars and irrigation treatments excepting Rangelander, where the returns were lower. The results obtained from this study indicated a trend towards comparable yields and net returns between the optimal and the 75% irrigation treatment with 40% depletion of available water at the root zone, for the irrigated alfalfa cultivars and a dryland type Rambler.

In western Canada, more money is spent on wild oat herbicides than on any other weed species, and wild oat resistance to herbicides is the most widespread resistance issue. A direct-seeded field experiment was conducted from 2010 to 2014 at eight Canadian sites to determine crop life cycle, crop species, crop seeding rate, crop usage, and herbicide rate combination effects on wild oat management and canola yield. Combining 2× seeding rates of early-cut barley silage with 2× seeding rates of winter cereals and excluding wild oat herbicides for 3 of 5 yr (2011 to 2013) often led to similar wild oat density, aboveground wild oat biomass, wild oat seed density in the soil, and canola yield as a repeated canola–wheat rotation under a full wild oat herbicide rate regime. Wild oat was similarly well managed after 3 yr of perennial alfalfa without wild oat herbicides. Forgoing wild oat herbicides in only 2 of 5 yr from exclusively summer annual crop rotations resulted in higher wild oat density, biomass, and seed banks. Management systems that effectively combine diverse and optimal cultural practices against weeds, and limit herbicide use, reduce selection pressure for weed resistance to herbicides and prolong the utility of threatened herbicide tools.

Soil organic matter (SOM) is a major driver of key agroecosystem functions. Our objective was to examine the dynamics of organic matter in whole soil, particulate (POM; > 53 mu m size), and mineral-associated (MAOM) fractions under varying crop rotations and nutrient managements at two long-term experimental sites (Breton and Lethbridge). Soil samples were collected from simple (2 yr) and complex (5 or 6 yr) crop rotations at the 5 - 10 cm depth. We found associations between SOM pools versus microbial community and soil aggregation. Compared to cropped soils, an adjacent forest exhibited a significantly higher soil total organic carbon (TOC) and a shift in SOM fractions with substantially higher POM. However, the forest soil had the lowest microbial biomass C among all the assessed land use systems (P

Inclusion of legumes in crop rotations is a sustainable approach to reducing nitrogen (N) fertilizer requirements and increasing subsequent crop yields. However, the magnitude of the benefit will depend on the specific legume, the subsequent crop and site-specific conditions. This study compared the effects of preceding legumes and non-legumes on yields and economic optimum N rates (EONR) in a Hard Red Spring wheat (Triticum aestivum L.)–hybrid canola (Brassica napus L.) cropping sequence. Field pea (Pisum sativum L.), lentil (Lens culinaris Medik), faba bean (Vicia faba L.; faba bean-seed), canola and wheat grown for grain, and faba bean grown as green manure (faba bean-GRM) were the preceding crops and were direct-seeded at six locations in western Canada in 2010. Wheat was seeded in 2011 and canola in 2012, with N fertilizer applied at 0, 30, 60, 90 and 120 kg N ha−1 in each year. Averaged across preceding crops, N application increased crop yields at all sites. Wheat grain yield was greater, with a corresponding lower EONR, following legumes than non-legumes due in part to increased N availability. Greater non-N benefits to wheat following legumes than non-legumes were also evident at all but one site, with non-N benefits being lowest for preceding wheat. While preceding legumes had no effect on canola seed yield across sites, EONR for canola were >50% lower for legume-wheat than non-legume-wheat rotations. Among the legumes, growing faba bean-GRM, field pea and lentil were most likely to increase crop yields and reduce EONR as compared to faba bean-seed. Overall, growing legumes for seed before a wheat–canola cropping sequence in conventional cereal cropping systems can increase crop yields, reduce EONR and improve the long-term sustainability of cereal cropping systems.

Smith, E. G., Janzen, H. H. and Krobel, R. 2015. Yield and profitability of fallow and fertilizer inputs in long-term wheat rotation plots at Lethbridge, Alberta. Can. J. Plant Sci. 95: 579–587. A long-term, 42-yr study was used to determine the impacts of crop rotation and fertility management on wheat yield and profitability. Crop rotations included continuous wheat (W), fallow–wheat (FW), and fallow–wheat–wheat (FWW). Original plots were split for nitrogen (N) and phosphorus (P) fertility treatments, a two-factor factorial for N (0 and 45 kg ha−1) and P (0 and 20 kg ha−1). Phosphorus increased yield during the first half of the period, but had little impact during the last half. Nitrogen had no yield impact on fallow crops during the first half of the period, but had a positive impact during the last half, and throughout for wheat after wheat. The soil became incapable of releasing adequate N for wheat after fallow. Simulated distributions of net returns determined the W rotation with N and P fertilize...

Wheat (Triticum aestivum L.) is a major food source supplying nutrients required for adequate human nutrition. Changing fertility and cropping practices could alter the concentration of essential e...

Managing nitrogen (N) inputs to sustain high yields while minimizing losses to adjacent environments remains among the foremost aims in agroecosystems. We studied the N balance in a study established in 1911 at Lethbridge, AB, Canada. The experiment includes three cropping systems — continuous wheat (W), fallow–wheat–wheat (FWW), and fallow–wheat (FW) — with a factorial of two N rates (0 and 45 kg N ha−1) and two phosphorus (P) rates (0 and 20 kg P ha−1) superimposed beginning in 1967. In unfertilized subplots, grain yields generally increased for the first eight decades, but then declined, perhaps partly because of growing N deficiency. Yield response to N increased over time, especially under continuous cropping and when co-applied with P. Soil N concentration in the surface 15 cm declined in the first few decades, and then approached an apparent steady state. Application of N increased soil N, roughly in proportion to the amount of residue returned. For the first half-century (1911–1967), N removal was...

High costs of fertilizer in western Canada have generated interest in alternative N sources. Legumes produce N through fixation, and may increase soil residual and mineralizable N, thus reducing the need for fertilizer N in subsequent crops. Hybrid canola (Brassica napus L.) has a high N requirement for optimum yield, but knowledge of rotational effects of legumes on canola is limited. The objective was to determine the effects of legume and non-legume preceding crops on yield and quality of canola grown the follow ing year and malting barley (Hordeum vulgare L.) grown after canola. Field pea ( Pisum sativum L.), lentil (Lens culinaris Medik.), faba bean (Vicia faba L.), canola, and wheat (Triticum aestivum L.) harvested for grain, and faba bean grown as a green manure were direct-seeded at seven locations in 2009. Canola was seeded in 2010 and barley in 2011, with fertilizer N applied at 0, 30, 60, 90, and 120 kg ha –1 . On average, all legumes, except faba bean for seed, produced higher canola and barley yields than when wheat was the preceding crop. Faba bean green manure produced the highest yields, while canola on canola produced the lowest canola yield. The legumes had little negative effect on canola oil or barley protein concentration. Yields of both crops increased with increasing N rate, but canola oil concentration decreased, and barley protein increased. The results indicate that growing legumes for seed before hybrid canola can improve canola and subsequent barley yield without negatively affecting canola oil or malting barley protein.

In western Canada, canola is traditionally grown in rotation once every 4 years to restrict losses due to pests. Recently, growers have begun to produce canola more intensively due to market opportunities and cultivar improvements. This study was initiated to investigate the consequences of more intensive production of canola in rotations, integrated with currently available disease management practices, including blackleg resistant cultivars and fungicides. A 4 replicate split-plot experiment was established at Scott and Melfort, Saskatchewan with canola rotation treatments ranging from yearly to every second, third or fourth season in combination with pea, wheat and flax using a blackleg resistant and a blackleg susceptible cultivar. Sub-plots were fungicide treatments for blackleg and sclerotinia stem rot diseases. Blackleg incidence and severity was increased in rotations comprising more than one canola crop every four years, regardless of cultivar, although the blackleg resistant cultivar wa...

Canola (Brassica napus L.) is the most widespread profitable cash crop in Canada. In 2014 and 2015, direct-seeded experiments were conducted in 16 western Canada environments. “Small” canola seed (average 3.32–3.44 g 1000−1) was compared to “large” canola seed (average 4.96–5.40 g 1000−1) at five seeding rates (50, 75, 100, 125 or 150 seeds m−2). Large canola seeds increased crop density and crop biomass but decreased plant mortality, days to start of flowering, days to end of flowering, days to maturity, and percent green seed. Seed size did not influence harvested seed weight, seed oil content or seed protein content. Increasing the seeding rate of small seeds improved canola yield, but the same response did not occur for large seeds. Increasing seeding rates also increased crop density, plant mortality, crop biomass, and seed oil content, but decreased days to start of flowering, days to end of flowering, days to maturity, percent green seed, and seed protein content. Seeding rate had no impact on harv...

We assessed the extent to which summer fallow in the Dark Brown soil zone is likely to return as a response to net return (NR) risk. An economic model was used to identify, delineate, and quantify ...

A western Canada field study investigated the effects of seeding date and rate on malting barley quality. Seeding date had little effect on quality. Increasing the seeding rate up to 300 seeds m-2 resulted in higher germination and Kolbach indices, lower β-glucan, and better endosperm modification without compromising malt extract.

Over the last decade, the level of competition in the Canadian apple industry has been affected by growing competitive pressures from increasing imports and the availability of other fresh fruits. In response to intensifying competition, the industry has introduced new apple varieties that are more desirable to consumers in terms of eating quality and improve growers’ profitability. British Columbia (BC) apple sales data were employed to examine the implicit value of apple attributes for apples sold in several metropolitan areas of western Canada (Vancouver, Calgary, Edmonton, Saskatoon, and Winnipeg). Linear hedonic price functions were estimated to determine price premiums paid for newer varieties, higher grades, and larger fruit size. In addition, the price effects of cold storage and seasonality were considered because of their association with apple quality. Wholesale prices were significantly influenced by apple fruits of newer varieties, grades, fruit sizes, and metropolitan area. Wholesalers also distinguished between Canadian and BC grades of different varieties. Wholesale prices varied across urban centers; they were relatively higher in Winnipeg and Saskatoon than in Vancouver [EconLit Classifications: Q110, Q130].

Tree-based intercropping (TBI) integrates tree production within annual grain cropping. The system is widely used in tropical regions, but is not common in temperate regions. This study evaluates the annualized return from TBI systems in southern Ontario, Canada against annual grain crop production. The TBI systems include hybrid poplar, Norway spruce, and red oak. The annualized return for all TBI systems is less than for annual cropping using the base prices; however, when tree prices are high and grain prices low the hybrid poplar TBI system has a higher return than annual cropping. Grants for planting trees, technologies to reduce the cost of establishing and maintaining trees, and improving the returns from tree production will be required for producers in temperate regions to adopt TBI systems. Un systeme de cultures intercalaires (SCI) integre la production d’arbres dans la culture annuelle de cereales. Ce systeme est largement utilise dans les regions tropicales, mais peu courant dans les regions temperees. La presente etude evalue le rendement annualise des SCI dans le sud de l’Ontario, au Canada, par rapport a celui de la production annuelle de cereales. Les SCI integrent le peuplier hybride, l’epinette de Norvege et le chene rouge. Le rendement annualise des SCI est inferieur a celui des cultures annuelles si l’on utilise les prix de reference. Toutefois, lorsque les prix des arbres sont eleves et que les prix des cereales sont faibles, le SCI qui integre le peuplier hybride obtient un rendement superieur a celui des cultures annuelles. Pour que les agriculteurs des regions temperees adoptent les SCI, il faudra offrir des subventions a la plantation d’arbres, offrir des technologies qui permettront de reduire les couts de plantation et d’entretien des arbres et ameliorer les rendements/revenus de la production d’arbres.

Hybrid (HY) canola (Brassica napus L.) produces a higher seed yield than open-pollinated (OP) canola. While it is expected higher-yielding HY canola may require higher total available nutrients, especially nitrogen (N), the evidence is not conclusive. This study used canola yield data from several site-years and fertility experiments to determine whether HY and OP canola types require different rates of total available N (TAN) and total available phosphorus (TAP). The yield response of the two canola genotypes to TAP was the same, but for TAN the yield response was greater for HY canola. The quadratic yield response results were confirmed using three plateau equations. Optimal TAN for HY canola was higher than for OP canola. Soil test laboratories and producers growing HY canola need to modify N fertility for HY canola, compared with OP canola for which most of the current N fertilizer recommendations were developed. Key words: Economics, fertilizer, yield response, canola, hybrid, open-pollinated

The high cost of hybrid (HY) canola (Brassica napus L.) seed has some producers considering F 2 generation hybrid farm-saved seed (HY-FSS), or open-pollinated (OP) varieties (both certified and farm-saved seed). The net return (NR) of different varieties, genetic backgrounds, seeding rates, seed treatments, and seed sizing was evaluated from three experiments over eight site-years of field data from western Canada. One set of experiments included variety, genetic background and seeding rate, while another included seed treatment, genetic background and seed sizing. The experiments used randomized complete block designs. The NR accounted for yield, green seed price discount, seed costs, and other production costs. Analysis of variance indicated certified F 1 hybrid seed (HYC) was more profitable than HY-FSS (15%, P = 0.0057) and OP (22%, P = 0.0001). With delayed weed control, NR was lower for HYC and not statistically different than HY-FSS. Higher seeding rates and seed sizing for HY-FSS did not increase NR compared to HYC. The findings of this study support the use of HYC canola seed, especially at high canola prices. Canola producers will not increase their NR by using HY-FSS or OP seed to reduce their seed cost because the lost value of production exceeds the higher cost of HYC seed.

Relatively high seed prices and low canola (Brassica napus L.) grain prices created a controversy over using farm-saved seed from hybrids. Agronomic implications of saving seed from a canola crop were investigated by planting certified seed and saved-seed of an open-pollinated and a hybrid canola cultivar at eight site-years in Saskatchewan and Alberta, Canada. In one series of experiments cultivars and seed rates were compared, while in another experiment seed treatments and use of sized seed were investigated. Results tend to agree with similar studies with other crops where agronomic performance was unaffected when farm-saved seed from open-pollinated crops was used, but declined when this practice was used with hybrid cultivars. Using farm-saved seed from hybrid canola (HY-FSS) compared with hybrid certified seed (HYC) reduced plant population density by 16 to 18% at the time of crop maturity and yield by an average of 12%, delayed maturity by 2 d, reduced seed oil content by 5 g kg -1 , and resulted in a small increase in incidence of green seed. Yield and quality loss associated with using HY-FSS could not be recovered by using increased seeding rates or by sizing and planting only large seed. The inability to use the most effective combined insecticide plus fungicide seed protectant treatments with farm-saved seed resulted in a 20% yield loss compared with treated certified hybrid seed. Our study demonstrates the production risks of growing HY-FSS on plant density, yield, maturity, and seed oil content.

Biodiesel is currently produced in Canada mostly from recycled oils and animal fats. If biodiesel is to supply 5% of diesel usage, a government objective, first-time vegetable, likely from canola and soybean, oil will also be required to provide adequate feedstocks. In this review, we estimate the life cycle energy balances for biodiesel produced from soybean and canola oil under Canadian conditions. The three broad areas of energy inputs were crop production, oil extraction, and transesterification of the vegetable oil into biodiesel. Per unit seed yield, farm production energy inputs for canola were about three times higher than for soybean, mostly because of higher nitrogen fertilizer requirements for canola. Energy required for processing and oil extraction, per unit oil, was higher for soybean. Energy allocation for co-products was allocated using a system expansion approach. Protein meal was assigned about 12% of the energy expended for canola to grow the crop and extract the oil, and about 37% for soybean. Glycerine produced during the transesterification process was allocated energy on a weight basis (11.4%). The ratio of biodiesel energy produced per energy input ranged from 2.08 t o 2.41. The energy ratio was similar for soybean and canola:soybean required less energy inputs, but also produced less oil than canola, for a given weight of seed. Key words: Biodiesel, energy, life cycle analysis, soybean, canola

Applying a polymer seed coat (PSC) to canola (Brassica napus L. and B. rapa L.) seed could be economically beneficial for dormant fall seeding. Field trials at three locations and across 3 yr were used to evaluate the effect of seeding date, use of a PSC, and canola cultivar on crop yield and net returns. The net returns were used to estimate the economic value of using a PSC for three locations, two seeding dates, and four canola cultivars. Net returns differed across locations, and cultivar differences occurred in one of the three locations. Net returns were higher for late-fall seeding, compared with early-fall seeding, with or without the use of a PSC. The value of a PSC was generally positive for early-fall seeding and negative for late-fall seeding. However, at a location prone to midwinter mild spells during which seed germination could occur, the PSC generally had no value. Despite the PSC having a positive value for early-fall dormant seeding, its potential use will be limited because early-fall seeding with a PSC had lower net returns than late-fall seeding without a PSC.

Integrated weed management (IWM) systems that combine seeding date, seeding rate, herbicide rate, and timing of nitrogen (N) fertilizer application were assessed for their economic performance in the Dark Brown and Black soil zones. A barley-field pea IWM system in the Black soil zone at Lacombe, Alberta, and a wheat-canola IWM system in the Dark Brown soil zone at Lethbridge, Alberta, and Scott, Saskatchewan, were used to assess contributions of seeding date (April or May), seeding rate (recommended or 150% of recommended), fertilizer timing (fall or spring), and in-crop herbicide rate (50% or 100% of recommended). The factorial set of treatments was applied in 4 consecutive years at each site. For barley-field pea production, the highest contribution margin (CM) (returns over variable production costs) was earned with 50% of the recommended herbicide rate, spring application of N fertilizer, seeding barley later at the high seeding rate, and seeding field pea early at the recommended seeding rate. This IWM system had a CM benefit of at least $51 ha-1 compared with current common practices. The wheat-canola system results were site specific. At Lethbridge, it was more profitable to use 50% of recommended herbicide rates and to seed both crops early, with an early seeding date being very important for canola. The CM of this IWM system was $48 ha-1 higher than current common practices. At Scott, the wheat-canola system was more profitable with spring fertilizer application, 50% of the recommended herbicide rate, and an early seeding date for canola. The best IWM system had a CM $15 to $75 ha-1 higher, depending on the year, than common practices. Our results confirmed the economic merits of using IWM practices for cereal-oilseed and cereal-pulse cropping systems in these regions of western Canada. Key words: Economic, integrated weed management, contribution margin, canola, wheat, field pea, barley

This study examines the changing structure of the apple industry in Canada and the United States over the last two decades. We attempt to describe whether changing policy environments (e.g., Canada-U.S. Free Trade Agreement) and strengthened intellectual property (IP) rights have affected innovativeness and the competitive position of the North American apple industry. Our analysis shows that Canadian apple production has been on a decline, with apple imports expanding to satisfy production shortfalls and changing consumer preferences for cultivar diversity and year-round supply. By contrast, U.S. apple production expanded in the 1990s because of strengthened exports stemming from export promotion programs and slight increases in foreign demand in selected Asian markets. Our results show that U.S. inventors are protecting their IP by the use of patents to a larger extent than their Canadian counterparts.

A spatial model of intensive livestock production for a region in southern Alberta was used to evaluate the impact of economic factors and regulation on regional returns and optimal manure management. Under current conditions, profit maximizing application of manure met nitrogen requirements but phosphorus application was about three times the crop requirements. Higher commercial nitrogen prices did not significantly alter the optimal manure application, but reduced regional returns. With a phosphorus limit regulation, it was less costly to compost about half of the beef cattle manure to remove it from the region than to truck manure long distances to meet the regulation. A $0.91/t reduction in the costs of composting, or a subsidy to reduce costs, was required to meet the phosphorus regulation. The net costs of the subsidy were slightly less than that ofphosphorus regulation. Future research needs to explore the economic market and limitations of composting for manure management before any composting policy is initiated. Nous avons utilise un modele spatial de la production animale intensive dans une region du sud de l'Alberta pour evaluer l'impact de la reglementation et de facteurs economiques sur les rendements economiques regionaux et la gestion optimale du fumier. Dans les conditions actuelles, l'epandage de fumier effectue en vue de maximiser les profits a respecte les exigences en azote, tandis que la quantite de phosphore etait trois fois superieure aux besoins des cultures. Le prix eleve de l'azote commercial n'a pas modifie de maniere significative l'epandage optimal de fumier, mais a diminue les rendements economiques dans la region. En raison de la reglementation sur le taux d'application limite du phosphore, il a ete moins couteux de composter environ la moitie du fumier de bovins pour l'eliminer de la region que de le transporter par camion sur de longues distances. Pour respecter la reglementation sur le phosphore, il faudrait diminuer le cout du compostage de 0,91 $/tonne ou offrir une subvention equivalente pour diminuer les couts. Les couts nets de la subvention etaient legerement inferieurs a ceux de la reglementation sur le phosphore. Des recherches ulterieures devront etre effectuees pour explorer le marcheeconomique et les limites du compostage dans le cadre de la gestion du fumier avant d'elaborer toute politique sur le compostage.

The number of canola varieties released, since the enactment of Plant Breeders' Rights (PBR) legislation in Canada in 1990, has increased substantively. The effect of genetic enhancements, including PBR, on canola yield and its variance is estimated for canola production regions of Manitoba using the Just-Pope production function. Diagnostic tests reveal the presence of heteroscedasticity in the data. The percentage of varieties seeded with PBR has a negligible effect on canola yield. Hybrid and herbicide tolerant varieties (HY/HT) seeded on over 90% of canola production area increases average yield by about 6.8%. Increased spatial diversity (more varieties planted on fewer acres) has reduced canola yield by up to 1.7%. Temporal diversity (turnover of varieties) has no significant impact on yield. Nitrogen and sulphur fertilizers are yield increasing. The variance of yield is not impacted by PBR, HY/HT, other technology measures, or by fertilizer other than potassium. Canola breeding programs have not compromised canola yield stability. Depuis l'adoption de la Loi sur la protection des obtentions vegetales (LPOV) au Canada en 1990, le nombre de varietes de canola mises au point a augmente considerablement. L'effet des ameliorations genetiques, y compris l'effet de la LPOV, sur le rendement du canola et sa variance a ete estime dans les regions du Manitoba productrices de canola a l'aide de la fonction de production Just-Pope. Des tests de diagnostic ont revele la presence d'heteroscedasticite dans les donnees. Le pourcentage de varietes ensemencees depuis la LPOV a un effet negligeable sur le rendement de canola. Les varietes hybrides et les varietes tolerantes aux herbicides (HY-HT) ensemencees sur plus de 90% des superficies cultivees en canola ont augmente le rendement moyen d'environ 6.8%. L'accroissement de la diversite spatiale (plus de varietes sur moins de superficies) a diminue le rendement du canola jusqu'a 1.7%. La diversite temporelle (rotation des varietes) n'a aucun impact significatif sur le rendement. Les engrais azotes et soufres augmentent les rendements. La variance du rendement n'est pas influencee par la LPOV, ni les HY-HT, ni les autres mesures technologiques ni les engrais autres que le potassium. Les programmes de selection du canola n'ont pas compromis la stabilite du rendement du canola.

Integrated weed management (IWM) decision strategies in herbicide-resistant canola-production systems were assessed for net returns and relative risk. Data from two field experiments conducted during 1998 to 2000 at two locations in Alberta, Canada, were evaluated. A herbicide-based experiment included combinations of herbicide system (glufosinate-, glyphosate-, and imazethapyr-resistant canola varieties), herbicide rate (50 and 100% of recommended dose), and time of weed removal (two-, four-, and six-leaf stages of canola). A seed-based experiment included canola variety (hybrid and open-pollinated), seeding rate (100, 150, and 200 seeds m−2), and time of weed removal (two-, four-, and six-leaf stages of canola). For the herbicide-based experiment, strategies with glyphosate were profitable at Lacombe, but both imazethapyr and glyphosate strategies were profitable at Lethbridge. Weed control at the four-leaf stage was at least as profitable as the two-leaf stage at both sites. For the seed-based experiment, the hybrid was more profitable than the open-pollinated cultivar, seed rates of 100 and 150 seeds m−2were more profitable than 200 seeds m−2, and weed control at the two- and four-leaf stages was more profitable than at the six-leaf stage. When risk of returns and statistical significance was considered, several strategies were included in the risk-efficient set for risk-averse and risk-neutral attitudes at each location. However, the glyphosate-resistant cultivar, the 50% herbicide rate, and weed control at four-leaf stage were more frequent in the risk-efficient IWM strategy set. The open-pollinated cultivar, 200 seeds m−2rate, and weed control at the six-leaf stage were less frequent in the set. The risk-efficient sets of IWM strategies were consistent across a range of canola prices.

Organic crop production systems are increasingly being adopted by producers in the northern Great Plains. This study evaluated the expected net returns and risk of organic crop rotations, compared to conventional rotations. Field plot data of organic and conventional crop rotations were used to determine the net returns of the systems, using four different levels of premiums for organic produce. The risk of returns was evaluated using estimated cumulative density functions and stochastic dominance. The most profitable organic rotation required high price premiums to dominate the most profitable conventional rotation. However, the most profitable organic rotation dominated some conventional rotations that are commonly used in the northern Great Plains. The organic rotations had slightly higher risk, but the relative risk of rotations had little impact on the optimal rotation.

Sensory methods have been used to evaluate subjective apple characteristics such as juiciness, flavour, and texture. There is very little information to indicate the value wholesalers place on objective apple characteristics such as cultivar, grade, and fruit size. In this study, a hedonic price function for apples was estimated to evaluate the relationship between British Columbia (BC) apple (Malus domestica Borkh.) prices and the wholesalers’ perception of product quality characteristics. In this study, sales data and cultivar characteristics were obtained for three large wholesalers in western Canada that purchase BC fruit. Cultivar, fruit size, and grade were the most significant variables influencing apple prices. Wholesalers paid price premiums ($2.25 to $5.25 per tray) for speciality cultivars such as Gala, Fuji and Braeburn compared with traditional cultivars such as McIntosh, Red Delicious and Spartan. Large fruit size earned a price premium ($1.73 per tray) and small fruit were discounted ($2.00 per tray) compared with medium size apples. Apples graded Canada Extra Fancy (One Stripe) and BC Extra Fancy provided packing houses with price premiums ($1.50) over Canada Fancy. Apples in controlled-atmosphere (CA) storage earned price premiums ($0.96 to $1.89 per tray) in the months of January through June. Key words: Apple characteristics, wholesalers' preference, hedonic price function.

Straw-tillage treatment and N fertilizer rate were assessed for their impact on plant growth, N uptake, and profitability of irrigated cereals and oilseeds on a Dark Brown Chernozemic Lethbridge loam in southern Alberta. Straw was either retained or removed by baling. Tillage treatments were fall plowing, spring plowing, and direct seeding. Four N fertilizer rates (0, 50, 100, and 200 kg ha-1) were imposed on the straw-tillage treatments. The data were analyzed by crop using analysis of covariance with year and replication as random factors, straw-tillage treatment as a fixed effect, and fertilizer and fertilizer squared as covariates. Grain and straw yields were higher for fall plowing than for spring plowing or direct seeding at zero N rate, but were not different at the high N rate (200 kg ha-1). Grain and straw N concentrations were higher for fall plowing than spring plowing or direct seeding at the low N rate (50 kg ha-1), but similar at the high N rate. Total N uptake was higher for fall plowing or spring plowing without retaining straw than direct seeding without retaining straw or spring plowing with retaining straw at the low N rate, but similar at the high N rate. Net returns were higher for fall plowing and treatments that sold the straw, and were maximized at a N rate of about 100 kg ha-1. Key words: Crop residue, fertilizer nitrogen, economics, tillage timing, irrigation