Mohammad Khakbazan

Effect of Rotation on Crop Yield and Quality in an Irrigated Potato System

The productivity of potato (Solanum tuberosum L.) systems may be strongly influenced by rotation. A field study consisting of six rotations (potato with canola (PC), wheat (PW), canola-wheat (PCW), oat-wheat (POW), wheat-canola-wheat (PWCW), and canola underseeded to alfalfa-alfalfa-alfalfa (PCAA)) arranged as an RCBD was established on a clay loam in Manitoba, Canada in 1998 and monitored for twelve years to determine effects on potato yield and quality. Higher yields for canola-containing rotations were evident in three years (P < 0.10), but not beyond 2005. From 2007 onward, 2-year rotations produced a markedly lower yield than other rotations. Yields of 3- and 4-year rotations were similar, although PCW and PCAA were most frequently among the higher-yielding rotations. Overall, PC had a lower specific gravity than other rotations. Results suggest 3- and 4-year rotations, particularly PCW and PCAA, helped maintain productivity. Two-year rotations of PC and PW were not sustainable due to declining yields.ResumenLa productividad de los sistemas de papa (Solanum tuberosum L.) pueden estar fuertemente influenciados por la rotación. Se estableció un estudio de campo consistente en seis rotaciones; papa con canola (PC), con trigo (PW), con canola-trigo (PCW), con avena trigo (POW), con trigo, canola, trigo (PWCW), y con canola mezclada con alfalfa-alfalfa-alfalfa (PCAA), arreglado en un diseño experimental de bloques completos al azar, en un suelo franco-arcilloso en Manitoba, Canadá, en 1998, y monitoreado por doce años, para determinar los efectos en rendimiento y calidad de la papa. Se hicieron evidentes más altos rendimientos en las rotaciones que incluían a la canola en tres años (P < 0.10), pero no más allá de 2005. A partir de 2007, las rotaciones de dos años produjeron un rendimiento más bajo bien marcado que en otras rotaciones. Los rendimientos de rotaciones de 3 y 4 años fueron similares, aunque PCW y PCAA estuvieron entre las más frecuentes de las rotaciones de mayores rendimientos. En general, PC tuvieron gravedad específica más baja que otras rotaciones. Los resultados sugieren que rotaciones de 3 a 4 años, particularmente PCW y PCAA, ayudaron a mantener la productividad. Rotaciones de dos años de PC y PW no fueron sostenibles debido a la disminución en rendimientos.

Cultivar Developments, Fertilizer Inputs, Environmental Conditions, and Yield Determination for Potatoes in Manitoba

While potato production on the Canadian Prairies has expanded significantly since the early 1990s and accounted for roughly one third of Canada’s production over the period 1990–2006, few studies have looked at Plant Breeder’s rights and cultivar releases in Canada, and the determinants of potato yield in Manitoba. This paper examines potato breeding developments in terms of cultivar releases, the extent that new cultivar releases are protected by Plant Breeders’ Rights (PBR), and the contribution of cultivar improvements, environmental conditions and fertilizer inputs to potato yield in Manitoba. The results from our study indicate that professional person-years devoted to potato breeding has declined since 1990 and that PBR granted to European and U.S. breeders have exceeded those granted to Canadian domestic breeding institutions. Manitoba processing potato yields have been affected more so by a combination of fertilizer inputs and regional effects than by improved cultivars. In the current study, the limited effect of protected cultivars on yield may be due to the small number of protected cultivars being assessed, and the relatively short time period considered. Lack of adoption of new cultivars in Manitoba may reflect slow adoption of new cultivars by the processing industry as it ensures that quality and processing specifications are met.ResumenMientras que la producción de papa en las praderas Canadienses se ha expandido significativamente desde inicios de 1990 y contabilizados someramente para un tercio de la producción de Canadá en el periodo 1990–2006, pocos estudios han analizado el derecho de los Genetistas en Plantas y lanzamiento de cultivares en Canadá, y los determinantes del rendimiento de papa en Manitoba. Este artículo estudia los desarrollos genéticos en papa en términos de lanzamiento de cultivares, la magnitud en que el lanzamiento de nuevas variedades es protegido por los Derechos de los Genetistas en Plantas (PBR), y la contribución en mejoras de cultivares, condiciones ambientales y aportes de los fertilizantes en el rendimiento de papa en Manitoba. Los resultados de nuestro estudio indican que persona profesionales-años dedicados al mejoramiento de papa ha declinado desde 1990 y que el PBR otorgado a los genetistas europeos y de Estados Unidos han excedido a aquellos otorgados a las instituciones genéticas domésticas canadienses. Los rendimientos de procesamiento de papa en Manitoba han sido más afectados, tanto por la combinación del aporte de los fertilizantes y efectos regionales que por cultivares mejorados. En el presente estudio, el efecto limitado de los cultivares protegidos en rendimiento podrían deberse al pequeño número de cultivares protegidos que son evaluados, y al relativamente corto periodo de tiempo considerado. La falta de adopción de nuevos cultivares en Manitoba podrían reflejar una adopción lenta de nuevos cultivares de parte de la industria de procesamiento mientras se aseguren conseguir las especificaciones de calidad y procesamiento.

Economic analysis and stochastic simulation of alternative beef calving and feeding systems in western Canada

Khakbazan, M., Carew, R., Scott, S. L., Chiang, P., Block, H. C., Robins, C., Durunna, O. N. and Huang, J. 2014. Economic analysis and stochastic simulation of alternative beef calving and feeding systems in western Canada. Can. J. Anim. Sci. 94: 299-311. Biological and economic data from three field-experimental sites in Manitoba (Brandon Research Centre) and Saskatchewan (Western Beef Development Centre; Semi-Arid Prairie Agriculture Research Centre) were used to determine the economic and financial benefits of alternative beef calving and feeding systems. Stochastic budgets and Monte Carlo simulation techniques were used to evaluate the profitability and risk levels of four alternative livestock beef management systems: early-calving/rapid-gain post-weaning feeding (ER), late-calving/rapid-gain post-weaning feeding (LR), early-calving/slow-gain post-weaning feeding (ES), and late-calving/slow-gain post-weaning feeding (LS). Economic budgets were constructed to evaluate the viability of different phases of beef production including backgrounding, pasture, swath grazing and finishing. Statistical analysis considered operational costs (feed, yardage, implants, medicine, labor, marketing, and other costs), price variables (fed-steer, feeder cattle, and grid pricing premiums/discounts) and steer performance measures such as average daily gain (ADG). Results from the simulation analysis revealed that late-calving systems provided higher returns for livestock producers, while rapid-feeding systems were more preferable for producers who were more risk-averse.

The effects of spring versus summer calving on beef cattle reproductive and growth performance in western Canada

Durunna, O. N., Girardin, L. C., Scott, S. L., Robins, C., Block, H. C., Iwaasa, A. D., Khakbazan, M. and Lardner, H. A. 2014. The effects of spring versus summer calving on beef cattle reproductive and growth performance in western Canada. Can. J. Anim. Sci. 94: 259-271. The majority of beef producers in western Canada have adopted a spring calving system. Evaluating alternative calving systems such as summer calving may lead to better use of forage resources to optimize cow-calf productivity. In order to evaluate the impact of calving system on cow-calf productivity, 346 Hereford or Angus crossbred cows were used in a 3-yr research study (2007 to 2009) at Brandon, Manitoba; Swift Current, Saskatchewan and Lanigan, Saskatchewan. Cows were bred to calve from February to May (early-calving system, EC) or from May to August (late-calving system, LC). Each system was evaluated for effect on performance and reproductive efficiency. Forage yield, utilization and nutritive value were assessed. Cow body weights (BW), ultrasound measures of backfat and calf BW were evaluated at precalving, breeding and weaning. There was no difference between calving systems for pregnancy rate (P=0.13) EC (93.0%) vs. LC (95.8%); calving rate (P=0.89) EC (92.0%) vs. LC (91.7%) or proportion of calves born alive (P=0.85) EC (99.5%) vs. LC (99.6%). The average length of calving season was not different (P=0.26) between the two systems. The EC cows had greater (P=0.002) BW losses from calving to breeding but greater (P=0.001) BW gain from breeding to weaning than LC cows. Although calves born in LC had greater birth BW (P=0.003) than EC calves, calf weaning rate (P=0.01) and calf weaning BW (P<0.0001) were greater in EC. The higher weaning rate and higher weaning BW with EC has the potential to increase cow-calf productivity and may be more attractive to beef producers in western Canada.

Impact of calving seasons and feeding systems in western Canada. I. Postweaning growth performance and carcass characteristics of crossbred steers

Durunna, O. N., Block, H. C., Iwaasa, A. D., Thompson, L. C., Scott, S. L., Robins, C., Khakbazan, M. and Lardner, H. A. 2014. Impact of calving seasons and feeding systems in western Canada. I. Postweaning growth performance and carcass characteristics of crossbred steers. Can. J. Anim. Sci. 94: 571-582. Crossbred steers (n=272) weaned from early (EC) and late (LC) calving systems (CS) were used to evaluate the impact of two feeding systems (FS) on postweaning performance and carcass characteristics. The steers were randomly assigned to either a rapid-gain feeding (RF) or a slow-gain feeding (SF) system. The RF steers were managed to have body weight (BW) gain of 1 kg d-1 on a silage-hay diet during the backgrounding period prior to finishing, while the SF steers were first backgrounded on a hay diet (gain of 0.7 kg d-1), then grazed alfalfa-meadow bromegrass pasture and annual cereal swaths prior to finishing. All treatment groups received a conventional diet during finishing until the steers attained a target backfat thickness or BW or both. There was no difference (P=0.48) between the two FS for the average age of the steers at the beginning of the experiment. There was a CS×FS effect (P<0.01) on the age at slaughter, where the steers in the EC-RF, EC-SF, LC-RF and LC-SF were 426, 659, 504 and 606 d, respectively. The longer time on feed for LC-RF steers compared with EC-RF suggests the potential effect of summer ambient temperatures at finishing. The EC-RF group had the least carcass fat thickness (P<0.01), but there was no main or interaction effect (P>0.08) on dressing percentage or lean meat yield. There was a FS effect (P<0.05) on meat colour and marbling texture where SF steers had more desirable meat colour and marbling texture. Beef producers adopting EC-RF would finish their calves earlier but at a lighter weight.

Economic Comparison of Conventional and Conservation Management Practices for Irrigated Potato Production in Southern Alberta

Conventional (CONV) potato (Solanum tuberosum L.) production in Alberta has relied on high levels of soil disturbance which may result in long-term degradation of soil resources. A 12-yr (2000–2011) study was conducted to address issues with the CONV system and to evaluate the effects of conservation (CONS) practices on the economics of irrigated potato production. Potato was grown in 3- to 6-yr rotations which included dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.), soft wheat (Triticum aestivum L.), oat (Avena sativa L.), and timothy (Phleum pratense L.). CONS included reduced tillage, cover crops, compost addition, and solid-seeded bean. Averaged over 12-yr, potato yields for 4-yr CONV rotations (potato–wheat–beet–bean) were lower than those for CONS systems. However, the decreased costs associated with not using compost in 4-yr CONV offset the losses in yield, thereby resulting in an overall net income higher than that of CONS systems.ResumenLa producción convencional de papa (CONV, Solanum tuberosum L.) en Alberta se ha respaldado en altos niveles de alteraciones del suelo, que pudieran resultar en su degradación a largo plazo. Se condujo un estudio de 12 años (2000–2011) para enfatizar temas con el sistema CONV y para evaluar los efectos de prácticas de conservación (CONS) en aspectos económicos de la producción de papa de riego. Se cultivó la papa en rotaciones de 3 a 6 años, que incluían frijol (Phaseolus vulgaris L.), remolacha (Beta vulgarins L.), trigo suave (Triticum aestivum L.), avena (Avena sativa L.) y el pasto bohordillo o hierba timotea (Phleum pratense L.). CONS incluyó labranza mínima, cultivos de cobertura, agregado de composta y frijol en alta densidad. Promediando sobre 12 años, los rendimientos de la papa en rotaciones CONV por 4 años (papa, trigo, remolacha, frijol) fueron más bajos que los de los sistemas CONS. No obstante, la disminución de costos asociada con no usar composta en 4 años de CONV compensa la pérdida en rendimiento, resultando entonces en un ingreso neto total más alto que el de los sistemas CONS.

The effects of spring versus summer calving on beef cattle economic performance in western Canada

Khakbazan, M., Durunna, O. N., Sirski, T. K., Brewin, D. G., Huang, J., Berry, N., Iwaasa, A. D., Scott, S. L., Robins, C. D., Block, H. C. and Lardner, H. A. 2015. The effects of spring versus summer calving on beef cattle economic performance in western Canada. Can. J. Anim. Sci. 95: 475-486. The choice of calving date influences the net revenue of a calving operation as it affects the number of days that calves spend in each feeding phase and when they are subsequently marketed. These two factors determine the costs, revenue, and risk (variance) of each calving system for the calving phase of a beef system. The majority of cow-calf producers in western Canada have adopted early calving (EC) in spring due to management factors. However, late calving (LC) in the summer is an alternative beef calving system associated with higher returns due to lower system costs and higher beef prices. It may offer a better match between cow nutritional requirements and pasture availability. The objective of this study was to compare the revenues and risks for a traditional EC system and an alternative LC system at three sites in western Canada. Biological and economic data from three field experimental sites in western Canada (Brandon Research Centre in Manitoba, Western Beef Development Centre in Lanigan, Saskatchewan and Semi-Arid Prairie Agriculture Research Centre in Swift Current, Saskatchewan) were used to determine the costs and benefits of the alternative beef calving system. The results showed that even though the EC has higher cost than the LC, the EC is slightly better than LC in terms of higher net revenue potential, but it comes at a greater risk due to higher revenue variances. The EC system is usually more preferable for risk-neutral producers, whereas the LC system is more preferable for risk-averse producers.

Impact of calving seasons and feeding systems in western Canada. II. Meat composition and organoleptic quality of steaks

Durunna, O. N., Block, H. C., Iwaasa, A. D., Scott, S. L., Robins, C., Khakbazan, M., Dugan, M. E. R., Aalhus, J. L., Aliani, M. and Lardner, H. A. 2014. Impact of calving seasons and feeding systems in western Canada. II. Meat composition and organoleptic quality of steaks. Can. J. Anim. Sci. 94: 583-593. Fatty acid profiling, meat and organoleptic quality assessments were conducted on 160 carcasses of crossbred steers born into one of two calving systems and later assigned to one of two postweaning feeding systems. The steers were weaned from either an early calving or late calving system and later assigned to either a rapid-gain feeding (RF) or a slow-gain feeding (SF) system. The RF steers received a silage-hay diet during the backgrounding period prior to finishing, while the SF steers received a hay diet at backgrounding and then grazed alfalfa-meadow bromegrass pasture and annual cereal swaths prior to finishing. All treatment groups received a conventional diet during finishing until the steers attained a target backfat thickness or body weight. Fatty acid analyses were conducted on longissimus dorsi muscle (LDM) and subcutaneous fat samples. Other analyses included LDM composition, tenderness and taste panel evaluations. Total saturated fatty acid was greater (P<0.02) in samples from RF steers, while total monounsaturated fatty acid was greater (P<0.01) in SF steers. The SF steers had greater (P<0.01) conjugated linoleic acid concentration. There was no main or interaction effect (P>0.05) on beef aroma, flavour and tenderness but the SF steaks had lower (P=0.02) cooking losses than RF steaks. The SF strategy has the potential to create a value chain that would lead to finished steers with higher backfat omega-3, conjugated linoleic acid and trans vaccenic acid and less cooking moisture losses.

Energy Use Efficiency of Conventional versus Conservation Management Practices for Irrigated Potato Production in Southern Alberta

A 12-yr. (2000–2011) study was conducted in Alberta, Canada to compare the energy use efficiency (EUE) of conventional (CONV) and conservation (CONS) potato (Solanum tuberosum L.) management practices. Potato was grown in 3- to 6-yr. rotations which included dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.), soft wheat (Triticum aestivum L.), oat (Avena sativa L.), and timothy (Phleum pratense L.). CONS included compost application, reduced tillage, cover crops, and solid-seeded bean. Findings suggested that potato in 5-yr. CONS produced the highest EUE compared to the other CONS or CONV rotations. CONS can be used as a means of reducing the reliance on non-renewable energy inputs and improving overall EUE of potato production when less than 21% of the N content of compost applied was counted toward energy input use of potato production. At more than 21%, potato in the 4-yr. CONV became more favorable compared to potato in other rotations.ResumenSe condujo un estudio de 12 años (2000–2011) en Alberta, Canadá, para comparar la eficiencia en el uso de energía (EUE), en prácticas de manejo convencional (CONV) y de conservación (CONS) en papa (Solanum tuberosum L.). Se cultivó la papa en rotaciones de 3 a 6 años, que incluía frijol (Phaseolus vulgaris L.), remolacha azucarera (Beta vulgaris L.), trigo suave (Triticum aestivum L.), avena (Avena sativa L.) y el pasto fleo (Phleum pratense L.). El CONS incluía la aplicación de composta, labranza mínima, cultivos de cobertura y frijol de semilla sólida. Lo que se encontró sugirió que la papa, en un CONS de 5 años, producía la más alta EUE, comparada con las otras rotaciones CONS o CONV. El CONS puede usarse como un medio para reducir el respaldo en la aportación de energía no renovable, y mejorando la EUE en general de la producción de papa cuando se contaba con menos del 21% del contenido de N de la composta aplicada, hacia el uso de la aportación de energía de la producción de papa. A más del 21%, la papa en los 4 años de CONV, se volvía más favorable en comparación a la papa en otras rotaciones.

Economic and Risk Effects of Rotation Based on a 14-Year Irrigated Potato Production Study in Manitoba

Crop rotations can be used to optimize economic return by preserving or enhancing soil quality and reducing pest pressure. A field experiment consisting of six rotations of potato with canola (P-C), wheat (P-W), canola-wheat (P-C-W), oat-wheat (P-O-W), wheat-canola-wheat (P-W-C-W), and canola underseeded to alfalfa-alfalfa-alfalfa (P-C(A)-A-A) organized in a Randomized Complete Block Design was established on a clay loam soil in Manitoba, Canada and monitored for fourteen years to assess the relative economic performance of potato in each rotation. A stochastic budget based on returns and risk of returns trade-offs was used to determine each rotation’s profitability. While differences in average annual net income of all crops between rotations were not significant, the P-C-W rotation was the most stable. Despite the economic advantage of P-C in the first two cycles, longer P-C-W or P-C(A)-A-A rotations are recommended, as two-year rotations increase plant disease and decrease economic viability in the long run.ResumenLas rotaciones de cultivos pueden usarse para optimizar la recuperación económica mediante la preservación o aumento de la calidad del suelo y en la reducción de presión de plagas. Se estableció un experimento de campo consistente en seis rotaciones de papa con canola (P-C), trigo (P-W), canola-trigo (P-C-W), avena trigo (P-O-W), trigo-canola-trigo (P-W-C-W), y canola mezclada con alfalfa-alfalfa-alfalfa (P-C(A)-A-A) organizado en un diseño de bloques completos al azar, en un suelo arcillo-limoso en Manitoba, Canadá, y monitoreado por 14 años para evaluar el comportamiento relativo económico de papa en cada rotación. Se usó un presupuesto estocástico basado en recuperaciones y en el riesgo de compensaciones de recuperaciones para determinar la redituabilidad de cada rotación. Mientras que las diferencias en el promedio anual de ingresos netos de todos los cultivos entre rotaciones no fueron significativas, la rotación P-C-W fue la más estable. A pesar de la ventaja económica de P-C en los primeros dos ciclos, se recomiendan las rotaciones más largas P-C-W o P-C(A)-A-A, ya que las rotaciones de dos años aumentan enfermedad de la planta y a la larga disminuyen la viabilidad económica.