30 results on '"Bell, Lindsay"'
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2. Impacts of reducing fallow periods on indicators of soil function in subtropical dryland farming systems
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Williams, Alwyn, Kay, Phillip, Stirling, Graham, Weng, Xinting, and Bell, Lindsay
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- 2022
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3. Short phases of tropical forage legumes increase production of subsequent cereal crops in the seasonally dry tropics of eastern Indonesia
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Bell, Lindsay W., Hossang, Evert Y., Traill, Skye R., Dalgliesh, Neal P., Budisantoso, Esnawan, and Nulik, Jacob
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- 2022
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4. Above- and belowground dry matter partitioning of four warm-season annual crops sown on different dates in a semiarid region
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Zhang, Zhixin, Yu, Kailiang, Jin, Xiuliang, Nan, Zhibiao, Wang, Jianfeng, Niu, Xueli, Whish, Jeremy P.M., Bell, Lindsay W., and Siddique, Kadambot H.M.
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- 2019
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5. Plant development and solar radiation interception of four annual forage plants in response to sowing date in a semi-arid environment
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Zhang, Zhixin, Christensen, Michael, Nan, Zhibiao, Whish, Jeremy P.M., Bell, Lindsay W., Wang, Jianfeng, Wang, Zhiwei, and Sim, Richard
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- 2019
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6. Indices of forage nutritional yield and water use efficiency amongst spring-sown annual forage crops in north-west China
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Zhang, Qingping, Bell, Lindsay W., Shen, Yuying, and Whish, Jeremy P.M.
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- 2018
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7. Forage production, quality and water-use-efficiency of four warm-season annual crops at three sowing times in the Loess Plateau region of China
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Zhang, Zhixin, Whish, Jeremy P.M., Bell, Lindsay W., and Nan, Zhibiao
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- 2017
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8. Evolution in crop–livestock integration systems that improve farm productivity and environmental performance in Australia
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Bell, Lindsay W., Moore, Andrew D., and Kirkegaard, John A.
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- 2014
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9. Impacts of soil damage by grazing livestock on crop productivity
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Bell, Lindsay W., Kirkegaard, John A., Swan, Antony, Hunt, James R., Huth, Neil I., and Fettell, Neil A.
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- 2011
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10. Clinicians' Perceptions of Collaborative Palliative Care Delivery in Chronic Kidney Disease.
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Ernecoff, Natalie C., Bell, Lindsay F., Arnold, Robert M., Shea, Christopher M., Switzer, Galen E., Jhamb, Manisha, Schell, Jane O., and Kavalieratos, Dio
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PALLIATIVE treatment , *CHRONIC kidney failure , *INTEGRATED health care delivery , *MEDICAL personnel , *MEDICAL care , *COMMUNICATIVE disorders , *CANCER pain , *CANCER patient care , *TREATMENT of chronic kidney failure , *NURSING , *NEPHROLOGY , *RESEARCH funding , *HOSPICE nurses - Abstract
Context: Guidelines recommend palliative care for patients with chronic kidney disease (CKD), who experience a high pain and symptom burden, and receive intensive treatments that often do not align with their values. A lack of scalable specialty palliative care services has prompted calls for attention to primary palliative care, delivered in primary care and nephrology settings.Objectives: The objectives of this study were to 1) describe expectations for care to meet the palliative care needs of people living with CKD, and limitations to meeting those expectations in the current model, and 2) identify potential interventions to meet patients' palliative care needs.Methods: We conducted semi-structured interviews with clinicians from primary care, nephrology, and palliative care to assess 1) reasonable expectations for meeting palliative needs, 2) barriers to integrating primary palliative care, and 3) potential intervention points.Results: Clinicians discussed their expectations for high-quality communication (e.g., discussing disease understanding, assessing goals of care) and better integration of palliative care services. Clinicians expressed barriers to delivering that care, including poor inter-clinician communication. To address barriers, clinicians outlined potential intervention points, such as building collaborative models of care, and structural triggers to identify patients who may be appropriate for palliative care.Conclusion: Interventions to address gaps in palliative care delivery for people living with CKD should incorporate systematic identification of patients with palliative care needs and structural mechanisms to meeting those needs via specialty and primary palliative care. [ABSTRACT FROM AUTHOR]- Published
- 2022
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11. Lack of Exposure to Palliative Care Training for Black Residents: A Study of Schools With Highest and Lowest Percentages of Black Enrollment.
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Bell, Lindsay F., Livingston, Jessica, Arnold, Robert M., Schenker, Yael, Kelsey, Riba C., Ivonye, Chinedu, and October, Tessie W.
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INTERNS (Medicine) , *PALLIATIVE treatment , *MEDICAL students , *TRAINING of medical residents , *HISTORICALLY Black colleges & universities , *MEDICAL school curriculum , *PALLIATIVE medicine - Abstract
Context: The palliative medicine workforce lacks racial diversity with <5% of specialty Hospice and Palliative Medicine (HPM) fellows identifying as black. Little is known about black trainees' exposure to palliative care during their medical education.Objectives: To describe palliative care training for black students during medical school, residency, and fellowship training.Methods: We conducted a cross-sectional descriptive study using Internet searches and phone communication in September 2019. We evaluated 24 medical schools in three predetermined categories: historically black colleges and universities (HBCUs; N = 4) and non-under-represented minority-serving institutions with the highest (N = 10) and lowest (N = 10) percentages of black medical students. Training opportunities were determined based on the presence of a course, clerkship, or rotation in the medical school and residency curricula, a specialty HPM fellowship program, and specialty palliative care consult service at affiliated teaching hospitals.Results: None of the four HBCUs with a medical school offered a palliative care course or clerkship, rotation during residency, or specialty HPM fellowship program. Three of four HBCUs were affiliated with a hospital that had a palliative care consult service. Institutions with the highest black enrollment were less likely to offer palliative care rotations during internal medicine (P = 0.046) or family medicine (P = 0.019) residency training than those with the lowest black enrollment.Conclusion: Residents at schools with the highest black medical student enrollment lack access to palliative care training opportunities. Efforts to reduce health disparities and underrepresentation in palliative care must begin with providing palliative-focused training to physicians from under-represented minority backgrounds. [ABSTRACT FROM AUTHOR]- Published
- 2021
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12. Optimizing ecosystem function multifunctionality with cover crops for improved agronomic and environmental outcomes in dryland cropping systems.
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Garba, Ismail I., Bell, Lindsay W., Chauhan, Bhagirath S., and Williams, Alwyn
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COVER crops , *CROPPING systems , *CASH crops , *SOIL respiration , *SOIL structure , *ECOSYSTEMS - Abstract
Integrating cover crop mixtures into dryland crop-fallow rotations may foster ecological intensification by enhancing ecosystem function multifunctionality compared with conventional fallows and monoculture cover crops. However, the expression of functional traits in cover crop mixtures is influenced by arrays of agronomic and environmental filters that differently influence cover crop performance. To (1) determine the identity and diversity effects of different cover crop functional types on ecosystem functions and trade-offs, and (2) determine the optimal cover crop mixture that maximizes ecosystem function multifunctionality in a subtropical dryland environment. Using three-site-year field experiments, we assessed if cover crop mixtures enhanced ecosystem function multifunctionality (MF) above that of monoculture cover crops and conventional fallow. We measured a range of ecosystem functions as indicators of three major ecosystem service categories: 1) provisioning services (biomass production, cash crop yield, and profitability); 2) supporting services (weed suppression, soil active carbon accrual, soil aggregate distribution, nitrogen (N) mineralization, N supply, and N retention); and 3) regulating services (parasitic nematode suppression, promotion of free-living nematodes, soil respiration, and soil water conservation). We found greater suite of ecosystem functions following mixture cover crops compared to monocultures, likely due to synergistic trait combinations that increased ecosystem function multifunctionality. The legume and forage brassica monocultures had consistently low multifunctionality (MF < 0.5). The oat:legume mixture resulted in the highest multifunctionality (MF > 0.5), driven by moderate water use and aboveground biomass production, and high groundcover residency, thus favouring higher cash crop yields and system profitability. They also generated overall improvements in soil health by providing additional carbon inputs, increasing the proportion of larger soil aggregates, and improving soil food web structure. We predicted the optimum cover crop mixture to maximize ecosystem function multifunctionality was 64% oat, 36% legume and 0% forage brassica. This study offers novel insight into the agronomic and environmental impacts of replacing fallow with cover crops in a subtropical dryland. It shows that integrating mixture of oat:legume cover crops can increase multifunctionality. Further research is required on the extent of ecosystem trade-offs between competing ecosystem functions. The predicted optimum cover crop mixture composition will likely vary when different ecosystem functions are considered or if long-term experiment data are used. Hence, the recommended optimum cover crop mixture must be interpreted with caution and cover crop selection should be based on practical recommendations according to target management goals. [Display omitted] • Integrating cover crops into a dryland crop rotation enhanced ecosystem functions compared to conventional fallow. • Cover crops enhanced 8 of the 14 measured ecosystem functions in a three-year rotation. • Oat:legume mixtures provided greater ecosystem multifunctionality than monocultures and Brassicaceae-associated mixtures. • The predicted optimum cover crop mixture that maximized ecosystem multifunctionality was 64% oat, and 36% legume. • Cover crop selection should be based on targeting specific ecosystem functions and local context. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Modelling the impacts of diverse cover crops on soil water and nitrogen and cash crop yields in a sub-tropical dryland.
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Garba, Ismail I., Bell, Lindsay W., Chapman, Scott C., deVoil, Peter, Kamara, Alpha Y., and Williams, Alwyn
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COVER crops , *CASH crops , *CROP yields , *NITROGEN in water , *DRY farming , *NITROGEN in soils - Abstract
Understanding the implications of replacing fallows with cover crops on plant-available water (PAW) and soil mineral nitrogen (N) and their carry-over effects on subsequent cash crops is critical for understanding their potential for ecological intensification in water-limited environments. We modelled the impacts of different cover crop functional types over historical climate to predict how climate variability influences soil water and N acquisition and subsequent availability to a maize crop in a dryland farming system of subtropical Australia. Following local validation of simulation models (APSIM) with 3-site-years of field data, 70 years of crop-fallow rotations were simulated comparing conventional fallow against a diverse range of cover crops comprising monocultures and mixtures of grass vs. legume vs. brassica. Cover crops consistently reduced soil water and mineral N at maize sowing compared to conventional fallow. In dry to normal precipitation years, this induced a maize yield penalty of up to − 18% relative to fallow, primarily due to reduced water availability. In wet years, increased in maize grain yield (+4%) was predicted following legume and grass-associated cover crop mixtures with concomitant reductions in N leaching and soil surface runoff of up to 40%. Cash crop yields following grass-cover crops were more stable and carried lower downside risks; multi-species (grass-legume-brassica) cover crop mixtures carried higher yield penalties and greater downside risks due to high biomass accumulation and high soil water extraction. These long-term predictions in water-limited environments indicate that increasing cover crop complexity by using mixtures with diverse functional traits can lead to a greater risk of yield losses and increased yield instability unless they are managed differently to monoculture cover crops. Therefore, for successful integration of cover crops into dryland agroecosystems, cover crops should be considered as a flexible choice grown under favourable precipitation and economic scenarios rather than for continuous fallow replacement. • Applied APSIM to assess potential dryland fallow replacement cover crop options. • Cover crops reduced yields by 12% relative to fallow in dry to normal years. • Predicted yield gains in wet years following fababean and multi-species mixture. • Dryland cover crops should be considered as an opportunistic practice. [ABSTRACT FROM AUTHOR]
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- 2023
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14. Labour demand – The forgotten input influencing the execution and adoptability of alternative cropping systems in Eastern Australia.
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Kotir, Julius H., Bell, Lindsay W., Kirkegaard, John A., Whish, Jeremy, and Aikins, Kojo Atta
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CROPPING systems , *ALTERNATIVE crops , *CROP rotation , *LABOR supply , *AGRICULTURAL productivity , *HARVESTING - Abstract
Understanding the quantity and timing of labour to fulfill the goals of different cropping systems or crop rotations is critical, but poorly quantified and understood in many agricultural systems, including the grain-growing regions of eastern Australia. Yet, labour supply and demands are important considerations for farmers and can significantly influence their agronomic management and decisions to adopt modified crop rotation systems. Here, we investigated the extent to which crop rotation systems, that differed in their intensity (i.e. the proportion of time when crops were growing), and diversity (i.e. the range of crops grown) influence labour requirements and labour productivity. We used the Agricultural Production Systems sIMulator (APSIM) to simulate a set of different crop rotations and combined the output with farmer survey data and expert knowledge derived from farm advisers to compute the labour inputs for key crop operations (i.e. sowing, spraying, harvesting). This information was used to calculate the labour required and the timing of this demand for each cropping system. We showed that as the cropping intensity increases the labour demand also increases, and vice versa. However, only small differences in labour demands were identified between systems with differing crop diversity (i.e. range of crops grown). Thus, when it comes to labour demands, crop diversity is less critical than cropping intensity. Labour demand was highly seasonal, with peaks around the intense operations of sowing and harvesting. These peak demands constrained the area that could be managed by a unit of labour, particularly as the cropping intensity increased. Further, this analysis highlights that the most profitable systems may not necessarily be the most efficient in terms of labour productivity (i.e. return per unit of labour). This analysis shows that when labour is limiting, labour demands and especially peak periods may contribute to a farmer's choice of cropping systems, adding to other critical factors like risk aversion and profit maximisation. The analysis contributes to the literature on the role of labour in the context of influencing the implementation and adoption of what are seemingly more productive or profitable farming systems. In particular, the results demonstrate how labour as a critical farm resource (i.e. its quantity, seasonality and timing, and productivity) can influence the design of crop rotations. [Display omitted] • Many cropping systems in Australia are being modified by altering their intensities and crop diversity, but their labour demands are unknown. • Crop rotations with distinct intensity and diversity are simulated in APSIM to estimate their labour demands, seasonality, and economic returns. • Altering cropping intensity had stronger influence on labour demands and returns than changing the crop diversity in the rotation. • Labour demands between rotations is not substantial to influence a farmers decision on adopting alternative or modified cropping sequences. • Findings contribute to the growing discussion on the role of labour for the design and potential feasibility of innovative cropping systems. [ABSTRACT FROM AUTHOR]
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- 2022
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15. Whole-farm economic, risk and resource-use trade-offs associated with integrating forages into crop-livestock systems in western China.
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Komarek, Adam M., Bell, Lindsay W., Whish, Jeremy P. M., Robertson, Michael J., and Bellotti, William D.
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FORAGE plants , *LIVESTOCK , *SOIL conservation , *AGRICULTURAL productivity , *AGRICULTURAL intensification - Abstract
Substantial initiatives are occurring in developing countries to integrate forage crops into crop-livestock systems to improve farmer livelihoods and reduce soil erosion. In particular, government authorities in western China focus on improving farmer livestock profits through greater forage crop production. We examined the whole-farm profit, downside risk, labour-use efficiency and feed balance effects of forage crop intensification on two simulated crop-livestock farm types in western China. Our methodology combined crop and livestock simulation modelling with whole-farm stochastic budgeting to capture both price and climate variability. We modelled the whole-farm effects of (1) introducing either forage vetch (Vicia sativa), forage oats (Avena sativa), or grain soybean (Glycine max) into current wheat (Triticum aestivum)-maize (Zea mays) systems and (2) replacing maize in current wheat-maize systems with either forage wheat, forage maize, or forage soybean. System intensification through incorporating a forage crop into current grain-cropping systems can increase average simulated profits without increasing downside risk on the simulated farms. As opposed to adding a forage crop into current grain-cropping systems, replacing a grain crop with a forage crop in current grain-cropping systems had a negative effect on profits, downside risk, and labour-use efficiency. Trade-offs existed between labour-use efficiency and profit as forage intensification increased labour demands. These effects were context specific, with greater positive profit effects of forage intensification for the higher-rainfall farm type. Overall, forage intensification in these systems benefited the households, but adoption will depend on household preferences and local agro-ecological and market factors. We demonstrated the importance of exploring proposed intensification options across different locations to capture impacts across diverse contexts. Providing these context-specific insights and exploring trade-offs within systems can help better understand livelihood improvement pathways. In locations with strong competing uses for labour, developing labour-saving practices appears critical. [ABSTRACT FROM AUTHOR]
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- 2015
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16. Integrated crop–livestock systems in Australian agriculture: Trends, drivers and implications
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Bell, Lindsay W. and Moore, Andrew D.
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INTEGRATED agricultural systems , *SUSTAINABLE agriculture , *CROPPING systems , *LIVESTOCK , *AGRICULTURAL diversification , *SOCIOECONOMIC factors - Abstract
Abstract: Australia has a long history of mixed farming. This paper examines the integration of Australian cropping and livestock production from three perspectives: as a factor in land use change, a consequence of individual management practices and a means of meeting farmers’ multiple objectives. Since about 1995, the proportion of cropped land has increased on Australian cropping farms while livestock numbers have decreased. Land use in the north-eastern, central and south-western regions of the cropping zone have diverged. Despite these changes, mixed farms still dominate Australia’s broadacre farming regions. Previous accounts of the dimensions in which farming enterprises are integrated can be simplified for Australian broadacre agriculture. For most purposes it is sufficient to consider a nested set of four integration options: “specialization” (not integrated organizationally), “separation” (integrated organizationally only), “rotation” (integrated organizationally and spatially, but not temporally) and “synchronization” (integrated in all three dimensions). We illustrate these integration options with a short survey of agronomic practices that affect crop–livestock integration. We review the farmer objectives that enterprise integration can meet and the constraints that limit it, seeking to balance social, economic and agronomic factors. We use a dynamic simulation model to make a first quantification of the economic risk reduction provided by enterprise diversification. Constraints imposed by limited labour, capital, and management attention cannot be overlooked; this is especially relevant in Australia where labour is increasingly in short supply. We characterize our surveyed set of agronomic practices with respect to the farmer objectives they affect. We find that farmers generally have the option of meeting a particular objective through different practices that affect different dimensions of integration. Practices that result in closer integration in time and space generally require greater management attention; practices that do not integrate in space typically require an increase in external inputs. History suggests that current commodity price ratios may be sufficient to slow or reverse the overall land use trend away from livestock production. In the longer term, forecast increases in worldwide demand for meat, energy costs and soil resource constraints will all encourage Australian cropping farmers to maintain mixed systems; however reduced availability of labour relative to capital will push land use toward specialized systems. Valuing the benefits and costs associated with differing degrees of enterprise integration is a major research challenge that will require insightful application of both biophysical and economic models. [Copyright &y& Elsevier]
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- 2012
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17. A preliminary whole-farm economic analysis of perennial wheat in an Australian dryland farming system
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Bell, Lindsay W., Byrne (nee Flugge), Felicity, Ewing, Mike A., and Wade, Len J.
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WHEAT , *AGRICULTURE , *FARM management , *PLANTING - Abstract
Abstract: The development of perennial wheat could have a number of advantages for improving the sustainability of Australian dryland agricultural systems. The profitability that might be expected from perennial wheat of different types was investigated using MIDAS (Model of an Integrated Dryland Agricultural System), a bioeconomic model of a mixed crop/livestock farming system. Although perennial wheat may produce a lower grain yield and quality than annual wheat, it is expected inputs of fertiliser, herbicide and sowing costs will be lower. Perennial wheat used solely for grain production was not selected as part of an optimal farm plan under the standard assumptions. In contrast, dual-purpose perennial wheat that produces grain and additional forage during summer and autumn than annual wheat can increase farm profitability substantially (AU$20/ha over the whole farm) and 20% of farm area was selected on the optimal farm plan under standard assumptions. Forage from perennial wheat replaced stubble over summer and grain supplement at the break of season and increased farm stock numbers. The additional value added by grazing also reduced the relative yield required for perennial wheat to be profitable. This analysis suggests perennial wheat used for the dual purposes of grain and forage production could be developed as a profitable option for mixed crop/livestock producers. [Copyright &y& Elsevier]
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- 2008
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18. Lack of Exposure to Hospice and Palliative Medicine Training for African American Students: The State of the U.S. Medical Education System (RP501).
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Bell, Lindsay, Livingston, Jessica, Schenker, Yael, Arnold, Robert, and October, Tessie
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AFRICAN American students , *PALLIATIVE treatment , *MEDICAL education , *MEDICAL students , *HISTORICALLY Black colleges & universities , *HISPANIC Americans - Published
- 2020
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19. Achieving stable and sustainable Mungbean yields in Australia via optimal sowing dates.
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Pasley, Heather, Williams, Alwyn, Bell, Lindsay, and Collins, Marisa
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WATER efficiency , *SOWING , *MUNG bean , *AGRICULTURAL productivity , *DEFICIT irrigation , *VAPOR pressure , *CROP rotation , *GROWING season , *WATER levels - Abstract
As a rainfed, short-season crop, mungbean is a particularly attractive summer rotation option for Australian farmers, but the rate of mungbean adoption in Australia is low due to its high yield instability. A lack of research conducted on modern mungbean in Australia has hindered farmers' ability to understand how to best manage the crop and close the yield gap. The aim of this study was to provide recommendations for optimal sowing windows (balancing maximum yield potential with minimum risk—i.e. instability and crop failure). We simulated 60 years of growing mungbean at 180 different sowing times, four different initial soil water levels and at seven sites across Queensland and New South Wales using the new Agricultural Production Systems sIMulator Next Generation (APSIM NextGen) Mungbean model. We then calculated the impact of sowing date on mungbean water use efficiency and on the soil water deficit for the subsequent crop in the rotation. Higher initial soil water levels decreased risk (instability and failure) at all sites. Arid sites with high evaporative demand had optimal sowing windows later (February) in the growing season. More temperate sites yielded better with higher levels of stability when sown between November and January. Sowing in September/October is not recommended in any site as it coincided with low yield stability and water use efficiency. Not all sites had a clear optimal sowing window. We conclude, therefore, that in some environments, sowing time can only marginally reduce risks in growing mungbean. We identified optimal sowing window that can reduce risks of a failed crop by 20 % and increase stability without losing yield potential. The timing of the optimal sowing window for a given site appears to be influenced by avoiding periods with high evaporative demand during the reproductive phase. Modelling has been critical for exploring the trade-offs between maximizing and stabilizing mungbean yields over a wide range of environments and growing seasons to determine the optimal sowing windows across the main growing environments in Australia. • Optimal sowing windows were identified for mungbean in Australia. • Aridity and Vapor Pressure Deficit influenced the timing of optimal sowing windows. • Spring sowing corresponds to high yield instability and low water use efficiency. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Ground cover, erosion risk and production implications of targeted management practices in Australian mixed farming systems: Lessons from the Grain and Graze program.
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Thomas, Dean T., Moore, Andrew D., Bell, Lindsay W., and Webb, Nicholas P.
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SOIL erosion , *FARM management , *GROUND cover plants , *AGRICULTURE , *SIMULATION methods & models - Abstract
Maintaining the productive capacity of the agricultural soils of Australia's broadacre cropping zone requires careful management, given a highly variable climate and soils that are susceptible to degradation. Mixed crop-livestock farming systems are the predominant land use across these regions and managers must operate farms for long-term sustainability as well as shorter-term profitability. Achieving profitable and sustainable businesses has required ongoing innovation and productivity gains, of which the integration of crop and livestock enterprises has been an important part. Production-soil erosion trade-offs associated with enterprise integration is critical information that has not been investigated to date at a whole-farm level. The objective of this study was to systematically evaluate management options developed in Grain and Graze (an integrated program of research, development and extension targeting mixed farms) to identify farm systems responses to soil erosion risks across seven regions spanning the mixed-farming area of Australia. To evaluate production-soil erosion trade-offs, we linked the APSIM soil water, soil nutrient cycling, annual crop and surface residue simulation models to the GRAZPLAN pasture and ruminant simulation models, using the AusFarm modelling software. Our results demonstrate that the management options tested in Grain and Graze support the principles of conservation agriculture and inform the sustainable intensification of mixed farming systems. Across the regions considered we found that: (1) Increasing pasture legume content and soil fertility can consistently benefit farm production and environmental indicators, (2) management interventions that target direct management of ground cover have the greatest potential to reduce soil erosion rates, (3) management during critical periods of naturally high soil erodibility and wind/water erosivity can substantially increase or decrease erosion risk; the timing of management interventions is therefore critical, and (4) grazing management to balance use of crop residues and pasture biomass is required to avoid developing hot spots of erosion and soil degradation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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21. Feedbase intervention in a cow-calf system in the flooding pampas of Argentina: 2. Estimation of the marginal value of additional feed.
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Berger, Horacio, Bilotto, Franco, Bell, Lindsay W., and Machado, Claudio F.
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LIVESTOCK systems , *FORAGE , *COW-calf system , *LIVESTOCK , *ECONOMIC seasonal variations , *MANAGEMENT - Abstract
Temporal variability in the availability of forage reduces the production and economic performance of livestock systems. The marginal value of feed (MVF, the possible gross economic benefit of additional feed on offer during an annual cycle), was assessed under the expected variability of climate and prices in a cow-calf operation from the Flooding Pampas, Argentina. Herbage mass accumulation (HMA) was simulated on a daily basis over 20 different years with DairyMod, grouped by month and season and where the HMA was equal or below 50% of its long-term average, it was tagged as “Dry”. Typical monthly pasture growth rates were synthetically depicted for average years (Average), or with dry autumn (D-Au), winter (D-Wi), spring (D-Sp) or summer (D-Su) conditions. These pasture growth curves were incorporated into whole-farm scenarios which were modelled with SIMUGAN, a bio-economic whole-farm model. Farm scenarios were baseline (unchanged HMA) or with additional 10% of the annual HMA. This additional feed was either evenly distributed across each month of the year (all year), or the full amount provided in one of the four seasons. These scenarios were repeated in a factorial design across a range of stocking rates (SR; 0.9–1.3 cows/ha) on an average year or years including one dry season (D-Au, D-Wi, D-Sp orD-Su). SIMUGAN results were fed to an ad-hoc built model to calculate production and market risk profiles. In years with average HMA, MVF were always below 0.05 US$/kg DM but the presence of a dry season caused significantly higher MVF. Years with dry autumn presented the highest economic responses when the extra feed was fed during autumn or winter. MVF analyses showed a positive impact of additional forage only above 1.1 head/ha and this increased with SR, whereas MVF at the low SR were mostly negative due to extra hay making costs. At 1.1 and 1.2 head/ha, allocating additional feed in autumn produced a higher return (0.04 and 0.08 US$/kg DM) than feed provided at other times of the year (averaging 0.02 and 0.05 US$/kg DM). Otherwise, at 1.3 SR extra feed in winter always had the highest MVF (up to 0.19 US$/kg DM). Bio-physical variables of livestock demand and seasonality of pasture growth were the main drivers of MVF variability. Overall, the framework developed by integrating forage, livestock and economic models “in a series” effectively identified the economic feasibility of changes to the farm feed-base under different climatic and livestock management conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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22. APSIM next generation mungbean model: A tool for advancing mungbean production.
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Pasley, Heather, Wenham, Kylie, Bell, Lindsay, Huth, Neil, Holzworth, Dean, Chaki, Apurbo, Gaydon, Don, and Collins, Marisa
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STANDARD deviations , *CROP management , *CROPPING systems , *CROPS , *AGRICULTURAL productivity , *MUNG bean - Abstract
Mungbean, a grain legume with high nutritional value, is grown widely throughout Asia and increasingly in Australia. Despite growing interest amongst farmers, mungbean remains an inconsistent and thus risky crop to plant in Australia. Cropping system models like the Agricultural Production Systems sIMulator (APSIM) are valuable tools for helping farmers to examine options for improving crop management and assess production risks across potential growing regions for mungbean. This paper outlines the simulation capacity of a new mungbean crop model parameterized using the Plant Modelling Framework in APSIM Next Generation, the newest version of the APSIM framework. The aim of the paper is to document the parameterization and validation processes of the model. The new mungbean model was built using data from 28 field experiments to simulate measured phenology, canopy development, biomass accumulation/partitioning, stress responses, N fixation, root growth, and yield across a wide range of environments. The root mean squared error (RMSE) in predictions for grain weight and aboveground weight were 25.4 g m−2 and 91.4 g m−2, respectively. The model successfully captured the dynamics of crop response to sowing dates, water/irrigation regimes, and climate. The new mungbean model is a robust and accurate tool for use in Australia and tropical/sub-tropical Asia. Researchers can use the new mungbean model to determine best management practices such as the optimal time to sow mungbeans in different environments. The output from model simulations can help farmers assess risks associated with sowing at different times and soil water conditions specific to their region. Such risk analysis can improve farmer decision-making confidence in mungbean, increasing its potential production for Australia. Overall, the new APSIM mungbean model can be used effectively to identify and close the mungbean yield gap, mitigate risk of crop failure, and increase profits for mungbean farmers in Australia and tropical/sub-tropical Asia; it has the capacity to assist with increasing mungbean production globally under changing climate conditions. • The APSIM Next Generation mungbean model was built using data from 28 diverse field experiments. • Detailed phenology, biomass and N partitioning, and canopy data was used to parameterize parameters. • The model captures mungbean's dynamic response to water stress and targeted irrigation. • It is a robust, data-driven crop model that performs well in Australia and tropical/subtropical Asia. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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23. Whole-farm effects of livestock intensification in smallholder systems in Gansu, China
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Komarek, Adam M., McDonald, Cam K., Bell, Lindsay W., Whish, Jeremy P.M., Robertson, Michael J., MacLeod, Neil D., and Bellotti, William D.
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LIVESTOCK , *SIMULATION methods & models , *FARMERS , *AGRICULTURE , *INCOME , *HOUSEHOLDS - Abstract
Abstract: Simulation models can help to identify the whole-farm economic and biophysical impacts of smallholder farmers altering their farming systems. Incorporating long-term climate-induced variability in crop and livestock production enables the implications for agricultural household income and risk to be explored over a range of seasonal conditions. In this study, a simulation model is used to answer the following question: can reducing the area used for grain production by allocating more land to lucerne (Medicago sativa) and increasing livestock numbers improve total net farm income, reduce income variability and maintain grain self-sufficiency for farmers in the Qingyang Prefecture of Gansu Province, China? This was examined for three representative farm types found in the region: a low land-labour ratio farm household, a subsistence-oriented farm household, and a livestock-focused farm household. The Integrated Analysis Tool (IAT), a simulation model of a household farming system, was used to combine crop and forage production simulations, a livestock production model and a household socio-economic model to explore the impact of changes to farming systems over a 40year simulation period. Data from 90 surveyed households were used to define the structure of the three farm household types and to calibrate the IAT model specifically for Qingyang Prefecture. Additional livestock increased total household net incomes, increased net livestock incomes and reduced net crop incomes for the subsistence-oriented and livestock-focused farm households. For these households, the greater commitment to livestock also reduced grain self-sufficiency due to increased frequency of purchasing grain for home-consumption. Nevertheless, additional livestock reduced income variability for these households whilst improving total net income. The methodology used is useful for understanding changes in farming systems as it focuses on the feasibility and profitability of alternative enterprise mixes and incorporates climate variability. The results support current debates on targeting livestock policies towards smallholders as subsistence-oriented farm households appear to be the largest beneficiaries from livestock interventions. The analysis demonstrates that tradeoffs between net income and grain self-sufficiency are important for households, especially when they are moving from subsistence-based to market-based production. [Copyright &y& Elsevier]
- Published
- 2012
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24. Assessment of stigma associated with attention-deficit hyperactivity disorder: Psychometric evaluation of the ADHD Stigma Questionnaire
- Author
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Kellison, Ida, Bussing, Regina, Bell, Lindsay, and Garvan, Cynthia
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SOCIAL stigma , *ATTENTION-deficit hyperactivity disorder , *RELIABILITY (Personality trait) , *CONFIRMATORY factor analysis , *SELF-esteem , *PSYCHOLOGICAL adaptation - Abstract
Abstract: This study evaluated the psychometric properties of the attention deficit hyperactivity disorder (ADHD) Stigma Questionnaire (ASQ) among a community sample of 301 adolescents ages 11–19 years at high (n =192) and low risks (n =109) for ADHD. Study subjects were drawn from a cohort study assessing ADHD detection and service use. The 26-item ASQ demonstrated good internal consistency. Confirmatory factor analysis using random parceling supported a three-factor structure with highly correlated subscales of disclosure concerns, negative self image, and concern with public attitudes, and a Schmid–Leiman analysis supported an overall stigma factor. Test–retest stability was assessed after two weeks (n =45) and found to be adequate for all three subscales. Construct validity was supported by relationships with related constructs, including clinical maladjustment, depression, self-esteem, and emotional symptoms, and the absence of a relationship with school maladjustment. Findings indicate that the ASQ has acceptable psychometric properties in a large community sample of adolescents, some of whom met Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for ADHD. [Copyright &y& Elsevier]
- Published
- 2010
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25. Adolescent Outcomes of Childhood Attention-Deficit/Hyperactivity Disorder in a Diverse Community Sample.
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Bussing, Regina, Mason, Dana M., Bell, Lindsay, Porter, Phillip, and Garvan, Cynthia
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ADOLESCENT psychopathology , *ATTENTION-deficit hyperactivity disorder , *OPPOSITIONAL defiant disorder in adolescence , *BEHAVIOR disorders in children , *COMORBIDITY - Abstract
The article presents a study which investigated adolescent outcomes of attention-deficit/hyperactivity disorder (ADHD) in a community sample. The study conducted ADHD screening in 1,615 students followed by a case-control study after 8 years. Results indicate that children with ADHD were more likely to show oppositional defiant disorders (ODD) and that ODD increased the risk of the use of cannabis and alcohol. It also notes that ADHD heralds persistance of ADHD and comorbid symptoms.
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- 2010
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26. Palliative Care Attitudes and Experiences among Resident Physicians at Historically Black Colleges and Universities.
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Bushunow, Vasilii, Alamgir, Laila, Arnold, Robert M., Bell, Lindsay F., Ivonye, Chinedu, Johnson, Mark, Kelsey, Riba, Larbi, Daniel, and Schenker, Yael
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INTERNS (Medicine) , *HISTORICALLY Black colleges & universities , *PALLIATIVE treatment , *PHYSICIANS , *RESIDENTS (Medicine) , *FERRANS & Powers Quality of Life Index , *ATTITUDE (Psychology) , *INTERNSHIP programs , *QUESTIONNAIRES , *RESEARCH funding - Abstract
Context: Seriously ill Black patients receive lower quality palliative care than White patients. Equitable access requires palliative care skills training for all physicians. Historically Black Colleges and Universities (HBCUs) play a key role in educating Black physicians and have less access to palliative care resources.Objective: To investigate palliative care attitudes and experiences among primary care residents at HBCUs.Methods: Internal Medicine and Family Medicine residents at two HBCUs completed an online survey assessing attitudes towards palliative care and teaching and clinical experiences in palliative care. We performed a descriptive analysis of survey items.Results: Among 91 residents who completed the survey (response rate 48%), 65% were women and 68% Black. Most (96%) said that learning about palliative care was moderately/very important to their career; however, two-thirds of respondents considered care for dying patients to be depressing and half reported receiving negative messages about palliative care from other physicians. Residents reported receiving less teaching about providing palliative care (5.4 ± 2.3 on 10-point scale) than about managing sepsis (8.3 ± 1.8; P < 0.05). Fewer residents rated their palliative care education as "Excellent" or "Very Good" compared to their overall education (13% vs 70%; P < 0.05).Conclusion: In the first survey exploring palliative care education at HBCUs, residents viewed palliative care as important but described the quality of their palliative care education as poor. This study highlights opportunities for improving palliative care education at HBCUs as a step toward addressing disparities in serious illness care. [ABSTRACT FROM AUTHOR]- Published
- 2022
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27. Boosting the productivity and profitability of northern Australian beef enterprises: Exploring innovation options using simulation modelling and systems analysis.
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Ash, Andrew, Hunt, Leigh, McDonald, Cam, Scanlan, Joe, Bell, Lindsay, Cowley, Robyn, Watson, Ian, McIvor, John, and MacLeod, Neil
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- *
BEEF cattle farming , *BEEF industry , *SIMULATION methods & models , *SYSTEM analysis , *AGRICULTURAL innovations , *PROFITABILITY - Abstract
The financial health of beef cattle enterprises in northern Australia has declined markedly over the last decade due to an escalation in production and marketing costs and a real decline in beef prices. Historically, gains in animal productivity have offset the effect of declining terms of trade on farm incomes. This raises the question of whether future productivity improvements can remain a key path for lifting enterprise profitability sufficient to ensure that the industry remains economically viable over the longer term. The key objective of this study was to assess the production and financial implications for north Australian beef enterprises of a range of technology interventions (development scenarios), including genetic gain in cattle, nutrient supplementation, and alteration of the feed base through introduced pastures and forage crops, across a variety of natural environments. To achieve this objective a beef systems model was developed that is capable of simulating livestock production at the enterprise level, including reproduction, growth and mortality, based on energy and protein supply from natural C 4 pastures that are subject to high inter-annual climate variability. Comparisons between simulation outputs and enterprise performance data in three case study regions suggested that the simulation model (the Northern Australia Beef Systems Analyser) can adequately represent the performance beef cattle enterprises in northern Australia. Testing of a range of development scenarios suggested that the application of individual technologies can substantially lift productivity and profitability, especially where the entire feedbase was altered through legume augmentation. The simultaneous implementation of multiple technologies that provide benefits to different aspects of animal productivity resulted in the greatest increases in cattle productivity and enterprise profitability, with projected weaning rates increasing by 25%, liveweight gain by 40% and net profit by 150% above current baseline levels, although gains of this magnitude might not necessarily be realised in practice. While there were slight increases in total methane output from these development scenarios, the methane emissions per kg of beef produced were reduced by 20% in scenarios with higher productivity gain. Combinations of technologies or innovative practices applied in a systematic and integrated fashion thus offer scope for providing the productivity and profitability gains necessary to maintain viable beef enterprises in northern Australia into the future. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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28. APSIM – Evolution towards a new generation of agricultural systems simulation.
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Holzworth, Dean P., Huth, Neil I., deVoil, Peter G., Zurcher, Eric J., Herrmann, Neville I., McLean, Greg, Chenu, Karine, van Oosterom, Erik J., Snow, Val, Murphy, Chris, Moore, Andrew D., Brown, Hamish, Whish, Jeremy P.M., Verrall, Shaun, Fainges, Justin, Bell, Lindsay W., Peake, Allan S., Poulton, Perry L., Hochman, Zvi, and Thorburn, Peter J.
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AGRICULTURE , *SIMULATION methods & models , *FEATURE extraction , *COMPUTER software development , *MOBILE apps , *WEB-based user interfaces - Abstract
Agricultural systems models worldwide are increasingly being used to explore options and solutions for the food security, climate change adaptation and mitigation and carbon trading problem domains. APSIM (Agricultural Production Systems sIMulator) is one such model that continues to be applied and adapted to this challenging research agenda. From its inception twenty years ago, APSIM has evolved into a framework containing many of the key models required to explore changes in agricultural landscapes with capability ranging from simulation of gene expression through to multi-field farms and beyond. Keating et al. (2003) described many of the fundamental attributes of APSIM in detail. Much has changed in the last decade, and the APSIM community has been exploring novel scientific domains and utilising software developments in social media, web and mobile applications to provide simulation tools adapted to new demands. This paper updates the earlier work by Keating et al. (2003) and chronicles the changing external challenges and opportunities being placed on APSIM during the last decade. It also explores and discusses how APSIM has been evolving to a “next generation” framework with improved features and capabilities that allow its use in many diverse topics. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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29. Resilience achieved via multiple compensating subsystems: The immediate impacts of COVID-19 control measures on the agri-food systems of Australia and New Zealand.
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Snow, Val, Rodriguez, Daniel, Dynes, Robyn, Kaye-Blake, William, Mallawaarachchi, Thilak, Zydenbos, Sue, Cong, Lei, Obadovic, Irena, Agnew, Rob, Amery, Nicole, Bell, Lindsay, Benson, Cristy, Clinton, Peter, Dreccer, M. Fernanda, Dunningham, Andrew, Gleeson, Madeleine, Harrison, Matthew, Hayward, Alice, Holzworth, Dean, and Johnstone, Paul
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COVID-19 , *VIRUS isolation , *VALUE chains , *POPULATION , *SARS-CoV-2 - Abstract
Since COVID-19 (SARS-CoV-2) was first identified in the human population, it has had immediate and significant effects on peoples' health and the worldwide economy. In the absence of a vaccine, control of the virus involved limiting its spread through restrictions in the movement of people, goods and services. This has led to unprecedented impacts on labour availability, provision of goods and services, value chains, and markets. Against the backdrop of COVID-19 control measures, this article summarises quantitative and qualitative assessments of the impacts, adaptations, and opportunities to increase the resilience of the agricultural systems in Australia and New Zealand. Using both survey and interview methodologies, we describe the various agri-food systems and the impacts of the COVID-19 control measures across different industries, and discuss the results applying a resilience framework. As essential services, all agricultural activities except for fibre production have been permitted to continue during quarantine periods but have been exposed to the major flow-on effects of movement control. We found that, to June 2020, the impacts of the COVID-19 control measures on the agri-food sectors in both Australia and New Zealand have been relatively small and that this has been due to the high levels of resilience in the agricultural systems and the people running them. We consider agri-food systems to be comprised of multiple subsystems with varying vulnerability to external influences. Agri-food systems were resilient to June 2020 at least, and that resilience was achieved via one or more subsystems that were able to compensate for the more vulnerable subsystems. We contrast the resilience of industries that have high plasticity (that can have a flow of material that can safely vary in time) to more rigid industries that are dependent on a steady flow of material with little or no storage. Ultimately both types of industries were resilient, but they achieved that resilience via compensating subsystems. High plasticity industries relied on their production and processing subsystem; rigid industries engaged their institutional subsystem to achieve the same end. The social and cultural subsystem was important across all industries. It is not yet clear if the current resilience mechanisms can persist under the continued onslaught of the virus. We indicate the need to capture longer term effects and analysis during the more sustained effects of the virus and through a recovery period. We anticipate a follow-up study in 2022. Unlabelled Image • Restrictions on physical gatherings to control COVID-19 has impacted agri-food systems via labour, goods and services, value chains and markets • We sought to understand the impacts by surveying and interviewing individuals across many industries and sectors in Australia and New Zealand • To June 2020, the industries have proved resilient but that resilience was achieved via multiple compensating subsystems • Industries with high plasticity used a production subsystem for resilience; low plasticity industries engaged an institutional subsystem for the same end • A follow-up study is needed to understand if the existing resilience mechanisms will withstand the continued onslaught of COVID-19 [ABSTRACT FROM AUTHOR]
- Published
- 2021
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30. Cropping system yield gaps can be narrowed with more optimal rotations in dryland subtropical Australia.
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Hochman, Zvi, Horan, Heidi, Navarro Garcia, Javier, Hopwood, Garry, Whish, Jeremy, Bell, Lindsay, Zhang, Xiying, and Jing, Haichun
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CROP rotation , *CROPPING systems , *CROP yields , *LEGUMES , *ROTATIONAL motion , *METEOROLOGICAL stations , *SORGHUM , *CHICKPEA - Abstract
Closing the gap between yields currently achieved on farms and those that can potentially be achieved with best practice and current technology (the yield gap) is a key strategy to intensify grain production without expanding cropland. Much research has been done to quantify the yield gap of wheat, maize and rice globally and of wheat, barley, canola, sorghum and pulse crops in Australia. However, crops are grown in rotations (recurring crop sequences) that vary in their cropping intensities and in the diversity of their species. Little is known about yield gaps at the cropping system level, especially in regions where there are many possible combinations of crop types and fallow periods. This prompted us to investigate crop rotations in Australia's subtropical grains region where current crop rotations include winter and summer cropping with cereal, pulse and oilseed crops interspersed with fallow periods ranging from nil to 18 months duration. To determine the system level yield gaps, we simulated the water-limited yield potential of 26 locally practiced crop rotations for over 800 weather stations by up to 3 soil types per station. We captured the impact of climate variability with 30–35 years by 2–7 fields per rotation for each site. We expressed the results in terms of energy, protein and revenue per hectare per year and mapped the results of the optimal rotations over the cropping zone. Surprisingly, a single rotation (sorghum/fallow/mungbean/wheat/fallow/chickpea rotation; with 4 crops in 3 years, balanced between summer and winter crops and between cereal and pulse crops) was optimal for revenue over almost the whole subtropical grain zone. Using revenue as the metric for yield gaps at statistical local area scale we found, over the whole subtropical zone, a mean revenue gap of 970 $/ha/yr. This represents a relative revenue (Revenue% = 100 x (actual revenue/water-limited revenue)) of 34% which is much lower than expected from the 40–60% relative yields achieved by individual crops. We investigated whether growers may select rotations that have lower revenue than the optimal rotation in response to economic factors such as profit and risk. We found that for much of the area the same rotation that optimised revenue also optimised profit. However, for some of the cropping zone, particularly in the south western portion, a different, less intensive and more winter dominant, rotation was most profitable. Similarly, risk averse farmers may choose less productive and profitable rotations with less risk. • This research has produced the first regional-scale maps of cropping systems yield gaps. • Productivity of cropping in Australia's subtropical grain zone is only 34% of its potential. • Profit-risk trade-offs may be responsible for growers choosing less productive rotations. • These maps and trade-off charts may be useful to engage stakeholders about cropping system design. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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