177 research outputs found

    Modeling Irrigated Cropping systems with Special Attention to Rice Wheat Sequences and Rice Bed Planting

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    The rice-wheat cropping systems of the Indo-Gangetic Plains (IGP) are of immense importance for food security for south Asia. Over the past 40 years the increase in rice and wheat production has kept pace with population growth due to improved varieties, increased inputs, especially fertilisers, and the expansion of irrigation. However yield stagnation, and possibly yield decline, water scarcity, and water and air pollution are major threats to the sustainability of rice-wheat systems and food security. Therefore the design and implementation of alternative production systems with increased resource use efficiency (especially water) and productivity and reduced adverse environmental impact are urgently required. Bed farming, practised for several decades for crops other than rice in Australia, Mexico and elsewhere, was introduced to the rice-wheat regions of the IGP in the mid 1990s. Farmer experience and research have shown that bed farming offers significant advantages for productivity and resource use efficiency for wheat and other non-rice crops. More recently, attention has focused on the possibility of also growing rice on beds in the IGP and Australia, with the associated potential benefits of permanent bed systems including reduced land preparation costs and turn around times, increased cropping flexibility, and increased productivity of “upland” crops grown in rotation with rice due to improved drainage and soil structure and improved rotations. The radical shift from ponded rice culture on the flat (with or without puddling and transplanting) to intermittently flooded bed layouts affects a host of interacting factors influencing productivity and resource use efficiency of both rice and crops grown in rotation with rice. These factors range from weeds to nutrient availability to pests and diseases to water dynamics to stubble management options. The potential benefits and disadvantages of permanent bed systems need to be quantified under a range of agroecological conditions, and optimum layouts and management systems need to be identified to maximise potential gains. The Australian Centre for International Agricultural Research (ACIAR) is funding a major new project LWR2/2000/89 Permanent beds for rice-wheat and alternative cropping systems in north west India and south east Australia. This is a collaborative project between Punjab Agricultural University, CSIRO Land and Water and NSW Agriculture, with additional support from the International Atomic Energy Agency (IAEA/FAO) for the work in India, and additional support for the work in Australia from the Rural Industries Research and Development Corporation (RIRDC) Rice program, the Grains Research and Development Corporation (GRDC) and Coleambally Irrigation Cooperative Ltd and Murray Irrigation Ltd. The major part of the project comprises field comparison of permanent bed and traditional layouts for rice-based cropping systems in Punjab, India and NSW, Australia, with detailed monitoring, in particular focusing on crop growth and development, water and nitrogen dynamics and balances, and options for stubble management. The project also seeks to further develop and refine models for rice-wheat and alternative systems, and apply them to evaluate permanent bed and traditional layouts for a range of agroecological environments, and to identify options for maximizing resource use efficiency and productivity of rice-wheat cropping systems in India, and rice-based cropping systems in Australia. Therefore an early activity in the project vi was a workshop bringing together a small group of international scientists leading in the development and application of crop models including the modelling of crop sequences and twodimensional approaches. The objectives of the workshop were: 1. to review the state of the art in the modelling irrigated cropping systems (crop sequences as opposed to single crops) and bed geometries (as opposed to “flat” layouts) 2. to workshop conceptualizations of the ways forward in modelling crop sequences and bed layouts, and with particular attention to rice-wheat systems 3. to establish a network of contacts working in these areas to share progress and problems in the future

    Simulation of Yield and Environmental Impacts of Wheat after Rice in Bangladesh and Australia

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    CERES-wheat and SWAGMAN Destiny models, respectively, were used to estimate the optimum time of sowing, and trade-off between yield and net recharge of the watertable, for wheat grown after rice in northern Bangladesh and southern NSW, Australia. Simulated wheat yields in Bangladesh, for sowings from Sept to Jan, with two supplemental irrigations, ranged from 0.4 to 4.6 t/ha. November-sown crops yielded more than the earlier- or later-sown crops due to reduced water and heat stress during grain filling. In Australia, simulated yields of non-irrigated wheat were always greater for April than June sowings due to less water deficit at the end of the season. With an initial shallow (0.5 m), fresh (1 dS/m) watertable, simulated yields usually exceeded 3 t/ha, and declined as watertable salinity increased. Nonirrigated wheat almost always lowered the watertable. Frequent irrigation increased simulated yields to 5-6 t/ha, regardless of initial conditions and sowing date, but this was at the cost of decreased discharge or increased recharge leading to rising watertables

    Increased Trauma Activation Is Not Equally Beneficial For All Elderly Trauma Patients

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    Background Physiologic changes in the elderly lead to higher morbidity and mortality after injury. Increasing level of trauma activation has been proposed to improve geriatric outcomes; but, the increased cost to the patient and stress to the hospital system are significant downsides. The purpose of this study was to identify the age at which an increase in activation status is beneficial. Methods A retrospective review of trauma patients ≥ 70 years old from October 1, 2011, to October 1, 2016 was performed. On October 1, 2013, a policy change increased the activation criteria to the highest level for patients ≥ 70 years of age with a significant mechanism of injury. Patients who presented prior to (PRE) were compared to those after the change (POST). Data collected included age, injury severity score (ISS), length of stay (LOS), complications and mortality. Primary outcome was mortality and secondary outcome was LOS. Multivariable regressions controlled for age, ISS, injury mechanism, and number of complications. Results 4341 patients met inclusion criteria, 1919 in PRE and 2422 in POST. Mean age was 80.4 and 81 years in PRE and POST groups respectively (p=0.0155). Mean ISS values were 11.6 and 12.4 (p<0.0001) for the PRE and POST groups. POST had more level 1 activations (696 vs. 220, p<0.0001). After controlling for age, ISS, mechanism of injury, and number of complications, mortality was significantly reduced in the POST group ≥ age 77 years (OR 0.53, 95% CI: 0.3 - 0.87), (Figure 1). Hospital LOS was significantly reduced in the POST group ≥ age 78 (regression coefficient -0.55, 95% CI: -1.09, -0.01) (Figure 2). Conclusions This study suggests geriatric trauma patients ≥ 77 years benefit from the highest level of trauma activation with shorter LOS and lower mortality. A focused approach to increasing activation level for elderly patients may decrease patient cost. Level of Evidence Level III Type of Study Economic/Decisio

    To Sleep, Perchance to Dream: Acute and Chronic Sleep Deprivation in Acute Care Surgeons

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    Background Acute and chronic sleep deprivation are significantly associated with depressive symptoms and felt to be contributors to the development of burnout. In-house call (IHC) inherently includes frequent periods of disrupted sleep and is common amongst acute care surgeons (ACS). The relationship between IHC and sleep deprivation (SD) amongst ACS has not been previously studied. The goal of this study was to determine prevalence and patterns of SD in ACS. Study Design: A prospective study of ACS with IHC responsibilities from two Level I trauma centers was performed. Participants wore a sleep tracking device continuously over a 3-month period. Data collected included age, gender, schedule of IHC, hours and pattern of each sleep stage (light, slow wave (SWS), and REM), and total hours of sleep. Sleep patterns were analyzed for each night excluding IHC and categorized as normal (N), acute sleep deprivation (ASD), or chronic sleep deprivation (CSD). Results 1421 nights were recorded amongst 17 ACS. (35.3% female; ages 37-65, mean 45.5 years). Excluding IHC, average amount of sleep was 6.54 hours with 64.8% of sleep patterns categorized as ASD or CSD. Average amount of sleep was significantly higher on post-call day 1 (6.96 hours, p=0.0016), but decreased significantly on post-call day 2 (6.33 hours, p=0.0006). Sleep patterns with ASD and CSD peaked on post-call day 2, and returned to baseline on post-call day 3 (p=0.046). Conclusion Sleep patterns consistent with ASD and CSD are common amongst ACS and worsen on post-call day 2. Baseline sleep patterns were not recovered until post-call day 3. Future study is needed to identify factors which impact physiologic recovery after IHC and further elucidate the relationship between SD and burnout

    Technical Efficiency of Hybrid Maize Production in Eastern Terai of Nepal: a Stochastic Frontier Approach

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    Maize is the second most important crop after rice in terms of area and production in Nepal. This article analyzes the technical efficiency and its determinants of hybrid maize production in eastern Nepal. Using a randomly selected data from 98 farmers (41 from Morang and 57 from Sunsari) in eastern Nepal, the study employed a stochastic frontier production model to find the production elasticity coefficients of inputs, determinants of efficiency and technical efficiency of hybrid maize farmers. The results showed that maize production responds positively to increase in amount of urea, DAP and the area planted, where as it is negative to seed quantity. The study indicate that farmers are not technically efficient with a mean technical efficiency 79 %. Socioeconomic variable age had a negative and significant while the household size had a positive and significant related to maize output. The younger farmers were observed more technically efficient than older farmers. Larger the members in the household higher the maize production. It is recommended that farmers should increase their fertilizer dose and farm size while they should decrease their seed rate for efficient production

    Evaluating the value of agricultural climate services using hindcast experiments Methods development in India and Bangladesh

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    This research note offers insights to a new method for understanding the economic benefits of utilizing climate services for decision making in agriculture, which can provide justification for the public and private investment in provision of climate services to farmers. In order to understand the potential benefits of weather information for improved farm decision making, case studies from wheat farming in India and Bangladesh are presented

    Can Bangladesh produce enough cereals to meet future demand?

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    Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather,management and soil data, and upscaled to the whole country.We assessed potential grain production in the years 2030 and 2050 for six land use change scenarios (general decrease in arable land; declining ground water tables in the north; cropping of fallow areas in the south; effect of sea level rise; increased cropping intensity; and larger share of cash crops) and three levels of Yg closure (1: no yield increase; 2: Yg closure at a level equivalent to 50% (50% Yg closure); 3: Yg closure to a level of 85% of Yp (irrigated crops) and 80% of water-limited yield potential or Yw (rainfed crops) (full Yg closure)). In addition, changes in demand with low and high population growth rates, and substitution of rice by maize in future diets were also examined. Total aggregated demand of the three cereals (in milled rice equivalents) in 2030 and 2050, based on the UN median population variant, is projected to be 21 and 24% higher than in 2010. Current Yg represent 50% (irrigated rice), 48–63% (rainfed rice), 49% (irrigated wheat), 40% (rainfed wheat), 46% (irrigated maize), and 44% (rainfed maize) of their Yp or Yw. With 50% Yg closure and for various land use changes, self-sufficiency ratio will be N1 for rice in 2030 and about one in 2050 but well below one for maize and wheat in both 2030 and 2050. With full Yg closure, self-sufficiency ratios will be well above one for rice and all three cereals jointly but below one for maize and wheat for all scenarios, except for the scenario with drastic decrease in boro rice area to allow for area expansion for cash crops. Full Yg closure of all cereals is needed to compensate for area decreases and demand increases, and then even some maize and large amounts of wheat imports will be required to satisfy demand in future. The results of this analysis have important implications for Bangladesh and other countries with high population growth rate, shrinking arable land due to rapid urbanization, and highly vulnerable to climate change

    Can Bangladesh produce enough cereals to meet future demand?

    Get PDF
    Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather,management and soil data, and upscaled to the whole country.We assessed potential grain production in the years 2030 and 2050 for six land use change scenarios (general decrease in arable land; declining ground water tables in the north; cropping of fallow areas in the south; effect of sea level rise; increased cropping intensity; and larger share of cash crops) and three levels of Yg closure (1: no yield increase; 2: Yg closure at a level equivalent to 50% (50% Yg closure); 3: Yg closure to a level of 85% of Yp (irrigated crops) and 80% of water-limited yield potential or Yw (rainfed crops) (full Yg closure)). In addition, changes in demand with low and high population growth rates, and substitution of rice by maize in future diets were also examined. Total aggregated demand of the three cereals (in milled rice equivalents) in 2030 and 2050, based on the UN median population variant, is projected to be 21 and 24% higher than in 2010. Current Yg represent 50% (irrigated rice), 48–63% (rainfed rice), 49% (irrigated wheat), 40% (rainfed wheat), 46% (irrigated maize), and 44% (rainfed maize) of their Yp or Yw.With 50% Yg closure and for various land use changes, self-sufficiency ratio will be N1 for rice in 2030 and about one in 2050 but well below one for maize and wheat in both 2030 and 2050. With full Yg closure, self-sufficiency ratios will be well above one for rice and all three cereals jointly but below one for maize and wheat for all scenarios, except for the scenario with drastic decrease in boro rice area to allow for area expansion for cash crops. Full Yg closure of all cereals is needed to compensate for area decreases and demand increases, and then even some maize and large amounts of wheat imports will be required to satisfy demand in future. The results of this analysis have important implications for Bangladesh and other countries with high population growth rate, shrinking arable land due to rapid urbanization, and highly vulnerable to climate change
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