关键词： APSIM   bias correction   bias propagation   bio-physical crop model   NARCliM   rainfall intensity   rainfall probability   RCMs   wheat cropping system  

摘要： Regional climate model (RCM) simulations are being increasingly used for climate change impact assessments, but their application is challenging due to considerable biases inherited from global climate model (GCM) simulations and generated from dynamical downscaling processes. This study assesses the biases in NARCliM (NSW and ACT regional climate modelling) simulations and quantifies the consequence of the climate biases in the downstream assessment of climate change impact on wheat crop system, using the Agricultural Production System sIMulator (APSIM). Results showed that post-processing bias-corrected temperature and rainfall data from NARCliM had small annual mean biases but large biases in the crop growing season (CGS). During the CGS, the mean bias error of rainfall was generally positive for rainfall probability and negative for intensity, which subsequently resulted in APSIM simulating negative biases for runoff and deep drainage and positive bias in soil evaporation. Bias in soil water balance and water availability resulted in less plant transpiration and less N uptake, ultimately, leading to large negative biases in crop yields. A simple bias correction of the simulated crop yield driven by RCMs could result in a largely consistent distribution with those generated with APSIM simulations forced by observed climate. Our results showed that RCM simulation biases could confound with the climate change signal and produced an unreliable estimate of the effects of the changes in climate and farm management variables on crop yields. The results suggested that RCM simulations with the current bias correction on the RCM-simulated outputs applied on an annual basis were inadequate for climate change assessments which involve biophysical models. Our study highlights the need for improved RCM simulations by eliminating the systemic biases associated with rainfall characteristics, although suitable post-processing bias correction on a seasonal or monthly basis may re

关键词： global climate changes   regional climate trends   dynamics of the annual temperatures and precipitation amount   environmental risks   climate adaptation  

摘要： Based on an analysis of climatic indices from the meteorological stations of the Republic of Buryatia for the period of 1970-2015, temperature trends and the dynamics of changes in the amount of precipitation were revealed for different regions of the republic. General climate warming, reduced precipitation, and an increase in the annual amplitudes of climatic indices are noted;regions with equal dynamics of the relationship between mean annual temperatures and precipitation amount are identified. The spontaneous adaptation of the crop area and structure to the changing conditions, as well as the number and structure of grazing livestock, is ascertained. The main directions in the systematic adaptation of agricultural environmental management in accordance with climate changes are formulated: optimization of cultivated land use, possibilities of irrigation, the development of traditional animal breeding based on small farms with the most adaptive cattle grazing.

关键词： Perception   Biofuel   Climate change   Rural development   Renewable energy   Agriculture extension  

摘要： Agricultural professionals play an important role in informing and educating farmers about biofuel through teaching or extension work. One of the questions commonly asked is if they are knowledgeable and possess positive attitude towards renewable energy sources. The aim of this article is to investigate Agricultural professionals' attitude and willingness towards biofuel using a random sample of professionals (n = 180) in a survey conducted in Zanjan province in Iran. Structural equation modeling showed that "Outcome efficacy", "problem perception" and "perceived benefits" can significantly predict just about 38% variance of Agricultural professionals' personal norm. In turn, personal norm can predict 35% variance of Agricultural professionals' willingness. The findings yield public policy recommendations for stimulating biofuel extension and deployment among Agricultural professionals. (C) 2018 Published by Elsevier Ltd.

关键词： Agricultural economics   Nonfiction  

关键词： Economics   Agriculture economics  

摘要： Agricultural practices are increasingly dependent on precise, real-time weather information. Irrigation, pest management, and even strategies for climate change adaptation require adequate information inputs. This dissertation starts with a valuation of weather information in California, assessing some of the the economic gains from the California Irrigation Management Information System (CIMIS). This system of weather stations and information portal was intended for water saving in irrigation, but turned out to have many unexpected uses. The next chapter uses CIMIS historical information to estimate the yield response of California pistachios to warm winters. This has been an ongoing challenge in the literature, as the available yield data are scarce and noisy. Merging them with CIMIS data is essential in estimating this response, and for predicting the yield effects of winter temperatures in the future. The last builds on these predictions, and analyzes the potential gains from a technology that could deal with the challenge of warming winter days: spraying the dormant trees with kaolin clay, which reflects part of the sunlight and keeps the trees cooler. To assess the gains, I take the estimated response function, climate predictions, and other variables to market model that is solved numerically and allows for welfare gain calculations. Beyond the potential of this specific technology for pistachios, tweaking temperature distribution tails seems like a promising concept for climate change adaptation. Many temperature challenges brought by climate change are in these distribution tails, where yield responses are often non-linear. This means that small temperature adjustments, local in time and place, might suffice for cost-effective adaptation strategies. I call this concept ``Micro-Climate Engineering'', and predict that such practices will be increasingly popular with the progression of climate change.

关键词： Statistics   Agriculture   Agriculture economics  

摘要： Agriculture is one of the most important activities on earth because we all need food to stay alive. Some critics are concerned about our capacity to satisfy global demand for food in the coming decades because of the significant expected increase in world population and threats caused by climatic variability and climate change. Others are more optimistic because they believe technological progress will be the answer, as is often shown by historical data. Independent of what causes climatic variability and climate change, there is evidence of observed changes in temperature and precipitation patterns. Thus, this study identifies and analyzes the drivers of agricultural productivity and investigates the impact of climatic variability on production and productivity across the Southern United States. The study is focused on the 16 states in the southern United States, as defined by the US Census Bureau, because of the role they play in US and world agriculture. We use data from the Economic Research Service (ERS) of the United States Department of Agriculture (USDA), the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA) and the US Geological Survey to estimate several stochastic production frontier (SPF) model specifications. The estimated parameters are then analyzed and used to compute and decompose Climate Adjusted Total Factor Productivity (CATFP) into several measures of efficiency. Results show that agricultural production in the southern United States is more responsive to labor and has been increasing at a 1.13 percent rate annually. The findings also suggest that while precipitation, on average, has a positive and significant impact on productivity, intra-annual variation in both temperature and precipitation, has a negative and significant impact on production. The impact of climatic effects on productivity was mixed. Technological progress has been the main driver of agricultural productivity, and all the stat

关键词： 气候变化   农作物   负面影响   农业生态系统  

摘要： 自21世纪以来,气候变化对整个人类社会的影响越来越大,尤其是全球气候变化对农业生态系统的影响远超历史上任何一个时期,这对人类的生存和发展提出了极大的挑战。本文将探讨气候变化对农业生态的影响,以期给未来农业发展提出一些建议。全球气候变化时人类迄今为止面临的最大的环境问题,也是21世纪人类面临的巨大挑战之一。根据联合国报告,环境问题被列为全球十大环境问题之首。我们在实际生活汇中,也已经切实感受到土

关键词： Agriculture   products loss   climate change   inter-country input-output (ICIO) model   cross-strait  

摘要： In order to estimate the direct and indirect losses caused by natural disaster, this study conducts an Inter-Country Input-Output (ICIO) analysis to discuss the impacts on cross-strait industries in the face of disasters losses. The present study includes data from 96 sectors' cross-strait Inter-Country Input-Output table and the statistics of agriculture during 2005-2011 in Taiwan and the period 2005-2010 in Mainland China. The results indicate the total value-added effect in Mainland China is larger than Taiwan, whereas the multiplier of agriculture losses in Taiwan is larger than Mainland China. This indicates that the losses caused by natural disasters are larger in Taiwan is than in Mainland China.

关键词： 气候变化   农业全要素生产率   Fare-Primont指数   农业科研投入   固定效应模型  

摘要： 农业是国民经济的基础,直接关系到国家粮食安全和社会经济发展全局。2004年以来中国粮食产量实现14连增,粮食增产为中国经济发展和社会稳定做出了巨大贡献。史清华等(2018)指出中国粮食产量连续增长来自于要素投入的增加和农业全要素生产率的增长,其中农业全要素生产率增长解释了 69.36%的粮食增产。虽然已有文献基于特定视角探讨了农业全要素生产率增长,极大地丰富了农业全要素生产率影响因素分析的研究内容,却始终缺乏对气候变化与农业全要素生产率的关系进行实证检验。农业全要素生产率不仅受到制度和投资等因素的影响,气候因素在其中也起了重要的作用。农业是经济再生产和自然再生产的交织,气温、降雨等气候因素在农业产量形成中也起到重要作用,必然会影响到农业各类投入的产出效率,因而也会对农业全要生产率产生重要影响。根据新经济增长理论,农业科技进步可以抵消气候变化对农业生产带来的不利影响,从而推动农业经济增长。农业科研投入是体现农业科技进步与效果的重要指标。农业科研投入可以减弱与农业相关的气候条件因素等带来的农业生产的风险性与不确定性。本文首先从气温和降水两方面分析说明了 1986-2016年中国及分区域典型的气候变化特征。其次,运用较为前沿的Fare-Primont指数测度并分解了 1986-2016年中国29个省份的农业全要素生产率。在计量模型方面,本文采用了面板数据模型,控制了年份和地区两个固定效应,实证分析气候变化对农业全要素生产率的影响,重点考察温度和降水对农业全要素生产率的差异性影响。为了准确反映出农业生产与气候变化之间的对应性,以冬小麦、玉米和粳稻为例进一步探讨了生长期气候因素变化对粮食全要素生产率的作用机制。最后将农业科研投入因素引入,考虑气候变化背景下农业科研投入对农业全要素生产率的作用机制。通过上述系统研究,论文主要得出以下结论:(1)1986-2016年间我国气温呈波动式增长,升温趋势明显,具体表现为低温持续的天数逐渐减少,高温持续的天数逐渐增加。全国年际降水量的变化趋势并不明显。各区域来看,气温呈上升态势但增温趋势差异明显,降水量变化也表现出明显的区域差异。(2)1986-2016年间我国农业全要素生产率及分解指标变动具有明显的阶段性特征。整体而言,我国农业全要素生产率呈明显的波动性增长趋势,其中技术进步不断增长,技术效率波动较大,我国农业全要素生产率地区差距随时间推移呈上升趋势。(3)气温与农业全要素生产率之间存在非线性关系,高温会显著降低农业全要素生产率;高温主要通过降低农业技术效率和技术进步进而降低全要素生产率,其中对技术效率的影响起主导作用;降水与中国农业全要素生产率之间不存在非线性关系。(4)农业科研投入会对气候变化产生反应,它会减缓气候变化尤其是高温对农业全要素生产率的不利影响,农业科研投入越多的地区,气候变化对农业全要素生产率的不利影响越小。

关键词： 农业经济发展   节能   研究   中国  

ISBN: (纸本)9787030605917

摘要： 研究共分为4篇19章：第一部分为研究的绪论，主要对研究的背景、研究目标及研究内容进行了说明；第二部分为面上研究，一是对气候变化的经济效应进行了检验，二是分析了农业温室气体的排放状况，此外，本部分还对低碳农业发展的必要性及基本机制进行了说明；第三部分为实验研究与模拟分析部分，研究选取了我国种植业温室气体排放较为突出的稻田及肥料领域，采用田间实验及DNDC模型模拟，测度了不同肥料管理、外部条件对稻田温室气体排放的影响，进而提出了相应的减排路径措施；第四部分为战略与政策部分，在课题研究的基础上，提出了我国低碳农业发展的战略构想与政策建议，并定量研究了我国农业温室气体减排的补偿标准。