China feels the heat: negative impacts of high temperatures on China's rice sector

We analysed a county‐level data set of single‐season rice yield and daily weather outcomes in China to examine the effects of temperature on China's rice sector. We found that rice yield exhibited highly nonlinear responses to temperature changes: rice yield increased with temperature up to 28°C and decreased sharply with higher temperatures. Holding current growing seasons and regions constant, average rice yield in China is projected to decrease by 10–19 per cent by 2050 and 11–33 per cent by 2070 due to future warming under the global climate models HadGEM2‐ES and NorESM1‐M. These results imply that future warming poses a major challenge for Chinese rice farmers and that the effectiveness of adaptations will depend on how well they reduce the negative temperature impacts on rice yield because of very hot days.     

全球变化背景下气候变暖对中国农业生产的影响

全球变化背景下,气候变暖势必对我国农业生产要素、生产环境、农业生产活动及粮食安全产生重大影响。文章采用文献综述与比较研究的方法,系统分析气候变化对我国光资源、温度、水环境和土壤环境等农业生产要素的影响特征及变化趋势,探讨气候变化对我国作物种植区域和种植制度、农作物病虫害、农业生产能力、农业经济与管理等农业生产活动以及农田生态系统过程、农业生态环境(水环境、土壤环境、耕作环境)的实际影响。在此基础上,明确了我国农业在应对气候变化过程中所面临的主要问题:极端气候事件发生频率加大,自然灾害、气象灾害的风险提高,农业生产的波动性增强;农业病虫害的为害时间延长、危害程度加剧、为害范围增大;农业生态环境日趋恶化,农田土壤的干旱化、盐渍化程度加剧,农业生产能力下降;应对气候变化的农业发展策略及其关键技术亟需解决。     

Policy interventions to promote the adoption of water saving sprinkler systems: the case of lettuce on the Gnangara Mound

The potential for improving irrigation scheduling decisions and adoption of more efficient irrigation systems is explored using a bioeconomic simulation model of lettuce production on the Gnangara Mound near Perth, Western Australia. Sandy soils with poor water and nutrient holding capacity are associated with declining marginal productivity of water at high water use, which would create an incentive to reduce water use and to adopt closer sprinkler spacing if farmers had correct information about the declining marginal productivity of water. Incorrect perceptions regarding water–yield relationships lead to over use of water by up to 50 per cent and reduce profits by 475 per crop hectare (12 per cent) in the short run, and remove the incentive to adopt more efficient systems in the long run. Higher water prices create an incentive to reduce irrigation scheduling time in the short term and to adopt more uniform sprinkler systems, and tend to reduce the discrepancies associated with poor information about the marginal productivity of water. The low level of adoption of efficient irrigation systems in the region might be explained partly by historically poor water governance and insufficient extension regarding water productivity and technology.     

Measuring and decomposing agricultural productivity and profitability change*

Profitability change can be decomposed into the product of a total factor productivity (TFP) index and an index measuring changes in relative prices. Many TFP indexes can be further decomposed into measures of technical change, technical efficiency change, scale efficiency change and mix efficiency change. The class of indexes that can be decomposed in this way includes the Fisher, Törnqvist and Hicks–Moorsteen TFP indexes but not the Malmquist TFP index of Caves, Christensen and Diewert (1982). This paper develops data envelopment analysis methodology for computing and decomposing the Hicks–Moorsteen index. The empirical feasibility of the methodology is demonstrated using country‐level agricultural data covering the period 1970–2001. The paper explains why relatively small countries tend to be the most productive, and why favourable movements in relative prices tend to simultaneously increase net returns and decrease productivity. Australia appears to have experienced this relative price effect since at least 1970. Thus, if Australia is a price‐taker in output and input markets, Australian agricultural policy‐makers should not be overly concerned about the estimated 15 per cent decline in agricultural productivity that has taken place over the last three decades.     

THE COST OF DIFFERENTIAL GENDER ROLES IN AFRICAN AGRICULTURE: A CASE STUDY OF SMALLHOLDER BANANA-COFFEE FARMS IN THE KAGERA REGION,TANZANIA

In 1982/83, due to either economic pressure or profit motivation, 30 per cent of the men in a random sample of 200 smallholder banana-coffee farms in the Kagera region of Tanzania had adopted a more liberalised division of labour, and engaged in operations and horticultural farm enterprises that traditionally are the responsibility of women. A linear programming model is used to estimate the impact of gender roles on farm incomes and resource productivity among the sample. The results suggest that by liberalising sex roles, cash incomes could increase by up to 10 per cent while the productivity of labour and capital would improve by 15 per cent and 44 per cent respectively. In view of the economic benefits to be reaped, it is recommended that, within the framework of economic adjustment, African governments should launch campaigns to enhance this process because gender roles impair efficiency.     

黄淮海区气候变化及其对冬小麦光温生产潜力的影响

气候变化对冬小麦生长发育及产量的影响、冬小麦生产对气候变化的适应已经成为学术界研究的热点问题之一。黄淮海区是我国第一大冬小麦主产区,研究选择黄淮海区为研究区域,首先运用线性倾向率方法分析了黄淮海区近50年来太阳辐射量和平均温度在全年和冬小麦生育期两个时段内的时间和空间变化特征,运用AEZ模型计算了黄淮海区各气象站点的冬小麦光温生产潜力;在此基础上,分析了太阳辐射量和温度变化对冬小麦光温生产潜力的影响。结果表明:(1)黄淮海区全年日均太阳辐射量和生育期内日均太阳辐射量均表现为减少的趋势,且全年日均太阳辐射量减少幅度较大;(2)黄淮海区年平均温度表现为上升的趋势,而冬小麦生育期内平均温度的上升趋势极不明显;(3)黄淮海区冬小麦生育期内太阳辐射量的减少和平均温度的降低是导致冬小麦光温生产潜力下降的主要原因。     

THE EFFECT OF PRICE SUPPORT POLICIES ON AGRICULTURAL INVESTMENT,EMPLOYMENT, FARM INCOMES AND LAND VALUES IN THE U.K.

Agricultural price policy has a major impact on the input markets as well as the output markets and a model is developed to analyse the effects of changes in support levels on U.K. agricultural employment, earnings, investment and land prices. This paper describes the specification, estimation and evaluation of the model and simulates the effects of a one per cent increase in support prices. The main conclusions are that net investment would increase in the years following the rise by a maximum in the second year of £12m and by a cumulative total of £44m (representing an increase of about 0.4 per cent in the capital stock). Employment on the other hand, while rising at first, would subsequently fall to almost one per cent below its original level, and earnings of hired labour also fall slightly. Net farm income increases by around 10 per cent and this is capitalised into a similar increase in land values.     

Distributional heterogeneity in climate change impacts and adaptation: Evidence from Indian agriculture

This study estimates the distributional heterogeneity in the effects of climate change on yields of three major cereal crops: rice, maize, and wheat in India using district-level information for the period 1966–2015. We distinguish between the effects of changes in growing season weather from those due to changes in long-term climate trends and the heterogeneity in these effects across the distribution of crop yields by estimating naïve and climate penalty inclusive models using fixed-effect quantile panel models. We observe an absence of adaptation against rising temperatures for rice and wheat. However, we find a statistically significant presence of adaptation for wheat and maize for changes in precipitation, though the magnitude is small. Moreover, we find that the effects are asymmetric, and are larger at the lower tail of productivity distribution and smaller at the upper tail of the distribution. A 1°C increase in temperature lowers rice and wheat productivity by 23% and 9%, respectively at the first quantile, but the damage is only 6% and 5% at the ninth quantile. Heterogeneity in impacts and adaptation estimates over the yield distribution curve and across crops suggests the importance of customizing strategies for adaptation to changing weather and climate conditions across regions, crops, and current productivity levels.     

The potential impact of climate change on Taiwan's agriculture

This paper intends to estimate the potential impact of climate change on Taiwan's agricultural sector. Yield response regression models are used to investigate the climate change's impact on 60 crops. A price‐endogenous mathematical programming model is then used to simulate the welfare impacts of yield changes under various climate change scenarios. Results suggest that both warming and climate variations have a significant but non‐monotonic impact on crop yields. Society as a whole would not suffer from warming, but a precipitation increase may be devastating to farmers.     

Broadacre farm productivity and profitability in south‐western Australia

This paper examines broadacre farm performance in south‐western Australia. This region has experienced pronounced climate variability and volatile commodity prices since the late 1990s. Relationships between productivity and profitability are explored using panel data from 47 farms in the study region. The data are analysed using nonparametric methods. By applying the Fare‐Primont index method, components of farm productivity and profitability are measured over the period 1998–2008. Growth in productivity is found to be the main contributor of profitability. Gains in efficiency and technical change are identified as jointly and similarly important in their contribution to total factor productivity for the farm sample in the region from 1998 to 2008. However, across environments, efficiency gains play an increasingly important role in influencing productivity as growing season rainfall increases. We conclude that R,D&E that delivers further improvement in technical efficiency and technical change is needed to support the profitability of farms across the study region.     

基于DSSAT模型的1961—2017年东北地区马铃薯潜在单产及其影响因子分析

目的 文章基于DSSAT-SUBSTOR作物生长模型, 分析1961—2017年东北三省马铃薯种植区域内均匀分布的21个国家气象局气象观测站点马铃薯的潜在单产的变化特征及气候因子对潜在单产的影响。方法 首先, 基于东北三省马铃薯种植区域内均匀分布的21个国家气象局气象观测站点1961—2017年逐日气象数据, 运用验证后的DSSAT-SUBSTOR模型模拟该时段站点位置马铃薯潜在单产;然后运用灰色关联法提取影响马铃薯潜在单产的优势气象因子;最后运用多元回归分析方法揭示主要优势气象因子对潜在单产的影响程度, 分析马铃薯潜在单产及其气候影响因子的时空差异性。结果 （1）1961—2017年东北三省国家气象局站点马铃薯潜在单产均呈减少趋势,潜在单产最低和最高的站点分别是五大连池和梅河口, 变化最小和最大的站点分别是兴城和绥芬河;（2）1961—2017年黑龙江省增温幅度最大, 吉林省气温日较差降低最多, 辽宁省日辐射量减少最明显;研究区生长季平均温的升高、气温日较差的降低以及辐射量的减少均导致马铃薯潜在单产降低, 其中, 平均温度是对研究区马铃薯潜在单产减产贡献最大的气象因子;对平均温度、气温日较差和日辐射量最敏感的站点分别是五大连池、公主岭和瓦房店。结论 东北三省地区已进入气候暖干化阶段, 在今后的马铃薯生产中应通过适时调整播期、培育或引进适应气候变化的新品种等科学农田管理措施, 充分利用气候资源、提高马铃薯生产力水平。     

Economic impacts of climate change on the Australian dairy sector

We analyse the economic implications of climate‐driven pressures on the pasture‐based dairy sector in Australia. We use an integrated assessment model that includes a climate scenario generator, a climate‐biophysical response framework and an economywide analytical framework. For the climate scenario generator, we use data from the OzClim database of the Commonwealth Scientific and Industrial Research Organisation. For the climate‐biophysical response framework, we use the DairyMod model with inputs of changes in climate variables from OzClim to quantify climate change effects on pasture growth and productivity. For the economywide analytical framework, we use the National Integrated Assessment Model to quantify the economic implications of these effects on the dairy sector. The simulated pattern of regional changes in dairy output is not a simple function of the changes in dairy productivity. Our results show that the relative size of productivity changes across regions affects the relative competitive advantage of dairy‐producing regions. Several factors affect the regional distribution of simulated dairy‐output changes, including substitution among sources of dairy output and competition for inputs like supplementary feed. An increased output in regions with moderate reductions in dairy productivity may occur because the severely climate‐affected regions absorb the greatest loss in output.     

Nonparametric estimates of productivity and efficiency change in Australian Broadacre Agriculture

This paper computes and decomposes Färe‐Primont indexes of total factor productivity of Australian broadacre agriculture by estimating distance functions. Using state‐level data from 1990 to 2011, the empirical results show that TFP grew at an average rate of 1.36 per cent per annum in the broadacre agriculture over the period 1990–2011. There are variations of total factor productivity (TFP) growth across states and fluctuations over time within each state and territory. However, overall, there is a clear movement towards slower TFP growth across the sample period. Further decomposition of TFP growth shows that it is declining growth in technical possibilities (technological progress) that is the main driver of the declining trend in productivity growth in broadacre agriculture in Australia.     

气候变化背景下哈萨克斯坦气候生产潜力时空特征分析

[目的]研究全球气候变化背景下气候生产潜力的时空分布特征,对于合理利用农业气候资源,促进农业生产力的提高具有重要意义。[方法]选择1901—2000年哈萨克斯坦24个代表气象站点的月平均气温和降水资料,采用Thortwaite Memorial、Miami模型估算气候生产潜力,并运用气候倾向率、M-K检验以及ArcGIS空间插值等方法对气候生产潜力时空分布特征进行分析。[结果](1)1901—2000年哈萨克斯坦气候生产潜力总体表现为增长趋势,不同时段气候生产潜力差异明显,相对于其他研究时段(T1,T3),T2(1936—1970年)时段气候生产潜力及增长速率最大,并且水热匹配状况最好;(2)哈萨克斯坦气候生产潜力空间分布地域性明显。YP(降水生产潜力)和Y E(蒸散生产潜力)总体表现为自东南向西北递减的趋势,YT(气温生产潜力)表现为自西南向东北递减的趋势,气候生产潜力高值区主要位于天山北麓及东部山区的河谷地带,低值区位于西部和南部荒漠区;(3)气候生产潜力对降水更为敏感,当气温保持不变,降水量增加(减少)10%、20%,YE将增加(减少)9.6%、19.94%。[结论]哈萨克斯坦东部气候生产潜力大于西部,天山北麓及河谷地区气候生产潜力大于平原地区,哈萨克斯坦气候生产潜力主要受降水量的制约,未来“暖干型”变化将会使研究区气候生产潜力下降。为提高农业生产潜力,必须加强对农业基础设施的建设和提高水资源的调配能力。     

Economic cost of environmental flows in an unregulated river system*

This paper applies a stochastic dynamic programming framework, incorporating links to hydrological and biophysical models, to assess the economic costs of environmental flows in an unregulated river system in the Namoi Valley of northern New South Wales, Australia. Structural adjustment decisions are included in the model to account for farmer responses to changes in environmental flows through the introduction of a water sharing plan. The results of the analysis indicate that the proposed level of environmental flows reduces water extractions by around 6 per cent, and imposes an opportunity cost of less than 1 per cent in terms of reduced net income over a 20-year period.     

THE IMPACT OF SCIENTIFIC RESEARCH ON AUSTRALIAN RURAL PRODUCTIVITY

In this paper the relationship between scientific agricultural research and aggregate rural productivity is investigated. The Solow 'residual' model is used to estimate productivity changes. An attempt is made to investigate the extent to which scientific research, measured by scientific personnel, 'explains' technical change. An education and climatic variable are added to the model. The results suggest a positive relationship between scientific research, climate and aggregate productivity.     

Traditional farm expansion versus joint venture remote partnerships

Traditionally, farms expand by buying out a neighbour. But might remote partnerships be a better way of expanding a farm business given projected climate change and price volatility? This question is addressed using farm business financial modelling. Representative farms at 27 locations in Western Australia are constructed to enable comparison of the value of buying out a neighbour versus expansion using geographically distant joint venture (JV) partners. The farm models consider economies of size, bulk purchase price discounts, the variability and correlation of returns associated with farm expansion, and impacts of climate change. Random selection of a remote partner generates little improvement in wealth; on average only 2.3 and 1.6 per cent, respectively, under current and projected future climate across all locations. However, there is large variation in wealth appreciation opportunities for each location and between locations. Preferred partnerships are a function of each farm's characteristics. Locations highly preferred as JV partners under current climate are similarly preferred partners under projected future climate. The main sources of additional wealth come from economies of size advantages, risk‐spreading benefits of combining geographically separated farms and bulk discounts. Farmers seeking business expansion will often benefit greatly from careful selection of a remote partner.     

US TENDANCES DE LA PRODUCTIVITE TOTALE DANS L'AGRICULTURE: CANADA, ONTARIO, QUEBEC, 1926–64

This paper measures and analyses the changes in total productivity of Canadian, Ontario and Quebec agriculture for the period 1926 to 1964. The rate of growth in productivity from 1945 to 1964 has been about the same for Canadian and Ontario agriculture while that of Quebec has been higher than either by one per cent a year. Total productivity gains correspond to decreases in the average costs of production at the farm level. Quebec's farmers have therefore improved their relative position as competitors. These productivity gains have important and far reaching implications not only for fanners and the agricultural industry but also for the provinces and the entire Canadian economy.     

Warming temperatures will likely induce higher premium rates and government outlays for the U.S. crop insurance program

Likely climate change impacts include damages to agricultural production resulting from increased exposure to extreme heat. Considerable uncertainty remains regarding impacts on crop insurance programs. We utilize a panel of U.S. corn yield data to predict the effect of warming temperatures on the mean and variance of yields, as well as crop insurance premium rates and producer subsidies. While we focus on corn, we demonstrate that the subsidy impacts are likely to carry over to other major program crops. We find that warming decreases mean yields and increases yield risk on average, which results in higher premium rates. Under a 1°C warming scenario, we find that premium rates at the 90% coverage level will increase by 39% on average; however, there is considerable statistical uncertainty around this average as the 95% confidence interval spans from 22% to 61%. We also find evidence of extensive cross‐sectional differences as the county‐level rate impacts range from a 10% reduction to a 63% increase. Results indicate that exposure to extreme heat and changes in the coefficient of variation are large drivers of the impacts. Under the 1°C warming scenario, we find that annual subsidy payments for the crop insurance program could increase by as much as $1.5 billion, representing a 22% increase relative to current levels. This estimate increases to 3.7 billion (57%) under a 2°C warming scenario. Our results correspond to a very specific counterfactual: the marginal effect of warming temperatures under current technology, production, and crop insurance enrollments. These impacts are shown to be smaller than the forecasted impacts under a commonly used end‐of‐century general circulation model for even the most optimistic CO₂ emissions projection.     

全面建成小康社会对农村居民肉类消费的影响——基于中国农村微观经济数据的实证研究

[目的]基于中国农村微观经济数据,分析全面建成小康社会对农村居民肉类消费的影响。[方法]文章运用恩格尔模型和考虑"零消费"问题的近乎理想需求系统模型(AIDS)的两阶段模型,对全国8个省份的农户数据进行实证分析。[结果]首先,肉类食品的需求收入弹性均为正值,农村居民肉类需求随着收入增长而增加。其次,肉类食品需求收入弹性存在差异,其中,禽肉收入弹性最大,牛羊肉收入弹性最小。再次,不考虑"零消费"问题时,牛羊肉的需求弹性被高估0.12～0.29,猪肉的需求弹性被高估0～0.02。最后,到达全面建成小康社会的标准时,目前低于收入标准的农村居民人均猪肉、禽肉和牛羊肉消费量将分别增加3.42kg、1.86kg和0.57kg,消费结构将进一步优化。[结论]全面建成小康社会将促进农村居民人均收入增长,进而扩大人均肉类消费量、优化肉类消费结构;农村家庭户主受教育程度与肉类消费具有正向相关关系。