Option Approach to Search for Threshold Rice Price Toward Sustainable Paddy Field Management

This paper applies an option approach to search for the threshold rice price toward the sustainable paddy field management under rice price stochasticity. Rice price is assumed to follow geometric Brownian motion. The management model for paddy fields is a discrete stochastic dynamic programming model with binomial approximation for geometric Brownian motion, where a control variable is a decision to sustain or terminate paddy yield management. Our computational experiments indicate that an increase in rice price volatility could lower the threshold rice price for farmers to continue rice production. It is also shown that depending on the degree of rice price volatility, even under a lower price level than production costs, maintaining the management could become beneficial. Considering an option to terminate production could make the higher expected value of rice production than without it. Using 12 sets of time series data on voluntarily marketed rice produced in Hokkaido, Aomori, Iwate, Miyagi, Akita, Yamagata, Fukui, Ibaragi, Chiba, Niigata, Toyama and Nagano, the minimum threshold rice price of 6,700 Yen/60 kg was found in Chiba with the largest volatility, and the maximum of 7,250 Yen/60 kg in Ibaragi with the smallest volatility. If the market price becomes lower than the threshold rice price, some policy measures would be necessary toward sustainable paddy field management by covering the difference between them.     

中国粳稻生产效率演变及区域差异

[目的]我国粳稻产量现阶段呈连续增长的态势,然而粳稻生产效率却存在无效率或波动剧烈的现象,研究我国的粳稻生产效率,有助于提升和稳定中国粳稻区域生产效率和水平从而间接保障我国粮食安全。[方法]使用超效率DEA方法测算中国13个粳稻生产省份的生产效率,分别从时间和区域上的差异进行分析。[结果]中国粳稻生产技术效率在时间趋势上逐渐趋于平稳,但是在2004—2007年间存在短暂的波动;在区域上主要是西南和东北粳稻生产区的技术效率水平较高,西北区在技术效率、纯技术效率与规模效率上都处于较低的水平;虽然河南、湖北、宁夏3个省份出现技术无效率,但规模报酬都处于递增的状态,仍有提升生产效率的潜力,应通过减少要素投入冗余来改变其无效率状态。[结论]粳稻生产技术无效率主要是由于种子费用、农药费用等生产要素的投入冗余造成的;若将来在保持纯技术效率和其他条件不变的情况下,通过提升规模效率水平会进一步提升我国粳稻的整体技术效率水平。基于上述分析有针对性地提出制定粳稻生产区域规划、发展适度规模经营、改善生产要素使用效率3方面的政策建议。     

气候变化下湖北省稻谷生长期降雨量指数保险设计

[目的]气候变化对我国粮食生产造成巨大损失,传统农业保险存在较多问题,天气指数农业保险作为金融创新工具,成为转移农业天气风险的有力路径。[方法]文章在分析降雨量指数保险合约设计思路的基础上,依照天气指数保险合约定义,选取稻谷生长期每日降水的累积降雨量作为天气指标,采用经济—气候模型和湖北省78个县市的面板数据,按风险区域分别设计了干旱指数保险合约和暴雨灾害指数保险合约。[结果]虽然湖北省全省累积降水的影响总体是负向的,但累积降水量对稻谷单产在十堰、襄阳等干旱区域的边际影响是正向的、显著的,累积降水量在暴雨集中区域江汉平原地区、咸宁市及辖内县市,有着显著的负向影响。[结论]气候变化对粮食生产的影响显著,根据面板数据的估计结果,有必要按不同的风险区域分别设计天气指数保险合约。该文的研究在天气指数保险设计方面做出了一定的探索,进一步使天气指数保险合约成为转移农业天气风险的有力创新工具。     

四川省水稻产投特征变迁及技术进步对单产的影响

[目的]了解四川水稻产投特征和技术进步对单产的影响,促进水稻可持续生产。[方法]分析了改革开放以来四川省水稻产投特征和技术特征变动,并基于索洛余值法测算了1980~2015年四川省科技进步对水稻单产的贡献情况。[结果](1)全省水稻单产水平及物质与服务费用投入均呈现波动增长趋势,人工投入逐年递减,但人工成本在生产成本中的比重较大;(2)四川省水稻品种选育、栽培管理技术、推广技术、稻作经营方式和农业政策不断变迁,更适应当前以普通家庭生产和新型经营主体共同发展的局面对技术的需求;(3)整体来看,近36年技术进步对四川省水稻单产水平提高的贡献率较低,生产经营较为粗放;(4)分时期看,2005年前,技术进步对全省水稻单产水平提高的贡献率较高,但之后尤其是近5年,技术进步并未对水稻单产水平提高产生影响,要素投入是水稻单产水平提升的主要因素。[结论]提出了加强科技研发及投入水平、"一主多元"联合推广、生产管理技术培训和丘区节本增效生产的政策建议。     

Accounting for the Gender Technology Gap Amongst Smallholder Rice Farmers in Northern Ghana

Narrowing the gender technology gap in agricultural production has become a critical policy issue in sub‐Saharan Africa. A better understanding of the gender technology gap is essential for policy formulation and programme planning to ensure equity in resource allocation, and household‐level food security in low and middle income countries, such as Ghana. We employ a metafrontier approach to analyse the differences in the efficiency of male and female farmers, recognising the endogeneity of some of the variables in the inefficiency effects model, in particular the credit constraints of the rice farmers under study. Our findings show that while the rice farms themselves are very similar, average yields for male managed farms tend to be significantly higher than female managed farms reflecting higher seeding and fertiliser application rates on male managed farms. However, there is no significant difference between the genders in either land used for rice or total output per farm household. We find some evidence that relative to the metafrontier, male managed farms are less efficient than female managed farms. The results further show gender technology gap amongst the smallholder rice farmers with females’ technology gap ratio being significantly greater than that of males, with females operating on a production frontier closer to the metafrontier. Policies that provide females more access to productive resources and other agricultural services could assist in the generation of relatively higher output.     

我国水稻产业供给侧结构性改革的思考

[目的]文章在供给侧改革视角下对水稻供需的结构性矛盾等方面进行梳理,分析基于供给侧改革战略的关键环节、实施路径和未来发展趋势,以期为制定我国水稻供给侧改革战略提供参考。[方法]采用文献分析法和调查研究法,从我国水稻生产供求结构、价格"天花板"和成本"地板"双重挤压、水稻生产的资源环境、市场调节等方面分析了我国水稻产业供给侧的现状和存在的问题;通过日本、泰国、中国五常大米政策特点和经验教训的启示,提出了我国水稻产业供给侧结构性改革的策略。[结果]在分析我国水稻产业供给侧现状的基础上,总结得出水稻产业供给侧改革措施:优化水稻产业空间和功能布局,以项目带动水稻产业结构调整,提高和优化稻米品种品质结构、审定标准向抗性优质专用水稻品种倾斜,因地制宜调减水稻生产面积,调整国家收储稻米标准,延长水稻全产业链等。[结论]加速我国水稻产业供给侧改革,能促进稻米产业结构快速升级,有效破解稻米产业的结构性矛盾,增强我国稻米产业可持续发展能力和国际竞争力。     

System of crop intensification for more productive,resource-conserving,climate-resilient,and sustainable agriculture: experience with diverse crops in varying agroecologies

With continually increasing demand for food accompanied by the constraints of climate change and the availability and quality of soil and water, the world’s farmers are challenged to produce more food per hectare with less water, and with fewer agrochemical inputs if possible. The ideas and methods of the system of rice intensification which is improving irrigated rice production are now being extended/adapted to many other crops: wheat, maize, finger millet, sugarcane, tef, mustard, legumes, vegetables, and even spices. Promoting better root growth and enhancing the soil’s fertility with organic materials are being found effective means for raising the yields of many crop plants with less water, less fertilizer, reduced seeds, fewer agrochemicals, and greater climate resilience. In this article, we review what is becoming known about various farmer-centred innovations for agroecological crop management that can contribute to agricultural sustainability. These changes represent the emerging system of crop intensification, which is being increasingly applied in Asian, African, and Latin American countries. More research will be needed to verify the efficacy and impact of these innovations and to clarify their conditions and limits. But as no negative effects for human or environmental health have been identified, making these agronomic options more widely known should prompt more investigation and, to the extent justified by results, utilization of these methodologies.     

Exploring Transition and Change in a Complex Traditional Market: The Case of the Rice Market in Bangladesh

This paper explores the unaddressed question of how the large, complex paddy‐rice market in Bangladesh is able to transform itself and evolve, in the face of changing risks and incentives, into a better‐functioning market system. It notes significant but opposing trends over two decades in different areas, particularly in terms of market structure, trade circuits and exchange relations. Evidence of a sharp decline in tied transactions points to the growing importance of impersonal exchange. The underlying causes of these changes are explored, with particular reference to microfinance, remittances, rural roads and mobile telephony.     

炎帝神农氏与湖南稻作农业的起源

炎帝神农氏是中华民族的始祖,也是稻作农业的创始人。据史实记载,炎帝神农氏在上古代农业方面作出了突出贡献。特别在史前稻作农业方面的贡献尤其突出。据现代考古发掘表明,与炎帝神农同时代的稻作农业非常发达。综合分析史实记载、历史传说、民俗民风和现代考古等都在很大程度上相互应证,形成了一条符合逻辑的证据链条。这些证据链条无一不指向长江中下游的"两湖"和湘江流域。特别是湖南境内的洞庭湖平原及湘江流域更是稻作农业的核心地。现代考古发掘也有力地证明了"南稻北粟"的学说和中国南北文化的差异。也有力批驳了"南蛮"之地的邪说,事实上,在远古时代,南方的文明在一定程度上先于并且胜过北方文明。南方也是中华文明的摇蓝。     

稻米市场销售价格形势分析及展望

本文论述了稻米市场销售价格形势分析及展望。