北京市瓜蔬类作物生产风险区划研究

北京市瓜蔬类作物的规模相对其他作物日渐扩大,并形成了明显的优势生产区域,但是仍面临着较高的生产风险。对此,该文选择单产变异系数、旱涝指数、温度距平值、规模指数和效益指数等多个指标,构建了风险测度模型,在分析北京市瓜蔬类作物生产现状及其演变趋势的基础上,对蔬菜、西瓜的生产风险进行了测度和评估,提出了通过运用农业保险工具、开展不同作物保险组合来分散风险的政策建议。     

Integrating Technology Traits and Producer Heterogeneity: A Mixed-Multinomial Model of Genetically Modified Corn Adoption

This article proposes a model of technology adoption that integrates demand for individual traits of new technologies with the potential for heterogeneity based on farm and farmer characteristics. The model is applied to recent genetically modified corn adoption data from Minnesota and Wisconsin farmers, using a mixed-multinomial logit (MMNL) model to estimate the effects of traits and farm and farmer characteristics on adoption outcomes. This approach allows explicit recovery of estimates of farmers' shadow prices for individual technology traits. Results show the importance of producer and regional heterogeneity in preferences for seed traits.     

Biodiversity and Optimal Policies Towards R&D and the Growth of Genetically Modified Crops

In this paper we provide a simple model illustrating the possible nature ofgovernment policy with regards to genetic modification, taking into accountits impact on the environment. We show that it is necessary not only tointervene in the growing of crops, but also to intervene in R&D througha tax on the adoption of new GM technology. Without intervention at bothlevels, both the cultivation of GM crops and the rate of innovation in GM willexceed their socially optimal levels.     

莲在低洼湿地农业中的应用——以浙江省嘉兴市王江泾镇为例

王江泾镇地处嘉兴北部,地势低洼,许多农田常年积水,雨水稍多时,易出现水涝灾害。莲有藕莲、子莲和花莲等类型,在嘉兴北部低洼湿地农业发展中有着不可替代的作用,因地制宜开发莲藕、子莲等水生作物种植,或种养结合,发展湿地莲产业;或建立荷花景观池,拓展湿地景观,展示湿地公园园林文化、生态文化和人文文化,促进休闲观光农业发展,具有良好的经济生态和社会效益,值得在同类地区推广。     

NDVI在农作物监测中的研究与应用

归一化差值植被指数(normalized difference vegetation index,NDVI)是农作物监测中应用最为广泛的光谱参数之一,在农作物生产与管理中具有重要的实际指导意义.该文就NDVI在作物产量、生物量、收获指数、叶面积指数、营养状况、作物冻害等方面的研究与应用作一综述,并总结当前研究中存在的问题与不足,提出了NDVI在今后作物监测中进一步的研究重点.     

Responding Public Demand for Assurance of Genetically Modified Crops: Case from Japan

Genetically modified (GM) crops provide a classic example of risk characterised with uncertainty and ambiguity. This article analyses the risk management of GM crops in Japan as a case and investigates how the Japanese government has responded to the growing public demand for safety assurance of new agricultural and food varieties. It argues that, while the government realised the need to respond to public reluctance in consuming GM food by adopting more resilient and discursive management, it has faced a dilemma to incorporate the new type of approach into conventional risk assessment. This tension was reflected in the process and policy outputs of the consensus conference on GM crops, which was ambiguously placed in the risk management process. This article shows the dynamics of opting for policies to manage scientifically uncertain risks in particular socio‐political and institutional contexts. Such understanding can suggest ways towards enhanced policy debates.     

小农的种粮逻辑——40年来中国农业种植结构的转变与未来策略

基于已有文献对中国粮食安全问题的质疑与担忧,作者回顾了改革开放40年以来我国农业种植结构调整从"去粮化"到"趋粮化"的历史性转变。文章认为,2003年以来中国粮食长期且连续的增长,并非由外生的经济因素直接激发,亦非农业税减免和农业补贴政策的直接诱导,而是由农户在要素流动与卷入农业分工的过程中所内生的自我执行机制来决定的。理论与实证研究表明,中国小农的种粮逻辑是通过要素配置、地权预期、分工深化三个方面来共同表达的。小规模分散化的农业家庭经营格局并不构成中国粮食安全的阻碍,相反,却内含着重要的组织优势与可动员潜力。文章进一步讨论了保障中国粮食安全的基本策略与政策选择。     

日照时间天气指数保险的费率厘定——以长沙县早稻作物为例

天气指数保险是传统农业保险、区域产量保险的创新。选择天气指数保险探讨其费率厘定,有助于克服道德风险和逆选择,确保农业保险快速、健康地发展。粮食作物日照时间天气指数保险的费率厘定,首先要测算日照过短（或日照过长）的严重程度,计算日照过短（或日照过长）测度指标;再分析气候因素导致粮食作物减产的程度,计算气候减产率;然后利用计量经济分析方法,确立气候减产率与日照过短（或日照过长）测度指标之间的定量关系;最后根据该定量关系以及日照过短（或日照过长）测度指标的期望值,求得日照时间天气指数保险的费率。     

世界生物技术作物的发展态势与我国的对策

从国别、作物的种类及特性的角度观察世界生物技术作物,其生产状况呈现出全面迅速增长态势。与此同时,世界生物技术作物的国际贸易也呈现出迅速增长的趋势。与上述发展态势伴生的是生物安全与国际贸易争端问题。我国应当从科技、安全管理、国际贸易等方面积极应对。