水资源价值及商品水定价问题的探析

以资源环境经济学理论为根据，探讨了水资源以及商品水资源的价值内涵；从资源价格、工程价格、生态环境价格等三个方面，论证了商品水资源价格的构成要素；分析了影响商品水定价的自然因素和社会因素，提出了当前制定水价的原则与策略。     

A Retrospective Economic Analysis of the Ontario Red Fox Oral Rabies Vaccination Programme

Ontario initiated a red fox (Vulpes vulpes ) oral rabies vaccination (ORV) programme in 1989. This study utilized a benefit‐cost analysis to determine if this ORV programme was economically worthwhile. Between 1979 and 1989, prior to ORV baiting, the average annual human post‐exposure treatments, positive red fox rabies diagnostic tests and indemnity payments for livestock lost to rabies were 2248, 1861 and $246 809, respectively. After baiting, from 1990 to 2000, a 35%, 66% and 41% decrease in post‐exposure treatments, animal rabies tests and indemnity payments was observed, respectively. These reductions were viewed as benefits of the ORV programme, whereas total costs were those associated with ORV baiting. Multiple techniques were used to estimate four different benefit streams and the total estimated benefits ranged from $35 486 316 to $98 413 217. The annual mean ORV programme cost was $6 447 720, with total programme costs of $77 372 637. The average benefit‐cost ratios over the analysis period were .49, 1.06, 1.27 and 1.36, indicating overall programme efficiency in three of the four conservative scenarios.     

Spotted wing drosophila infestation of California strawberries and raspberries: economic analysis of potential revenue losses and control costs

BACKGROUND: Economic costs of spotted wing drosophila (SWD) include yield and associated revenue losses, labor and material costs for monitoring and management and revenue losses due to the closure of export markets should fruit from SWD‐infested regions be banned by trading partners. This analysis focuses on two types of loss in the California raspberry and strawberry industries: yield losses in the absence of management, and insecticide material costs on a per treatment basis. It computes the cost of a specific management program for raspberries in California's Central Coast region. RESULTS: Insecticide material and application costs per treatment and the cost of the management program are small relative to the yield losses in the absence of management that are observed by growers, researchers and others in initial infestations. CONCLUSION: It is difficult to evaluate precisely the share of pest management program costs due to SWD because insecticides are sometimes used to manage multiple pests, and because labor‐intensive field sanitation efforts to control SWD are recommended practices already. Given these considerations, this analysis finds that the benefits to SWD management well outweigh the costs examined here. Evaluating the efficacy of managing SWD is essential in assessing the risks that SWD poses and the benefits of pest management programs. Copyright © 2011 Society of Chemical Industry     

王东沟农户经济浅析

该文以王东沟1987~1992年47户农民的定位观测资料为依据,分析了王东沟农户经济稳步发展的主要原因及其特点,论述了王东沟农户经济必将沿着承包户-兼业户-专业户-联合的道路发展,最后走上联合经济的道路?     

采用根滤去污工艺的污水净化植物补救系统决策支持软件

为了开发利用植物去除因吸收污染水而产生的重金属的商业化根滤系统和植物去污补救工艺,研究开发了微型计算机软件,以便为该系统的设计与运行提供参考。建立了一个基于Michaelis-Menton方程的工艺模型,可以定量确定在根滤系统中的植物积累和去除毒素物质的能力。采用一系列的算法处理信息并编入一个根滤设施的系统模型内。该系统模型将植物补救系统的物理元件——植物苗圃、根过滤系统、水的前处理与后处理、植物生物质的产后处理等与系统设计的工程方面包括工艺、运行、设施和系统集成结合起来。该软件内含的工程经济分析工具可用于分析主要设计变量对系统效率的影响     

Genetic and economic aspects of marker-assisted reduction of redundancy from a wild potato germplasm collection

The wild potato germplasm collection of the series Acaulia, maintained at the Centre for Genetic Resources, The Netherlands, consists of 314 accessions. In previous investigations, 15 potential duplication groups with a total of 36 accessions were identified based on AFLP analysis of a limited sample per accession. In the present study, the potential redundancies, plus one additional accession, were studied with increased sample sizes to examine intra- and inter-accession variation more accurately, with the aim to reduce the size of the collection. No variation was observed within two potential duplication groups, whereas only limited differentiation among accessions was detected within seven groups, resulting in a total of 15 redundant accessions (nearly 5% of the collection). A cluster analysis of all the accessions of the collection showed that these nine groups each had a distinct identity. It was decided to maintain the accessions of the remaining six groups as separate entries based on the large differentiation observed among accessions and the absence of a clear identity. An analysis of molecular variance in the set of 37 accessions showed that 91% of the observed variation could be found among accessions. This variance component appeared unaffected when the set was analysed without the 15 redundant accessions. The invested costs to identify redundancies in the series Acaulia by AFLP analysis are estimated at k 57.3, whereas the savings achieved by reduction of the collection are estimated at k 21.0 per generation. However, a cost-benefit analysis should not only focus on the short-term return of investments, but should also consider the value of newly obtained data and information. These include taxonomic information about accessions, optimised sampling strategies, optimised regeneration procedures, additional data for core collection formation and more efficient utilisation of germplasm.     

Economic land evaluation: why and how

Abstract. Economic land evaluation is a method for predicting the micro-economic value of implementing a given land-use system on a given land area. This is a more useful prediction of land performance than a purely physical evaluation, since many land-use decisions are made on the basis of economic value. Measures of economic suitability include the gross margin, net present value, internal rate of return, benefit:cost ratio, and utility functions based on these. The economic value of the in-situ resource quality of a land area may be inferred directly from land characteristics or from Land Qualities which, when less than optimum, result in decreased yields or increased costs. The economic value of geographic land characteristics may be determined by spatial analysis. Single or multi-criteria economic optimization and risk analysis can extend the economic land evaluation from a natural resource or management unit to a production or planning unit. Computerized tools may be used to assist in economic land evaluation.     

Quantifying the fine scale (1km × 1km) exposure,dose and effects of ozone: Part 2 estimating yield losses for agricultural crops

In Britain wheat is an important crop accounting for 41% of the total cereal production. In this study ozone concentrations for 1989 estimated as described in Part 1 of the paper are integrated with the estimated wheat distribution to derive a detailed estimate of the impact of ozone on wheat yields at a fine spatial scale (1km × 1km). These data provide estimates for calculating regional and national yield losses. The methodology can be applied to other crop species. Recent research on a range of crops has established relationships between the economic yield loss for certain crops, including wheat, and ozone exposure. Exposure is described as the accumulated exposure above a threshold experienced during the daylight hours (AOT). Critical AOT values are derived from yield exposure relationships which show linear reductions of yield loss with increasing ozone concentrations. This study has made use of land cover data from remotely sensed imagery at 25m resolution and nationally collected agricultural statistics for counties. These data were combined using an areal interpolation technique to provide more spatially articulate estimates of the location and intensity of wheat production. The results demonstrate the economic importance of ozone as a pollutant. Wheat yield losses attributed to ozone vary between different parts of the country but, for years when ozone levels are high, yield losses are likely to be significant in some areas.     

小黑麦生物学特性、营养价值及利用前景

通过对小黑麦和小麦的生物学特性和经济学特性的分析比较,说明小黑麦这种异源多倍体新物种较小麦具有更强的生命力、更高的生物产量、更优的理化特性、更好的营养品质和更广的适应性,因而它已成为推动我国种植业和畜牧业协调发展的新型作物,对农业结构的调整具有重要的作用。     

我国农业结构战略性调整的政策支持体系

基于农业基础地位转移理论和农业的多功能性分析,从增加农民收入、强化食品安全、提高农产品竞争力和保护生态环境等方面提出了我国新一轮农业结构调整的农业政策目标模式,构建了由国内支持政策、农业生产政策、农产品贸易政策、农业行政管理体制以及城镇化建设等组成的我国农业结构战略性调整的政策支持体系。