基于种养结合的种植户粪肥支付意愿研究

[目的]种植户的施用粪肥意愿对降低农业面源污染,提高养殖废弃物综合利用率,保护农村环境意义重大。[方法]利用CVM方法和Tobit模型分析北京市种植户的粪肥支付意愿及影响因素。[结果]98.07%的种植户愿意接受粪肥还田,对粪肥的平均支付意愿为82.99元/m~3。种植户不施用粪肥的主要原因是没有获取渠道与施用粪肥过程繁琐。种植户决策人性别为男性、加入专业合作社、年收入高、接受有机肥补贴、参加过施用粪肥培训、认可粪肥肥效长于化肥、认识到施用粪肥能提高农产品产量对种植户的粪肥支付意愿有显著正向影响。而种植规模大、农田肥力好、认为施用粪肥有助于农产品价格提高对种植户的粪肥支付意愿有显著负向影响。[结论]可以从以下3方面提高种植户的粪肥支付意愿:(1)帮助建立、巩固粪肥交易关系;(2)强化政府职能,提高对施用粪肥的帮扶力度;(3)加强对种植户的粪肥功能认知及环境保护宣传教育。     

生猪养殖规模化程度的省际差异及未来趋势*——基于13个生猪养殖优势省份的研究

［目的］2007年以来国家实施“一揽子”补贴政策，生猪养殖规模化程度显著提高，但也呈现出明显的规模差异和省际差异。［方法］基于相关统计数据，利用生猪规模养殖指数详细透视了生猪养殖优势省份规模养殖的发展历程及规模化特征。［结果］生猪规模养殖呈现向华北和东北地区富集的基本趋势，但目前生猪养殖规模化的层次仍较低； 吉林、黑龙江、山东属生猪规模养殖特快发展区，辽宁、江苏、河南和广东属于快速发展区，安徽、湖北、湖南、广西和四川属缓慢发展区，河北属约束发展区。［结论］在山东、江苏、河南和广东，重点推进年出栏50~100头的养猪场户向年出栏100头以上的养猪场户转化； 在黑龙江、吉林、辽宁应进一步鼓励年出栏100头以上的养猪场户适当的扩大规模； 而在河北，考虑产业布局和环境规制等因素，则有序退出生猪规模养殖。     

抑制微生物活动 做好农产品配送

农产品是生物有机体,在配送农产品的各个环节中,不可避免的要与环境中的微生物共存。微生物的生存是以生物体为寄主的,而微生物的存在必然对农产品的自身质量产生影响,从而对配送活动的有效性产生影响。通过控制外界条件,抑制微生物的生存及发展,保证农产品安全、新鲜、营养充分、损耗数量最低的配送到顾客手中,实现农产品的高效配送。     

Returns to public sector plant breeding in the presence of spill‐ins and private goods: the case of bean research in Michigan

This article illustrates a methodology for assessing economic returns to a publicly funded breeding program in the presence of private sector investments, and spill‐ins from other contemporary public institutions and past research efforts. The approach consists of determining yield gains from bean improvement research; applying these yield gain estimates to measure benefits attributable to different institutional players and time periods; and then assessing the benefit‐cost ratios of investments in a bean improvement program since 1980 by Michigan State University (MSU). The results indicate that investments in MSU's bean breeding program have yielded benefits to costs ratio in the range of 0.7 to 2.2, depending on the attribution rule used to estimate the benefits. The estimated benefit/cost ratios reported in this study are lower‐bound estimates, as they do not account for potential benefits from area planted to MSU varieties outside of Michigan (spillover effects), which was 1.5 times greater than the area planted to MSU‐bred varieties within Michigan in the period 1998–2002. The implications of the increasingly privatized bean seed markets for the role of public sector research in bean improvement research are discussed.     

纤维风积沙土归一化特性分析

基于纤维风积沙土的不固结不排水三轴剪切试验,为实现应变硬化型纤维风积沙土应力—应变关系的归一化,基于应变硬化型典型的双曲线特征,提出了以固结围压作为归一化因子。通过以固结围压为归一化因子,对纤维风积沙土应力—应变特性进行归一化分析和比较表明,纤维风积沙土的应力-应变特性归一化程度更高,效果更好。同时,建立了应变硬化型纤维风积沙土应力—应变特性的归一化方程。     

The Optimal Timing of Evaluation of Genebank Accessions and the Effects of Biotechnology

The lack of ex ante evaluation of germplasm in genebanks has been the single most prevalent and long-standing complaint of plant breeders about the management of genebanks. Advances in biotechnology offer the possibility of faster, cheaper and more efficient evaluation methodologies. Will these new technologies favor ex post evaluation, as some expect, or will it lead to more ex ante evaluation? Will it also lead to earlier development of varieties with disease resistance traits in anticipation of actual infestations? Will the prospect of further advances in biotechnology favor delay of evaluation and development? This paper addresses these questions in the case of evaluation of germplasm for resistance to a disease.     

Stakeholder views on issues to consider when assessing the sustainability of genetically modified potato

The importance of assessing socio-economic and sustainability aspects of genetically modified (GM) crops is increasingly recognized by policy-makers, both within the EU and internationally. Nevertheless, experience has shown that it is challenging to assess and implement these aspects in actual decision-making processes. This paper argues that stakeholder engagement may provide valuable insights when developing frameworks for sustainability assessment of GM crops. We organized two stakeholder workshops with the aim to gather perspectives on the sustainability of cultivating late blight resistant (LBR) GM potato in Norway. Sixteen Norwegian stakeholders involved in potato production and in agriculture in general took part in the workshops. Here, we present and discuss the outcomes of this participatory approach. The stakeholders identified several conditions that an LBR GM potato ought to satisfy in order to contribute to sustainable development. These conditions concerned environmental and health safety aspects of cultivating LBR GM potato, potential for fungicide reductions, durability of the LBR GM potato plant's resistance, farmers' profitability and consumer acceptance. In addition, the stakeholders considered issues such as maintenance of a diversity of potato cultivars, transparency during product development and risk assessment processes, ownership and control and opportunity for independent risk research as important considerations in a sustainability assessment. While focusing on a specific application of agricultural biotechnology, we believe that these findings are useful contributions to the ongoing efforts to develop frameworks and guidelines for assessing sustainability and socio-economic considerations of GM crops in general.     

几种废弃物作添加料养殖黄粉虫的试验

试验分别用西瓜皮、香蕉皮、水浮莲与麦麸按不同比例混合养殖黄粉虫高龄幼虫．探讨不同处理对黄粉虫生长繁殖的影响。结果表明：添加50％比例西瓜皮、香蕉皮的配方养殖黄粉虫总体效果最好。     

对农民增收的几点试想

伴随农业发展日趋重要，农业增肥已成为增加农民收入的一个有效途径，通过有效利用中心城区的大粪，能够为深山边远地区的乡村增加农作物所需养分；此外，根据不同蔬菜对养分的吸收不同，科学且合理地换种蔬菜，可充分利用土壤中各层次的养分，这也能够进一步提高农作物产量，为农民增加收入。     

“环境工程微生物学”双语教学分析

环境工程微生物学课程采用双语教学,可促进师生了解国外教学内容,提高英语水平。在教学中应增强学生学习的自信心,可另编课程词汇表发给学生并采用“讨论”教学法,提高教学效果。