交易成本、生产成本与农业生产环节外包——基于农地禀赋效应调节视角

农业生产环节外包是实现农业规模经济的重要途径。依据山东、河南2省6市小麦种植户调研数据,运用结构方程模型实证分析农户农地禀赋效应调节视角下外包交易成本、农业隐性生产成本对农业生产环节外包程度的影响。研究结论如下：①市场容量、资产专用性、交易不确定性和交易频率是外包交易成本的重要表现。市场容量的扩大可以降低单位面积外包交易成本,促进农业生产环节外包程度的提升;资产专用性、交易不确定性和交易频率的增强会增加外包交易成本,阻碍农业生产环节外包程度的提升。②农业生产经营风险和农业劳动机会成本是隐性生产成本的重要体现,二者均会促进农业生产环节外包程度的提升。③外包交易成本、隐性生产成本对农业生产环节外包程度的影响会受到农户农地禀赋效应的调节。在外包交易成本方面,农户农地禀赋效应会削弱市场容量对农业生产环节外包程度的促进作用,增强资产专用性和交易不确定性对农业生产环节外包程度的阻碍作用;在隐性生产成本方面,农户农地禀赋效应会增强农业生产经营风险对农业生产环节外包程度的促进作用,削弱农业劳动机会成本对农业生产环节外包程度的促进作用。④农业外包市场并不仅是一个简单的交易市场,而且是一个具有身份特征的情感市场。培育农业外包市场,需充分考虑和尊重农户的农地禀赋效应。     

资源和市场双重约束下的中国农村发展

我国“三农”问题最大的困境是面临着资源和市场的双重约束,在这个最大的国情面前,现实的选择是：扩大非农就业,保护耕地和土地肥力,促进农业可持续发展,改善农村社会服务环境等。     

运动员补糖、支链氨基酸和乳清蛋白的临床应用观察

目的：观察补充糖饮料、支链氨基酸和乳清蛋白等能量物质对阶段性大运动量训练维持或提高运动员身体机能和疲劳恢复的影响。方法：根据冬训阶段性训练计划安排,对10名散打运动员在30d的体能训练阶段,按营养补充方案进行能量补充,观察能量补充对机体无氧能力的输出总功、最大功率、疲劳指数,有氧能力的拉桨时间、功率、桨频,生化指标血乳酸（LA）尿素氮（BUN）、血糖（GL）、肌酸激酶（CK）的影响,另选10名队友作空白组,进行自身前后对照和空白对照。结果：观察组经过阶段性能量补充前后运动员的输出总功、最大功率、疲劳指数和桨频均显著提高（P〈0．01）,与空白组相比也有明显提高（P〈0．05）,训练课后血糖水平也明显提高（P〈0．05）,补充支链氨基酸和乳清蛋白后血BUN的恢复与空白组比有极显著好转（P〈0．001）。结论：训练期间补充糖、支链氨基酸和乳清蛋白等能量物质,能明显改善运动员的有氧运动能力和无氧运动能力,明显延缓运动性疲劳的发生,加速运动性疲劳恢复的作用。     

蔗糖业供应链风险因素的识别与评价

风险因素的识别和评价是风险研究的重要阶段.借鉴国内外关于供应链风险影响因素的识别方法,根据蔗糖业供应链的特点,提出了影响蔗糖业供应链的风险因素.最后运用灰色关联法建立蔗糖业供应链风险因素评价模型,并通过实例证明此模型的可行性.     

滁菊对淹水胁迫的形态及生理响应

为研究滁菊对淹水胁迫的响应进行本实验.选取滁菊进行淹水处理,观察其外观形态变化,测定了淹水期间滁菊的各项生理指标变化.结果表明：随淹水时间的延长,滁菊叶片逐渐萎蔫发黄、干枯,最后出现植株死亡现象.电导率、可溶性糖含量、脯氨酸含量呈现先上升后下降的趋势且基本高于对照值,叶绿素整体呈现下降趋势且低于对照,变化程度反映了滁菊受淹水胁迫的伤害程度.     

Local Farmers' Organisations: A Space for Peer-to-Peer Learning? The Case of Milk Collection Cooperatives in Morocco

Abstract

Purpose: The study investigated to what extent local farmers' organisations are spaces where farmers discuss, learn and innovate.

Design/methodology/approach: Two milk collection cooperatives in Morocco were studied. The study analysed the discussion networks, their impacts on farmers' knowledge and innovation, and the performance of collective action at cooperative level.

Findings: In both cooperatives, only two-thirds of the farmers regularly discussed dairy practices with other farmers. Most leaders of one cooperative were acknowledged to be experienced farmers and played key roles as advisors on dairy farming. Farmers' involvement in dialogue networks in this cooperative improved their capacity to innovate in dairy farming, even though their knowledge on some issues related to cattle, health and nutrition was not improved. In the other cooperative, experienced farmers did not share their knowledge and farmers' involvement in dialogue networks at cooperative level had no impact on their knowledge and practices. Dialogue networks and collective action were found to influence each other, since in the first cooperative, collective action was considered by members to be efficient, whereas in the second collective action was limited to milk collection.

Practical implications: The study enabled identification of stumbling blocks which need to be addressed to get local farmers’ organisations involved in farmer capacity-building.

Originality/value: While the importance of local discussion networks for knowledge creation and diffusion is widely acknowledged, taking such networks into account in farmers' capacity-building programmes in developing countries has been hindered by their informality. Combining the analysis of dialogue networks and collective action proved to be a productive way to assess the potentialities of working with farmers' organisations with the aim of establishing a connection with local discussion networks.     

Learning about agriculture within the framework of education for sustainability

The last two decades have seen increased threats to agricultural landscapes in Israel. Key factors include population growth, strong pressure from construction entrepreneurs and possible profit to land owners who benefit from a legal conversion of farmland into lands allocated for construction. While each Israeli elementary school student used to participate in agriculture classes, most students no longer experience this and their overall exposure to farming in schools is limited. The main objective of this study was to explore the ways farming is presented and addressed in the national curriculum and in learning materials. Additionally, it examines the actual status of teaching about agriculture and explores how farming is addressed in teachers' pre‐service programmes. The main finding is that very little teaching about agriculture and land management is carried out at most school levels. Only one college prepares agriculture teachers and science education programmes rarely address agriculture as a course topic. The paper also outlines an education for sustainability framework for integrating science, agriculture and environmental education.     

对延安市退耕还林(草)成果巩固的思考

退耕还林是促进人与自然和谐发展、改善生态环境、构建可持续发展平台的重大举措,是解决生态环境恶化问题的重要途径之一。延安作为率先实施退耕还林的地区,经过10年的退耕还林、封山禁牧和封山育林,有效改善了生态环境,促进了农业结构的调整,改进农村生产方式、帮助农民脱贫致富、优化农村产业结构、对农村经济发展具有十分重大现实和深远意义。     

曹魏屯田制略析

屯田制是中国传统社会用军事管理方式将劳动者束缚于国有土地上的一项特殊的土地制度。曹魏在特殊的历史时期,实行了这项特殊的制度,其军事编制的组织形式,自成体系的管理体制体现了效率与效益的有机结合;国民两便的分配机制和屯田所带动的水利基础设施建设,都具有创新的成分。     

中国古代农牧冲突与民族融合的阶段性

中国古代的农牧冲突与民族融合的全过程可以概要地划分为六个阶段:炎黄周秦时期的民族融合、春秋战国时期的民族融合、秦汉时期的民族融合、魏晋南北朝时期的民族融合、隋唐时期的民族融合、宋元明清时期的民族融合.这六个阶段农牧冲突与民族融合的特点各异,整体上呈现出由比较平衡到打破平衡的趋向.