水流环境与吴淞江流域的田制(10～15世纪)

昊淞江流域10-15世纪的圩田系统基本上处于一种大圩系统下.这种系统的功能是狭水以提高塘浦的水位,以此注水吴淞江,以清压浑,防止浑潮淤淀.由于围垦和运河堤的兴建,宋中叶以后吴淞江逐步淤塞,单注吴淞江的出水格局到15世纪发生了质的变化.塘浦提高水位的功能不再重视,大圩不再利于新形成的众浦排水格局的功能发挥,小圩代替了大圩.水流环境的改变导致了圩田制度的变化.     

The politics of the forest frontier: Negotiating between conservation,development, and indigenous rights in Cross River State,Nigeria

Nigeria's once thriving plantation economy has suffered under decades of state neglect and political and civil turmoil. Since Nigeria's return to civilian rule in 1999, in a bid to modernize its ailing agricultural economy, most of its defunct plantations were privatized and large new areas of land were allocated to ‘high-capacity’ agricultural investors. This paper explores the local tensions associated with this policy shift in Cross River State, which, due to its favorable agro-ecological conditions and investment climate, has become one of Nigeria's premier agricultural investment destinations. It shows how the state's increasing reliance on the private sector as an impetus for rural transformation is, paradoxically, crowding out smallholder production systems and creating new avenues for rent capture by political and customary elites. Moreover, as Nigeria's most biodiverse and forested state, the rapid expansion of the agricultural frontier into forest buffer zones is threatening to undermine many of the state's conservation initiatives and valuable common pool resources. The paper goes on to explain why and how private sector interests in Cross River State are increasingly being prioritized over natural resource protection, indigenous rights over the commons, and smallholder production systems.     

The positive impacts of irrigation schedules on rice yield and water consumption: synergies in Jilin Province,Northeast China

Food and water security in China are inextricably linked to the development of regional economy, especially for regions with temporary or sustained water shortage such as Jilin Province in northeast China. Water-saving irrigation practices are therefore urgently sought to maintain sustainable growth in grain production. To improve knowledge of the effect of irrigation water level on rice yield and water-use efficiency (WUE), we conducted a field experimental study over two growing seasons in central Jilin. The irrigation experiment included four schedules: (1) traditional irrigation (CK), (2) shallow wet irrigation (T1), (3) intermittent irrigation (T2), and (4) controlled irrigation (T3). Soil test pits were used to estimate evapotranspiration and seepage. The study showed that T3 had the highest WUE (1.64?kg/m³). However, the highest rice yield was found in T1 (9867?kg/ha¹) that achieved the second highest WUE (1.63?kg/m³). Compared with CK, T1 and T3 consumed 7.3% and 36.1% less water, respectively. If adopted at the operational scale, these two schedules could help reduce the pressure of local surface water supply and the production costs significantly. The results gained from this study could also have relevant implication in developing an effective irrigation management for other high-latitude regions.     

The impact of information on landowners’ participation in voluntary conservation programs - Theoretical considerations and empirical evidence from an agri-environment program in Saxony, Germany

The voluntary nature of programs that pay landowners for conservation measures raises the question of what factors favor participation in such programs. This article focuses on the controversial issue of the impact of information on the participation decision. We develop a straightforward model to analyze how information affects this decision, and empirically estimate the impact of information, as well as other factors, on participation in a conservation program in Saxony, Germany. We find in our theoretical analysis that information measures may affect program participation either in a positive or negative way, whereas our estimation results indicate that the influence of the diverse information measures that have been relevant in our empirical analysis is weak. We argue, however, that information measures may nonetheless be warranted, as they allow for better informed participation decisions, thus contributing to a more optimal selection of program participants.     

Harnessing sustainability,resilience and productivity through conservation agriculture: the case of likoti in Lesotho

Subsistence farmers in Lesotho have been able to boost agricultural yields and increase food production by adopting conservation agriculture. The practice, locally known as likoti, also contributes to combating soil erosion and to enhancing fertility. The socio-economic and environmental benefits help poor households to rehabilitate and strengthen their livelihood capital base and ultimately help rural communities to build system resilience in the face of widespread poverty and increasing vulnerability that affect the country. This paper discusses the major advantages associated with the spread of likoti. By drawing on primary data collected by FAO-Lesotho, it enquires into the determinants of adoption, thereby highlighting constraints and options for future up-scaling. The results show that attending appropriate training is a crucial prerequisite for the correct adoption of likoti. However, training is more effective when trainers pursue true participation and when social capital among farmers is stronger. Further important determinants of adoption are the level of education and the economic incentives provided to vulnerable households. Stronger policy and institutional support in all these areas would thus help address the cultural and resource constraints that limit the full potential of likoti to be harnessed and ultimately hinder its further spread throughout the country.     

Violent visions of an ownership society: The land administration project in Petén, Guatemala

This article is a case study of phase one of the World Bank's land administration project in Petén, Guatemala. Although the project's stated aims are merely to formalize an existing set of individual landed property rights, this development intervention necessarily changes the property regime, thereby changing underlying relationships that land as property embodies. Impact evaluations conducted by development economists may fail to substantively address displacement and violence that occur as a short-term effect of the project and long-term disparate impacts of the project that may exacerbate existing inequalities. The case of Petén also highlights the possibility for violent enforcement of property boundaries, where conflict surges between the disenfranchised and those who gain power under the new property regime.     

中国粮食非关税贸易措施的实证研究:1996-2001年

为了能为政府制定粮食政策提供更加科学的依据,本文首先给出了适用于中国粮食非关税贸易措施的计算方法。在验证中国粮食供给曲线垂直和测算中国粮食需求价格弹性的基础上,并根据中国的实际情况对测算方法进行适当调整后,从定量的角度测算了1996—2001年中国粮食非关税贸易措施的经济福利影响,进而提出入世后中国粮食政策改革的重点。     

The impact of water conservation and intensification technologies: empirical evidence for rice farmers in Ghana

This study employs the propensity score matching model to examine the impact of the adoption of water conservation and intensification technologies on farm output and income among small-scale lowland rice farmers in the Northern Region of Ghana. The matching was conducted based on the Mahalanobis distance combined with the propensity score. Balancing tests by checking the mean standardized absolute bias in the matched sample were conducted as well as a sensitivity analysis was conducted to check for hidden bias due to unobservable selection. The empirical results show a positive and significant impact of the adoption of bunds technology on input demand as well as a positive but insignificant impact on output supply and net returns. Adopters of the dibbling technology were found to have higher output supply, whereas no statistically significant difference was found between the incomes of adopters and nonadopters of dibbling seed method. The results, however, reveal a positive and significant effect on output and net returns when the dibbling method is combined with intensified weeding. The estimates were found to be relatively insensitive to hidden bias.     

The Closing Frontier: Agrarian Change, Immigrants and the 'Squatter Menace' in Gokwe, 1980-1990s

‘Squatting’ in the communal areas of Zimbabwe has been largely ignored in the literature because it is assumed that it does not exist in a ‘communal’ land tenure system. This article argues that ‘squatting’ in Gokwe villages has become a common strategy by landless immigrants to access land. Gokwe has been a frontier region for many immigrants in search of land since the 1950s with intense pressure on land by the 1990s. As the frontier closed, the question of citizenship in Gokwe villages became more signi?cant than ever before. Those who are not formally registered as residents are de?ned by local government authorities and established villagers as ‘squatters’ who should be evicted. The article traces how local authorities and established villagers have responded to what they perceive as the ‘squatter menace’. It further examines the means used by ‘squatters’ to lay claims to land and to defend those claims in Gokwe villages.     

Colonialism and conservation: Commercialisation of forests and decline of tribals in Madras Presidency, 1882–1947

This article attempts to analyse the colonial forest policy and its impact on the environment and tribals in Madras Presidency during the post-Forest Act period (1882–1947). During this period, the colonial regime has actively encouraged commercialisation of forest resources while several restrictions were clamped up on the tribals and other forest users. Here it is argued that the initiatives of the state towards conservation were primarily intended to curtail the access enjoyed by tribals and other forest users to facilitate commercial exploitation. Plunder of forest wealth continued unhindered in a systematic manner leading to denudation of vast stretches of green cover and a drastic decline in the living conditions of the tribals in Madras Presidency.     

城乡差距的本质、多面性与政策含义

本文采用两部门模型框架探讨了城乡差距的本质、成因、多面性及其政策含义。在中国经济转型过程中，城乡差距并没有随着经济增长而缩小．反而越过了改革初始的水平。城乡差距的本质是资源配置扭曲、收入分配倾斜与部门间技术进步不平衡三者共同作用的结果。缩小中国城乡差距的政策空间很大。未来改革的方向、力度和政策效率对其走势将起到决定性的影响。     

农业政策理论与实践研讨会(实践层面)综述

20 0 4年 1 1月 7— 8日 ,由中国农业大学人文与发展学院、河南农业大学经贸学院、农业经济问题杂志社共同举办的“农业政策理论与实践研讨会(实践层面 )”在河南农业大学学术交流中心召开。此次研讨会的主题是“粮食直补政策的效应”。来自全国各地的 5 0多名代表参加了此次研讨会 ,其中有长期从事粮食经济和农业政策研究的专家、学者 ,有来自吉林、安徽、湖南、河南等 4个粮食主产省的各级农业行政管理部门的领导 ,也有上述 4个省的农村基层干部和种粮大户及普通农户代表。先后有 2 0多位代表基于调研做了会议发言 ,就2 0 0 4年粮食直补政…     

我国农业政策实施效果评价--农业政策理论与实践研讨会(理论层面)综述

从 2 0 0 4年初中央 1号文件下发以后 ,中央一系列加强农业、增加农民收入、稳定农村的宏观政策 ,调动了广大农民的生产积极性。粮食增产、农民增收取得了明显的成效。农业政策实施效果及农村发展新情况是理论工作者和实践工作者共同关心的焦点。为此 ,2 0 0 4年 1 2月 4日由中国农业大学人文与农村发展学院、河南农业大学经贸学院和农业经济问题杂志社在北京共同举办了“农业政策理论与实践研讨会 (理论层面 )” ,出席会议的有来自国务院研究室、国务院发展研究中心、农业部、国家发改委、中央政策研究室农业部农村固定观察点办公室、中国…