加强水利工程造价工作提高国债项目投资效益

根据国债资金投入数量与项目工程造价之间的关系以及我国水利工程项目的特点,提出应树立水利工程全面造价管理的思想。阐述工程设计阶段进行优化设计和造价控制的重要性,并对工程建设概预算定额及计价依据进行分析。     

自然资源节约集约利用内涵与评价指标体系研究

自然资源节约集约利用内涵与评价体系研究是自然资源节约集约利用制度建设的重要内容之一。本轮国家机构改革之前,基于不同历史时期发展战略和部门管理职责不同,土地、矿藏、河流、森林、草原、海洋、湿地等自然资源分属不同行政机构管理,自然资源节约集约利用缺乏统一的评价维度和评价体系。这在一定程度上制约着自然资源节约集约利用状况的整体衡量以及不同区域间自然资源节约集约利用状况的横向比较。本研究重点围绕自然资源概念、自然资源节约集约利用内涵、自然资源节约集约利用评价体系开展研究,以期为开展区域性自然资源节约集约利用评价提供支撑。     

Market access by smallholder farmers in Malawi: implications for technology adoption,agricultural productivity and crop income

In Malawi, maize is the major crop and food staple. Given limited off-farm employment opportunities, much-needed increases in household income for improving food security must come from gains in agricultural productivity through better technology and more profitable crops. In the past, hybrid maize and more recently, tobacco were promoted by policy for increasing smallholder income. An analysis of determinants of adoption of these two crops and related income effects is presented. Apart from factor endowment and exposure to agroecological risks, differences in the household's access to financial and commodity markets significantly influence its cropping shares and farm income.     

A Comparative Value Chain Analysis of Smallholder Burley Tobacco Production in Malawi – 2003/4 and 2009/10

Smallholders grow the majority of Malawi's main export crop – burley tobacco. We analyse this value chain segment for the 2003/4 and 2009/10 seasons. The comparison shows smallholder profits in 2003/4 were limited by two main factors: a cartel of leaf merchants at auction and inefficient marketing arrangements. In 2009/10, there was greater competition at auction, improvements in marketing, tighter state regulation (including minimum prices) and much more contract farming. The paper concludes by reflecting on aspects of the political economy of the tobacco industry at national and global levels.     

Urban proximity,demand for land and land shadow prices in Malawi

We assess the spatial and intertemporal variation in farmland prices using per hectare minimum willingness to accept (WTA) sales and rental (shadow) prices in Malawi. We use three rounds of nationally representative farm household panel data from the Living Standards Measurement Surveys (LSMS), collected in 2010, 2013 and 2016. The sample is split in quintiles based on distance from the nearest major city, building on the land valuation and transaction cost theory, and agrarian political economy perspectives on global and national land transactions. Generally, farmland shadow prices decrease with distance from urban areas. However, farmland shadow sales prices increased more sharply between 2010 and 2013 in rural areas (+100 % vs +30 % in urban proximity). The results indicate that the sharp increase in demand for large-scale land transfers following the sharp increase in energy and food prices also affected rural smallholders’ land valuation, even in remote rural areas of Malawi. Conversely, by 2016 land shadow sales prices were again, like in 2010, about three times as high in areas near urban centres compared to remote rural areas. Even though sales prices declined in remote rural areas from 2013 to 2016, rental prices remained high. Using farm household-level population pressure variable, we show that local population pressure is a driver of farmland shadow prices, indicating land scarcity challenges, growing demand for land, and poorly developed land markets. With increasing land scarcity, land markets are becoming more important and need to be factored in when formulating development policies that aim to improve access to land in both peri-urban and rural areas.     

Production Risks and Food Security under Alternative Technology Choices in Malawi: Application of a Multinomial Endogenous Switching Regression

Employing nationally representative data, we investigate the impact of Sustainable Intensification Practices (SIPs) on farm households’ food security, downside risk and the cost of risk in Malawi. The analysis relies on a flexible moment‐based specification of a stochastic production function in a multinomial endogenous switching regression framework to correct for the selection bias stemming both from observed and unobserved heterogeneity. A quantile moment approach is used to estimate the cost of risk. After controlling for the effects of unobserved heterogeneity and several observable variables on maize production and downside risk functions, estimation results show that the adoption of SIPs increases food security and reduces downside risk exposure and the cost of risk. We estimate greater food security and larger reduction in downside risk from simultaneous adoption of both crop diversification (maize–legume intercropping and rotations) and minimum tillage, suggesting that there are complementary benefits from these practices. We find most of the cost of risk comes from exposure to downside risk. Our findings imply that in dealing with production risks development agents should encourage the adoption of agronomic and resource‐management practices along with other risk mitigation and food security improving strategies.     

Effect of changes in population density and crop productivity on farm households in Malawi

This study examines the ex‐ante farm‐household effects of changes in family size, yield potential, and yield gaps using a farm‐household simulation model that reflects the economic and biophysical conditions of central Malawi. Disparities between growth in human population and crop yields present challenges for farm‐household crop production and income in sub‐Saharan Africa. We focus on the effect of growth in yield potential and a more efficient use of livestock manure as approaches to improving crop production and incomes in the face of looming population pressures. Our results suggest that, even without considering climate change, expected changes in population density and crop prices in 2050 mean that per person crop production and income may fall by 21% compared to 2013 values if yield potential and yield gaps remain constant. However, per person crop production and income could increase in 2050 by 8% compared to 2013 values if (1) growth rates of yield potential rise for maize by 1.13% each year and for legumes rise by at least 0.4% each year, and (2) farmers use livestock manure more efficiently. Our foresight approach to considering crop production at the farm‐household scale supplements macro‐scale analyses of the production dimension of food security.     

Improving recommendations resulting from on-farm research: agroforestry,risk, profitability and vulnerability in southern Malawi

Leguminous agroforestry (AF) species have been investigated and promoted in Malawi as a means to improve soil quality and maize (Zea mays) yields. Our objective was to determine whether AF systems' recommendations that solely consider impacts on average maize yields differ from those that include an analysis of production risk, profitability among different wealth groups and socioeconomic vulnerability. Employing participatory quantitative and qualitative on-farm research techniques, we investigated three AF-based maize/legume relay-cropping practices in southern Malawi. The perennial legumes included Sesbania sesban, Tephrosia vogelii and Cajanus cajan (pigeonpea). We found that AF species recommendations did diverge from those based solely on maximizing maize yields when incorporating risk, profitability and socioeconomic vulnerability as additional variables. For instance, the highest yielding system (the S. sesban/maize relay crop) was never recommended for the most vulnerable farmers based on the vulnerability analysis, and the cropping systems were often more profitable for the least vulnerable farmers than they were for the most vulnerable farmers. Cropping system recommendations based solely on obtaining the highest average maize yields would also have generally overlooked the economic and nutritional importance of pigeonpea, and the difficulty for the most vulnerable farmers to profit from fertilizers, potentially placing these farmers at greater risk.     

Evaluating irrigation investments in Malawi: economy‐wide impacts under uncertainty and labor constraints

Irrigation expansion is critical to increase crop yields and mitigate effects from climate change in Sub‐Saharan Africa, but the low profitability has led to little irrigation investments in the region so far. Using an integrated modeling framework, we simultaneously evaluate the returns to irrigation arising from both economic and biophysical impact channels to understand what determines the profitability of irrigation in Malawi. Our results confirm that the returns to irrigation cannot cover the costs in Malawi. While labor‐intensive irrigation expansion leads to unfavorable structural change in the short‐run, the profitability hinges on low irrigated yields that fall far from expectations due to insufficient input use and crop management techniques. On the other hand, we find that the nonmonetary benefits of irrigation regarding higher food security, lower poverty, and reduced vulnerability to climate change make investments in irrigation worthwhile to improve the livelihoods of smallholders.     

试论高校自然博物馆的标本收集

本文以成都理工学院博物馆的标本收集为例,阐述了高校博物馆标本收集对博物馆的陈列展示,科学研究及持续发展的重要性和该馆猎取标本的途径。     

Impact of treadle pump irrigation technology on smallholder poverty and food security in Malawi: a case study of Blantyre and Mchinji districts

The Malawi Government has intensified the use of treadle pump irrigation technology in an attempt to increase agricultural production and also to enrich the livelihoods of resource-poor farmers. As a result, the treadle pump is gaining in popularity among smallholder farmers throughout the country. This study was conducted in the districts of Blantyre in the Southern Region and Mchinji in the Central Region of Malawi. A total of 50 treadle pump and 50 non-treadle pump farmers were interviewed in each district to assess the impact of treadle pump irrigation technology with regard to food security and poverty. Gross margin analysis showed that adopters of the technology had higher net farm incomes per hectare (NFIs/ha) than non-adopters per year. In Blantyre, NFI/ha value for adopters was MK122,855 (US$1007) compared with MK15,987 (US$131) for non-adopters under irrigation conditions. Similar results were found in Mchinji with MK51,858 (US$425) and MK16,090 (US$132) for adopters and non-adopters, respectively. Likewise, under rain-fed conditions, adopters had higher NFIs/ha than non-adopters: in Blantyre, the respective NFIs were MK19,497 (US$152) and MK3344 (US$27), whereas in Mchinji the respective values were MK16,896 (US$138) and MK10,084 (US$83). Furthermore, the well-being measurements and analyses of poverty revealed a higher poverty level among non-adopters compared with adopters. The former also had a greater relative risk of falling into deeper poverty than the latter. Transition matrices depicting movement in and out of poverty showed that from 2004 to 2005, some poor adopters moved out of poverty while some non-adopters dropped from being non-poor to poor. No adopter moved from non-poor to poor. From the results, it is concluded that the Government of Malawi should be urged to increase the availability of this kind of technology to the market at a reduced cost by offering tax incentives to local manufacturers and by using an input voucher system to subsidize qualified poor smallholder farmers.     

Gender and agricultural productivity: implications of the Farm Input Subsidy Program in Malawi

Alleviating gender differences in agricultural productivity is vital for poverty reduction. While numerous studies suggest that gender differences in agricultural productivity are a result of female farmers having limited access to resources, few studies investigate the role of agricultural interventions in alleviating the constraints to input use and subsequently the gender gap in productivity. This study investigates whether there are gendered gains in agricultural productivity from participating in an input subsidy program and if these gains help reduce the gender gap. Using nationally representative data that is disaggregated at the plot level, this study analyzes the large‐scale voucher‐based Farm Input Subsidy Program in Malawi. Focusing on the total value of output per hectare, relationships are identified using weighted estimators, where the weights are constructed from propensity scores, and spatial fixed effects, to address the unobservable factors that may confound the relationship between program participation and productivity. The findings suggest that participation in the program improves agricultural productivity for both male and female farmers but it does not provide disproportionate help to female famers to overcome gender disparities in agricultural productivity. This suggests that female farmers face additional constraints to productivity apart from nonlabor input use.     

An in-depth examination of maize yield response to fertilizer in Central Malawi reveals low profits and too many weeds

We examine the productivity of fertilizer used on maize in Central Malawi using field-level panel data from over 1,200 observations on more than 500 fields over 4 harvest years. There are several novel aspects of this analysis compared to other on-farm fertilizer efficiency studies, including (a) precise and accurate yield measurement using crop cuts, (b) estimating the impact of timely weeding, (c) the use of data on multiple soil characteristics from a panel of soil samples, and (d) the ability to control for field-level fixed effects by tracking the same land over time. We find critical ecological and management threshold effects on fertilizer effectiveness at 0.94% soil carbon content, 57–58% sandiness, and weeding within 4 weeks of planting. Overall, we estimate lower yield response to fertilizer than reported in earlier studies: 2.6 maize kg/N kg under ideal circumstances, and statistically nil under many other conditions. We discuss the implications of our findings for farmers, policymakers, and researchers.     

关于矿产资源税费制度改革的探讨

文章根据国内外学者的矿产资源税费理论观点以及目前我国矿产资源税费征收在实践操作过程中存在的问题,提出矿产资源补偿费在征收上应体现级差地租;矿产资源税费的制定要符合国家政策,并随着国家政策和经济形势的变化而调整;同时,对不同矿种的矿产资源补偿费费率的制定提出了建议。     

山西省天然林资源保护工程建设实践与思考

对山西省天然林资源保护工程5年来的建设实践进行了总结分析,指出工程实施中存在静态方案与动态管理矛盾突出、国有林场经济困难、森林经营工作滞后、林牧矛盾突出等问题。提出“十一五”期间需完善调整工程建设实施方案,加强科学经营,建立健全公益型事业保障体制,促进后续产业发展等对策。     

“双评价”分析及其在自然资源资产审计中的应用——以云南省蒙自市为例

以云南省蒙自市为例,根据土地、水、生态等资源要素的分析、赋权、叠加,计算出蒙自市资源环境承载力评价结果,根据对地形条件、区位条件以及限制条件各因素的整理和加权计算,得出蒙自市国土空间开发适宜性评价结果。对"双评价"研究结果应用到自然资源资产审计工作进行了分析,结果表明:(1)蒙自市资源环境承载力和国土开发适宜性高值区域主要重合在蒙自坝区南部和西北部,在进行自然资源资产审计工作的时候应重点关注地方新建、扩建开发区(园区)、城市新区情况,以及区域内林地资源变化情况和水资源保护与污染防治情况;(2)资源环境承载力和空间适宜性评价能够对领导干部在任期间对于自然资源资产和生态环境质量监管与分配的合理性进行客观、科学的评价,评价结果有助于审计工作组在正式建立审计方案前了解各类自然资源资产的现状,发现存在问题并确定重点审计区域,形成有力的审计证据;(3)"双评价"结果对自然资源资产审计工作具有导向作用,为自然资源审计工作提供了新思路。     

Perspectives on Natural Resources in the Global Economy: Polity Series Review

Polity's ‘Resources’ series is a set of scholarly books, each of them dealing with a single resource or resource‐based commodity from a generally global or international perspective. As of this writing, nine books have been published in the series, six of which I review here. The series is a welcome contribution to interdisciplinary and overall critical perspectives on the social and environmental dimensions and implications of the international appropriation, production and exchange of natural resources. While there is no clear disciplinary bent or theoretical foundation running across the volumes, together the books develop a transnational perspective, stressing the linkages between specific sites of appropriation and production, on the one hand, and broader political economic networks of processing, finance, coordination, commercial distribution and social regulation, on the other. The books should serve as valuable references to researchers in academic, government and non‐government institutional settings, but should also prove valuable for undergraduate teaching on contemporary natural resource industries and their social regulation.     

自然资源物权与民事物权之比较--兼谈自然资源物权制度的建构模式

学术界从民事权利的角度研究自然资源物权,忽略了自然资源的生态与社会属性,不利于自然资源的保护与可持续性利用。为此,运用比较分析的方法,严格区分了自然资源物权与民事物权的权利性质、权利客体、权利内容与权利的处分限制,认为自然资源物权是社会权,而不同于民事物权的私权属性。在此基础上,经分析批判现行自然资源物权制度设计模式后,提出了构建政府干预型自然资源物权制度的一般模式——政府主导的一级市场与政府介入的二级市场,希望有益于自然资源可持续发展战略的实现。     

Farm and farmer characteristics and off‐farm work: evidence from Algeria

Off‐farm work is a widespread, two‐edged, phenomenon that can help both the survival and the demise of small‐ and medium‐sized agricultural exploitations. Given the prevalence of poverty in rural areas, nonfarm income has been credited with helping farmers to survive. But the observed shrinking of rural areas has also raised the question of whether off‐farm work is pulling farmers permanently away from farming. This paper explores the impact of farmer characteristics on the decision to work off‐farm in developing countries where this phenomenon has been largely neglected. A review of theory and prior empirical work suggests four main hypotheses which we test empirically. The results suggest that while some farmer characteristics appear to be universal, others appear to be country‐ or culture‐specific.