基于地块单元的冬小麦遥感估产方法研究

[目的]以高分时序遥感影像为基础数据源,结合土地承包经营权地块数据,对冬小麦遥感估产方法及其精度进行研究和分析。[方法]文章以河南省兰考县为研究区,采用2019年4―5月份的GF-1C和GF-6 2 m PMS遥感影像提取了研究区冬小麦种植空间分布,并在地块单元控制下对冬小麦种植面积进行了修正和精度验证。其最优提取结果的修正阈值为0.93,地块单元内冬小麦总体分类精度为95.66%,Kappa系数为0.89。利用3月7日至5月20日6期GF-1 WFV遥感影像序列NDVI和RVI与冬小麦种植地块单元数据进行空间统计,得出各冬小麦种植地块单元内NDVI和RVI均值,通过分析冬小麦测产地块单元内均值植被指数与产量间的敏感性,提出一种组合均值植被指数的冬小麦遥感估产模型构建方法,通过交叉验证法对不同的估产线性回归模型进行精度评价。[结果]由4个均值植被指数组合变量的多元线性回归模型为最佳,决定系数为0.922 0,预测误差为40.96 g/m~2,预测精度为93.13%。通过该模型得出兰考县冬小麦平均产量为6 047.25 kg/hm~2,较2017年河南省统计年鉴研究区冬小麦平均单产6 001 kg/hm~2有所提高,土地承包经营权地块内和地块外冬小麦总产量分别为2.76亿kg和4 650万kg。[结论]该方法实现了冬小麦估产结果以像元为单位向以地块单元为单位的转变,解决了模型构建时光谱信息与实测产量间对应问题,为利用国产高分卫星进行县域地块尺度遥感单产精准化估算提供了方法支撑。     

Farmer Compensation and its Consequences for Environmental Benefit Provision in the Higher Level Stewardship Scheme

The Environmental Stewardship Scheme (ESS) provides payments to farmers for the provision of environmental services based on forgone agricultural income. Consequently, farmers with a relatively low opportunity cost of agricultural land will be particularly attracted to apply for entry into the ESS within a given payment region. This article tests whether there exists a significant relationship between Higher Level Stewardship (HLS) Scheme entry and agricultural yields. Empirically, HLS participation is found to be negatively related to cereal yields at the farm level. This could be associated with ‘auspicious selection’ of land into the Scheme, with greater ‘value for money’ provided by the higher entry of land with lower agricultural forgone income but higher environmental benefit within the region.     

A case study of land reform and coastal land transformation in southern Sonora, Mexico

This paper examines the coastal ejido (collectives of peasant landholders) sector's response to the 1992 amendment to Article 27 of Mexico's Constitution, which for the first time legalized the sale and rental of ejido lands. Our analysis is based on a case study of southern Sonora, Mexico. The results indicate a shift in land tenure from the ejido to the private sector and a corresponding conversion of coastal lands to shrimp aquaculture ponds. Our analysis suggests these land-tenure and land-use changes, and the implications of these changes for the coastal ejido sector, vary depending on the historical, geographic and socio-economic characteristics of the ejido communities.     

荆芥生态适宜性区划及挥发油品质的研究

[目的]荆芥作为解表药为我国临床常用的药材,在新型冠状病毒的治疗过程中有应用,目前栽培资源较多。研究划分荆芥在我国的适宜生长区,并对不同产地药材的挥发油进行分析,从而为种植环境的选择及药材的质量控制提供依据。[方法]文章通过生态适宜性区划研究,划分荆芥的最适宜区、较适宜区、不适宜区,利用气相色谱-质谱联用技术（GC-MS）分析不同产地荆芥及荆芥穗的挥发油成分,通过正交偏最小二乘法判别分析（OPLS-DA）筛选差异化合物,并对薄荷酮、胡薄荷酮、柠檬烯等7个主要挥发性成分进行含量测定,统计不同产地荆芥及荆芥穗挥发性成分的差异。[结果]荆芥在我国的最适宜区主要为中部地区,包括山东、河北南部、安徽北部等地,青海、西藏地区不适宜荆芥的种植。各产地间荆芥、荆芥穗的挥发油成分及含量有差异。[结论]荆芥穗挥发油含量高于荆芥,因此荆芥穗品质优于荆芥。河北、安徽、山东为荆芥的最适宜种植区,山东、安徽产荆芥质量优,河北产荆芥穗质量优。生境适宜度与挥发油品质研究结果一致。     

Modernizing wholesalers and guava farmers in Mexico

This article focuses on the rapid development of the “modernizing wholesale” channel, with a study of guava traders and farmers in Mexico. This adds to a literature on modernization of food markets that has focused primarily on exports, supermarkets, and large processors and addressed less wholesale in general and rarely modernizing wholesale per se. We find that participation in the modernizing wholesale channel, relative to the traditional broker channel, requires greater land, regional, and nonland assets, as well as confers a premium controlling for quality, and spurs employment in harvesting and handling locally.     

Do Community Supported Agriculture programmes encourage change to food lifestyle behaviours and health outcomes? New evidence from shareholders

Community Supported Agriculture (CSA) programmes have recently received attention for their potential to influence food lifestyle behaviours and health outcomes, though studies have mostly drawn from small samples (n?t-tests assess if paired means are statistically different, and multiple regressions of paired differences on socioeconomic factors, self-reported health, and years of CSA enrolment estimate the effect of respondent characteristics on behaviour change. The results strongly suggest that CSAs have the potential to positively impact shareholders’ food lifestyle behaviours and health outcomes, and that those reporting ‘poor health’ prior to CSA enrolment exhibited the most change overall. These results should be taken as an initial, yet promising, analysis of the impact of CSA participation on shareholder food lifestyle behaviours and health outcomes.     

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.     

Discouraging Rainforest Transformation: An Ex-ante Policy Impact Analysis

Despite extensive efforts made by national and international certification agencies, Indonesian smallholder farmers’ participation in palm oil certification schemes adoption remains low. A fundamental obstacle is the smallholder practice of rainforest transformation into oil palm plantation which is forbidden by the agencies. In this context, we investigate three policies that could lead to a reduction in rainforest deforestation by smallholders: price premium on certified palm oil; the provision of environmental information; contributor recognition. In order to evaluate the influence of the policies ex-ante, we conduct a social dilemma experiment involving rubber and oil palm smallholders in Jambi Province, Sumatra, Indonesia. The findings indicate that the price premium and provision of context-specific environmental information could reduce rainforest transformation. However, a statistically significant effect of contributor recognition was not found.     

Eliciting Willingness‐to‐Pay through Multiple Experimental Procedures: Evidence from Lab‐in‐the‐Field in Rural Ghana

This paper has the objectives of (a) comparing estimated willingness‐to‐pay (WTP) across three elicitation mechanisms (a Becker‐DeGroot‐Marschak [BDM] auction, a kth price auction, and a choice experiment [CE]) and (b) examining how these vary by participation fee. The product under consideration is kenkey made with nutritious maize, biofortified with vitamin A, which gives it a distinct orange color, in contrast to the white and yellow varieties that are traditionally consumed. We use an experiment consisting of 14 treatment arms, conducted in rural Ghana. Our estimation strategy explicitly accounts for the censored (typically at the market price) nature of the bids in the auctions, and the apparently lexicographic choices of several individuals in the CE. We find no evidence of economically meaningful (defined by the minimum currency unit of five pesewas) differences in WTP (although they may be statistically significant) across elicitation mechanisms, or by participation fee, a result that is in contrast to that found in much of the literature. A secondary finding is that the provision of nutrition information positively and significantly affects the marginal WTP for the new maize.     

Food Sovereignty and Fome Zero: Connecting Public Food Procurement Programmes to Sustainable Rural Development in Brazil

The global discourse on food sovereignty suggests several mechanisms for improving food security and agricultural livelihoods, including redistributive land reform and restructuring of markets to improve food distribution and access. In Brazil, the Fome Zero (Zero Hunger) social welfare programme has created innovative links between public nutrition and food security programmes and rural development initiatives through mediated market support for the family farm sector. We report on a participatory assessment of the experience of land reform beneficiaries in seven municipalities in Mato Grosso, Brazil, who were contracted to produce food for the Programa de Aquisição de Alimentos (Food Procurement Programme, PAA) and the Programa Nacional de Alimentação Escolar (National School Feeding Programme, PNAE) under the umbrella of Fome Zero. This analysis offers insight into the opportunities and challenges related to participation in mediated ‘farm‐to‐institution’ food procurement programmes, and assesses their influence on key food sovereignty principles, including agro‐ecological transition, increased market stability and farmer autonomy.     

Are Agricultural Values a Reliable Guide in Determining Landowners' Decisions to Create Forest Carbon Sinks?

This research examines the effects of various factors on farmer participation in agricultural tree plantations for economic, environmental, social, and carbon‐uptake purposes, and potential costs of sequestering carbon through afforestation in western Canada. Using data from a survey of landowners, a discrete choice random utility model is used to determine the probability of landowners' participation in and corresponding mean willingness to accept (WTA) compensation for a tree‐planting program. WTA includes positive and negative benefits to landowners from planting trees, benefits not captured by foregone returns from agricultural activities on marginal land. Estimates of WTA are less than foregone returns, but even so average costs of creating carbon credits still exceed their projected value under a CO₂‐emissions trading scheme. La présente étude a examiné les effets de divers facteurs sur la participation des producteurs agricoles à la plantation d'arbres à des fins économiques, environnementales, sociales et d'absorption du gaz carbonique, ainsi que les coûts potentiels de la séquestration du carbone au moyen du boisement dans l'Ouest canadien. À l'aide des données d'un sondage effectué auprès de propriétaires fonciers, nous avons utilisé un modèle d'utilité aléatoire à choix discrets pour déterminer la probabilité de participation des propriétaires fonciers à un programme de boisement et leur consentement à recevoir (CAR) une compensation financière pour leur participation. Le CAR inclut les avantages favorables et défavorables que le boisement procure aux propriétaires fonciers, des avantages non saisis par les revenus sacrifiés des activités agricoles sur des terres marginales. Les estimations du CAR sont inférieures aux revenus sacrifiés, mais malgré tout, les coûts moyens de la mise en uvre de programme de crédits pour le carbone demeurent supérieurs à leur valeur prévue dans un scénario d'échange de droits d'émission de CO₂.     

Exploring participation in a sustainable farming initiative with self-determination theory

Sustainable farming initiatives (SFIs), which aim to support farmers’ adoption of sustainable practices vary in the degree of farmer participation. In this study, we explored the influence of SFI design characteristics on farmer motivation to participate. Based on self-determination theory, we framed farmer participation by linking participants’ motives and motivational processes, participation context and participants’ perception of that context. Using a mixed-method investigation, we analysed Veldleeuwerik, a Dutch SFI with about 400 members. We observed four motive types, in order of importance: knowledge exchange, business opportunities, sustainability and social contact. By combining them with five types of motivational regulation, our research revealed that motives are directed by a diversity of underlying motivational processes, and that both are influenced by the participation context, or SFI design. Based on these results, we suggest that SFIs who wish to attract farmers who are not autonomously motivated for sustainability, need to rely on characteristics that meet either other motives than sustainability or other motivational processes than autonomous ones. To maintain participation, SFI characteristics should support autonomous motivational processes, by supporting the psychological basic needs of autonomy, competence and relatedness. The study illustrates how a socio-psychological perspective adds value to investigating SFI design characteristics for successful farmer participation.     

An alternative to ‘alternative development’?: Buen vivir and human development in Andean countries

In Bolivia and Ecuador the concept of Buen vivir, based on indigenous cosmologies, has been formulated by indigenous organisations as an alternative paradigm to mainstream development theory. It has also inspired environmentalist movements in their struggle for a different environmental governance beyond extractivism, and it has been appropriated by national governments to justify economic and social policies and their political agendas. In Peru, Buen vivir is emerging as a political project to express ecological concerns, as well as self-determination, territoriality and cultural rights of indigenous peoples. In these experiences the formulation and implementation of Buen vivir is a complex and contentious process which expresses the tensions and dynamics between indigenous politics and the political economy of extraction. This article explores the different meanings of Buen vivir in Bolivia, Ecuador and Peru and the struggle of indigenous peoples to re-appropriate the concept which has been co-opted by the state using conventional views of development. We argue that Buen vivir serves as a political platform on the basis of which different social movements articulate social and ecological demands based on indigenous principles, in order to challenge the economic and political fundamentals of the state and the current theory, politics and policy-making of development.     

Labour Migration and Gendered Agricultural Relations: The Feminization of Agriculture in the Ejidal Sector of Calakmul,Mexico

We examine the nature of the ‘feminization of agriculture’ in the semi‐subsistence, peasant production sector of southeastern Mexico, as associated with male labour out‐migration. Presenting findings from empirical work with smallholder producers, we discuss the impact of men's migration to the United States on women's participation in agriculture and gendered relations of agricultural production. In 2007, we conducted a survey of 155 semi‐subsistence, smallholder households in six ejidos. This survey was supplemented by ethnographic research in a single ejido. Our findings demonstrate the need to distinguish between farm labour and management in this sector, and the potentially significant (but focused) changes in the local relations of agricultural production wrought by gendered patterns of labour migration – specifically in tenure, land‐use decision‐making and the management of hired labour.     

Cost-Sharing Incentive Programs for Source Water Protection: The Grand River's Rural Water Quality Program

Over the last few years, Canadian provinces have come to see watershed-based source protection as a means of improving water quality that has been subject to upstream agricultural contamination. Cost-sharing incentive programs—whereby farmers are reimbursed for some portion of out-of-pocket expenses when they voluntarily adopt Best Management Practices—have been identified as possible means of achieving the goal. This paper uses data from the first seven years of operation of Ontario's Rural Water Quality Program for the Grand River to examine the role of financial incentives in encouraging participation. Program data supplemented with Statistics Canada's Census of Agriculture data are used to estimate a Heckman two-stage model of participation rates. Program-specific cost-sharing incentive factors, along with farm income and computer usage, are important determinants in the first-stage discrete participation decision. The most significant factor in the second-stage degree of participation decision is the maximum dollar value of grant that can be obtained by the farm; however, participation response elasticities are inelastic, ranging between 0.02 and 0.25. Au cours des dernières années, les provinces canadiennes en sont venues à considérer la protection des sources d’eau à l’échelle des bassins versants comme un moyen d’améliorer la qualité de l’eau susceptible d’être contaminée par les activités agricoles en amont. Les programmes d’incitatifs à frais partagés – dans le cadre desquels une partie des dépenses que les producteurs engagent leur sont remboursées lorsqu’ils adoptent volontairement de meilleures pratiques de gestion – sont perçus comme des moyens qui pourraient permettre d’atteindre l’objectif. Dans le présent article, nous avons utilisé les données des sept premières années d’application du Rural Water Quality Program, mis en place par l’Ontario pour la protection de la rivière Grand, afin d’examiner le rôle des incitatifs financiers dans l’encouragement à la participation. Nous avons utilisé les données de ce programme ainsi que des données tirées du Recensement de l’agriculture de Statistique Canada pour analyser les taux de participation à l’aide du modèle en deux étapes de Heckman. À la première étape, les incitatifs à frais partagés spécifiques à un programme, de même que le revenu agricole et l’utilisation d’un ordinateur, sont des facteurs importants dans le choix de participer ou non. À la deuxième étape, la valeur maximale de la subvention que peut obtenir une exploitation agricole représente le facteur le plus important. Toutefois, l’élasticité des réponses de participation est inélastique, et varie de 0,02 à 0,25.     

Fictitious commodification and agrarian change: Indigenous peoples and land markets in Highland Ecuador

Creating private property rights and establishing land markets were fundamental to the historical development of capitalism in the Global North and remain at the centre of capitalist development in the Global South. This article contributes to debates about these processes by analysing the relationship between land markets and indigenous peoples in Highland Ecuador. Building on Karl Polanyi's concept of fictitious commodities, it elaborates a new concept that makes an analytical distinction between the activation and development of land markets. The former refers to the occasional participation of actors in markets to secure land, whereas the latter relates to the establishment and expansion of markets that regulate the distribution and value of land through market prices. Focusing on indigenous land struggles in the late 20th century, this article shows that the activation of land markets created opportunities for indigenous peasants to secure land, whereas the development of land markets closed them down. Social and class differentiation among the highland indigenous population increased through this contradictory process. The article connects this historical analysis to recent developments in Ecuador to contribute to empirical and theoretical debates about contemporary land struggles and agrarian change elsewhere in the Global South.     

What socioenvironmental impacts did 35 years of export agriculture have in Mexico? (1980–2014): A transnational agri‐food field analysis

In this article, I propose to study environmental degradation and the deterioration of the health of workers and other inhabitants in regions of Mexico where intensive fruit and vegetable production for export has been developed. My proposition is that to understand the unsustainability of such agricultural practices in all their complexity, it is necessary to analyse historically the total agri‐food field of relations established by producers, distributors, and consumers in codependency with the natural environment. This analysis of the agri‐food field allows a multidimensional and multiscale study to be conducted of the hierarchical distribution of power and of economic benefits among the different social actors of the food system. This analysis also allowed us to study the development of the capitalist regime without going into the dichotomy of centre and periphery and to propose that it is a decentralized process with a multiplicity of locations that operates on the basis of mutual associations and influences between human and non‐human elements, with the active participation of a great variety of independent, collective, and institutional actors who have differentiated motivations, ranges of power and scales of value. The case study of Mexican export agriculture was the result of long‐term research based on a wide review of regional studies, field work statistics, and archives in Mexico and the United States. This cross‐border study makes it possible to identify asymmetrical transnational relations in a context in which the Mexican government has renounced its territorial and agri‐food sovereignty and Mexican consumers face greater vulnerability.     

Why Beautify the Plaza? Reproducing Community in Decentralized Neoliberal Peru

Peruvian development and government analysts criticize communities for irrationally using local development funds deriving from recently instituted political decentralization to beautify their villages rather than to improve infrastructural services, education and health, or to alleviate poverty. This paper challenges this critique by explaining why such cosmetic improvements are of interest to rural people. Using a case study of the peasant community of Allpachico, I argue that these projects encourage the return of pensioners and visits from migrants. Residents and migrants are mutually dependent as a result of livelihood strategies based on agriculture and the foreign‐controlled resource extraction sector over the past 80 years. The relative position of these two groups in the social reproduction of the vernacular community has changed with the Peruvian political economy. Currently, in the neoliberal resource extraction economy, residents pragmatically opt to maintain relations with those who have stable wage or pension incomes.     

Development And Adjustment Policy For A Low Income Farm Area1

This paper attempts to develop profit-maximizing plans for a low income farm area and to indicate the magnitude of resource adjustment required to meet this optimum. A secondary objective is to evaluate the usefulness of the variable resource programming technique as a device for determining resource misallocation and as a guide to regional and national policy. The study set out to develop optimum plans for the individual farm units and for the area using the variable resource programming technique. The results of the individual farm programs indicate that considerable income development potential exists on farms through internal farm resource reorganization and development. Results of the area programs suggest a need for substantial farm unit adjustment in order to achieve efficient resource use, particularly in achieving minimum farm income needs of the future.     

Institutional Market Power in Comté: Insights from a ‘Double Marginalisation’ Model

This article explores the economic efficiency of a horizontally and vertically coordinated industry where upstream producers are atomised, but downstream processors are few, explicitly considering participation incentives and allowing the coordinated industry to exert market power towards buyers. The model offers insight into the probable social impacts of the government‐sanctioned supply control scheme in place in the French Comté cheese market, suggesting it falls short of constituting a Pareto‐improvement compared with a laissez‐faire situation. More generally, our theoretical model provides guidance to identify instances where encouraging industry coordination may be socially desirable. We formally introduce the concept of ‘seller‐equivalent degree of overall market power’ of the separated industry, a market characteristic comprised of measurable or inferable parameters, the value of which is shown to determine the potential for Pareto improvements through industry integration.