农业绿色发展背景下的玉米化肥减量化研究

目前中国玉米生产中,普遍存在着化肥过量施用问题。本研究参照中国玉米区域大配方施肥标准,测算了玉米主产区的化肥减量目标,并结合玉米主产区的化肥施用总量、播种面积、单位面积化肥施用强度及吨粮化肥施用量综合分析了玉米的化肥施用现状,精准识别了化肥急需减量的关键地区,并进一步探索了种植玉米的化肥减量路径。结果显示:中国玉米主产省化肥的减量目标为255万吨,占玉米化肥施用总量的19%;化肥急需减量的省份有吉林、云南、甘肃、宁夏、新疆、江苏和山东;中国应进一步提高用肥效率、推广农业技术培训和提供服务、完善经济管控政策和健全化肥管控法规。     

农业绿色发展背景下的小麦化肥减量化研究

目前中国小麦生产中,普遍存在着化肥过量施用问题。本研究参照中国小麦区域大配方施肥标准,测算了小麦主产区的化肥减量目标,并结合小麦主产区的化肥施用总量、播种面积、单位面积化肥施用强度及吨粮化肥施用量综合分析了小麦的化肥施用现状,精准识别了化肥急需减量的关键地区,并进一步探索了种植小麦的化肥减量路径。     

老龄化、社会资本与农户化肥减量施用行为

[目的]近年来,化肥的过量施用引发了一系列环境问题,农业面源污染形势不容乐观。文章主要分析老龄化、社会资本以及两者的交互作用对农户化肥减量施用行为的影响,并探讨不同维度的社会资本作用效果是否具有异质性,进而在一定程度上为促进化肥减量施用行为提出相关建议。[方法]基于2015年陕西省和山东省14个苹果主产县种植户的微观数据,运用因子分析法分别从网络、信任和规范3个维度衡量农户社会资本,采用多元线性回归模型,分析老龄化、社会资本对农户化肥减量施用行为的作用效果及其路径。[结果]老龄化对农户化肥减量施用行为具有负向影响,社会资本则能正向促进农户化肥减量施用行为;从不同维度的社会资本影响来看,社会网络指数与社会规范指数对化肥减量施用行为有显著正向影响,而社会信任指数的影响则不显著;社会资本的拓展能很好地缓解老龄化对农户化肥减量施用行为的不利冲击,但只有社会网络与社会规范的缓解效应较为显著,社会信任不能发挥类似的缓解作用。[结论]要推广化肥减量施用,需充分考虑人口老龄化的现状,进一步加强农业技术培训,搭建社交平台,拓宽农户间的信息交流,加强信任体制建设,规范矫正农户生产行为,构建新型农业经营体系,促进农业可持续发展。     

土地转入、地块规模与化肥减量——基于湖北省水稻主产区的实证分析

化肥减量施用是实现农业可持续发展的重要举措。既有研究普遍强调土地转入、规模经营的化肥减量贡献,然而,不同土地转入情景所表达的规模经营内涵和化肥减量潜力差异尚未得到充分重视。本文将转入地块的空间分布特征纳入理论分析框架,探析在分散化和连片化两类土地转入情景下农户化肥施用量的差异,并利用湖北省水稻主产区1314户稻农的样本数据进行实证检验。研究结果表明,若土地转入呈分散化特征,经营规模扩张将伴随土地细碎程度的加深,由此经营规模扩张的化肥减量效应会被抵消,土地细碎化甚至会加剧农户的化肥增施行为;若土地转入呈连片化特征,经营规模与地块规模将同步扩张,由此形成的地块层面的规模经济性将显著促进化肥减量施用。     

中国水稻生产与化肥施用的脱钩关系及其关联效应分析

[目的]推进水稻生产和化肥施用的脱钩,实现粮食安全和生态安全的同步提升。[方法]文章采用脱钩模型分析2003—2018年中国水稻生产与化肥施用的脱钩状况,构建两者之间的关联模型,运用对数平均迪氏指数分解法将水稻产量变化分解为规模、结构、强度和效率4种效应,揭示它们对中国水稻生产和化肥施用脱钩关系的影响。[结果]（1） 2010年之前我国水稻生产和化肥施用总量之间以扩张负脱钩为主,之后则以弱脱钩和扩张连接为主。分肥料种类看,就氮肥和磷肥而言,2010年之前其与水稻生产的脱钩关系和化肥施用总量与水稻生产的脱钩关系差别不大,但之后水稻生产与氮肥以强脱钩关系为主,与磷肥以扩张负脱钩关系为主;对钾肥而言,在整个2003—2018年其与水稻生产都以扩张负脱钩关系为主。（2）全国和省域层面分析均表明,扩大规模效应,提高结构效应能够显著推进水稻生产和化肥施用脱钩,但在人多地少的条件下,寄希望于持续扩大规模效应和提高结构效应来实现水稻生产和化肥施用脱钩的目标难以实现。（3）强度效应是促进水稻增产的重要因素,但化肥投入的长期增长已严重威胁稻田的生态安全和可持续生产能力,使其水稻边际产出水平明显下降,导致效...     

中国粮食耕作面积与农用化学品投入的时空协同分析

[目的]耕地保护是中国的基本国策,也是粮食安全的重要保障。耕地总量动态平衡是落实耕地保护政策的具体形式,这也造成耕地向欠发达地区转移。在此背景下,农用化学品投入也有向经济欠发达地区、特别是西部地区转移的风险,加剧西部生态脆弱区环境保护压力。然而,目前研究还鲜有这方面的报道,特别缺乏对粮食耕作面积与相应农用化学品投入间时空协同关系的分析。[方法]文章基于2000—2019年省级粮食耕作面积和用于粮食生产的农用化学品投入（化肥、农药、地膜和农用柴油）数据,利用重心模型、标准差椭圆和耦合协调度模型,对全国以及东、中、西部地区粮食耕作面积和农用化学品投入的时空协同特征进行分析。[结果] 2000—2019年中国粮食耕作面积和用于粮食生产的农用化学品投入重心整体向西北或西部移动,其中地膜投入重心移动速度最快,重心迁移速度大小依次为：地膜（11.16 km/年）>农用化肥（5.95 km/年）>粮食耕作面积（5.18 km/年）>农药（4.01 km/年）>农用柴油（3.67 km/年）;全国粮食耕作面积与地膜、化肥、农药、柴油的耦合协调度整体呈上升态势。[结论]随着粮食耕...     

基于玉米种植的农地规模对化肥减量增效的影响分析

目的 探讨农地规模对化肥施用强度和化肥利用效率的影响。方法 文章基于1 135个玉米种植户的调查数据,运用普通最小二乘法、工具变量法以及分位数回归法分析农地规模对化肥施用强度和化肥利用效率的影响,并利用2003—2018年20个玉米主产省份面板数据进行检验,最后探索并分析农地规模变化的驱动因素及其对化肥使用的短期和长期影响。结果 （1）农地规模对化肥施用强度具有显著的负向影响,农地规模每扩大1%,化肥施用强度随之降低0.1%～0.2%,且农地规模对化肥施用强度较低的农户的影响相对较大;（2）农地规模对化肥利用效率具有显著的正向影响,农地规模每扩大1%,化肥利用效率随之提高0.2%～0.3%,且农地规模对化肥利用效率较低的农户的影响相对较大。结论 鼓励适度扩大农地规模,有助于降低化肥施用强度,提高化肥利用效率;通过推广农业生产托管服务和联耕联种,可以有效解决地块狭小、土地分散等问题,促进化肥减量增效。     

基于政策工具视角的多主体绿色施肥行为决策研究

[目的]为加快推进化肥减量增效,探索政府应用信息传递型、激励型及控制型3类政策工具对农户及农业社会化服务组织绿色施肥行为的动态影响机制,为构建高效施肥调控政策体系提供理论支撑。[方法]文章基于演化博弈理论,以黑龙江省为例,应用matlab2016b软件进行数值仿真分析,以得出不同水平政策工具组合下农户与农业社会化服务组织绿色施肥策略变动过程。[结果]（1）政府、农户及农业社会化服务组织在推进化肥减量增效方面存在动态博弈关系,科学合理地制定施肥调控政策是协调三方利益冲突的关键。（2） 3类政策工具中,高水平的信息传递型工具对各主体绿色施肥行为的刺激效果最佳,而组合应用信息传递型与激励型工具对主体行为的推动作用更稳定,同时应用3类工具则更能全面构建起化肥减量增效的良性循环。[结论]政府应重视农户及农业社会化服务组织在推进化肥减量增效方面的主体作用,及时开展施肥调控工作;根据各主体的个体特征与政策需求差异化地制定政策内容,着重应用信息传递型政策工具,必要时与激励型、控制型工具组合应用以获取叠加效应,推行绿色施肥。     

城镇化对农药、化肥施用强度的影响——基于中介效应的分析

目的 探讨城镇化对农药、化肥施用强度的影响及其作用机制。方法 文章基于文献梳理，归纳城镇化对农药、化肥施用强度的影响机理；利用2000—2018年河南省106个县的面板数据，分别探讨城镇化对农药施用强度和化肥施用强度的影响；通过分析农地经营规模与居民收入水平的中介效应，探索其影响机制。结果 （1）城镇化对农药、化肥施用强度均具有显著的负向影响；（2）城镇化的农地规模效应显著，城镇化有利于扩大农地经营规模，从而有利于降低农药、化肥施用强度；（3）城镇化的收入效应显著，居民收入水平对农药、化肥施用强度的影响呈“倒U型”变化趋势，超过1/3的县已跨过农药施用强度的拐点，全部县均已跨过化肥施用强度的拐点；（4）城镇化对农药、化肥施用强度较低的县的影响更大。结论 适度推进新型城镇化建设有利于促进农药、化肥减量；鼓励农地适度规模经营，可以充分发挥城镇化的农地规模效应，降低农药、化肥施用强度；持续增加居民收入，同时促进居民选择环境友好型食物、减少食物浪费，可以从需求侧助推农药、化肥减量。     

经营规模、分工深化对小农户化肥减量施用的影响——以黄河流域玉米种植户为例

[目的]通过分析黄河流域3省区玉米种植户化肥施用强度与减施情况,探析经营规模与化肥施用强度非线性关系及纵向分工深化的中介作用。[方法]文章基于扩展回归模型,使用2020年黄河流域中甘肃、宁夏以及陕西3省区玉米种植户问卷调查数据,分析经营规模和分工深化对农户化肥使用量的影响及作用机制。[结果]（1）扩大经营规模可以显著抑制农户化肥的过量施用,但当达到一定规模后,这种抑制效应消失,继续扩大经营规模将不再降低农户化肥施用强度。（2）经营规模与纵向分工卷入程度之间也存在“U型”的非线性关系,在达到一定规模之前,经营规模的扩大会显著提高农户服务外包的程度。（3）扩大经营规模可以通过提高纵向分工卷入程度进而降低农户化肥施用强度。[结论]玉米种植农户经营规模与化肥施用强度间存在“U型”的非线性关系,且纵向分工卷入程度在经营规模与化肥使用强度间存在完全中介作用。     

Price transmission between products at different stages of manufacturing in forest industries

The theory of demand and supply implies a positive relationship, or “price transmission” between the prices of products at different stages of manufacturing. This relationship was investigated with quarterly prices of softwood stumpage in the US South, and national prices of forest products, from 1977 to 2002. All prices, net of inflation, were found to be nonstationary and there was no evidence of co-integration between prices. Vector autogressive models, augmented by Granger causality tests and multiplier analysis showed that there was a one-to-one permanent positive response of the southern sawtimber stumpage price to a permanent change in the national lumber price. There was also a one-third permanent positive response of the national paper price to a permanent change in the national pulp price. There was no relation between regional pulpwood prices and national pulp or paper prices. When price transmission was significant, the full adjustment took about 2 years.     

Application of an ecosystem function framework to perceptions of community woodlands

Owners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the management of semi-natural ecosystems.     

In Vino ‘No’ Veritas: impacts of fraud on wine imports in China

China is one of the largest wine importing countries in the world and is poised for continued import growth in the future. Increased wine purchases throughout China have given rise to persistent fraud where fake wines are packaged and sold with counterfeit contents and labels. For exporting countries like France, counterfeit wines displace market share, damage foreign brand reputation, and cause distrust in consumers who are aware of counterfeiting problems throughout the country. We examine the impact of fraudulent wine events (as measured by negative media reports) on Chinese wine demand differentiated by supplying country. We employ the Rotterdam demand system and a switching regression procedure to estimate import demand and compare results across different media variable specifications. Results consistently show that negative reports disproportionately affect French wine regardless of how the media variable is specified. This is not surprising because most fraudulent events involve French wine counterfeits.     

An evaluation framework for earthquake-responsive land administration

In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.     

Agrarian Poverty,Nutrition and Economic Class – A Study of Gujarat,India

This paper analyses poverty and calorific undernourishment in the Indian state of Gujarat, where high and market‐led industrial growth has resulted in rapid economic improvement. The study is carried out through a combination of secondary and survey‐based data. We conclude that the neoliberal agenda of uncontrolled, outward‐looking growth has not resulted in significant reduction of poverty or malnourishment in rural areas. Furthermore, while land ownership is officially used as a proxy for wealth distribution, class position appears a better predictor of poverty status in the rural areas than landownership per se. At the policy level, there is a need to revive the agrarian economy and create new non‐agricultural assets, and the primary focus in the state must shift to the distribution of created assets rather than a single‐minded focus on growth.     

Does sustainable agricultural growth require a system of innovation? Evidence from Ghana and Burkina Faso

This paper tests the ‘systems of innovation’ hypothesis for a selection of crops in Ghana and Burkina Faso that have shown significant growth in production over an approximately 20-year period. The question is whether such growth can only occur if supported by a system of innovation. Using two indicators (a common understanding on objectives and priorities, and a high level of interactivity), we find little evidence for the existence of anything that might be considered a high functioning system of innovation.     

Local impacts of industrial tree plantations: An empirical analysis in Indonesia across plantation types

The values ascribed to industrial tree plantations are often controversial. Hence knowledge of their perceived impacts is important for improving their integration in rural landscapes. In 2016 we conducted household surveys with 606 respondents living in villages adjacent to acacia, teak and pine plantations across three islands in Indonesia (Java, Borneo, Sumatra). Results show that perceptions toward pine and teak plantations tend to differ from those toward acacia pulpwood plantations in several ways. Pine and teak plantations are perceived to have a higher number and variety of benefits and services, a higher number of positive impacts, a better environmental record, and to present more opportunities to local people for use of plantation land and products for improving rural livelihoods. In addition, we find that villagers around acacia pulpwood plantations tend to seek economic development and infrastructure to open up remote areas, yet their expectations were often only partially met. Recommendations from our analysis include: the role of the State in plantations must be clarified and potentially reinforced; the role of institutions as intermediaries is fundamental; and contributions by communities to design of management plans should be accommodated.     

土地学科的建设和发展——"土地学科发展规划研讨会"综述

中国土地科学学科发展已取得很大成就,表现为专业教育和人才培养成绩突出、初步形成学科体系、取得大批研究成果.而存在的问题主要是基础理论研究欠缺、独特的土地科学研究方法体系尚未形成、研究角度单一、学术交流质量不高和学科带头人的影响力不足.土地科学学科发展目前面临着巨大的机遇和挑战,应明确土地科学学科发展的基本思路、发展目标及2010-2020年的主要建设任务和保障措施.     

Upstream demand for water use by new tree plantations imposes externalities on downstream irrigated agriculture and wetlands*

Large‐scale tree plantations in high rainfall upstream areas can reduce fresh water inflows to river systems, thereby imposing external costs on downstream irrigation, stock and domestic water users and wetland interests. We take the novel approach of expressing all benefits and costs of establishing plantations in terms of $ per gigalitre (GL) of water removed annually from river flows, setting upstream demands on the same basis as downstream demands. For the Macquarie Valley, a New South Wales sub‐catchment of Australia’s Murray‐Darling Basin, we project changes in land and water use and changes in economic surpluses under two policy settings: without and with a policy requiring permanent water entitlements to be purchased from downstream parties, before plantation establishment. Without the policy, and given a high stumpage value for trees ($70/m³), upstream gains in economic surplus projected from expanding plantations are $639 million; balanced against $233 million in economic losses by downstream irrigators and stock and domestic water users for a net gain of $406 million, but 345 GL lower mean annual environmental flows. With the policy, smaller gains in upstream economic surplus from trees ($192 million), added to net downstream gains ($138 million) from sale of water, result in gains of $330 million with no reduction in environmental flows. Sustaining the 345 GL flow for a $76 million (406–330) reduction in gains to economic surplus may be seen to cost only $0.22 million/GL; but this is much lower than the market value of the first units of that water to agriculture and forestry.     

Underpayment of Small Producers of Coffee and Cocoa in Sierra Leone

Fieldwork shows that many Sierra Leonean producers do not receive the official producer price for their coffee and cocoa, due to the concentration of buying stations, credit relations, the small quantities offered for sale, and the lack of marketing knowledge of the numerous and unorganized farmers. To the traders underpayment may seem economically justifiable to a certain extent, but to the farmers it means poverty and debt. A new village marketing centre project aims at remedying this situation and has already led to higher prices. Although no longer allowed to take their "just" share from the producers, traders are still willing to deal with the new centres.