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1.
本文采用文献法和比较法,对中国耕作制度的历史演变进行梳理和总结,探讨当前中国实行耕地轮作休耕制度的现实背景,归纳轮作休耕国家试点和地方试验的做法,分析传统耕作制度对轮作休耕的经验意义,提出完善轮作休耕制度的思路。研究发现:(1)中国主要经历了撂荒耕作、休闲耕作、连作耕作和复种轮作4种耕作制度,形成了精耕细作的土地用养结合模式及相关的一整套技术措施。(2)目前高度集约化的复种轮作制使耕地产能严重透支,耕地总体健康状况堪忧。(3)中国实行轮作休耕可从传统的用地养地模式中汲取经验,但并非简单的复制。(4)实行轮作休耕制度需要综合考虑国内外制度基础和政策环境,需要在区域操作模式、技术路径、时空配置等方面进行完善。  相似文献   
2.
We investigate the impact of direct payments on agricultural commercialisation in Kosovo. Kosovo is one of the poorest countries in Europe but, with European assistance, provides substantial funds to support agriculture, made up of many small and often semi‐subsistence farms. Thus, the effect of this support is a central policy issue. Identifying the effect of direct payments on market participation faces endogeneity issues arising from the possible simultaneous determination of participation in support programmes and market participation. In order to achieve proper identification of the endogenous direct payments, we use a strategy of targeted identification search that employs several different methodological approaches. We find that direct payments for fruit and vegetables, and those for cereals and oilseeds have a positive effect on market participation. However, we cannot identify any definite effect of livestock payments.  相似文献   
3.
[目的]基于地方普遍反映低效工业用地利用量最大,程度最重的问题,文章将探寻城镇低效工业用地认定和查询的新方法,为地方政府科学化、层次化管理工业用地提供帮助,更好地促进土地资源的集约节约利用。[方法]基于多层级指标体系,以企业基础设施完备度为控制轴,企业经济效益和社会效益为评价轴,构建工业用地三维认定查询模型,创新工业用地的结果查询模式。[结果]以山西省榆社县为例,采用多层级指标体系能够得出,越是规模以上企业,其基础设施越完备、经济效益和社会效益分值越高,从侧面也可以反映出来地均税收和地均产值是造成该宗地高效利用和低效利用的关键。[结论]采用多层级指标体系确定的低效工业用地于与《山西省城镇低效用地编制要点》中确定的低效工业用地一致。且多层级指标体系不仅能将工业用地划分为高效利用、一般利用、低效利用、极差利用4个层次,还能对每个层级的分数进行比较,从而找出低效用地产生的原因,更好地指导地方政府对于工业用地的差异化管理和再开发工作。  相似文献   
4.
Limited opportunities for crop switching and lengthy preharvesting periods make the plantation sector particularly vulnerable to climate change. Surprisingly, however, the economic consequences of climate change on plantation crops are seldom analysed. Drawing on a unique primary panel data set from a representative cross section of 35 tea estates in Sri Lanka over the period 2002–2014, this study implements a structural model of estate profit maximisation to estimate the elasticity of labour demand with respect to different components of weather. Results indicate a negative relationship between labour demand and rainfall in the south‐west monsoon, the north‐east monsoon and the second inter‐monsoon. A positive relationship is found between labour demand and rainfall in the first inter‐monsoon. Overall, predicted changes in rainfall by 2050 are anticipated to reduce labour demand by approximately 1,175,000 person‐days per year across Sri Lanka's tea plantation sector. This is likely to have considerable social and welfare implications, particularly for the Indian Tamil women who comprise the majority of the sector's workforce.  相似文献   
5.
[目的]软硬变化区的划分是进行遥感变化检测技术识别农作物的基础。为解决人工判读方法中存在人为主观因素影响以及自动判别和交互式判别方法对不同研究区的适用性问题,该文提出基于剖线梯度变化(Profile based Gradient Change Magnitude,PGCM)进行软硬变化区划分的方法。[方法]该研究选择破碎农业景观种植区域为研究区,计算拔节期Quick Bird影像和播种期模拟影像两个时相的变化强度,从作物地块内部向外绘制剖线,利用剖线强度的梯度变化确定硬变化区(Hard change region,HCR)、软变化区(Soft change region,SCR)和未变化区(Non change region,NCR)3者间的划分阈值。[结果]从识别结果来看,PGCM能够有效在地块边界处探测到软变化像元,进而确定HCR、SCR。像元分辨率在5~60 m不同尺度下,识别HCR区混入比例为11%~16%,混入比例随着分辨率下降而降低;NCR区混入比例为3%~4%,受分辨率尺度影响不大;SCR区识别比例为74%~86%,识别精度较高,识别结果与冬小麦空间分布结果保持一致。[结论]PGCM方法能够自动、便捷地确定阈值,摆脱人工判定的主观性,有效地划分出HCR、SCR和NCR 3个区域,为进一步HCR、SCR区内的作物识别提供基础。  相似文献   
6.
This article provides a critical review of the foundations of the new Keynesian apparatus, to evaluate the actual strength of the Keynesian inheritance. As a reference of the Keynesian vision, Fausto Vicarelli’s recognition of the Keynesian message is adopted. The critical recognition of the new Keynesian methodology focuses on its analytical foundations, the recent extensions and on the criticality of its empirical performances and controls. The new Keynesian construction is shown to lack truly Keynesian roots in at least three key theoretical features: the role of the microfoundations, the stability of equilibrium, and expectations formation. The directions of an ongoing research narrowing the new Keynesian theoretical fracture from Keynesian economics are addressed.  相似文献   
7.
As the decision-makers and implementers of a firm’s financial strategy, executives play a critical role in cash holding activities, and their psychological characteristics have a major impact on cash holdings. This paper investigates the association between CEO organizational identification and firm cash holdings. The empirical results show that CEO organizational identification is negatively associated with firm cash holdings, and the negative association is more pronounced when the level of financial development is higher and economic uncertainty is lower. Further analysis reveals that the higher a CEO’s organizational identification, the higher the firm’s R&D investment and capital expenditure, and high CEO organizational identification can increase the value of firm cash holdings. Overall, our findings supplement the literature on organizational identification and cash holdings, and on the effect of executives’ psychological characteristics on corporate financial decision-making.  相似文献   
8.
This paper analyses the economic and financial repercussions of the 2020 COVID‐19 pandemic. It argues that the pandemic has inflicted serious injuries to the labor force but has not damaged the physical capital stock. Therefore, the resolution policies of this crisis ought to be carefully tailored to supporting structural adjustments to the labor market. The analysis asserts that the impact of the pandemic crisis is exacerbated by the identification gap between the unobserved and the officially reported cases of COVID‐19. The gap increases financial risks, including market‐, credit‐, default‐, and foreign exchange risks.  相似文献   
9.
中国节水农业成效、形势机遇与展望   总被引:1,自引:0,他引:1  
目的 我国是世界上水资源缺乏的国家之一,发展节水农业在保障国家粮食安全和农业绿色高质量发展大局中具有重要战略地位。全面总结“十三五”节水农业发展成效与经验,认真分析节水农业的现状、形势和任务,加快“十四五”期间节水农业发展,推进节水增粮、节水增效,具有十分重要的意义。方法 文章对我国近10年来的水资源、农业用水、灌溉用水、旱作农业生产和用水效率进行系统总结和数据分析。结果 “十三五”期间,我国节水农业发展取得显著成效,农业用水总量及其占全国用水总量的比例“双下降”,农业用水效率和效益“双提升”,切实提高农业用水效率,为保障粮食和食物安全做出重要贡献。结论 中国农业生产面临着干旱缺水的长期威胁,大力发展节水农业,解决好农业用水问题,是保证我国粮食和食物安全、转变农业发展模式并促进绿色高质量发展的需要,也是实现农业现代化和生态文明的根本路径。  相似文献   
10.
The decisions a researcher makes at the model building stage are crucial for parameter identification. This paper contains a number of applied tips for solving identifiability problems and improving the strength of DSGE model parameter identification by fine-tuning the (1) choice of observables, (2) functional specifications, (3) model features and (4) choice of structural shocks. We offer a formal approach based on well-established diagnostics and indicators to uncover and address both theoretical (yes/no) identifiability issues and weak identification from a Bayesian perspective. The concepts are illustrated by two exemplary models that demonstrate the identification properties of different investment adjustment cost specifications and output-gap definitions. Our results provide theoretical support for the use of growth adjustment costs, investment-specific technology, and partial inflation indexation.  相似文献   
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