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591.
China’s low agricultural labor productivity has become the key weakness of its agricultural competitiveness and sustainable development, and strategies for improving China’s agricultural labor productivity lack clear and consistent theory and empirical support. To address this issue, the current study uses the methods of convergence index, correlation coefficient, and nonparametric test, to analyze the characteristics and influencing factors of agricultural labor productivity among 32 major agrarian countries during 1961-2013. This analysis shows that the development gap among countries has been narrowing. The USA takes the leading position among all the countries, while some countries with scarce land like Japan have succeeded in achieving transcendence, and other countries like India have experienced relatively slow speed. The agricultural labor productivity is significantly driven by agricultural labor surplus, agricultural product processing, and agricultural industrial structure. The effects of land resource endowment, agricultural mechanization, and biochemical inputs have been declining and in some cases are no longer even significant. It is therefore necessary to shift attention to marketization, diversification, and high quality, instead of the former focus on agricultural intensification, concentration and large-scale operations, and this shift is probably more closely aligned with current practices. There are more people and less land in China, and the agricultural labor force in China still accounts for nearly 30% of the total population. Considering these national conditions, it is very important to simultaneously improve the efficiency of agricultural production of small farmers and promote the successful urbanization of the agricultural labor force. In the medium and long term, it is imperative to improve the competitiveness of Chinese agriculture by adopting related policy arrangements such as induced agricultural technological innovation, production factor substitution, and multifunctional agriculture development.  相似文献   
592.
Further utilization of global agricultural resources and the expansion of potential international cooperation space are necessary measures to promote a new level of China’s national food security and optimize the structure of domestic food consumption. This study measured the global potential cultivated land area and national grain self-sufficiency. Based on the two-above measures, the authors made a classification of China’s foreign agricultural cooperation countries and depicted the spatial pattern of cooperation based on the grain trades of those countries with China. The grain exporters include Australia, North America, South America, Eastern Europe and Central Asia; and the target countries for “going abroad” of Chinese grain enterprises are mainly located in Sub-Saharan Africa and northern Latin America. This study proposes that China’s policy of cooperation on grain should be shifted to non-traditional partners alongside the “Belt and Road Initiative” region. Specifically, China could expand grain imports from Russia, Kazakhstan, Ukraine and other East European and Central Asian countries, and the direction for China’s agricultural enterprises “going abroad” should shift to Sub-Sahara Africa.  相似文献   
593.
Changes of multiple cropping in Huang-Huai-Hai agricultural region,China   总被引:2,自引:1,他引:1  
Multiple cropping index (MCI) is the ratio of total sown area and cropland area in a region, which represents the regional time intensity of planting crops. Multiple cropping systems have effectively improved the utilization efficiency and production of cropland by increasing cropping frequency in one year. Meanwhile, it has also significantly altered biogeochemical cycles. Therefore, exploring the spatio-temporal dynamics of multiple cropping intensity is of great significance for ensuring food and ecological security. In this study, MCI of Huang-Huai-Hai agricultural region with intensive cropping practices was extracted based on a cropping intensity mapping algorithm using MODIS Enhanced Vegetation Index (EVI) time series at 500-m spatial resolution and 8-day time intervals. Then the physical characteristics and landscape pattern of MCI trends were analyzed from 2000–2012. Results showed that MCI in Huang-Huai-Hai agricultural region has increased from 152% to 156% in the 12 years. Topography is a primary factor in determining the spatial pattern dynamics of MCI, which is more stable in hilly area than in plain area. An increase from 158% to 164% of MCI occurred in plain area while there was almost no change in hilly area with single cropping. The most active region of MCI change was the intersection zone between the hilly area and plain area. In spatial patterns, landscape of multiple cropping systems tended to be homogenized reflected by a reduction in the degree of fragmentation and an increase in the degree of concentration of cropland with the same cropping system.  相似文献   
594.
This paper quantitatively analyzes the utilization efficiency of agricultural resources in Central Asia by calculating the consumption coefficient of the main resources, including arable land, water and fertilizers. The results of these investigations reveal the following: (1) The average consumption coefficients of cultivated land resources in Central Asia are much higher than the world average value of up to 7.74 m2/kg, which is 3.6 times that of China, suggesting that the cultivated land resource consumption coefficient of cultivated land resource utilization efficiency is low in the Central Asian region. (2) Up to 80% of available water Central Asia is about 9.43 m3/kg, or nearly 9.3 times the average value elsewhere in Asia, indicating that agricultural water use efficiency in this region is very low and water resources are wasted. (3) The fertilizer consumption coefficient in Central Asia is 0.035 kg/kg, which is close to the world average, but the utilization efficiency of fertilizer is relatively high. Therefore, in the future development of agriculture, Central Asia should pay more attention to the management of agricultural water resources in order to improve the utilization efficiency of these resources as well as that of arable land.  相似文献   
595.
基于国际耦合模式比较计划第六阶段(CMIP6)模式模拟以及观测数据,评估了9个CMIP6模式对亚洲地区叶面积指数(LAI)、总初级生产力(GPP)和净初级生产力(NPP)的模拟性能。模拟评估结果表明,9个CMIP6模式能够较好地模拟出亚洲地区陆地生态系统LAI、GPP和NPP的时空分布特征。综合来看,多模式集合(MME)模拟效果最佳,其模拟的LAI、GPP和NPP与观测的空间相关系数分别达到0.90、0.81和0.89,均方根误差在0.5左右。在此基础上,利用MME结果进一步预估了亚洲地区陆地生态系统在SSP1-2.6、SSP2-4.5和SSP5-8.5情景下的未来变化。总体而言,亚洲地区LAI、GPP和NPP到21世纪末都呈现上升趋势。其中,温室气体高排放情景下的上升趋势大于温室气体低排放情景下的上升趋势,亚洲中高纬度地区的增幅大于低纬度地区的增幅。从区域平均来看,到21世纪末期,与当今气候态相比,北亚LAI、GPP和NPP的增幅最大,其在SSP5-8.5情景下分别增加68%、106%和90%;东南亚增幅最小,分别为15%、34%和39%。在SSP1-2.6情景下,北亚LAI、GPP和NPP在21世纪末的增幅分别为23%、29%和26%;东南亚分别为3%、10%和11%,意味着未来全球变暖背景下亚洲区域陆地生态系统变绿和固碳幅度加强。  相似文献   
596.
基于ArcGIS Obejects,设计并开发了基于粮食安全的村镇区域农用地质量综合评价系统,该系统能够对不同尺度的农用地进行评价,特别是村镇区域,充分考虑了污染物对农用地质量的影响,融合了多种指标获取、指标量化、权重确定、分值计算等技术,并能够对评价的成果进行专题图的制作,适用于不同目的的农用地质量评价。  相似文献   
597.
基于生境质量的城市增长边界研究——以长三角地区为例   总被引:5,自引:1,他引:4  
基于“生态优先”理念,提出一种利用生境质量评估策略的城市增长边界划定方法。结合ArcGIS和InVEST模型,通过综合评估生境自身及其在威胁情境下的质量,模拟各市独立规划、建设用地指标再分配及区域一体化发展的三类建设用地扩张情景,分别划定2024和2034年的长三角地区城市增长边界。结果表明:研究区生境质量总体呈南高北低格局,平均生态系统服务价值密度为10 770.604元/(hm2·a),高质生境位于西南地区;根据指标再分配及一体化发展情景模拟的2024年研究区建设用地总量分别为10 583.273 km2和10 489.090 km2,2034年达到13 603.535 km2和13 252.370 km2;模拟的建设用地集中在东部沿海地区,并向北部及环杭州湾区域拓展;建设用地指标再分配能从整体上减少建设用地对优质生境的占用,区域一体化发展则能进一步降低城市发展造成的生态压力。  相似文献   
598.
环渤海地区海洋产业生态系统适应性时空演变及影响因素   总被引:2,自引:0,他引:2  
李博  张志强  苏飞  韩增林 《地理科学》2017,37(5):701-708
将产业生态系统引入到海洋研究中,开展海洋产业生态系统适应性研究,界定海洋产业生态系统适应性的内涵及特征;采用均方差赋权法进行权重赋值,构建海洋产业生态系统适应性评价指标体系与评估模型,分析环渤海地区海洋产业生态系统的适应性时空演变及影响因素。结果表明: 从整体来看,环渤海地区海洋产业生态系统适应性差异较大,主要问题是环渤海地区各省市海洋产业发展参差不齐,产业基础和发展速度差异较大,海洋生态环境建设水平不一; 从空间来看,海洋产业生态系统适应性呈现山东>辽宁>天津>河北的空间分布特征;在海洋产业子系统各要素中,呈现敏感性越大,弹性越大的特征,海洋环境子系统适应性特征不明显; 从时间来看,环渤海地区海洋产业生态系统适应性在波动中不断增强,各省市适应性综合指数差距呈现逐渐扩大的趋势,这种扩大的趋势是由于海洋产业子系统年均增长的差异所致; 区域内部海洋产业生态系统适应性差异明显:天津市海洋产业子系统适应性指数最高,海洋环境子系统发展水平滞后;河北省海洋产业、环境子系统适应性指数较低,海洋产业生态系统发展水平低;辽宁省海洋产业、环境子系统适应性指数较小,海洋产业、环境子系统发育较平衡;山东省海洋产业、环境子系统适应性指数较高,海洋产业生态系统发展水平高,海洋产业子系统发展迅速。  相似文献   
599.
全球植被与大气之间碳通量的模式估计   总被引:15,自引:0,他引:15  
用大气植被相互作用模式(AⅥM)模拟了全球陆地植被的净初级生产力(NPP)。AⅥM由相互耦合的两部分组成:物理过程,包括陆地表面水分和能量在土壤、植被与大气之间的传输;以及生理生态过程,如:光合、呼吸、干物质分配、凋落和物候等。全球的植被分为13类,土壤按质地分为6类。用EMDI提供的全球1637个包括不同植被类型的NPP观测点数据对模型进行了检验。NPP模拟的结果表明:全球陆地植被的平均NPP为405.13 g C m-2yr-1,不同植被类型的平均NPP变化范围在99.58 g C m-2yr-l(苔原)到996.2 g C m-2yr-l(热带雨林)之间。全球年总NPP为60.72 Gt C yr-l,其中最大的部分为热带雨林,15.84 Gt C yr-1,占全球的26.09%。最大的碳汇是在北半球的温带。模式模拟的NPP在全球的空间和季节分布是合理的。  相似文献   
600.
山东省农业生产条件现代化可持续发展研究   总被引:9,自引:1,他引:9  
农业生产条件现代化是实现农业现代化的重要基础 ,包括农业机械化、农业水利化、农业化学化和农业电气化 4个方面。本文根据山东省近 2 0年的统计资料 ,全面分析了山东省在由传统农业向现代化农业转变过程中 ,在农业生产条件方面所取得的进展和明显存在的问题。如农业机械发展结构欠合理、农田水利工程建设标准不高、化肥施用构成比例不当等 ,针对上述问题 ,提出实现农业生产条件现代化可持续发展的战略措施 :1完善农机服务体系 ,大力开展农机社会化、市场化服务 ;2狠抓以水利为重点的农田基础设施建设 ,提高农田水利建设的科技含量 ;3加大对磷肥使用宣传力度 ,降低化肥农药造成的环境污染 ;4继续大力实施“科教兴农”战略 ,加速农业科技成果转化。  相似文献   
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