首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
宁夏农牧业发展方向与草地农业结构调整问题的探讨   总被引:3,自引:0,他引:3  
针对宁夏农牧业发展结构失衡的现状,指出长期推行重农轻牧的农区模式而不是发展草地农业是一种方向性失误。为此探讨了宁夏农牧业结构调整的生态学依据,分区调整方向与拓宽结构调整思路的问题。  相似文献   

2.
在分析青海省农业资源及环境状况的基础上,就如何把握和处理好经济的发展与环境保护问题,从不同角度进行分析论证,并提出在有效地保护或改善好自然环境的同时,通过合理开发利用农牧业资源来解决青海粮食自给和脱贫致富的问题,从而为使青海农牧业的持续稳定健康发展创造良好环境提供必要的依据。  相似文献   

3.
右玉县是一个农牧交错区域,过去自然灾害频繁,人民生活艰苦。从1952年开始,大抓植树种草,至今已基本控制了灾害的影响,农牧业生产不断发展,人民生活不断提高。本文概略地总结了综合农业生产发展的成就,提出了合理布局和调整问题,强调加速畜牧业和野生经济动植物种养事业的发展,大抓农牧产品加工体系的建立,以促进农林各业的进一步发展,以适应形势发展的要求。  相似文献   

4.
在遥感生态指数(Remote Sensing Ecological Index,RSEI)的基础上引入PM10作为大气环境质量指标,提出了改进的遥感生态指数(Improved remote sensing ecological index,IRSEI),并基于IRSEI分析了宁夏2000-2020年的生态环境质量时空分布格局与演变,以及宁夏生态环境质量的变化趋势,此外还深入讨论了不同的指标归一化方式对IRSEI结果的影响。结果表明,1)2000-2020年,宁夏生态环境质量呈现“先上升,后下降,又上升”的趋势,21年间IRSEI从0.329上升至0.426,总体上升了约29.48%;空间分布上,生态环境质量等级为“优”和“良”的地区主要分布在宁夏北部、南部以及黄河流域沿岸,生态环境质量等级为“差”和“较差”的区域主要分布在宁夏中部。2)宁夏生态环境质量改善面积远大于退化面积,21年间改善面积占比达到54.42%,且极强改善区域集中在宁夏南部,中部以较强改善为主,退化面积占比为14.98%,主要分布在北部城市区域。3)趋势分析结果表明,宁夏生态环境质量呈改善趋势的区...  相似文献   

5.
试论土壤基层分类与种植业结构调整的关系   总被引:1,自引:0,他引:1  
在分析土壤基层分类内涵与种植业结构调整背景及目标的基础上,揭示了土壤基层分类与种植业结构调整的内在联系、探讨了种植业结构调整的原则。提出了典型土壤基层分类与种植业结构调整的应用典例。为土壤基层分类与种植业结构调整的深化研究提供了基础依据。  相似文献   

6.
将农药使用量增长的驱动因素分解为播种面积、各农作物用药强度和种植结构调整3个因素,利用2006—2016年农药使用量及农作物种植结构相关数据,从全国和区域2个层面,系统测算了这3个因素对农药使用总量增长的贡献率,着重分析了种植结构调整对农药使用总量增长的影响作用。近年来我国农作物种植结构总体呈现高用药农作物种植比例不断增加而中低用药农作物种植比例逐渐减少的变化趋势,高用药作物中蔬菜占比增加最明显,增加1.38%。西南地区是农业种植结构变化幅度最大的区域,其高用药作物种植比例增长8.54%。从农药使用量增长的驱动因素分解结果来看,种植结构调整对农药使用量增长的平均贡献率达50.10%,在部分年份种植结构调整甚至是促使农药使用量增长的最主要因素。西南、华中和东南地区高用药农作物对中低用药农作物的替代程度较高,种植结构调整是这3个地区农药使用量增长的最主要驱动因素。提出如下农药使用量控制管理的种植结构调整策略:采用合理的经济手段,引导农业种植结构向"节药型"方向转变;加强农药使用区域化治理,重点调整高强度用药地区农业种植结构;加大农药减量替代技术的政策支持力度,提高农户技术采纳率;完善农药使用总量控制制度建设,保障农业绿色化发展。  相似文献   

7.
宁夏素有"长城博物馆""长城之乡"之称,三关口明长城作为宁夏特色旅游资源,一直处于养在深闺无人知的状态,尚未发挥"无烟工业"的积极作用。文章应用层次分析法,评价宁夏三关口明长城旅游资源质量,分析其开发条件,并提出其旅游开发和保护对策。  相似文献   

8.
右玉县是一农牧效错区域,过去自然灾害频繁,人民生活艰苦。从1952年开始,大抓植树种草,至今已基本控制了灾害的影响,农牧业生产不断发展,人民生活不断提高,本文概略地总结了综合农业生产发展的成就,提出了合理布局和调整问题,强调加速畜牧业和野生经济动植物种养事业的发展,大抓农牧产品加工体系的建立,以促进农林各业的进一步发展,以适应形势发展的要求。  相似文献   

9.
以黄河宁夏段干流水质监测资料为基础,利用多元统计法对水质样本点进行主因子分析、方差检验和聚类分组,对分组后的水质指标样本点应用综合水质标识指数进行综合评定.结果表明:(1)黄河宁夏段干流水体水质量为Ⅱ—Ⅴ类水质,入境断面水质量为Ⅱ类水质,出境断面水质量为Ⅲ类水质.(2)从上游到下游断面水质呈现恶化趋势,平水期最好,丰水期次之,枯水期最差.(3)水质评价结果分辨率高,客观反映了黄河宁夏段综合水质特征信息.因此,基于多元统计与综合水质标识指数的水质评价方法对黄河宁夏段水环境的水质评价工作具有较好的适用性.  相似文献   

10.
1961—2010年宁夏无霜期变化特征   总被引:3,自引:0,他引:3  
利用1961—2010年宁夏全区20个气象站的逐日最低气温资料,根据霜冻气候指标计算了各站逐年的无霜期。采用基础统计方法和气候诊断分析方法,研究了宁夏全区及不同区域的无霜期基本特征和变化趋势。结果表明:近50年来宁夏无霜期的空间差异明显,多年平均无霜期最长达166 d(吴忠站),最短仅有117 d(隆德站),空间差异最大为49 d;从时间上分析,1972年全区平均无霜期最短,只有121 d,2000年和2001年最长,达167 d,年际间最大相差46 d;在3个区域中,多年平均无霜期以及80%和90%保证率的界限值均是引黄灌区>中部干旱带>南部山区;近50年来,全区平均无霜期以4.7d/10 a的速率延长,3个区域的无霜期均呈延长趋势,其中南部山区的延长速率最快,达5.8 d/10 a;全区的无霜期在1982年发生突变,其中引黄灌区和中部干旱带的突变年与全区一致,南部山区的突变年提前了2年;从年代际看,20世纪70年代的平均无霜期最短,21世纪初的最长,两个年代相差20 d。宁夏无霜期呈现明显延长趋势,这与1961年以来宁夏平均气温明显升高的趋势保持一致,春、秋季的平均气温均在升高使得终霜日提前、初霜日推迟是无霜期延长的主要原因。如果不考虑其他因素,无霜期延长对宁夏的农业生产较为有利。  相似文献   

11.
As part of its development policy to relieve rural poverty in west China, the Chinese government has introduced measures such as agricultural tax exemptions, agricultural subsidies, and scientific, technological and restructuring improvements to agriculture. Following these actions, farmers’ incomes have increased greatly and the economy in poor areas of west China has seen rapid improvements. However, agricultural restructuring, infrastructure construction and ecological restoration projects have reduced the area of land under arable farming, restricting opportunities for increasing total grain yield. Regional food security is therefore threatened and an imbalance between economic development and food security is created. Shaanxi is a representative province in west China where agricultural restructuring has resulted in large areas of arable land being converted into orchards that produce higher economic returns. This study randomly surveyed 1430 farm households in three counties in the apple-producing region of Shaanxi Province (Luochuan, Changwu and Baishui). The standard of living and household income of farmers in the fruit production areas were higher than in grain-producing areas, thus discouraging grain production. Land under agriculture in the counties studied comprised 59% orchards and 39% arable, with 2% under other uses. Per capita, 204.3 kg of grain was produced, 51% of that required for self-sufficiency. Other staple foods produced amounted to only 13.9% of that needed for self-sufficiency. As a result, nearly half of the grain needed by the community was purchased from outside, resulting in very poor regional food security. Clearly, fruit production in this region seriously affects regional food security. Coordination of relationships between rural economic development and regional food security is key for sustainable development of the regional agriculture and economy of west China.  相似文献   

12.
Modern agricultural practices have been strongly linked with increased NO3-N loadings in surface waters. Nitrate leaching increases as land use progresses from forest and moorland through grassland, to arable agriculture. There are, within the UK, few studies on a regional scale capable of displaying a relationship between land cover (agricultural intensity) and water quality. This relationship can be investigated using computer manipulation of spatial geographic information together with conventional river and agricultural census data.

Simple regression analysis against primary land cover suggests that agriculture is reponsible for annual losses of nitrate in North East Scotland river catchments. Further multi-linear regression analysis, using the GIS data and agricultural census returns indicate that most of the outstanding variation can be accounted for if the agricultural variable is related to agricultural practice, such as spring, winter and grass cropping.  相似文献   

13.
Following the renewed effort at achieving a new green revolution for Africa, emphasis has been placed on modernizing smallholder agriculture through the deployment of improved inputs especially mechanized technologies. In Ghana, the government has in the last decade emphasized the provision of subsidized mechanized ploughing services to farmers alongside a rapidly growing private sector tractor service market. While mechanized technology adoption rates have increased rapidly, the deployment of these technologies has been without critical analysis of the impacts on production patterns and local agrarian systems. This paper examines the distributional impacts of agriculture mechanization on cropping patterns and farm sizes of smallholder farmers in northern Ghana using Geographic Information Systems (GIS) techniques, and semi-structured interviews with smallholder farmers (n=60). Specifically, comparative analysis of the field sizes and cropping patterns of participant farmers prior to and after the adoption of mechanized technologies was conducted. In-depth interviews were used to contextualize the experiences of smallholder farmers toward understanding how mechanization may be impacting traditional agriculture. Our findings reveal a mechanization paradox in which farm sizes are expanding, while cropping patterns are shifting away from traditional staple crops (pearl millet and sorghum bicolor) to market-oriented crops (maize, rice and groundnuts). This transition we argue, has adverse implications on the cultural dimension of food security, the organization of social life, and climate change adaptation. We recommend a retooling of the current agricultural policy focus to ensure context sensitivity for a more robust battle against food insecurity.  相似文献   

14.
The impacts of land‐use change on biodiversity in the Himalayas are poorly known, notwithstanding widespread deforestation and agricultural intensification in this highly biodiverse region. Although intact primary forests harbor many Himalayan birds during breeding, a large number of bird species use agricultural lands during winter. We assessed how Himalayan bird species richness, abundance, and composition during winter are affected by forest loss stemming from agriculture and grazing. Bird surveys along 12 elevational transects within primary forest, low‐intensity agriculture, mixed subsistence agriculture, and intensively grazed pastures in winter revealed that bird species richness and abundance were greatest in low‐intensity and mixed agriculture, intermediate in grazed pastures, and lowest in primary forest at both local and landscape scales; over twice as many species and individuals were recorded in low‐intensity agriculture than in primary forest. Bird communities in primary forests were distinct from those in all other land‐use classes, but only 4 species were unique to primary forests. Low‐, medium‐, and high‐intensity agriculture harbored 32 unique species. Of the species observed in primary forest, 80% had equal or greater abundance in low‐intensity agricultural lands, underscoring the value of these lands in retaining diverse community assemblages at high densities in winter. Among disturbed landscapes, bird species richness and abundance declined as land‐use intensity increased, especially in high‐intensity pastures. Our results suggest that agricultural landscapes are important for most Himalayan bird species in winter. But agricultural intensification—especially increased grazing—will likely result in biodiversity losses. Given that forest reserves alone may inadequately conserve Himalayan birds in winter, comprehensive conservation strategies in the region must go beyond protecting intact primary forests and ensure that low‐intensity agricultural lands are not extensively converted to high‐intensity pastures.  相似文献   

15.
农业管理措施对N2O排放的影响   总被引:1,自引:0,他引:1  
结合国内外文献资料 ,介绍了目前N2 O排放的研究现状 ,详细分析了种植方式、作物类型、肥料施用、水分管理、耕翻等农业管理措施对土壤N2 O排放的影响 ,并对今后的研究重点进行了讨论。  相似文献   

16.
中国农业发展正呈现现代化、结构优化、产业化、标准化、信息化、生态良性化等发展趋势。在经济全球化背景下 ,中国加入WTO后 ,农业生态学也面临着新的问题和任务 ,主要包括 :(1 )农业结构调整中的生态学问题 ;(2 )农业生物安全问题 ;(3)食物安全与生态农业建设问题 ;(4)农业资源与物种多样性保护问题 ;(5)农业生态管理与生态补偿问题 ;(6)农业与农村生态环境建设与生态恢复问题 ;(7)农业人口迁移与城市化过程中的生态学问题 ;(8)贫困地区的农业生态经济与可持续发展问题  相似文献   

17.
生态农业系统综合效益评价研究动态与展望   总被引:8,自引:0,他引:8  
总结了国内外生态农业发展和生态农业系统生态经济评价体系及评价的方法,阐述了生态农业综合效益评价的特点及国内外研究的最新动态。提出土壤健康在农业持续发展评价中的重要性。最后指出了生态-经济系统整合模型在建立生态农业最优化模式中的应用前景。  相似文献   

18.
Agricultural practices should modify the diversity of soil microbes. However, the precise relationships between soil properties and microbial diversity are poorly known. Here, we study the effect of agricultural management on soil microbial diversity and C turnover in tropical grassland of north-eastern Laos. Three years after native grassland conversion into agricultural land, we compared soils from five land use management systems: one till versus two no-till rotational cropping systems, one no-till improved pasture and the natural grassland. Soils were incubated in microcosms during 64 days at optimum temperature and humidity. Bacterial and fungal diversity were evaluated by metagenomic 454-pyrosequencing of 16S and 18SrRNA genes, respectively. Changes in soil respiration patterns were evaluated by monitoring 12C- and 13C-CO2 release after soil amendment with 13C-labelled wheat residues. Results show that residue mineralization increased with bacterial richness and diversity in the tilled treatment 7 days after soil amendment. Native soil organic C mineralization and priming effect increased with fungal richness and diversity in improved pasture and natural grassland. No-till cropping systems represented intermediate situations between tillage and pasture systems. Our findings evidence the potential of controlling soil microbial diversity by agricultural practices to improve soil biological properties. We suggest the promotion of no-till systems as a fair compromise between the need for agriculture intensification and soil ecological processes preservation.  相似文献   

19.
现代生态农业与农业安全   总被引:19,自引:7,他引:19  
赵其国 《生态环境》2003,12(3):253-259
现代生态农业是现代农业的发展方向;现代生态农业的核心是农业的可持续发展,其重要内容是农业安全。文章着重提出现代生态农业的基本概念与内涵,指出现代生态农业是以生态理论为基础,以现代生态农业技术为手段,通过农业与环境,生态与经济的平衡,达到农业可持续发展、农业安全和人类健康的最终目标。在总结国家发展现代生态农业的经验的基础上,列举了我国东南沿海经济发达地区(包括江苏省)存在的生态环境质量和农业安全问题,最后提出现代生态农业建设和解决农业安全问题的对策与建议。  相似文献   

20.
Although sustainable development has already been promulgated as one of its fundamental strategies by the national government since 1993, sustainable development, as an exotic new paradigm characteristic of profound philosophical and ethical thinking initiated in developed countries, is still not familiar to the Chinese people. Fortunately, in parallel to the evolution of sustainable agriculture, mainly in developed countries, since the beginning of the 1980s, Chinese agricultural scientists and technicians have already innovated their own unique form of Chinese Ecological Agriculture (CEA), on the basis of traditional agriculture that has been sustained for more than 4000 years. The basic principle of CEA emphasizes the obeying of both ecological rules and economic rules, as well as the approach of systematics and ecological engineering exactly corresponding to those adopted by sustainable development. The major difference between the two is that CEA has already been executed on a very large scale and has served as an effective and popularized way to implement sustainable agriculture in most parts of China. Also, as an active way of intensifying agriculture in terms of more inputs of skills, knowledge and labour, CEA is contributing much to all-round rural development throughout China.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号