首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   193篇
  免费   16篇
  国内免费   4篇
林业   29篇
农学   9篇
基础科学   15篇
  26篇
综合类   97篇
农作物   14篇
水产渔业   5篇
畜牧兽医   9篇
园艺   2篇
植物保护   7篇
  2024年   4篇
  2023年   14篇
  2022年   12篇
  2021年   11篇
  2020年   10篇
  2019年   9篇
  2018年   12篇
  2017年   5篇
  2016年   7篇
  2015年   5篇
  2014年   15篇
  2013年   18篇
  2012年   4篇
  2011年   2篇
  2010年   5篇
  2009年   9篇
  2008年   6篇
  2007年   7篇
  2006年   11篇
  2005年   9篇
  2004年   6篇
  2003年   4篇
  2002年   7篇
  2001年   3篇
  2000年   1篇
  1999年   5篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1981年   1篇
排序方式: 共有213条查询结果,搜索用时 23 毫秒
71.
China is characterized as ‘a large country with many smallholder farmers’ whose participation in modern agriculture is key to the country's modern agriculture development. Promoting smallholder farmers’ adoption of modern agricultural production technology is one effective way to improve the capabilities of smallholder farmers. This paper aims to explore the impact of Internet use on the adoption of agricultural production technology by smallholder farmers based on a survey of 1 449 smallholders across 14 provinces in China. The results suggest that Internet use can significantly promote technology adoption, with the probability of adopting new crop varieties, water-saving irrigation technology and straw-returning technology increasing by 0.200, 0.157 and 0.155, respectively. Furthermore, the effect of Internet use is found to be heterogeneous with a greater effect on smallholder farmers having low education levels, limited training, and high incomes. To increase agricultural production technology adoption by smallholders, rural Internet infrastructure and Internet use promotion should be the focus for the Chinese government.  相似文献   
72.
多项绿色生产技术的采纳决策:影响因素及相关性分析   总被引:1,自引:0,他引:1  
为探索农户面临多项绿色生产技术时如何做出采纳决策,本研究采用多元Probit模型在控制误差项相关的基础上,分析农户采纳不同属性绿色生产技术(保护性耕作技术、绿色防控技术、农膜回收处理技术)的可观测影响因素,并研究多项技术采纳决策之间的相关性。进一步地,通过技术采纳的条件概率与平均处理效应(ATT)来估计相关性对每一项技术采纳的影响。结果表明:1)不同资源禀赋的农户对采纳属性各异的技术有一定的选择偏向,但又不必然采纳对应属性的技术。2)不同阶段的绿色生产技术采纳相互依赖,存在着较强的正相关性。通过对比其影响效应发现,农户采纳绿色生产技术的项目数量对采纳概率的提升具有"叠加效应",不同绿色生产技术间相关性的影响具有异质性。因此,本研究提出应结合农户的资源禀赋和技术属性,采用差异化的技术推广策略,并根据技术间相关性影响的大小,合理安排技术组合与推广的先后顺序,以最大化绿色生产技术推广的效果。  相似文献   
73.
我国生物农药的推广应用现状及发展策略   总被引:3,自引:0,他引:3  
郭荣 《中国生物防治》2011,27(1):124-127
我国生物农药的应用具有良好的基础,在20世纪80年代至90年代曾得到迅速发展.21世纪以来,我国生物农药的应用发展缓慢甚至停滞不前.在我国农作物病虫害防治中,生物防治占防治总面积的8%左右,其中88%为生物农药,12%为人工释放天敌昆虫和昆虫信息素诱杀,而生物农药品种中,杀虫剂占1/3,杀菌剂占2/3.制约我国生物农药推广应用的主要因素,除生物农药自身覆盖的靶标对象少、防效受环境因子影响大等因素外,缺乏激励政策、药效评价标准单一、重基础研究轻应用开发也影响了我国生物农药的发展.近年来,"公共植保,绿色植保"理念的提出和实践,为生物农药的发展提供了平台和手段,通过政府制定鼓励政策、对农民应用生物农药给予补贴、设立生物农药及生物防治技术示范推广项目等途径,可以在政策和技术层面上切实促进生物农药的推广和应用;同时,需要加大农民技术培训力度,不仅为农民提供优质高效的生物农药品种,还要使农民掌握生物农药的应用技术.  相似文献   
74.
Natural rubber (Hevea brasiliensis) is one of the major plantation crops of the state of Kerala in India and intercropping is practised during the initial gestation period of the crop. In this paper a to bit model was used to study the decision making behaviour of farmers in adoption and extent of adoption of intercropping in three regions of Kerala. The availability of family labour and the type of intercrops were found significant in explaining the adoption behaviour in all three regions. The perception of profitability of intercropping was also found to influence decision on adoption. The probability of adoption of intercropping was highest for three intercrops, banana (Musa spp.), cassava (Manihot esculenta) and pineapple (Ananas comosus). Targeting extension efforts to groups of farmers with available family labour and popularising selected intercrops may result in higher rates of adoption of intercropping in all three regions of the state.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   
75.
Adoption of a new technology, such as irrigation, is a complex phenomenon. Several factors of economic and social nature contribute to the farm-level decisions affecting adoption. In this study, the role played by attitudes of potential adopters towards irrigation and its subsequent adoption on their farm unit was estimated. Two models were estimated, one incorporating only adopters' socio-economic characteristics, and the other, only their attitudes towards irrigation. Results suggest that adopters' attitude, particularly with respect to economic and environmental effects of irrigation, were significant determinants of their decision to proceed with adoption of irrigation, and have a role to play in adoption of irrigation over and above that explained by socio-economic characteristics. In particular, these results suggest that negative perceptions with respect to economics of irrigation and those related to its detrimental impacts on environmental quality, particularly through soil salinity, may be significant deterrents for adoption of irrigation. The study suggests that planning of large scale water development projects, particularly those involving irrigation, must be cognizant of attitudes of potential adopters. Furthermore, during the planning stages, more attention should be paid to the development of proper educational programs, as well as extension packages, to ensure that potential adopters formulate correct attitudes towards the new technology.  相似文献   
76.
This paper investigates the adoption of bench terraces by applying a three‐stage analysis using data from 301 households in the highlands of Rwanda. Ongoing adoption of bench terraces is ‘unpacked’ to consider both adopters willing to retain and increase the intensity of using terraces already constructed and new adopters willing to develop new bench terraces. Results suggest that farmers' inability to maintain existing terraces may explain the reluctance to adopt new terraces. The same inability explains why some of the terraces constructed earlier are not well maintained and fully used by farmers in northern and southern Rwanda. Policy actions aimed at improving farmer's capacity to invest in complementary inputs will sustain future generations of soil and water conservation measures in Rwanda. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
77.
This study examines the impact of farmers' cooperatives participation and technology adoption on their economic welfare in China. A double selectivity model(DSM) is applied to correct for sample selection bias stemming from both observed and unobserved factors, and a propensity score matching(PSM) method is applied to calculate the agricultural income difference with counter factual analysis using survey data from 396 farmers in 15 provinces in China. The findings indicate that farmers who join farmer cooperatives and adopt agricultural technology can increase agricultural income by 2.77 and 2.35%, respectively, compared with those non-participants and non-adopters. Interestingly, the effect on agricultural income is found to be more significant for the low-income farmers than the high-income ones, with income increasing 5.45 and 4.51% when participating in farmer cooperatives and adopting agricultural technology, respectively. Our findings highlight the positive role of farmer cooperatives and agricultural technology in promoting farmers' economic welfare. Based on the findings, government policy implications are also discussed.  相似文献   
78.
This study examined wetland farming systems in Edo State, Nigeria, with specific focus on practitioners’ response to Fadama technologies, as well as factors that might promote adoption behavior. Primary data were sourced from 301 wetland farmers across the three political districts in the state. Responses were analyzed using frequency distribution and multiple regression. Fertilizers, herbicides, insecticides, and improved varieties were the most adopted technologies; cost was the most serious constraint to adoption. The average earnings derived from wetland farming enterprises were 291,400.28 (US$1,942.60) per annum. Important determinants of wetland farming technology adoption by farmers include education, contact with extension agents, revenue, and credit. The study recommends an improvement in Fadama farmers’ access to credit and extension services.  相似文献   
79.
The credibility, reliability, and adequacy of information sources are cardinal to adoption of technologies that increase agricultural productivity. Date palm production in Nigeria is low and, considering its high demand, makes the country a net importer of date to meet local demands.

This study assessed the sources of information on date palm in Dutse Local Government Area of Jigawa State. A multi-stage sampling technique was used to select 115 date palm farmers. The results show that friends and relatives, extension agents, and radio are the preferred sources of information. The frequency and adequacy of use follow a similar pattern of preference.  相似文献   
80.
This study analyses the influences of sociodemographic factors, business orientation of farmers, and farm characteristics on adoption of ICT-based information through primary data collected from 461 farmers in eight districts of Uttar Pradesh, India. A personal interview survey was conducted using a pre-tested structured questionnaire. The Poisson Count Regression Model was used to analyze the factors influencing use of the information derived through ICT-based systems on various agricultural practices. The findings indicate that education, income, and social category of farmers are important sociodemographic factors affecting the adoption of ICT-based information systems. Similarly, farmers who consider farming as a business venture, practice a diversified cropping system, and have small farms are more likely to use ICT-based information.  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