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131.
Traditional farming practices conform to sustainable rural livelihoods, while agricultural modernisation tends to undermine these practices through various perturbations. A case study in Tengchong County (western Yunnan, China) shows that transformation of traditional alder (Alnus nepalensis) and dry rice (upland rice) rotational farming to introduced Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations leads to localised water scarcity and soil fertility decline. While farmers are aware of ecological sustainability of traditional farming, they prefer Chinese fir forestry because it is less labour-intensive, has a high market value, and releases time for profitable off-farm work. Farmers adapt to economic liberalization by planting high value crops and trees. However, alternatives to make local agricultural production more profitable through competitive business strategies, cooperative approaches, innovations in integrating high value crops and ‘downstream’ processing for sustainable rural livelihoods have been overlooked largely due to poor information availability and lack of organisational framework.  相似文献   
132.
A MULTIDISCIPLINARY AND INTEGRATED STUDY OF RICE PRECISION FARMING   总被引:1,自引:0,他引:1  
In terms of demands of rice farming in the southern China,the information processing system and the yield measurement system that is installed in combine harvester,are designed and completed.Now the systems have been used in demonstration site in the Experiment Base of Shanghai Precision Agriculture.Based on the idea of spa-tial-oriented,object-oriented,user-oriented,the Farm Geographic Information System for precision farming of rice was developed,which is characterized by intelligence and visualized.The Decision-making Management System is integrated with rice growth model,expert model for rice cultivation.The DGPS,RS,GIS and intelligence sensors and computer technique were adopted in building the artificial intelligence system for measuring grain yield that is installed in combine har-vester,so the combine harvester could provide the grain yield distribution map real-timely.The environmental and econom-ic assessment shows that the precision rice farming applied in the demonstration site will benfit the society,economy and ecology greatly.  相似文献   
133.
岩体内部接触关系的研究是花岗岩等级体制划分及填图的唯一途径。1:5万区调证实,以造山带复杂地壳组份为背景的西秦岭洮坪地区花岗岩类发育,其成因为以S型为主兼有Ⅰ型,因而兼有结构序列和成分序列双重演化规津。这对更有效地综合运用两种类型的划分方法和划分原则来进行超单元—单元划分并指导填图提供了方便。本文着重介绍划分原则、划分方案及野外识别复式岩浆侵入序次和演化序列等重要特征的内部接触关系。  相似文献   
134.
综述了河蚌养殖育珠对水域水质影响以及养殖模式优化,指出采用适当的养殖模式养殖育珠,可修复水域环境与改善水质状况.  相似文献   
135.
Expanded organic food production has been an issue of public debate in Denmark since its promotion by two government-sponsored plans. Yet the number of organic farms, constituting 5% of alt Danish farms, is still small. Farmers' attitudes and motivations around converting their farms to organic agriculture were surveyed in the counties of Ribe and Vestsj?lland in order to assess the feasibility of expansion. New organic farmers come either from the ranks of conventional farmers or from ‘beginners’ who initiate organic agriculture from the start. Only 7% of conventional farmers plan to convert their farms by the year 2003, but beginners will have increasing importance and augment the number. Farmers most frequently mentioned consideration for the environment as a reason for conversion. A considerable expansion of organic agriculture will be difficult, due to an insufficient number of farmers interested in organic agriculture. A high number of less productive hobby or spare-time farmers among new organic farmers also hinders expanded organic food production. Organic agriculture shows parallels to conventional agriculture, with a surplus of very small and very large farms, regional specialisation, and oil-farm specialisation.  相似文献   
136.
Shifting cultivation is often blamed for deforestation in tropical upland areas. Based on a case study of three villages in northern Lao PDR, this paper combines household surveys with a remote sensing based analysis of forest cover, covering the period 1989–1999, in order to analyse changes in shifting cultivation practices and livelihood strategies and the impact of these on deforestation. Due to population pressure and relocation of villages, easily accessed land is increasingly scarce and fallow periods have been shortened during the 1990s. A net annual deforestation of about 1% was found in the area during the study period. This deforestation rate reflects shorter fallow periods in secondary forests rather than encroachment on mature forests, which are not used for cultivation by the farmers in the three villages. Farmers rate scarce labour as a major constraint on shifting cultivation; nonetheless, a tendency towards lower labour input with shorter fallow periods is observed, contradicting conventional intensification theory. Livelihoods are diversifying through the establishment of plantations, cultivation of wet rice and adoption of animal husbandry, but given the socio-economic conditions in the area, shifting cultivation is likely to remain the most suitable farming system in the near future.  相似文献   
137.
Geografisk Tidsskrift-Danish Journal of Geography 111(2):149–167, 2011

The modernization of agricultural food production has diminished and is diminishing the sustainable use of the local natural resource base, resulting in the fragmentation of landscapes and the decline of biodiversity. In this paper we analyze the revitalization of ecological capital, which provides insights into how effective adjustments in land-use and farming practices can stimulate a reconnection between farming, nature and society. The paper focuses on a case study about endogenous knowledge on the relation between farm activities and the reproduction of the landscape and its flora and fauna in the (Dutch) Friesian Woodlands. We suggest that building adequate, local institutional frameworks that strengthen landscape structures, regional identity and the ‘branding’ of food products will sustain rural development in the area. The results should be of value for increasing the understanding among researchers and policymakers of the potential of endogenous knowledge in governing the increase of the ecological stock in an area.  相似文献   
138.
The feasibility of ranching wild cod in ‘herds’ was compared with three other scenarios: on-growing of wild cod in sea cages, full-cycle cod farming with hatchery produced juveniles, and commercial cod fishery. In the calculations it was assumed that an existing fishing company could either fish, ranch or on-grow 200 tons of cod quota to increase the quota yield or sell it to invest in full-cycle farming. The results indicate ranching to be the most profitable, fishing as the second and on-growing as the third, whereas full-cycle farming appears to be unrewarding. The net present value (NPV) of the four scenarios was €754 000, €532 000, €198 000 and €−95 000, respectively. Ranching based on aggregating and growing wild cod in a reserved coastal area with anthropogenic feeding thus has the potential of decreasing the cost of fishing, improving growth rate and enhancing quota yield without the investments required in conventional farming. As cod ranching is in the initial stages of development the risks are higher than in the well established cod fishery.  相似文献   
139.
2013年5月、8月和11月调查了象山港大黄鱼网箱养殖区及附近沉积物中总有机氮(TON)、总有机碳(TOC)和总磷(TP)含量,并采用实验室模拟法研究了底泥耗氧率(SOCs)和沉积物-水界面营养盐(NH+4、NO-2+NO-3和PO3-4)通量。结果表明:养殖区(YZ)沉积物中的TON和TP含量显著高于距离养殖区50 m(F1)和100 m(F2)的区域(P<0.05)。底泥释放NH+4到上覆水中,但是从上覆水中吸收NO-2+NO-3和PO3-4。沉积物-水界面营养盐通量表现出明显的季节性变化,在8月,NH+4及PO3-4的释放量达到最大值。上覆水中NH+4、NO-2+NO-3和PO3-4的质量浓度随着沉积物-水界面营养盐通量的变化而变化。研究表明,象山港大黄鱼养殖活动对养殖区底泥造成了一定污染,且通过影响沉积物-水界面营养盐通量影响上覆水中营养盐分布,最终给整个养殖系统造成生态负担。  相似文献   
140.
野生动物友好型耕作(Wildlife-friendly Farming,WFF)实践是一种维持农田生态恢复的良好方式。本研究的目的在于探讨影响日本佐渡岛农民实施WFF的因素和提出影响这种实践传播的政策。对佐渡岛上把大米销售给日本农业合作社(Japan Agricultural Cooperatives,JA)的5010个农户进行了问卷调查,总共收到2231农户反馈问卷(反馈率45%)。通过与未经认证农民的态度和属性对比,我们确定了影响农民实施WFF的关键因素。与未经认证的农民相比,已认证的农民:(1)对生物多样性和WFF的经济效益表现出更高的兴趣;(2)拥有更多的已认证农民朋友;(3)感受到了来自消费者的更多的压力和期望;(4)当实施WFF时,不受恶劣劳动力或农田条件的限制。为了在佐渡岛进一步宣传WFF,我们建议把WFF实践对稻田生物多样性的有效性信息应用到公共教育中,并在非认证农民和已认证农民之间、农民与消费者之间创建交流的机会。  相似文献   
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