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1.
黄土高原生态经济分区的研究 总被引：6，自引：1，他引：6
在概述生态经济分区现状的基础上, 提出了在黄土高原进行生态经济分区的重要意义.选取自然资源、社会经济等22个指标, 以行政县(区)为单元, 利用聚类分析、主成分分析和GIS相结合的分区方法, 把黄土高原划分为4个生态经济带即南部暖温带半湿润农林生态经济带(Ⅰ)、中部暖温带半湿润半干旱农林牧生态经济带(Ⅱ)、西北部温带半干旱农牧生态经济带(Ⅲ)、北部温带干旱半干旱农牧生态经济带(Ⅳ)和18个生态经济区.通过该研究的实践, 不仅可为后续有效布设黄土高原的生态经济项目提供参考, 而且可为较大尺度区域进行生态经济区划研究奠定理论基础. 相似文献
2.
Most palms used in agroforestry systems are exploited from wild stands or are only occasionally cultivated, while only a few
palms have been domesticated. In this study we investigated how socio-economic factors and people's perceptions of changes
in palm use and availability, influenced palm cultivation among indigenous Shuar and mestizo settlers in south-eastern Ecuador.
We also looked at how different uses of palms influenced which species they cultivated. Our results showed that perceptions
of declining palm availability in combination with heavy reliance on palm products was positively related to palm cultivation.
Hence, cultivation was more common in more remote villages where alternative products were hard to get. In addition, palm
cultivation was more common among wealthier people and among indigenous people than among recent settlers. This points to
a limiting role of assets such as land and to the importance of history and culture with regard to cultivation. It was not
possible to identify any single palm use as the primary reason for cultivating a species, but the more uses a species had,
the more likely it was to be cultivated. These findings have important implications for development projects that promote
cultivation of palms and other long-lived tree crops. They illustrate how market access and lack of necessary assets may undermine
cultivation of native species even though these are regarded as important resources. 相似文献
3.
4.
《Plant Production Science》2013,16(3):149-164
AbstractThis review paper examines some of the issues concerned with sustainable production of two major cereal crops – wheat and rice. We compare the perceived threats to sustainability in intensive production of rice in Japan and wheat in Europe, and evaluate the contrasting experiences with minimum tillage as a possible technique for greater sustainability. The contrasts which are presented reveal how perceptions about environmental threats vary widely, and how social and economic factors, as well as purely environmental issues, greatly influence the conclusions reached about sustainability. Before drawing these comparisons, however, we present a brief outline of the two crop systems as practised in Japan and Europe, and describe the experiences in both regions of using minimum tillage.The comparison presented has shown that there are no simple solutions to the problem of sustainability. Management techniques which work well in one situation, for example minimum tillage for wheat, may be inappropriate for another crop. Furthermore, the search for sustainability is strongly constrained by social and economic circumstances which ultimately determine which management options are viable. Indeed, although awareness of the need for more sustainable agricultural practices is growing, both in Japan and Europe, short-term economic considerations continue to be the dominant influence affecting agricultural practice in both regions. 相似文献
5.
Gum arabic production in Sudan has developed over the years in a well-established traditional bush-fallow system in which
the gum tree (Acacia senegal) is rotated with annual crops. Following the Sahel drought, the gum area has suffered from deforestation and gum production
has declined. Several programs have been developed to stimulate gum production; however, many original adopters have disadopted
gum production and the bush-fallow system. In this paper we apply a logit model to study the decision-making behavior of farmers
in west Sudan and to identify the socio-economic factors influencing disadoption of gum production and gum agroforestry system.
Variables that measure farmer’s wealth were found significant in explaining the disadoption behavior. Off-farm work was also
found to positively influence the disadoption decision. Results show that a higher level of income from annual crops decreases
the probability of disadoption, which suggests that annual crops and gum production do not compete but rather complement each
other within the farm household economy. Therefore, policy measures aiming to boost the production of annual crops in the
region might reduce seasonal labor migration and accordingly stimulate gum production.
相似文献
| Afaf H. RahimEmail: |
6.
Adoption of rubber-integrated farm-livelihood systems: contrasting empirical evidence from the Indian context 总被引：2，自引：0，他引：2
This paper examines the influence of important socio-economic, institutional/policy level factors in determining the adoption/non-adoption
of rubber-integrated farming systems in traditional and non-traditional rubber-growing regions in India. The empirical analysis
is based on a survey of rubber growers in the traditional rubber regions of Kerala (south India) and the non-traditional rubber
regions of Assam, Meghalaya, and Tripura (north east India). In sharp contrast to Kerala, where smallholder responses toward
adoption of rubber-integrated farming systems have been lukewarm, the emerging rubber economies (most of which are tribal
communities) of north east (NE) India have shown interest in adopting rubber as an integrated farming system along with pre-existing
land-use livelihood activities. The study clearly demonstrates contrasting empirical evidence of adoption of rubber-integrated
farm-livelihood systems in the rubber-growing regions in Kerala and the NE states in India. The contrasting scenarios of adoption
of rubber-integrated farming systems are mostly explained by region-specific factors dominated by socio-economic, institutional
variables, and policy-level constraints, as also revealed by multivariate analysis. By and large, the findings of the study
have significant bearing on the socio-economic outcomes and the existing institutional development paradigm underlying the
rubber-development programmes introduced in India since independence. The study shows that the existing institutional arrangements
and policies, which evolved historically to facilitate rubber area expansion in the traditional regions (including Kerala),
have been highly instrumental in perpetuating rubber farming as a monoculture system. However, such an institutional mechanism
proves to be highly redundant in the context of the NE states which are otherwise diverse in terms of integrated farm-livelihood
systems and shifting cultivation. 相似文献
7.
Agroforestry systems, though at subsistence level are well established in Garhwal Himalayas. The farmers undertake cultivation of various crops, seasonal and biennials crops with trees all in mixtures on the same piece of land. Farm animals and poultry form an essential component of the systems. The intimate association of different species provides both subsistence and commercial products which give additional income to the farmer. The paper describes the general scenario of socio-economic condition and existing agroforestry practices and some suggestions for their improvement in the Garhwal Himalayas. 相似文献
8.
H. K. Barth 《Agricultural Water Management》1999,40(2-3):283-290
Since scarcity of water is a major problem in semi-arid and arid areas of Spain and many other Mediterranean regions, water consumption in irrigated agriculture has to be reduced to a sustainable level that is also adapted to the environment. This goal can be reached by applying the highly effective and resource preserving techniques of micro-irrigation. In order to improve these techniques, a new subsurface irrigation system was developed by modification of conventional subsurface systems through the following innovative elements:
a new design of the lateral hoses which prevents the penetration of roots into the external water outlets and the block up by soil particles;
an impermeable polyethylene foil placed below the lateral pipes to prevent water loss through deep percolation, especially in sandy substrates;
a special installation equipment consisting of a V-shaped device which releases foil and pipe simultaneously into the soil without disturbing the natural soil profile.
After the experience of several years of operation, these elements have proved to be highly effective. Compared to other irrigation methods, the high irrigation efficiency achieved by this system was outstanding. Minimum maintenance requirement and a long life span are additional positive characteristics of the system. The beneficial outcomes of this system give reason for an optimistic appraisal of the strategies involved towards sustainable irrigated agriculture. 相似文献
9.
Analysis and evaluation of mortality losses of the 2001 African swine fever outbreak,Ibadan, Nigeria
Babalobi OO Olugasa BO Oluwayelu DO Ijagbone IF Ayoade GO Agbede SA 《Tropical animal health and production》2007,39(7):533-542
The mortality losses of pigs of various age groups affected by the 2001 African swine fever outbreak in Ibadan Nigeria were
analyzed and evaluated. Thirty one thousand nine hundred and sixteen (31,916) pigs on three hundred and six (306) farms reported
by the Pig Farmers Association of Nigeria and the State Ministry of Agriculture and Natural Resources were involved. Gross
mortality was ninety one percent (91%), while age group mortality ranged from 75.9% (growers), 83.1% (weaners), 91.2% (finishers)
and 99.8% (piglets); to 100.0% in gilts, sow and boars. Losses were estimated to worth nine hundred and forty one thousand,
four hundred and ninety one dollars, sixty seven cents (US $941,491.67). Highest financial loss was from sows (29.5% of total
loss), followed by gilts (16.6%), finishers (15.2%), weaners (10.7%), boars (10.6%), growers (10.6%) and piglets (8.2%). Average
mortality loss per farm of $3076.77 was of great financial and socioeconomic consequences for a developing country like Nigeria
with a low Gross Domestic Product figures. In conclusion, the need to immediately revisit and take recommended actions on
the 1998 Report of the FAO Consultancy Mission to Nigeria on Control and Eradication of an Outbreak of African swine fever
in Western Nigeria is stressed. 相似文献
10.
气候与社会经济因素对土壤有机质影响的空间异质性分析--以黑龙江省中部地区为例 总被引：2，自引：0，他引：2
为探讨土壤性质对外部因素的响应机制及空间规律,本文以黑龙江省中部为例,利用地统计学理论、GIS空间分析与地理加权回归模型(geographically weighted regression,GWR),从空间分异角度分析了气候和社会经济因素对土壤有机质的影响程度。结果表明,有机质含量分布在研究区域西部呈现出东高西低的特征,在研究区域东部则表现为中部高南北低;气候变量(均在0.01水平上显著)中,降水和年均温对有机质含量以负影响为主;年日照时数对除嫩江平原西南部和松江平原南部外的多数区域有机质含量产生正影响。社会经济因素(均在0.01水平上显著)中机械化耕作水平对嫩江平原北部、西部和克拜丘陵部分区域有机质含量产生正影响;灌溉面积对有机质含量的正影响范围较广;施肥量对嫩江平原南部、松江平原西北部和三江低平原东北部等有机质含量主要产生负影响,其他区域则主要为正效应;地膜用量对有机质含量的正影响范围较广;农药用量对研究区域西部以正影响为主,对东部以负影响为主。因此,反映自然条件差异的气候因素与反映农业投入的社会经济因素对土壤有机质的影响均具有空间异质性,采用允许局部估计的GWR模型是适合的。 相似文献