农业生态观光园规划设计研究

农业生态观光园在规划设计理念上必须体现观光、休闲、生态环保和教育综合性特点,满足都市游客在快节奏城市生活压力下渴望回归田园的心理需求,因此在农业观光园的设计过程中必须始终保持以科技支撑的现代生态农业为载体,在规划和景观设计上注重时代性与传统性的结合,最大限度地体现自然性。生态观光园规划设计应表现自然生态环保理念,具有包容性、完善的功能设施和高质量的服务。     

Assessing the Potential Effects of Fungicides on Nontarget Gut Fungi (Trichomycetes) and Their Associated Larval Black Fly Hosts

Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far‐reaching consequences within aquatic ecosystems.     

农户对替代生计的选择及其影响因素分析——以甘南黄河水源补给区为例

论文通过实地调查获得研究数据,分析了农区、 半农半牧区、 纯牧区农户替代生计选择的结果及特征,采用Logistic回归模型对影响农户替代生计选择意愿的因素进行分析。研究得出:①在替代生计的选择上,纯牧区农户主要选择特色产品加工、 做生意、 现代畜牧业,农区和半农半牧区农户主要选择做生意、 外出打工和旅游服务业;②农户对替代生计的选择表现出生计路径依赖性、 区域差异性和多样性特征;③农户对替代生计的选择偏好受生计资本的影响,自然资本、 社会资本、 家庭整体劳动能力、 家庭整体受教育水平、 家庭拥有的牲畜数量、 户主的学历和年龄分别对不同替代生计的选择影响显著。地方政府应深入了解农户选择替代生计的特点和影响因素,根据不同家庭的情况设计相应的转型政策促进农户尽快提高生计能力。     

Is aridity restricting deforestation and land uses in the South American Dry Chaco?

In this paper, we explored how aridity influences the regional deforestation and land-use patterns (i.e. crops/pastures) in South American Dry Chaco. To do this, we contrasted land use during last decade (2001–2012) with a spatially explicit aridity index, which we complemented with a crop water balance model. Land-use classifications were performed by considering the temporal variability of NDVI from MODIS satellites, showing that 40 and 60% of deforested land was assigned to crops and pastures, respectively. Results indicate that although the regional deforestation pattern was not associated with the aridity gradient, with drier areas similarly deforested as wetter areas, contrasting differences were observed in the use of this land, with crops mostly located (90%) in wetter areas and pastures evenly distributed across the whole aridity gradient. This research highlighted the strong effect of water limitations on the land-use option after deforestation and may help to set the basis for future land-use planning policies.     

Moving towards sustainable development: rhetoric,policy and reality of ecological agriculture in China

Past decades have witnessed the rise of sustainable agriculture movements throughout the world. In parallel with this international trend, ecological agriculture (with essential goals of food security, rural employment, poverty alleviation, natural resource management and environmental protection) has been advocated as a workable approach for the realization of sustainable agriculture in China. Two decades of ecological agricultural development have shown that it not only gained legitimacy at the senior policy level but also became a focus of scientific research in fields such as ecological economics, ecology, and agricultural and environmental sciences. However, this endeavour is hardly known in the West and little attention has been paid so far to examining the broader politico-economic and sociocultural contexts within which it has evolved. This paper attempts to provide a general review of the emerging background, development history, policy initiatives and recent tendencies of ecological agriculture. In addition, the extant problems and potential contributions of this alternative practice to China's sustainable agricultural development are discussed. The purpose of this study is to identify the gap between the policy rhetoric and practical implementation of Chinese ecological agriculture and therefore to facilitate its moving towards sustainable development.     

国际标准产业分类体系的农、林、牧、渔业分类演化及启示

国际标准产业分类体系是目前国际上最有影响和权威的产业分类体系。深入了解国际标准产业分类体系中农、林、牧、渔业分类演化,对正确收集、处理和测算我国农、林、牧、渔业的指标以及国际间数据比较至关重要。论文首先详细地剖析国际标准产业分类体系的农、林、牧、渔业的分类演化,然后依据国际标准产业分类体系的最新变化,结合我国农、林、牧、渔业现状,为我国国民经济行业分类中农、林、牧、渔业的修改和调整提供建议。     

Interrelation of Cd‐lon concentrations and the growth and activities of microorganisms in two growth media†

Partitioning of native or anthropogenic heavy metals in solid and solution phases of soil is a result of network of several physico‐chemical reactions. The attainment of equilibrium between two phases is also regulated by biochemical processes. For practical purposes, the bioavailability of metal present in soil is predominantly regulated by the soil solution phase which is in dynamic equilibrium with the solid phase. The results of a model laboratory and greenhouse growth experiments have been used to investigate the effect of Cd‐ion concentrations (either in soil solution or in nutrient solution) on the growth and activities of microorganisms. The soil solution has been simulated by preparing a suspension of soil with 0.1 M NaNO₃ (1: 2.5) equilibrated for two hours. Important conclusions are as follows:

Increase in Cd‐ion concentration in soil solution or in nutrient solution induces corresponding adverse effect on the growth and activities of microorganisms. Thus, it seems that Cd‐ion concentration is a more sensitive indicator for assessing the effect of metal pollution upon the growth and activities of soil microorganisms in comparison to total Cd contents.

During active microbial growth phase, a large part of the organically bound Cd was released in the soil solution which is largely bioavailable. This process is termed as mobilisation. There was momentary increase of Cd‐ion concentration in soil solution which intoxicated the growing organisms. After this stage, the Cd ions from the solution phase were removed by the newly formed solid phase (nonviable biomass) and were transformed in non‐available form. This process is termed as immobilisation.

The consequences and importance of these results for practical agriculture and in deciding the limits or guidelines on the maximum tolerable metal load in soils are discussed.     

Multicriteria analysis applied to the sustainable agriculture problem

SUMMARY

The aim of this paper is to present an operational approach to compare the relative sustainability of existing farming systems. Sustainability rests on the assumption that an equilibrium must exist among three domains: social, economic and ecological. If we are to look for a solution to the problem, we must face a multi-dimensional approach. We propose that multicriteria analysis, a multi-dimensional method, is an appropriate methodology to study the issue. As sustainability cannot be measured directly, the way out is to use indicators. We have performed a thorough analysis of four farming systems existing in Guaíra, SP, Brazil to validate the methodology. Thirty indicators of sustainability (ten ecological, ten social, and ten economic) were defined and used to perform the analysis. The results of the multicriteria analysis proved useful because of its capability of reducing the dimensionality of the problem. From the three dimensions of sustainability, a final score was derived that can easily compare the relative sustainability of each farming system.     

Application of analytical hierarchy process and geographic information systems in land-use suitability evaluation: a case study of Dümrek village (Çanakkale,Turkey)

This study used both analytical hierarchy process (AHP) and geographic information systems (GIS) to make a land-use suitability analysis for the village of Dümrek, NW Turkey. Primarily, alternative land uses for agriculture, meadow–pasture and forest were determined along with criteria for these alternatives and a hierarchical structure was produced and used to determine the weights of the criteria. Spatial data were identified by means of GIS and calculations were made using the suitability values specified and weights obtained from AHP. Suitability maps were then produced for the above land use alternatives. Subsequently, a synthesized suitability map was formed from these maps. According to the weights specified by AHP, the order of land use preferences among the alternatives for rural development of Dümrek was agriculture, forest and meadow. The synthesized suitability map showed that the areas allocated for forest and agriculture were close to the present ratios of use; however, meadow land, which does not exist at present, should be allocated as a land use to constitute 12.5% of the study area. Achieving sustainability in land use is possible by planners and administrators considering results obtained from land suitability mapping studies at the stage of allocating land uses. The method applied in this research is considered useful when taking policy decisions covering the evaluation of rural land use, particularly for subunits of the state administration.     

Biofuels and agriculture: a past perspective and uncertain future

The US corn ethanol industry has grown from virtually nothing in the early 1980s to over 14 billion gallons in 2011. Subsidies have been an important impetus for the industry, and they have existed in one form or another throughout the life of the industry. This paper provides (1) a brief look at the history of the linkages between energy and agriculture and how they have changed with biofuels; (2) a review of some of the major impacts of the US corn ethanol program; and (3) analysis of prospective impacts of cellulosic biofuels. There is no doubt that biofuels have brought about a new era for global agriculture. Historically, the prices of agricultural and energy products moved in response to supply and demand factors relevant to each market, but moved largely independent of one another. Corn ethanol has changed that, and today there is a link between crude oil and corn that is driven by the demand side. Since agricultural commodity prices are linked both on the demand and supply sides, the corn–crude oil link spills over to other agricultural commodities as well. Development of cellulosic biofuels has been much slower than hoped. The feedstocks are more expensive than initially believed. Conversion technologies remain uncertain and expensive. There are many uncertainties through the cellulosic supply chain, and government policy remains uncertain as well. Thus, the future of the cellulosic biofuels industry is, at this point, an open question.