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NUMERICAL CLASSIFICATION OF REGIONAL STRUCTURE OF agro-ecosystem IN GUANGDONG

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Chinese Geographical Science 1991年第2期1卷 60-71页

作者：罗曼嘉 South China Agricultural University Guangzhou 510642 PRC

On the basis of 'The Statistical Data of Guangdong Province in 1981' and the 14 selected original variables, 107 counties and suburbs in Guangdong are classified. In the classification, cluster analysis is applied, and the cluster hierarchy of the agro-ecosystem is achieved with a computer. According to output level, planting structure, and input level of energy, there is an evident regionalism in the agro-ecosystem of Guangdong, which presents approximately concentric circles centralized by Guangzhou City.

关键词： agro-ecosystem regional structure cluster analysis location quotient

Advances in Nitrogen Denitrification and N_2O Emission in agro-ecosystem

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Agricultural Science & Technology 2011年第2期12卷 268-273,304页

作者： ZHANG Yu-shu DING Hong QIN Sheng-jin Institute of Soil and Fertilizer Fujian Academy of Agricultural Sciences Fuzhou 350013

Nitrification and denitrification are two key links of nitrogen flow cycle in soil.N2O and N2,generated from biochemical process of nitrogen,can cause not only the nitrogen losses and reduction of nitrogen use efficiency,but also the boosted concentration of greenhouse gases,severely endangering the ***,nitrification-denitrification has been more and more concerned from whether an agricultural view,or an environmental *** to the related literatures published at home and abroad in recent years,we overviewed the denitrification-caused N loss and N2O emission in various agro-ecosystems,and based on which we put forward countermeasures to reduce the denitrification-caused N loss and N2O emission and its research prospects in the future.

关键词： agro-ecosystem Denitrification Nitrogen emission amount

The breaking and reconstruction of nutrient recycling chains in agro-ecosystem in China

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The breaking and reconstruction of nutrient recycling chains...

Emergy Efficiency and Structural Adjustment of Hunan agro-ecosystem

International Symposium on Phytoremediation and ecosystem Health

作者： Luqiang Zhang College of Life Science Shandong University of Technology

＜正＞Chinese traditional farming technology is primarily environmental-friendly agriculture or *** along with the transition to massive production,market economy and the urban and rural division,agricultural resource... 详细信息

关键词： agro-ecosystem breaking China nutrient recycling chain reconstruction

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Agricultural Science & Technology 2012年第12期13卷 2648-2654页

作者：侯茂章朱玉林中南林业科技大学经济学院湖南长沙410004

[Objective] To analyze the efficiency of Hunan agro-ecosystem in 1980- 2010. [Method] This paper adopts the emergy methods to evaluate the emergy input and output. [Result] The growth of total emergy input was mainly caused by the auxiliary factors in this phase. The proportion of the nonrenewable purchased emergy input to the total auxiliary emergy input increased from 21.80% in 1980 to 33.04% in 2010. In 1980-2010 the total emergy output of the system increased by 2.43 times, the proportions of the stock farming emergy output and fishery emergy output to the total emergy output increased sharply, while those of the planting emergy output and forestry emergy output showed a considerable decline. [Conclusion] The emergy yield ratio of this system was improved but its sustainability was worrying.

关键词： Emergy input Emergy output agro-ecosystem Emergy yield ratio Structural adjustment

Enhancing the Social and Natural Capital of Canadian agro-ecosystems through Incentive-Based “Alternative Land Use Services” (ALUS) Programs: Recurring Themes and Emerging Lessons

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Journal of Geoscience and Environment Protection 2019年第12期7卷 139-162页

作者： Robert France Jeffrey Campbell Kate Sherren Rural Research Centre Faculty of Agriculture Dalhousie University Halifax Canada School for Resource and Environmental Studies Dalhousie University Halifax Canada

Alternative Land Use Services (ALUS) is an incentive-based program established in Canada to pay farmers for their voluntary delivery of ecosystem services (ES). All seven ALUS programs across the country were examined using a standardized case-study approach based on site visits, reading internal documents, attending program meetings, and engaging in semi-structured interviews with program administrators, participating farmers, and advisory board members. Direct content analysis was used to highlight recurrent themes and emerging lessons in relation to the salient particulars of program physical location, administration framework, delivery of ES, and development and receipt by communities. Our three major findings are: 1) Overall, ALUS has been judged by participants to be a very successful program, whose strength is that it is completely voluntary, non-permanent, and readily adaptable to each location’s environmental conditions, economic funding base, and cultural milieu. 2) One serious shortcoming of all ALUS programs is a general lack of quantifiable data on their ability to increase ES. Instead, environmental benefits are either assumed or based on the idea that the areal extent of enrolled land is the sole measure of its environmental worth. 3) It may be that the social impact of ALUS is its greatest success. In this regard, for farmers, it is the process of engaging in land-use decision making and the recognition of their role as environmental stewards that is a bigger motivation for participating in an ALUS program than the modest financial incentives which they receive.

关键词： agro-ecosystem Services Incentive Payments Grassroots Participation Natural and Social Capital

Spatial and temporal variability of soil freeze-thaw cycling across Southern Alberta, Canada

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Agricultural Sciences 2011年第4期2卷 392-405页

作者： Andrew J. Phillips Nathaniel K. Newlands 不详

Soil freeze-thaw cycles play an important role in all aspects of agro-ecosystems, such as crop productivity, the evolution of the soil matrix, including trace-gas emissions. In regions that experience synoptic weather conditions throughout the winter, freeze-thaw cycles generally occur in one of two categories;seasonal or winter cycles. Current soil vegetation atmosphere models (SVAT’s) often include a heat-transport soil freeze-thaw algorithm, but lack detail on complex interactions between the main driving variables. Boundary conditions for these models are often based only on a few climate variables and typically lack regional context. A nested statistical analysis was applied to identify the optimal set of environmental variables (via a stepwise regression selection procedure) to track soil freeze-thaw dynamics. Historical data collected between the years 2006-2009, for 17 long-term climate stations distributed across southern Alberta Canada was utilized. Cross-correlation between wind speed and maximum air temperature identified Chinook-driven freeze-thaw events, with such interaction varying significantly across the region and by soil depth. Climate-soil interactions were most significant predictors of soil temperature during winter months. The seasonal freeze-thaw cycle is estimated to vary between 112 - 131 days, consisting of 12 - 20 winter cycles (1 cm depth), and 1-5 winter cycles (5 cm depth) with average lag time of 26 - 112 days. Freeze-thaw prediction was greatly improved when higher-order climate interaction terms were considered. Our findings highlight the importance for soil-water and more complex ecosystem, SVAT models to better resolve regional-driven climatic trends. Alongside improved representation of regional trends aimed at reducing model-based uncertainty, such efforts are expected to, in tandem, help advance the geostatistical design, and implementation of agroenvironmental monitoring systems that combine in-situ and satellite/remote-sensi

关键词： Freeze-Thaw Soil Temperature agro-ecosystem Modeling Regional Climate Soil Science

Levels of Heavy Metals in the Soil: Effects of Season, agronomic Practice and Soil Geology

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Journal of Agricultural Chemistry and Environment 2015年第4期4卷 109-117页

作者： Monsurat Temitope Osobamiro Gregrory Olufemi Adewuyi Department of Chemical Sciences Olabisi Onabanjo University Ago-Iwoye Nigeria Department of Chemistry University of Ibadan Ibadan Nigeria

Heavy metals status of agricultural soils should be monitored in order to prevent soil-plant pollution. This study evaluates the effect of season, agronomic practice and soil mineral composition on the levels of some heavy metals (Pb, Mn, Ni, Fe, and Zn) in the arable and oil palm soils of three Farm Settlements in Ogun-State Southwest, Nigeria. Soil samples were collected in two consecutive seasons between 2010 and 2012 and digestion was carried out using Standard Wet Acid Digestion method. Total heavy metals in the digest were determined using Flame Atomic Absorption Spectrophotometer (FAAS). The total levels of heavy metals (in mg/kg) found in the sampled soils were as follows: in the rainy season Mn (28.4 - 34.2), Fe (1599.7 - 2013.2), Pb (11.0 - 16.9), Zn (100.5 - 112.9) and Ni (11.3 - 13.8) and in the dry season Mn (32.1 - 40.1), Fe (1701.4 - 2455.5), Pb (13.0 - 18.7), Zn (105.7 - 110.4) and Ni (15.5 - 16.3). Levels of the heavy metals found in the sampled soils were significantly lower (p < 0.05) than their permissible levels in agricultural soils. Although the levels of heavy metals determined in dry season were higher than those of the rainy season, the only seasonal difference was that of Fe in Sawonjo soil significant at p = 0.05. The level of heavy metals in oil palm soils was significantly higher than the level in arable soils (p < 0.05). At present, pollution level of heavy metals in the sampled soils is low and poses no environmental risk, yet, they have to be regularly monitored before they bio-accumulate into toxic. Government should therefore set up soil monitoring agency and provide irrigation facilities to encourage dry season farming.

关键词： Heavy Metal Farm-Settlement agro-ecosystem Seasonal Variation Soil Mineral

The Shift of Traditional agroecosystems in the in Eastern Arc Catchments of Tanzania

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Agricultural Sciences 2019年第10期10卷 1343-1358页

作者： Agnes G. Kapinga Abimbola Sangodoyin Olayinka O. Ogunkoya Marko B. Sulley Franco J. Mbegallo Gordon T. Madamombe Department of Environmental Management Pan Africa University Life and Earth Sciences Institute (PAULESI) University of Ibadan Ibadan Nigeria Department of Agriculture and Environmental Engineering University of Ibadan Ibadan Nigeria Department of Department of Geography Obafemi Awolowo University Ile-Ife Nigeria Pan Africa University Life and Earth Sciences Institute (PAULESI) University of Ibadan Ibadan Nigeria Department of Agricultural Economics and Business University of Dar es Salaam Dar es Salaam Tanzania Environmental Management Renewable Energy and Climate Change Research Centre Harare Institute of Technology Harare Zimbabwe.

The purpose of this study was to identify the drivers of the shift of traditional agro-ecosystems and their implication on catchment resources management of Eastern Arc Catchments of Tanzania. Lower Mngeta and Upper Zigi water catchments are situated within Eastern Arc Mountains of Tanzania. Household questionnaire, key informant interviews and focus group discussion were used for collecting primary data. The findings indicated that most of the participants (85.9% and 90.4% in Lower Mngeta and Upper Zigi catchments respectively) depend on subsistence rain-fed agriculture for their livelihoods. However, there are significant changes in production as a result of land fertility deteriorating and negative climatic changes (seasonal shift). This has become a major challenge for most of the farmers. To cope with agro-ecosystem dynamics, farmers in the study areas use both traditional and modern strategies as illustrated in the results section. While tradition always reported to be inexpensive, some modern agro-ecosystem practices reported to cause siltation, killing of fish and herbal plants, easy rotting of seeds (for maize) and bad aroma (for rice)in spite of having a high rate of return. It was also reported that depletion of traditions and norms of conduct, accelerated by multi-cultural interaction from immigrants, have led to deterioration of traditional agriculture practices. Moreover, arrival of agriculture companies and introduction of spice farming was reported to have caused manpower imbalance, unequal distribution of natural resources and less diversity of indigenous plants. The study concludes that communities are much into economic opportunity derived from agro-ecosystem than stewarding it. The study recommends that the effort restoring catchment ecosystem should come from both traditional and modern strategies so as to harmonize and accommodate environmental, economic and traditional values.

关键词： agro-ecosystem Culture and Diversity

Measurement on the Harmony Coefficient of agro-eco-economic System in the Arid Region

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Asian Agricultural Research 2016年第8期8卷 47-52页

作者： Qijun LIU Zhaonan LI School of Economics Beifang University of Nationalities

On the basis of the present research progress of ecological agriculture,we take Minle County and Linze County located in the middle reaches of Heihe River as the typical research *** on the rural social and economic data during the period of 2000-2010,theory and method of mathematical statistics are used to establish the measure theory and model of agro-eco-economic system harmony coefficient,including efficacy function,function of harmony coefficient,harmony coefficient and level of harmony *** on the actual situation of research region,evaluation indicator system of agro-eco-economic system is established and measurement is carried *** show that the regional agro-eco-economic system in research region was in a serious imbalance in *** harmony coefficient of Minle showed a slight rise from 2000 to 2004,and then presented a fluctuating *** rank of harmony coefficient experienced serious imbalance-extreme imbalance-moderate imbalance-low imbalance-serious imbalance-high *** the same time,the similar tendency happened in Linze *** measuring results of subsystem in 2000-2013 further indicated that except that the harmony coefficient of economic subsystem in Minle County and Linze County was moderate and high,the ecological subsystem was at Level II and Level III,and social subsystem was at Level IV and Level III,in high and low imbalance ***,several recommendations were put forward for optimizing agro-eco-economic system.

关键词： Middle reaches of Heihe River agro-ecosystem Harmony coefficient