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1.
应用危险确认模型评估土地管理的可持续发展   总被引:4,自引:1,他引:4  
New Zealand is highly dependent on its soil resource for continued agricultural production.To avoid depleting this resource,there is a need to identify soils and associated land management practices where there is a risk of soil degradation.Environmental integraity and ecosystem services also need to be maintoained.Accordingly,to ensure sustainable production,The on -and off-site environmental impacts of aldn management need to be identified and managed.We developed a structural vulnerability index for New Zealand soils.This index ranks solis according to their inherent susceptibility to physical degradation when used for agricultural (pasture,forestry and cropping) Purposes.We also developed a rule-based model to assess soil sompaction vulnerability by characterising the combined effects of resistance and resilience,Other soil attributes have been approatised using seven chemical,physical and biological indicators of soil quality.These indicators have been applied in a nation -wide project involving data collection from over 500 sites for a range of land uses.These soil quality data can be interpreted via the World Wide Web -through the in teractive decisionsupport tool SINDI,The land-use impact model is a framework to assess agricultural land management and environmental sustainability,and may be applied to land units at any scale.Using land resource data and information the model explicitly identifies hazards to land productivity and environmental integrity,It utilises qualitative expert and local knowledge and quantitative model-based evaluations to assess the potential environmental impacts of land-management pratices.The model is linked to a geographic information system(GIS),allowing model outputs.such at the environmental impacts of site-specific best management practices,to be identified in a spatially explicit manner,The model has been tested in New Zealand in an area of pastoral land use.Advantages of this risk identification model include:utilising current knowledege of the causes and effects of land-management practices on soil degradation;linking land management practice to both on-and off-site environmental consequences;identifying important gaps in local knowledge,and providing spatially explicit information on the environmental impact of land-management practices.  相似文献   

2.
Soil and land degradation in the tropics can be identified and described in terms of physical,chemical,and biological changes from its pristine state brought about by natural and anthropogenic influences.A characteristic of these ecosystems is their capacity to recycle nutrients through soil organic matter(SOM). Following disturbance through changed land management.SOM is rapidly mineralized and there is a cor responding decline in fertility and the variable charge component of the cation exchange capacity.As these ecosystems are strongly dependent on SOM for their functionality,changed land use can have irreversible impacts on the productivity of these systems.The paper focuses on quantifying chemical degradation throughbenchmaking using data from paried sites in tropical China and Thailand using surface charge finger printing.Using values taken from the fingerprint of an undistubed soil,an index of chemical degradation from ideality was calculated.Various management stratgeies that attempt to reverse degradative trends or improve poor quality soils in their natural condition are discussed.such as the ddition of natural clays and silicated materials.Results are present to whow the effect of each of the aforementional strategies on surface charge characteristics and associated increases in plant productivity.  相似文献   

3.
基于带权值的模糊关联规则的土壤质量评价   总被引:1,自引:0,他引:1  
Fuzzy association rules (FARs) can be powerful in assessing regional soil quality, a critical step prior to land planning and utilization; however, traditional FARs mined from soil quality database, ignoring the importance variability of the rules, can be redundant and far from optimal. In this study, we developed a method applying different weights to traditional FARs to improve accuracy of soil quality assessment. After the FARs for soil quality assessment were mined, redundant rules were eliminated according to whether the rules were significant or not in reducing the complexity of the soil quality assessment models and in improving the comprehensibility of FARs. The global weights, each representing the importance of a FAR in soil quality assessment, were then introduced and refined using a gradient descent optimization method. This method was applied to the assessment of soil resources conditions in Guangdong Province, China. The new approach had an accuracy of 87%, when 15 rules were mined, as compared with 76% from the traditional approach. The accuracy increased to 96% when 32 rules were mined, in contrast to 88% from the traditional approach. These results demonstrated an improved comprehensibility of FARs and a high accuracy of the proposed method.  相似文献   

4.
Land use alternatives are sought to boost agricultural income and productivity in Hainan Island,China.Regional differences exist in crop limitations,such as typhoon risk,low temperatures,poor soil fertility,and drought.In this study a crop zonation was made for a range of crops,among which is banana,as a way to:1) establish areas for potential expansion for banana,and 2) identifylimitations and options for crop and land management.A spatial soil and terrain database of Hainan Island(1:250000) was linked to the automated land evaluation system(ALES).The qualitative models were verified by comparing suitability maps with actual land use.Theresults may support policy formulation on issues such as alternatives to current land use,assessment of best management practices,and the need for fertilizer programmes.  相似文献   

5.
黄土高原小流域土壤有机碳空间变异性研究   总被引:12,自引:0,他引:12  
Soil organic carbon (SOC) has great impacts on global warming, land degradation and food security. Classic statistical and geostatistical methods were used to characterize and compare the spatial heterogeneity of SOC and related factors, such as topography, soil type and land use, in the Liudaogou watershed on the Loess Plateau of North China. SOC concentrations followed a log-normal distribution with an arithmetic and geometric means of 23.4 and 21.3 g kg-1, respectively, were moderately variable (CV = 75.9%), and demonstrated a moderate spatial dependence according to the nugget ratio (34.7%). The experimental variogram of SOC was best-fitted by a spherical model, after the spatial outliers had been detected and subsequently eliminated. Lower SOC concentrations were associated with higher elevations. Warp soils and farmland had the highest SOC concentrations, while aeolian sand soil and shrublands had the lowest SOC values. The geostatistical characteristics of SOC for the different soil and land use types were different. These patterns were closely related to the spatial structure of topography, and soil and land use types.  相似文献   

6.
免疫算法在土壤资源质量评价中的应用   总被引:3,自引:0,他引:3  
Based on the geographic information system (GIS) technology, ArcInfo software was adopted to collect, process and analyze spatial data of Guangdong Province for an evaluation of soil resource quality. The overlay analysis method was used in combining evaluation factors of Guangdong soil resource quality to determine the evaluation units. Because of its favorable convergent speed and its ability to search solutions, the immune algorithm was applied to the soil resource quality evaluation model. At the same time, the evaluation results of this newly proposed method were compared to two other methods: sum of index and fuzzy synthetic. The results indicated that the immune algorithm reflected the actual condition of soil resource quality more exactly.  相似文献   

7.
<正>Soil organic matter (SOM), which associates carbon (C) to key plant nutrients, has been stored in soil for thousands of years. Scientists have long recognised its positive impact on key environmental functions such as food production and climate regulation. As soon as a virgin land (forest or grassland) is cultivated, there is a tendency for the soil to lose its SOM, and we still largely misunderstand the underlying mechanisms, leading to inappropriate decisions being taken to fight soi...  相似文献   

8.
Soil health is an important component of “One Health”. Soils provide habitat to diverse and abundant organisms. Understanding microbial diversity and functions is essential for building healthy soils towards sustainable agriculture. Arbuscular mycorrhizal fungi (AMF) form potentially symbiotic associations with approximately 80% of land plant species that are well recognized for carbon flux and nutrient cycling. In addition to disentangling the signaling pathways and regulatory mechanisms between the two partners, recent advances in hyphosphere research highlight some emerging roles of AMF and associated microbes in the delivery of soil functions. This paper reviews the contribution of AMF to soil health in agroecosystems, with a major focus on recent progress in the contribution of hyphosphere microbiome to nutrient cycling, carbon sequestration, and soil aggregation. The hyphosphere microbiome and fungal stimulants open avenues for developing new fertilizer formulas to promote AMF benefits. In practice, developing AMF-friendly management strategies will have long-term positive effects on sustainable agriculture aiming at simultaneously providing food security, increasing resource use efficiency, and maintaining environment integrity.  相似文献   

9.
The Miyun Reservoir is the most important water source for Beijing Municipality, the capital of China with a population of more than 12 million. In recent decades, the inflow to the reservoir has shown a decreasing trend, which has seriously threatened water use in Beijing. In order to analyze the influents of land use and cover change (LUCC) upon inflow to Miyun Reservoir, terrain and land use information from remote sensing were utilized with a revised evapotranspiration estimation formula; a water loss model under conditions of human impacts was introduced; and a distributed monthly water balance model was established and applied to the Chaobai River Basin controlled by the Miyun Reservoir. The model simulation suggested that not only the impact of land cover change on evapotranspiration, but also the extra water loss caused by human activities, such as the water and soil conservation development projects should be considered. Although these development projects were of great benefit to human and ecological protection, they could reallocate water resources in time and space, and in a sense thereby influence the stream flow.  相似文献   

10.
ZHAO Qi-Guo  XU Meng-Jie 《土壤圈》2004,14(3):313-321
Agricultural sustainability for economic development is important and a complex issue throughout the world; however,it is difficult to synthetically evaluate its use in the policy making process. The objective of this study was to evaluate sustainable agriculture in the red soil hill region of Southeast China through a newly proposed method combining four separate sub-systems: regional population (P), resource (R), environmental (E), and socio-economic (S). This new index system was proposed to appraise synthetically the agricultural sustainability of the red soil hill region from 1988 to 1996 with a two-step method assessing: a) the agricultural sustainability in each province independently and b) the relative sustainability of each province to the whole region. The first step only provided a development trend for each province based on its original situation, while the second step provided additional information on the comparative status of each province in agricultural development to the region as a whole. Higher index scores were found for the economy and resource categories denoting improvement. However, lower scores in the environment category indicated the improvement was achieved at the cost of deteriorating ecological surroundings due to an increasing population that demanded more from the agro-ecosystem and put heavier pressures on it. Results also showed that water and soil losses in this region were the major obstacles encountered in sustainable agriculture development. The assessment results were verified when compared with results from another method. This suggested that the new assessment system was reliable and credible in evaluating agricultural sustainability on a regional scale.  相似文献   

11.
12.
The People's Republic of China‐Global Environment Facility Partnership to Combat Land Degradation in Dryland Ecosystems promotes an integrated ecosystem management (IEM) approach to restore, sustain and enhance the productive capacity of dryland ecosystems. This paper provides an analysis and synthesis of the funding strategies, methods and approaches that have been applied and tested under the Partnership to pilot and scale up IEM and sustainable land management (SLM) practices in the western People's Republic of China under its first 10 years. On the basis of a mix of methods using literature reviews, data collection at selected pilot sites through household questionnaire surveys, stakeholder workshops and field sampling, the following lessons were generated: (i) mainstreaming of IEM into relevant policy and development frameworks has been the most effective way of mobilizing funding for scaling up of SLM; (ii) SLM best practices need to be combined with economic incentives for land users, and pilot demonstrations of SLM need to be integrated into larger investment programmes to achieve impacts and economies of scale; (iii) market‐based approaches to scaling up of SLM, such as payment for ecosystem services and public–private partnerships, have a role to play, but cost–benefit analysis need to be better integrated into payment schemes; (iv) the economic benefits of carbon sequestration are too low to fund eco‐compensation schemes on their own but can provide supplementary funding; and (v) land degradation and SLM monitoring and assessment systems should be multiscale to support decision‐making on SLM and to monitor impact from the local to the national level. Copyright © 2014 Asian Development Bank  相似文献   

13.
The need for analytical support in agricultural research and development has long been recognized, especially for soil fertility evaluation and management, assessment of crop and food quality, and selection and breeding of nutritious food staples. In addition, the demand for analytical research support in the general areas of agriculture interfacing with human health and environmental quality has greatly increased in recent years. The trend for increased demand for analytical support will most likely continue in the future. To meet such diverse, increasing demands for analytical support, we need to upgrade infrastructure facilities and simultaneously teach and train students and young researchers in the use of modern analytical tools. This is prerequisite to providing timely, efficient, and effective analytical support, as such support is the key to monitoring, assessing, and maintaining soil, food, and environmental quality and to breeding nutritious food staples.  相似文献   

14.
土地整治中底泥质耕作层土壤的构建方法及应用效果   总被引:2,自引:1,他引:2  
开展底泥质耕作层土壤的构建方法研究,是确保土地整治工程质量和效益的重要举措。该研究以河流疏浚底泥土地利用为主线,从底泥质耕作层土壤构建方法的基础理论、底泥环境肥力调查评价、底泥重金属稳定化修复、底泥改造土壤工程及底泥应用案例等方面系统地探讨了土地整治工程中底泥质耕作层土壤构建方法的基础、内容、设计方法、施工工艺、工程参数。污染底泥修复后大田种植空心菜试验表明:重金属含量可达到无公害蔬菜安全标准、Cd降低率在38.61%~85.69%,稳定化修复明显降低蔬菜重金属含量;底泥质耕层土壤适宜开展种植,可提蔬菜高产量8.7%~13%,增加土壤有机质含量0.95~2.18倍。  相似文献   

15.
Some major developments in soil science since the mid-1960s   总被引:6,自引:0,他引:6  
A. R. Mermut  H. Eswaran 《Geoderma》2001,100(3-4):403-426
Although the science of soil was established about 150 years ago with the modern soil science taking off after the Second World War, the new Millennium has brought other challenges and new opportunities. Rapidly increasing population in countries that can least afford it have made them food-insecure. With inadequate inputs in agriculture, developing countries are degrading their lands rapidly and destroying ecosystems. Affluence in the richer countries has precipitated other problems hampering ecosystem functions and quality of land resources. These changing conditions have placed new demands on both the society and the soil science community. The latter has resulted in new areas of soil sub-disciplines such as land and soil quality, land degradation and desertification, cycling of bio-geochemicals, soil pollution assessment and monitoring etc. Advances in information technology have also enabled the science to meet the new demands of the enviro-centric world. In the last decade, noticeable changes are evident in methods and research priorities in the discipline. Soil resource assessment and monitoring is entering a new era, in terms of quality of information produced by new information technologies through the innovative use of Geographic Information Systems and remote sensing and significantly improving the acceptance and use of soil survey information. Electronic technology has dramatically increased the demand for and ability to process more data. Other innovations have resulted in quantitative approaches in soil genetic studies and demonstrated the integral role of soils in ecosystems. For global and regional resource assessment, concepts and procedures were refined. The World Reference Base for soil classification and the Global Soil and Terrain Database are the first steps towards standardisation and a more detailed assessment of global soils. The global assessment of human-induced land degradation and vulnerability to desertification are benchmark products of the databases. Environmental pollution and its effects on human and ecosystem health have become public concerns and soil science has contributed to localising, quantifying, and developing mitigation technologies to address the problems. The challenges of climate change and the charge to maintain ecological integrity have been met with technologies such as conservation tillage, agroforestry, precision agriculture etc. New concepts such as multi-functionality of land, soil quality, sustainability of agriculture and carbon sequestration, have emerged leading to new management strategies and an enhanced quality of life.  相似文献   

16.
耕地自然质量条件与立地系统共同决定了耕地可持续的生产能力,测算二者之间的协同比例关系可为耕地资源的保护分区提供理论和方法借鉴。该文以辽宁省不同地貌区为例,通过构建不同地貌区耕地自然质量评价系统与耕地立地条件评价系统,运用耦合协调度模型量化分析二者之间的协同关系,最后依据二者之间协同关系特征建立耕地资源保护分区。研究结果表明:在辽宁省西部的丘陵地貌区、中部的平原地貌区以及东部的山地地貌区,耕地资源保护优势条件特征存在区域差异,3个地貌区耕地自然质量条件与立地条件协同关系比值分别为4:6、6:4和5:5,应遵循耕地资源条件的地域差异特征实行协同保护。在此基础上,依据耕地资源优势条件特征将辽宁省耕地区域划分为核心保护区、优势整治区以及重点调控区,并提出不同区域耕地资源差异化的利用和保护措施。该研究结果体现了不同地貌区耕地资源优势保护条件特征的差异性与规律性,可为省域尺度耕地资源的永续利用提供参考借鉴。  相似文献   

17.
Soil degradation threatens sustainable food production and accelerates global warming. Poorer countries, whose agricultural sectors are highly dependent on their natural resource bases, are hit particularly hard by declining soil productivity. Calls for soil‐quality monitoring are therefore, justified and this could inform decision‐makers on the preparation of appropriate interventions. However, the provision of monitoring methodologies is not an easy task. Soil degradation affects several soil characteristics that at larger scales cannot be evaluated with models or remote‐sensing techniques. Therefore, this study focuses on investigating the use of field‐based soil assessment methodologies to differentiate degrees of soil degradation. Specifically, we test the Visual Soil Field Assessment Tool (VS‐Fast) for detecting and monitoring soil degradation using a cross‐section of 71 sites in Senegal, the soil quality of which were classed by local experts. We found low correlation between VS‐Fast classes and expert assessments. By using an ordered logit model to quantify class boundaries, we show that experts categorized areas as ‘degraded’ for a wider range and higher VS‐Fast scores than the corresponding VS‐Fast class. Yet, from general linear models and analysis of variance procedures we found that areas classed by experts as ‘degraded’ had statistically significant lower VS‐Fast scores compared to those that were judged as ‘normal’ and ‘good’, while differences of the VS‐Fast scores between the latter two were negligible. It is remarkable that the visual assessment, the cheaper component of the VS‐Fast score, performs better in differentiating degradation status than its measured counterpart. The results support the need to investigate the applicability of other VSA methodologies that only use field observations and tactile methods.  相似文献   

18.
基于半方差函数与等别的耕地质量监测样点优化布设方法   总被引:3,自引:3,他引:3  
耕地的数量和质量在维护国家安全、社会稳定方面具有举足轻重的作用。该文以浙江省耕地质量监测试点松阳县为例,探讨县级尺度的耕地质量监测样点的布设方法。选择自然等指数的均方差和绝对偏差计算在允许误差范围内监测样点的样本容量;采用地统计学半方差函数分析耕地质量的变异情况,利用自然等指数的变异特征与规律实现监测样点的预布设;重点分析耕地质量等别、分等因素、耕地质量潜在变化区域的空间分布,结合等别组合的空间分布特征对预布设的监测样点进行优化,得到40个监测样点。研究成果提高了监测样点的精度、代表性、科学性,方法易操作推广,具有很好的应用价值,能为耕地质量监测的管理工作提供参考。  相似文献   

19.
水土保持与耕地资源持续利用   总被引:3,自引:0,他引:3  
耕地资源持续利用是农业和国民经济发展的基础。我国耕地资源的现状为:人均耕地少、优质耕地少、耕地后备资源少、耕地退化严重、耕地浪费严重和耕地保护措施不力;耕地水土流失范围广、面积大,人为因素是加剧耕地水土流失的根本原因;水土流失导致耕地数量减少、质量下降,严重制约粮食生产的发展;加强水土保持,可防止耕地数量减少、质量下降,且能有效地改善耕地环境状况,是实现耕地资源持续利用的有效措施。  相似文献   

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