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1.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(2-3):149-151
A simple deterministic simulation model for landscape-scale soil water deficits has been developed. Standard weather station data are used to estimate ‘daily’ precipitation and actual (regional) evapotranspiration (AET). The balance is added to soil moisture, which is accounted by a simple bucket model. AET is the daily integral of the lesser of supply and demand: supply is governed by current soil moisture, demand by estimated net radiation and temperature. The model estimates geographical patterns of soil water deficit at a scale suitable for comparison with the distributions of plant species and vegetation types. The model provides a way of quantifying soil moisture stress in biogeographical research. 相似文献
2.
A vital and indisputable link exists between phosphate rock and world food supply. Phosphate rock is the source of phosphorus used to make phosphatic fertilizers, essential for growing the food needed by humans in the world today and in the future. We modeled the depletion of the known reserves and reserve base (which includes reserves) of phosphate rock based on various scenarios for increasing population and future demand for phosphate. Using these scenarios, the presently known reserves will be depleted within about 50 years, and the remainder of the reserve base will be depleted within the next 100 years. For this model, we used rates of growth of demand for phosphate rock of between 1 and 1.7 percent annually. We also examined demand rates that decrease over time toward demand stasis. Growthrate scenarios that stabilize demand at the year 2100 are little different from unconstrained growth. Demand stabilization by 2025 extends the reserve base by only about 50 years. Additional considerations could affect these depletion scenarios, causing them to be substantially too high or too low. Nonetheless, the incluctable conclusion in a world of continuing phosphate demand is that society, to extend phosphate rock reserves and reserve base beyond the approximate 100 year depletion date, must find additional reserves and/ or reduce the rate of growth of phosphate demand in the future. Society must: 91) increase the efficiency of use of known resources of easily minable phosphate rock; (2) discover new, economically-minable resources; or (3) develop the technology to economically mine the vast but currently uneconomic resources of phosphate rock that exist in the world. Otherwise, the future availability of present-cost phosphate, and the cost or availability of world food will be compromised, perhaps substantially. 相似文献
3.
传统农业地区能值生态足迹分析——以贵州省从江县为例 总被引：3，自引：3，他引：0
传统农业生态系统正面临着来自现代化发展及其带来的技术经济变革的严重威胁,在一些传统农业地区现代农业替代传统农业已经引发了严重的生态环境问题。生态足迹,作为可持续发展评价的方法之一,由于无法全面衡量人类活动对生态系统造成的各种影响,因此无法揭示传统农业地区真实的生态环境状况,也无法给出科学合理的可持续发展评价。能值生态足迹是对传统生态足迹的一种改进,试图利用能值分析理论的优点囊括人类利用生态系统产品和服务的各种活动。然而,目前能值生态足迹研究往往受到传统生态足迹理论的局限,无法真正将人类消费的各种资源、产品和服务纳入进来。为此,本文将生态系统服务概念引入能值生态足迹理论框架中,进一步改进和完善了能值生态足迹模型,使之能够全面衡量人类活动的生态环境影响。本文利用改进的能值生态足迹模型,以我国传统农业地区贵州省从江县为例,开展生态环境状况评估和可持续发展评价。结果表明,从江县2007年人均能值生态承载力为9.3311 ha,人均能值生态足迹为14.5638 ha,人均能值生态赤字为5.2327 ha。可见,从江县的生态承载力仅能满足当地居民消费总需求的64%,当地处于不可持续发展状态,生态环境状况不容乐观。这与传统生态足迹的评价结果差异十分显著。传统生态足迹评价结果显示,从江县的生态承载力不仅能够满足当地居民的消费需求而且有少量生态盈余。进一步分析显示,从江县居民对生态系统的污染物吸纳服务和侵蚀控制服务的消费,在从江县总生态足迹中占有相当大的比例。这说明,从江县传统农业生产方式受现代农业影响而发生的部分改变,所产生的生态环境影响已经逐步显现。过量施用化肥农药所引起的面源污染以及频繁翻耕和砍伐森林所引起的水土流失,已经严重威胁当地的生态环境健康和可持续发展。 相似文献
4.
Waste disposal constitutes an acute problem in numerous African cities. One solution could lie in the recycling of the nutrient-rich waste into agriculture taking place in and around cities. Farmers involved in vegetable production around Jos, Nigeria, have developed a sophisticated soil fertility management strategy combining inorganic fertilizers, manure and urban waste ash. This paper: (1) investigates the socio-economic constraints linked to obtaining scarce organic inputs, particularly urban waste ash and the health hazards (particularly heavy metal contamination of soil and crops) caused by using this ash and (2) suggests ways to improve use of this important resource. 相似文献
5.
基于遥感与GIS技术的研究进展，采集洮河流域高程数据、土地利用类型、土壤类型特性、气象数据等，在SWAT模型中模拟与面源污染有关的降水、地表径流、壤中流、下渗和蒸散发等水文过程，计算侵蚀量、总氮和总磷等面源污染负荷，研究洮河流域面源污染特征。结果表明：洮河流域多年平均侵蚀量为0.70×108 t，多年平均总氮面源污染负荷为244.11 t，洮河流域多年平均总磷面源污染负荷为27.91 t，洮河流域1967—2017年多年平均侵蚀量、总氮面源污染、总磷面源污染负荷总体呈不明显的波动减少趋势，同时提出了改变土地利用方式、设置植被过滤带、坡改梯等面源污染防治对策及建议。 相似文献
6.
猫头刺群落对土壤养分空间异质性的响应 总被引：7，自引：6，他引：1
选择腾格里沙漠边缘内蒙古阿拉善左旗境内的猫头刺群落为研究对象,探讨了猫头刺群落植物属性和土壤属性随尺度变化\,空间异质性的变化以及植物属性对土壤属性空间异质性的响应。结果表明,尺度从800 m2增加到1 600 m2,土壤有机质和土壤全氮的空间异质性减小,全磷和有效磷的空间异质性增加,有效氮空间异质性不变,而群落内3种植物密度和叶量的空间异质性基本都趋于增加,说明全磷和有效磷是目前猫头刺群落存在的主要限制因素,尤其是多年生草本植物骆驼蓬。进一步分析表明,这种现象是由于荒漠地区的灌丛“沃岛效应”和植物耗用有效磷以增大吸水力的补偿机制所致。 相似文献
7.
COMPARISON OF THE ALKALI MARSH SOIL ANDAGRICULTURE SOIL ON NUTRIENT RETENTIONIN WESTERN JILIN, CHINA
XU Xiao-feng SONG Chang-chun SONG Xia YAN Bai-xing WANG Yi-yong.WANG Guo-ping ZHANG Yu-xiaNortheast Institute of Geography Agricultural Ecology CAS Changchun China The Institute of Geography Science the Natural Resource Research CAS Beijing China 《湿地科学》2003,1(2):147-152
An intact alkali marsh soil (MS) core and an agriculture soil (AS) core were studied by the simulated test in order to get the comparison of the nutrients retention in alkali MS and AS. The soil cores extracted from the Xiang-hai Wetland, western Jilin Province, China, were leached with solution contained carbon, nitrogen and phosphorus. Then the effluent water from the outlets of soil core with different depths was measured, including chemical oxygen demand (COD), total phosphorus (TP), phosphate (PO43-- P) and nitrogen existed as nitrate (NO3- - N), nitrite (NO2- - N) and ammonia nitrogen (NH4+- N) and the total nitrogen (TN) in the effluent water. COD and TP are decreased with the depth, the changing trends of TN, NO3- - N and NH4+ - N contents are similar to COD and TP, whereas NO2- - N in both MS and AS effluent have a little transition at 40cm depth. It is similar efficiency of MS to AS in significantly cutting down COD, TP, PO43- - P, TN, NO3- - N, NH4+ - N and NO2- - N in nutrient water. The fun 相似文献
8.
The black soil area in Northeast China serves as a “ballast” to ensure China’s food security. Unreasonable development and utilization lead to serious black soil degradation in some areas and affect regional food production and economic and social development. In the context of the intensification of the contradiction between food supply and demand worldwide, we should pay more attention to the overall situation of regional sustainable development and seek for systematic, scientific, and economic solutions. This study establishes a regional all-for-one customization model of black soil granary on the basis of the regional system of human-land relationship, customized and accurate management, agricultural system theory, and agricultural informatization with the guidance of integrated geography concept. The aim of this regional all-for-one customization model is to systematically diagnose the key problems and leading factors of black soil degradation and determine a solution that combines the commonness and individuality of black soil protection from the perspective of multiscale linkage, multifactor coupling, and multitechnology cooperation. The regional all-for-one customization model of black soil granary integrates the two perspectives of “regional” and “customization” into the protection and comprehensive utilization of black soil for the first time. It adopts zoning, grading, and classification as the main strategy and big data and artificial intelligence as the main technical approaches. This model constructs three strategies of different scales by combining the “satellite-air-ground-network” 3D monitoring system and the all-for-one customization platform driven by big data and artificial intelligence. First, the “implementing strategies by regions” are implemented at the regional scale to formulate the regional agricultural resource allocation scheme and agricultural zoning, which can provide strategies to protect and utilize black soil effectively. Second, the “determining strategies in accordance with villages” are implemented at the village scale to formulate a black soil protection and utilization model for different categories of villages, which can promote the organic integration of black soil protection and rural revitalization. Third, a “one strategy for one field” concept is applied at the field scale to provide accurate strategies for soil restoration and yield improvement in a fixed, quantitative, and regular manner. Multiscale integrated demonstration and scheme verification of the regional all-for-one customization model of black soil granary are conducted in Qiqihar City at three scales, namely, region, village, and field, to solve the key issues in black soil protection and utilization and form a replicable and popularized system solution, thereby providing a model for the sustainable development of Chinese and global black soil agriculture. The proposed regional all-for-one customization model of black soil granary has important theoretical and practical value in promoting the high-quality development of regional agriculture and rural revitalization, and provides a demonstration model of land protection and utilization for the black soil area in China and the whole world. 相似文献
9.
东北黑土地是中国粮食生产的“压舱石”。不合理开发利用导致部分地区黑土地退化严重,影响局部区域粮食生产和经济社会发展。在全球范围内粮食供需矛盾加剧的背景下,亟需着眼于区域可持续发展战略全局,寻求系统性、科学性和经济性的解决方案。黑土粮仓全域定制模式以地理学综合思想为指导,系统诊断黑土地退化的关键问题与主导因素,构建多尺度联动、多要素耦合、多技术协同的黑土地保护共性与个性相结合的解决方案。该模式依托“星—空—地—网”立体监测系统,结合大数据与人工智能驱动的全域定制平台,构建3个不同尺度策略：① 市域尺度实施“分区施策”,制定服务于黑土保护的农业资源优化配置方案和全域农业区划方案等;② 村域尺度实施“依村定策”,制定不同类型村庄的黑土地保护利用模式;③ 地块尺度实施“一地一策”,提供黑土保护与种植管理等土壤修复和产量提升精准策略。在齐齐哈尔市开展“市域—村域—地块”多尺度的方案验证与集成示范,以破解黑土地保护与利用难题,形成可复制可推广的系统解决方案,为中国和全球黑土地农业的可持续发展提供示范样板。 相似文献
10.
延津县风沙土系黄河故道主流沉沙经风力搬运后发育而成,因而形成的各类土壤均具有质地轻粗,有机质贫乏,保肥能力弱和富钾缺磷等特点。所以,在改良利用上应该积极营造防护林,引黄淤灌,创造细土层,改造粗骨性,大力施用有机肥,因地制宜,综合发展,并以广开肥源,种植绿肥,培育和提高土壤肥力为重点。 相似文献
11.
黄河流域农业生产现状及其结构调整 总被引：6，自引：0，他引：6
2003年黄河流域耕地面积占全国的12.4%，粮食总产占全国的7.7%，棉花总产占全国的3.4%，苹果总产占全国的40.6%。尽管粮棉产量占全国的比重不大，然而，黄河流域的农业仍是我国重要的生态屏障，是国家生态安全和区域食品安全的保证。本流域农业生产中存在的问题主要为生产水平低、农业结构单一、社会需求与资源环境之间的矛盾突出等。根据农业生产的现状与存在问题、结构调整的原则和比较优势分析，该流域农业结构调整的关键是强化特色农业的发展，即大力发展特色种植业、草食畜牧业、优质果业和特色生物医药产业。据预测，由于特色农业的发展，2000～2020年本流域农林牧渔业总产值年增长率将为3.9%，农业产值所占比重将下降11.0个百分点，牧业产值所占比重将上升12.1个百分点。 相似文献
12.
高亢类型风沙化土地综合开发治理研究：以夏津县苏留庄治沙示范区为例 总被引：2，自引：0，他引：2
在对夏津县风沙化土地基本特征进行研究和生产力评价的基础上，与地方政府结合，规划建立了“苏留庄粮棉果草复合型稳产高产开发模式”。在风沙化土地治理研究的同时，及时将优良作物品种和树种推广到示范区，并采用沙地土壤改良、立体种植和绿肥轮作等先进有效的耕作技术。现在，示范区已成为一个集农、林、牧为一体的综合开发体系，取得了显著的社会、生态和经济效益，示范区第３年的农业总产值已达４０１．４３万元，相当于建设投资的总和。 相似文献
13.
Ilse Gräber Jørgen F. Hansen Svend E. Olesen Jens Petersen Hans S. Østergaard Lars Krogh 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):15-22
Geografisk Tidsskrift, Danish Journal of Geography 105(2):15–22, 2005 The change of Cu and Zn concentrations in Danish agricultural soils was studied in areas with intensive pig production. Cu and Zn are found in pig manure as the metals are added to pig feed as growth promoters. The changes in concentrations of total and 0.02 MEDTA extractable Cu and Zn in soils from 1986 to 1998 were determined from samples taken at two depths (0–25 cm and 25–50 cm) from 73 sites. Pig manure and mineral fertilizer was added to 60 sites whereas fertilizer only was used on 13 sites. During the survey period soil Cu concentrations increased in both depths but mostly in the sites where pig manure was added. Furthermore, the results indicated that some plant-available Cu and Zn were transported from the topsoil to the subsoil. No significant change in soil Zn concentration was found although a slight reduction was observed. Comparing soil metal concentrations observed in 1998 to the total pig manure application in a 12-year period, it was observed that application of manure caused an accumulation of Cu and of Zn in the upper 50 cm soil. The accumulation rates correspond to the Cu and Zn concentrations in the pig manure. 相似文献
14.
洪河自然保护区湿地主要植被类型物种多样性与表层土壤性质的相关性研究 总被引：1，自引：0，他引：1
对洪河湿地主要植被类型物种多样性特征、土壤性质特征及二者之间的相互关系进行了研究。结果表明:按沼泽—沼泽化草甸—湿草甸—灌丛草甸—岛状林的序列,物种丰富度呈逐渐增加的变化格局,物种多样性、均匀度呈先下降后上升的格局,优势度呈先上升后下降的格局;而土壤性质特征则呈不规则变化格局。植物物种多样性与土壤性质之间只有均匀度与速效氮之间存在着极显著正相关,其他均无显著相关。这说明在洪河湿地,土壤性质不是决定上述序列的植被类型的物种多样性的主要因素,而土壤速效氮含量是影响物种均匀度的关键因素,同时,对其他物种多样性特征也有一定影响。 相似文献
15.
Soil erosion is a major threat to sustainable agriculture. Evaluating regional erosion risk is increasingly needed by national and in-ternational environmental agencies. This study elaborates a model (using spatial principal component analysis [SPCA]) method for the evaluation of soil erosion risk in a representative area of dry-hot valley (Yuanmou County) at a scale of 1:100,000 using a spatial database and GIS. The model contains seven factors: elevation, slope, annual precipitation, land use, vegetation, soil, and population density. The evaluation results show that five grades of soil erosion risk: very low, low, medium, high, and very high. These are divided in the study area, and a soil erosion risk evaluation map is created. The model may be applicable to other areas of China because it utilizes spatial data that are generally available. 相似文献
16.
通过对东昌府区PRED系统特征与系统惯性增长的分析揭示制约PRED系统协调发展与可持续农业发展的主要矛盾,在此基础上确立农业可持续发展的总方向,并有针对性地提出可持续发展的对策,主要包括：优化农业结构,促进农业可持续发展;促进农业市场化、企业化和专业化基地发展,推进农业产业化进程;加大盐碱地、中低产田挖潜改造,提高土地生产力;建立农业可持续发展的调控机制。 相似文献
17.
Soil calcium carbonate(CaCO_3) has a strong solid phosphorus effect, and high content of CaCO_3 can significantly reduce the effectiveness of soil phosphorus. To reveal the limiting effect of soil CaCO_3 on the growth of plants on sand land and its mechanism of plant physiology, we performed pot experiments with a two-factor randomized block design and a three-factor orthogonal design for different soil CaCO_3 content treatments using Artemisia ordosica seedlings. In the experiments, we surveyed plant height, aboveground biomass, root length and root weight and analyzed N, P concentrations and RNA content of the seedlings, and discussed the relationships between relative growth rate(RGR) of the seedlings and N:P ratio as well as RNA. Results show that, the RGRs of plant height and above-ground biomass of the seedlings decreased significantly with the increase of soil CaCO_3 content, and those for root length and root weight decreased. The RGRs of plant height and above-ground biomass of the seedlings were significantly negatively correlated with leaf N:P ratios, but significantly positively correlated with leaf RNA content and leaf P concentrations. It can be seen that soil CaCO_3 is a stress factor for the growth of A. ordosica seedlings, and the growth response of the seedlings under the influence of soil CaCO_3 is in line with the Growth Rate Hypothesis. 相似文献
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19.
利用2005年安排在临泽边缘绿洲沙地农田的长期施肥定位试验，研究不同用量有机肥、化肥、有机肥和化肥配施对绿洲沙地土壤肥力及有机碳积累的影响。试验包括高量有机肥单施（M3），氮磷化肥单施（NP3），低、中、高量氮磷钾化肥单施（NPK1，NPK2，NPK3），及低、中、高量氮磷钾化肥配施高、中、低量有机肥9个处理（NPK1M3，NPK2M2，NPK3M1），测定分析10年后不同施肥处理耕层（0~20 cm）土壤物理化学性状特征及有机碳动态。结果表明：施有机肥及有机无机配施处理较单施化肥处理容重下降0.13 g·cm-3，田间持水量提高6.7%，单施有机肥、有机无机配施较单施化肥，土壤有机碳（SOC）和全氮含量分别提高64.8%、36.3%和64.9%、49.5%。高量施用氮磷化肥和氮磷钾化肥处理全磷含量最高，有机肥及有机无机配施较单施化肥有效氮含量显著增加，有机无机配施及高量施用磷肥土壤有效磷积累明显，高量施用有机肥能显著提升有效钾含量。连续施肥处理10年后，SOC含量提高了1.68~2.84倍，土壤全氮、全磷、碱解氮及有效磷均有一定程度的提高，但单施化肥及有机肥与氮磷化肥配施有效钾含量下降。SOC的积累速率单施化肥、有机无机配施，单施有机肥处理分别为0.27、0.59，0.87 g·kg-1·a-1。增施有机肥、适量减少化肥投入、氮磷钾化肥的平衡施用是绿洲沙地农田土壤肥力持续提升的施肥管理对策。 相似文献
20.
分析了湛江市农业生产结构的演化历程,认为湛江市农业在发展过程中,自然条件、生产传统的影响逐渐减弱,市场需求、国家产业政策等影响因素作用增强。湛江市的农业竞争优势包括土地资源、光热资源、热带作物资源、人力资源等内部驱动因素和交通区位、市场需求以及发展政策等外部环境因素两个方面。为了提升区域农业竞争力,湛江市应加强基础设施建设,加大科技与资金投入,优化农业生产要素,同时应积极发展创汇农业,调整农业产业结构,推进农业产业化,不断改善农业产业经营、市场营销和政府管理等环节。 相似文献