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1.
辽西走廊农业生态系统区位优势分析梁文举(中国科学院沈阳应用生态研究所,110015)LocationalSuperiorityAnalysisofAgroecosystemsinWestLiaoningCorridor¥LiangWenju(InstituteofAppliedEcology,AcademiaSinica,Shenyang110015).ChineseJournalofEcology,1993,12(2):59-60.Basedontherelativeaggregationdegreesamonghierarchiesofdifferentagroecosystems,theauthorpro-posedthatlocationalquotientmodelcouldbeusedtomeasurethelocationalsuperiorityofagroecosystem.Themainpurposeofthispaperistoprovideascientificbasisforchoosingagriculturalmarketablebasesandestablishingahig  相似文献   

2.
No.1 (Jan.,2 0 0 2 )AnalysisontheCharacteristicsofUrbanVegetationandItsMappingBasedonRemoteSensingandGeographicInformationSystemGAOJ  相似文献   

3.
用全息观点看农业生态经济系统   总被引:3,自引:0,他引:3  
用全息观点看农业生态经济系统曹志平(北京农业大学生物学院,100094)AnalysisofAgro-EcolomicSystemFromtheViewpointsofHolograpby.¥CaoZhiping(CollegeofBiology,B...  相似文献   

4.
郭中伟  李典谟 《生态学杂志》1995,14(1):58-61,42
生态系统的环分析方法郭中伟,李典谟(中国科学院动物研究所,北京100080)LoopAnalysisinEcosystemStudy.¥GuoZhongwei;LiDianmo(InstituteofZoology,,AcademiaSinica,B...  相似文献   

5.
Bifurcation,Chaos and Control in Nervous System   总被引:2,自引:2,他引:0  
Bifurcation,Chaosand ControlinNervousSystemGongYunfan(龚云帆);XuJianxue(徐健学)(DepartmentofEngineeringMechanics,Xi'anJiaotongUnive...  相似文献   

6.
持续农业的理论基础──农业生态系统原理   总被引:6,自引:3,他引:3  
持续农业的理论基础农业生态系统原理陈欣章熙谷李萍萍(南京农业大学农学系,210095)ABasisforSustainableAgricultureThePrincipleofAgroecosystem.ChenXin,ZhangXigu,LiPin...  相似文献   

7.
森林生态系统生物能流的瞬态分析欧阳兵(中国科学院大气物理所大气数值模拟国家重点实验室,北京100080)Transient-StateAnalysisonBioticEnergyFlowinForestEcosystem.¥OuyangBing(LA...  相似文献   

8.
河南开封淀粉厂生态经济示范工程结构模型与投入产出模型的研究刘玉萃,赵伟(河南农业大学,郑州450002)StructuralModelandInput-OutputModelofEcolomicalDemonstrationProjectinKaifengStarchFac-toryofHenanProvince¥.LiuYucui;ZhaoWei(HenanAgriculturalUniwrsity,Zhengzhou450002).Chi-neseJourualofEcology,1993,12(2):61-65.Basedontheintegrityofsystemandrelationshipbetweenvarioussubsystemsandemployingtransitionalstructuralmodel,themultilevelgradientstructuresofsystemarefoundfromtemporalandspatialdimen-sions.Accordingtothedissipateandreproductivefeaturesofecosystemandus  相似文献   

9.
重金属在土壤—水稻系统中的行为特性   总被引:36,自引:3,他引:33  
重金属在土壤_水稻系统中的行为特性王新吴燕玉(中国科学院沈阳应用生态研究所,110015)BehaviourPropertyofHeavyMetalsinSoil_RiceSystem.WangXin,WuYanyu(InstituteofAppl...  相似文献   

10.
浸润垄作稻田土壤生态系统的研究   总被引:7,自引:0,他引:7  
浸润垄作稻田土壤生态系统的研究魏朝富,高明,车福才,邓春(西南农业大学土化系重庆630716)AStudyonInfiltrated-RidgedPaddySoilEcosystem¥.WeiChaofu;GaoMing,CheFuchai;DengChun(SouthwestAgriculluralUniversity,).ChineseJournalofEcology,1993,12(3):26-30;Thispaperdealswichaninfiltrated-ridgedpaddysoilecosystemwhichisconstructedbyridgingandcon-tinuousfurrowinfiItratiOnirrigation,ComparingwithlevelinfiItratedpaddysoilecosystem,thisecosys-temhascoexistedgas-liquid,gas-solidandliquid-solidinterfaces,enlargessoilsurfaceby38%andincreasescuItivatedlayerby5-10cm.  相似文献   

11.
The farm household responsibility system (FHRS) was adopted in Chinese rural areas during the economic reform in the early 1980s. Since then, many farm households have increased cropping intensity by using large quantities of nitrogen (N) fertilizers in their responsible fields to increase agricultural income. However, intensive cropping systems with low N input are still common in remote places of the southwestern region of China. Maintenance and improvement of soil quality in intensive cropping systems is critical for sustaining agricultural productivity and environmental quality for future generations. The effects of intensive cropping of vegetables on paddy rice (Oryza sativa L.) yield using small quantities of N fertilizers through N mineralization of paddy soil in irrigated rice-based multiple cropping systems were studied in 15 paddy fields in Sichuan Province, China for 3 years. Intensification of vegetable cropping with negative N balance and removal of vegetable crop residues has greatly decreased total N (TN) contents in paddy soil leading to low levels of effective cumulated soil temperature and thickness of plow layer. As a result, the N mineralization in paddy field during paddy rice growing period was decreased. In addition to the low levels of chemical fertilizer N input and residual mineral N input, the lower level of N mineralization in paddy fields and low N recovery efficiency decreased the amount of N accumulated in aboveground biomass of paddy rice at maturity, resulting in limited rice yields. The amount of mineralized N only correlated with TN (partial correlation analysis). Therefore, in paddy fields with very low N input, the N mineralization in paddy soil during the paddy rice-growing period was the major limiting factor affecting the total yield increases. In addition, a decline in soil fertility can be determined using TN as an indicator. To improve paddy rice yield and avoid soil deterioration, the development and adoption of rational soil management programs are needed. These include input of plant residues, conscientious soil tillage for the maintenance of soil temperature and thickness of the plow layer, and the split application of fertilizer for the improvement of N recovery efficiency.  相似文献   

12.
“双季稻-鸭”共生生态系统稻作季节氮循环   总被引:2,自引:0,他引:2  
“稻鸭共生”是对我国传统农业稻田养鸭的继承与发展.2010年5-10月在长江流域双季稻主产区湖南布置了稻田养鸭田间试验,以常规稻作为对照,研究了早、晚稻两季“稻鸭共生”生态系统氮(N)循环特征.结果表明:“早稻-鸭”共生系统N输出是239.5 kg· hm-2,其中鸭产品N是12.77 kg·hm-2.“晚稻-鸭”共生系统N输出是338.7 kg· hm-2,其中鸭产品N是23.35 kg· hm-2.在早、晚稻两季,“稻鸭共生”系统在目前的N养分投入水平下,土壤均存在N亏缺;鸭子系统N输入主要来自系统外投入的饲料N;鸭粪N作为系统内被循环利用的养分,早、晚稻两季循环率分别为2.5%和3.5%.两季稻作后,土壤截存的N量是178.6 kg·hm-2.  相似文献   

13.
“稻鸭共生”是对我国传统农业稻田养鸭的继承与发展.2010年5-10月在长江流域双季稻主产区湖南布置了稻田养鸭田间试验,以常规稻作为对照,研究了早、晚稻两季“稻鸭共生”生态系统氮(N)循环特征.结果表明:“早稻-鸭”共生系统N输出是239.5 kg·hm-2,其中鸭产品N是12.77 kg·hm-2.“晚稻-鸭”共生系统N输出是338.7 kg·hm-2,其中鸭产品N是23.35 kg·hm-2.在早、晚稻两季,“稻鸭共生”系统在目前的N养分投入水平下,土壤均存在N亏缺;鸭子系统N输入主要来自系统外投入的饲料N;鸭粪N作为系统内被循环利用的养分,早、晚稻两季循环率分别为2.5%和3.5%.两季稻作后,土壤截存的N量是178.6 kg·hm-2.  相似文献   

14.
隋月  黄晚华  杨晓光  李茂松 《生态学杂志》2013,24(11):3192-3198
南方地区是我国重要的农业种植区,季节性干旱严重影响该地区的农业生产.本文基于南方地区不同干旱分区中选取的13个典型地区1981-2007年气象资料和作物生育期、产量等资料,依据各地逐年降水量将其分为干旱年、正常年和丰水年3种不同降水年型,利用作物水分临界期需水量与降水量的耦合度、气象产量、单位面积产值以及全生育期的水分利用效率和降水量5个指标,对典型地区种植模式的综合效益进行评价,得到南方不同区域不同降水年型下的优化种植模式.结果表明: 半干旱区在干旱年型下,宜采取2种抗旱种植模式:马铃-玉米-甘薯和冬小麦-中稻-甘薯.半湿润区在干旱年型下,种植模式以冬小麦-中稻-甘薯最优,油菜-中稻-甘薯次之.在温润区(即典型的季节性干旱区),江南地区在3种年型下均以马铃薯-双季稻最优;西南地区宜搭配抗旱作物进行三熟制种植,如冬小麦-中稻-甘薯、冬小麦-玉米-甘薯、马铃薯-双季稻等.从最大程度利用水热资源角度考虑,三熟种植模式最优,以水旱轮作为主,丰水年型宜搭配水稻.  相似文献   

15.
South Asian countries will have to double their food production by 2050 while using resources more efficiently and minimizing environmental problems. Transformative management approaches and technology solutions will be required in the major grain‐producing areas that provide the basis for future food and nutrition security. This study was conducted in four locations representing major food production systems of densely populated regions of South Asia. Novel production‐scale research platforms were established to assess and optimize three futuristic cropping systems and management scenarios (S2, S3, S4) in comparison with current management (S1). With best agronomic management practices (BMPs), including conservation agriculture (CA) and cropping system diversification, the productivity of rice‐ and wheat‐based cropping systems of South Asia increased substantially, whereas the global warming potential intensity (GWPi) decreased. Positive economic returns and less use of water, labor, nitrogen, and fossil fuel energy per unit food produced were achieved. In comparison with S1, S4, in which BMPs, CA and crop diversification were implemented in the most integrated manner, achieved 54% higher grain energy yield with a 104% increase in economic returns, 35% lower total water input, and a 43% lower GWPi. Conservation agriculture practices were most suitable for intensifying as well as diversifying wheat–rice rotations, but less so for rice–rice systems. This finding also highlights the need for characterizing areas suitable for CA and subsequent technology targeting. A comprehensive baseline dataset generated in this study will allow the prediction of extending benefits to a larger scale.  相似文献   

16.
The cropping systems of seventeenth century traditional organic agriculture in the Jiaxing region of eastern China required about 2000 hr of labor per hectare for rice production. Rice and related grain crops were produced employing only human power. The input was about 200 times that for most mechanized grain production today. The charcoal or fossil energy input to produce simple hand tools accounted for only 1–2% total energy in the crop systems. Organic wastes including manures, pond sediments, and green manure crops supplied most of the nutrients. Rice yields, ranging as high as 6700–8400 kg/ha, were similar to some of the highest yields today. The energy output/input ratio ranged from 9 for compost-fertilized rice to 12 for green manure-fertilized rice production. These ratios were 2–10 times higher than most mechanized rice production systems of today. Knowledge of the crop and soil system enabled the early Chinese farms to maintain high crop yields and sustain highly productive soils.  相似文献   

17.
我国稻田氮磷流失现状及影响因素研究进展   总被引:8,自引:0,他引:8  
张子璐  刘峰  侯庭钰 《应用生态学报》2019,30(10):3292-3302
水稻是我国主要的粮食作物,分析现阶段我国稻田氮磷流失现状及影响因素,对明确不同区域水稻化肥减施潜力具有重要意义.本研究对我国主要稻区地表径流氮磷流失现状特征和降雨、种植模式、栽培技术、施肥管理、水分管理方式及其他影响因素进行了总结.六大稻区全氮(TN)、全磷(TP)径流损失量范围分别在5.09~21.32和0.70~3.22 kg·hm-2,均以华南双季稻区最高,TN径流损失量以华北单季稻区最低,TP径流损失量以西南高原单双季稻区最低.各稻区农户习惯施肥的水稻田田面水TN、TP峰值普遍高于径流水.水稻施肥后一周内为氮磷流失高峰期.与优化施肥相比,农户习惯施肥仍具有20%左右的氮磷减施潜力.各因素中,降雨和施肥管理是影响稻田径流氮磷流失的主要因素,而施肥管理和水分管理则最具可控性,具体调控措施包括化肥减量、施用新型肥料、有机肥代替化肥和节水灌溉等.整体上我国稻田氮磷流失风险在南方更突出.应以资源高效利用模式进行水稻种植以降低养分流失风险.未来研究应侧重稻田面源污染监测、氮磷流失风险评估、氮磷流失特征和机理、化肥减施增效新技术等方向.  相似文献   

18.
Lowlands comprise 87% of the 145 M ha of world rice area. Lowland rice-based cropping systems are characterized by soil flooding during most of the rice growing season. Rainfall distribution, availability of irrigation water and prevailing temperatures determine when rice or other crops are grown. Nitrogen is the most required nutrient in lowland rice-based cropping systems. Reducing fertilizer N use in these cropping systems, while maintaining or enhancing crop output, is desirable from both environmental and economic perspectives. This may be possible by producing N on the land through legume biological nitrogen fixation (BNF), minimizing soil N losses, and by improved recycling of N through plant residues. At the end of a flooded rice crop, organic- and NH4-N dominate in the soil, with negligible amounts of NO3. Subsequent drying of the soil favors aerobic N transformations. Organic N mineralizes to NH4, which is rapidly nitrified into NO3. As a result, NO3 accumulates in soil during the aerobic phase. Recent evidence indicates that large amounts of accumulated soil NO3 may be lost from rice lowlands upon the flooding of aerobic soil for rice production. Plant uptake during the aerobic phase can conserve soil NO3 from potential loss. Legumes grown during the aerobic phase additionally capture atmospheric N through BNF. The length of the nonflooded season, water availability, soil properties, and prevailing temperatures determine when and where legumes are, or can be, grown. The amount of N derived by legumes through BNF depends on the interaction of microbial, plant, and environmental determinants. Suitable legumes for lowland rice soils are those that can deplete soil NO3 while deriving large amounts of N through BNF. Reducing soil N supply to the legume by suitable soil and crop management can increase BNF. Much of the N in legume biomass might be removed from the land in an economic crop produce. As biomass is removed, the likelihood of obtaining a positive soil N balance diminishes. Nonetheless, use of legumes rather than non-legumes is likely to contribute higher quantities of N to a subsequent rice crop. A whole-system approach to N management will be necessary to capture and effectively use soil and atmospheric sources of N in the lowland rice ecosystem.IRRI-NifTAL-IFDC joint contribution.  相似文献   

19.
The level of chemical fertilization in China is considerably higher than that normally applied in Western countries. For example, in the last decade the use of N-P-K chemical fertilizers increased, within the province of our study, from about 300 kg/ha in 1980 to about 850 kg/ha in 1990. Data on total amounts on nitrogen, phosphorus, and potassium that are removed with the harvest are necessary in determining and optimizing the amount of chemical fertilizers to be applied to different crops and in different cropping patterns. In this article we report the results of analyses of N, P, and K content of soils and different parts of different plants (soybean, cotton, rice, peanut, radish, Chinese cabbage, sesame, pepper, eggplant, and ambary) typically grown in rural areas of Southern China and provide an estimate of the balance of these nutrients under the five cropping systems that are dominant in the studied area.  相似文献   

20.
陕南秦巴山区水稻施肥现状评价   总被引:4,自引:0,他引:4  
为了解陕南秦巴山区水稻施肥现状及农户养分资源投入中存在的问题,提出解决问题的对策,对测土配方施肥项目2006-2009年的11个县2854户调查数据进行了分析和评价.结果表明: 陕南秦巴山区水稻平均产量为7822 kg·hm-2,中等产量农户所占比例为509%.总氮(N)、磷(P2O5)、钾(K2O)养分投入量分别为169、68、54 kg·hm-2,其中化肥氮(N)、磷(P2O5)、钾(K2O)养分投入量分别为159、62、45 kg·hm-2,偏生产力分别为51.52、135.69和158.26 kg·kg-1.根据养分分级等级,农户化肥氮、磷、钾投入合理比例分别为48.0%、42.4%和7.2%,过量比例分别为22.6%、11.2%和0.6%,不足比例分别为29.4%、46.5%和92.2%.如果化肥养分投入不足的农户将施肥量增加到合理水平,陕南秦巴山区水稻可增产7.70万t.该区域水稻施肥存在的问题主要包括:氮肥和磷肥投入过量和不足并存,钾肥和有机肥投入不足.今后该区域水稻施肥的重点是平衡氮肥和磷肥用量,增加钾肥和有机肥用量,增加追肥尤其是钾肥的施用.  相似文献   

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