生态景观型灌排系统面源污染防治试验及生态响应   总被引：3，自引：1，他引：3  

张雅杰  邵庆军  李海彩  叶梁倩  姚星  胡将军 《农业工程学报》2015,31(1):133-138

设计由灌排合一生态环沟、生态景观型斗渠和斗沟组成的新型土地整治灌排系统,以上海市临港土地整治项目区为试验场地进行不同灌排系统面源污染防治效果对比试验,最后引入生态服务价值模型分析其产生的生态响应。结果表明:1)生态景观型灌排系统涵盖稻田-萍-鱼-蔬菜种植版互利共生系统和生态环沟-迂回式生化塘-斗沟湿地面源污染防治系统,实现了稻田养鱼和农业现代化经营共赢;同时在土地整治灌排系统稻田排水口处设置迂回式生化塘,为农业面源污染防治提供了一种新思路;2)生态景观型灌排系统通过植物吸收和截留、基质和底泥吸附及细菌和微生物降解等作用,在水稻生长周期6-10月面源污染防治效果均明显高于其他灌排系统,COD、NH4+-N、TN、TP的平均去除率分别为77.57%、78.99%、69.77%、73.74%;3)生态景观型灌排系统带来的(正,负)生态响应中,正响应为4.95万元,是负响应的45倍,气候调节、水源涵养、废物处理、生物多样性保护、土壤保持和提供美学景观等功能均显著增强。  相似文献   

河龙区间坝库参数与减沙效益关系研究     

冉大川  上官周平  刘斌  白志刚 《水土保持学报》2007,21(2):44-48

对黄河中游河龙区间晋西北片、陕北片坝库控制面积占比、坝库单位面积库容等参数与水利水土保持措施减沙效益关系进行了研究，结果表明：（1）晋西北片若没有坝库工程，仅靠水土保持坡面治理措施只能取得14％的减沙效益；每增加100km^2的坝库控制面积，即可提高2％的减沙效益；每增加400万m^2的库容，即可提高1％的减沙效益;坝库单位面积库容每提高1万m^2／km^2，减沙效益即可提高约10％。（2）陕北片减沙效益主要由坝库工程产生。减沙效益提高10％，坝库单位面积库容需要提高5万m^2／km^2。要使流域水土保持综合治理减沙效益达到20％以上，坝库单位面积库容应在6万m^2／km^2以上。（3）在黄河中游多沙粗沙区，要实现40％左右的减沙效益，坝库单位面积库容应达到167／m^2／km^2以上。  相似文献   

论农业药械发展中降低污染的途径   总被引：3，自引：0，他引：3       下载免费PDF全文

高良润 《农业工程学报》1991,7(1):1-8

本文综述了中国农业药械发展现况,药械施用中的污染问题;探讨了药械发展中降低污染的途径。如“控制”与“消灭”的选择,综合防治与法规防治的推行,新型药械的创制,物理防治和生物防治器械的研制以及新型制剂及其施布机械的应用。  相似文献   

宜兴茶园土壤侵蚀及生态影响   总被引：9，自引：2，他引：9  

张燕  杨浩  金峰  张洪  彭补拙 《土壤学报》2003,40(6):815-821

茶园是苏南丘陵坡地的一种典型利用方式 ,其上发生的土壤侵蚀及产生的生态影响不容忽视。而要测度土壤侵蚀 ,137Cs示踪法是目前使用较多的一种有用工具 ,但要用此法 ,需找到研究区的137Cs背景值 ,并建立合适的估算模型。本文在对宜兴茶园研究时 ,确定了这里的137Cs背景值为 2 2 0 0Bqm- 2 ,并建立了估算耕作土壤的较合理的模型h =Hc× (Cref-Ct) /(Cref-Cin)。在此基础上衡量了研究对象的土壤侵蚀量 ;并进一步探讨了由此引发的生态影响 ,包括土层减薄、土壤质地改变和养分流失这样的直接影响 ,以及与之相应的一些间接影响 ,如能耗增加、水体富营养化及土地适宜性变化等 ;并且 ,还采用等值侵蚀模数这个指标 ,在与其他地区尤其是黄土和红壤区比较中揭示了苏南地区土壤侵蚀的生态危害的严重性  相似文献   

鄱阳湖生态经济区畜禽养殖土壤环境承载力及污染风险研究   总被引：3，自引：0，他引：3  

潘丹 《水土保持通报》2016,36(2):254-259

[目的]测算和评价鄱阳湖生态经济区畜禽养殖过程中的土壤环境承载力及其污染风险,为合理规划鄱阳湖生态经济区畜禽养殖空间布局、实现可持续养殖提供参考。[方法]利用2000—2012年鄱阳湖生态经济区24个县(市)的统计数据进行土壤环境承载力及畜禽污染物排放量的测算和评估。[结果]2000—2012年鄱阳湖生态经济区畜禽粪便耕地负荷警报值在0.7左右,总氮耕地负载警报值为0.5~0.6,总磷耕地负载警报值超过了1,畜禽养殖对环境造成了污染威胁。畜禽养殖污染风险较高的地区为高安市、东乡县、余江县、德安县以及南昌县。[结论]污染风险较高的地区应强制实行畜禽养殖总量控制和污染物消减措施,而湖口县、都昌县和彭泽县畜禽污染风险较低,可以适当扩大养殖规模。  相似文献   

秦岭北麓城市新兴开发区生态系统服务价值变化   总被引：1，自引：0，他引：1  

赵丹  马俊杰  刘哲  吕继强 《水土保持通报》2015,35(5):279-283

[目的]选取秦岭北麓典型城市区域陕西省西安市浐灞生态区为研究对象,从景观格局变化、生态服务价值两方面分析城市新区建设及可持续性,以期为城市生态建设提供决策参考。[方法]以遥感数据为基础,对研究区土地利用类型和景观格局进行定量分析,研究城市新区尺度下的景观生态系统和生态服务价值变化特征。[结果](1)2004—2014年,浐灞生态区城乡转换特征明显,农业景观比重显著降低,建设用地景观增幅达88.2%,生态景观增幅高达201.5%以上,区域"生态含量"明显提高。(2)生态服务价值以农田、绿地和水体景观变化较为明显,其中农田生态服务价值损失近65%,到2014年全区85%以上的生态服务价值来自于绿地和水体景观。[结论]浐灞生态区10a间生态用地动态变化强烈且持续,城市生态服务价值增加明显,反映该区在保障城市化建设的同时,有效且显著提高了环境质量,其生态建设政策有利于区域生态系统的建设和发展。  相似文献   

日光温室番茄的氮素追施与反馈调控   总被引：7，自引：6，他引：7  

汤丽玲  陈清  张福锁  李晓林 《植物营养与肥料学报》2004,10(4):391-397

在施用足量有机肥的基础上,以山东寿光当地的常规氮肥追施措施为对照,通过结合硝酸盐速测技术对日光温室秋冬茬番茄不同生育时期的氮素供应进行实时动态调控,以确定合理的追肥数量。结果表明,同当地农民的常规处理相比,采用实时调控处理的氮素投入总量减少了N170kg.hm2,但对番茄的生长(株高、茎粗、果实发育速度等)、产量和品质等指标没有任何影响。根据追肥前根层土壤氮素的供应水平(0—30cm土壤NO3--N含量+氮素追施数量)的监测,可初步确定日光温室秋冬茬番茄在第一穗果膨大期、第二穗果膨大期和第四穗果膨大期时的氮素供应目标值最多为N296kg.hm2、216kg.hm2和191kg.hm2。与此同时,将每个时期所确定的目标值应用在同期生长的其它3个日光温室的番茄氮素追施调控,结果发现与相应的农民常规处理相比,实时调控处理对作物的生长同样没有影响,这表明在日光温室秋冬茬番茄生产过程中,结合植株和土壤硝酸盐速测技术,通过施肥调控满足作物在不同生长时期的氮素供应水平是可行的。  相似文献   

固定态铵的含量及中国某些耕地土壤NH₄⁺的固定能力   总被引：3，自引：0，他引：3  

WEN Qi-Xiao  CHENG Li-Li  ZHANG Xiao-Hua 《土壤圈》1995,5(4):315-323

Fixed ammonium contents and NH4^ fixation capacities of some representative cultivated solis collected from 16 provinces of China were studied.Results showed that the contents of fixed ammonium in soils ranged from 35 to 573 mg N kg^-1,with an average of 198mg Nkg^-1.The content of fixed ammonium correlated very significantly with mica content for tropical and subtropical soils,whereas this was not the case for soils in the temperate zone.At the end of K-exhausting experiment the fixed ammonium content increased in most soils studied.However,it decreased in smom temperate soils.Generally,fixation of added NH4^ could not be found either before or after K-exhausting experiment for highly weathered soils,including tropical soils and soils derived from granite-gneiss or Quaternary red clays in the subtropic zone,while for most soils in the Yangtze River dalta the NH4^ fixation capacity was rather high and increased significantly in the K-exhausted soils.  相似文献   

Competition for electron donors among nitrate reducers,ferric iron reducers,sulfate reducers,and methanogens in anoxic paddy soil   总被引：17，自引：0，他引：17  

Christof Achtnich  Friedhelm Bak  Ralf Conrad 《Biology and Fertility of Soils》1995,19(1):65-72

Slurries of anoxic paddy soil were either freshly prepared or were partially depleted in endogenous electron donors by prolonged incubation under anaerobic conditions. Endogenous NO ₃ ^– was reduced within 4 h, followed by reduction of Fe³⁺ and SO ₄ ^2– , and later by production of CH₄. Addition of NO ₃ ^– slightly inhibited the production of Fe²⁺ in the depleted but not in the fresh paddy soil. Inhibition was overcome by the addition of H₂, acetate, or a mixture of fatty acids (and other compounds), indicating that these compounds served as electron donors for the bacteria reducing NO ₃ ^– and/or ferric iron. Addition on NO ₃ ^– also inhibited the reduction of SO ₄ ^2– in the depleted paddy soil. This inhibition was only overcome by H₂, but not by acetate or a mixture of compounds, indicating that H₂ was the predominant electron donor for the bacteria involved in NO ₃ ^– and/or SO ₄ ^2– reduction. SO ₄ ^2– reduction was also inhibited by exogenous Fe³⁺, but only in the depleted paddy soil. This inhibition was overcome by either H₂, acetate, or a mixture of compounds, suggesting that they served as electron donors for reduction of Fe³⁺ and/or SO ₄ ²⁺ . CH₄ production was inhibited by NO ₃ ^– both in depleted and in fresh paddy soil. Fe³⁺ and SO ₄ ^2– also inhibited methanogenesis, but the inhibition was stronger in the depleted than in the fresh paddy soil. Inhibition of CH₄ production was paralleled by a decrease in the steady state concentration of H₂ to a level which provided a free enthalpy of less than G=–17 kJ mol^-1 CH₄ compared to more than G=–32 kJ mol^-1 CH₄ in the control. The results indicate that in the presence of exogenous fe³⁺ or SO ₄ ²⁺ , methanogenic bacteria were outcompeted for H₂ by bacteria reducing Fe³⁺ or SO ₄ ²⁺ .Deceased on 27 December 1992  相似文献   

Influence of liquid cattle manure on reduction processes in soil     

Søren O. Petersen 《Biology and Fertility of Soils》1993,15(2):137-143

Summary Reduction processes in cultivated soil during the decomposition of liquid cattle manure were studied in laboratory experiments. Anoxic slurries of soil and manure in different proportions or alone were followed over 5 weeks. Upon NO _inf3 ^sup- depletion, ferrous Fe appeared in solution in soil-manure slurries. Sulfide levels were generally low in the presence of both soil and manure, probably because of precipitation by Fe²⁺; Fe thereby counteracted the production of free hydrogen sulfide. Methane formation was the quantitatively most important electron sink under prolonged anoxic conditions. When extra sulfate was added to soil-manure slurries, the concentration of Fe²⁺ remained low and less methane was produced. The detection of Fe²⁺ was examined in a model system with a gel-stabilized soil-manure mixture sandwiched between two soil phases with a water content near field capacity. Large methodological problems made it impossible to quantify Fe²⁺ in this oxic-anoxic environment, but the results indicated that reducing conditions were maintained in the manure-saturated zone for the 20-day period of this experiment.  相似文献