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J. Scullion 《Land Degradation \u0026amp; Development》1992,3(3):161-168
Surface mining activities and other large civil engineering works often involve the removal, storage and reinstatement of topsoil. Disturbance disrupts normal biological functions within the soil and can markedly change the environment within which soil organisms must exist. This has implications for soil fertility and for the overall ecology of replaced land. A number of studies have investigated the impact of opencast coal mining practices on soil organisms and their capacity for recovery following site reinstatement. The extent and duration of any adverse effect varies from one group of organisms to another according to their vulnerability to damage, their capacity for recovery and their ability to recolonize areas from which they have been eliminated. Three groups of organisms—earthworms, aerobic bactería and vesicular arbuscular endophytes—are considered, to illustrate their differing responses to soil disturbance and the various factors limiting their early recovery throughout a restored area. Given favourable management, consistent with good general rehabilitative practice, the re-establishment of normal earthworm populations depends entirely on the distribution of an inoculum. For aerobic bacteria adverse physical conditions in reinstated soils are the overriding influence determining levels of activity. For mycorrhizal fungi both soil conditions and the absence of an inoculum may delay recovery, although the evidence in support of this view is inconclusive. 相似文献
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长期施磷稻田土壤磷素累积及其潜在环境风险 总被引:7,自引:1,他引:7
应用常规化学分析法和数学统计方法,基于太湖地区13年的长期定位试验,研究长期不同施磷水平下[0(不施磷)、30 kg.hm 2.a 1(低磷)、60 kg.hm 2.a 1(适磷)、90 kg.hm 2.a 1(高磷)]稻麦轮作系统稻田土壤磷素累积规律及磷素流失引发的环境风险。在本试验区土壤环境条件下,可能发生稻田磷素淋溶及径流的土壤耕层(0~15 cm)Olsen-P临界值分别为26.0 mg.kg 1和24.8 mg.kg 1。连续13年适磷、高磷施肥,土壤耕层Olsen-P含量分别达到26.9 mg.kg 1和33.2 mg.kg 1,均高于临界值浓度,且已导致稻田田面水与30 cm渗漏水中总磷浓度显著升高,大大提高了稻田磷素淋溶及径流的风险。低磷施肥土壤Olsen-P长期稳定在(10.1±2.0)mg.kg 1水平,并且每年的稻麦产量与高磷、适磷处理相比并无显著差异,而长期低磷施肥土壤磷的流失风险也较小。因此,在太湖地区稻麦轮作体系下,磷肥不宜以常规适磷水平长期施用,建议以低磷水平(30 kg.hm 2.a 1)长期施用或以适磷水平(60 kg.hm 2.a 1)间歇式施用。 相似文献
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念青唐古拉山东南坡高寒草原生态系统表层土壤活性有机碳的影响因素研究 总被引:1,自引:0,他引:1
高寒草原是青藏高原广泛分布的植被类型。本文以念青唐古拉山东南坡高寒草原生态系统为对象,采用野外调查与室内分析相结合的方法,对影响高寒草原生态系统表层(0~20cm)土壤活性有机碳分布的因素进行了研究。结果表明:念青唐古拉山东南坡高寒草原生态系统表层(0~20cm)土壤活性有机碳平均含量为2.61±0.31g·kg?1;影响表层土壤活性有机碳分布的地形因子是海拔和坡度,植被因子是0~10cm、10~20cm土层地下生物量,物理因子是0~10cm、10~20cm土壤含水量和0~20cm土壤容重,化学因子是土壤全钾含量。其中0~10cm、10~20cm土壤含水量和0~20cm土壤容重影响达显著水平。在海拔4421~4598m范围内,随着海拔升高,表层土壤活性有机碳含量表现出增加→减少→增加→减少的分布特征。 相似文献
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