| 摘要: |
| 【目的】探索玉米根系代谢活动对土壤微生物生态的影响。【方法】2003和2004年,采用定位试验法,研究了西北干旱半干旱地区不同栽培模式(常规、补灌、覆膜、覆草、休闲地(对照))对玉米根区(R)和根外(B)土壤细菌、真菌及放线菌数量的影响。【结果】①覆盖处理能强化玉米根区、根外细菌及真菌的数量差异,提高玉米根区与根外土壤微生物数量比值(R/B)。细菌和真菌的平均R/B分别为常规处理的2.26和2.28倍,但覆盖处理对根区和根外放线菌数量影响不大;②玉米生长活动及根系代谢产物对土壤细菌、真菌和放线菌数量的增加有促进作用。种植玉米后,土壤细菌、真菌和放线菌数量均高于休闲地。③根系的代谢活动能够降低土壤中细菌与真菌、放线菌与真菌数量的比值,提高细菌与放线菌数量的比值,覆盖模式下降低或提高作用得到加强。但补灌处理与之相反。【结论】覆盖和根系均能大幅度增加根区细菌、真菌和放线菌的数量,强化玉米根区根外细菌和真菌数量的差异。玉米根系的活动能改变土壤中细菌、真菌和放线菌的组成比例。 |
| 关键词: 栽培模式 土壤微生物区系 玉米 根系 旱作农业 |
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| 基金项目:国家自然科学基金重点项目“西北旱地优质高产高效栽培的生理生态基础”（30230230） |
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| Effects of the maize root on soil microbial flora under different cultivation patterns |
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| Abstract: |
| 【Objective】 The experiment studied the effect of maize root on soil microbial flora under different cultivation models.【Method】 The effects of different cultivation patterns on the quantity of soil bacteria,fungi and actinomycetes of maize rhizosphere and bulk soil were studied by using the orientation mensuration method in the arid and semiarid area in the northwest.【Result】 Results of orientation mensuration of two successive years showed that:①The mulching enhanced the difference in the number bacteria and fungi in rhizospere and bulk soil,and increased the R/B of number of edaphon in rhizospere and bulk soil.The average R/B of bacteria and fungi respectively were 2.26 and 2.28 times of conventional.But the influence of mulching was not strong on the number of actinomycetes.②The growth and metabolism of maize root increased the number of soil bacteria,fungi and actinomycetes.After culturing maize,the number of soil bacteria,fungi and actinomycetes were more than that in fallow field.③Ratios of the number of bacteria to fungi and the number of actinomycetes to fungi were reduced by maize root metabolizing.Mulching enhanced the effect of reducing and increasing.But it was contrary under the supplemental irrigation.【Conclusion】 Mulching and maize root increased obviously the number of bacteria,fungi and actinomycetes in maize rhizospere and enhanced the difference in the number of bacteria and fungi in maize rhizospere and bulk soil.The metabolizing of maize root changed the ratio of bacteria, fungi and actinomycetes. |
| Key words: cultivation model soil microbial flora maize root dry farming |
