砂龄对砂田土壤微生物区系及理化性状的影响

发布时间：2018-02-10 00:53

本文关键词： 干旱半干旱地区砂田不同覆盖年限土壤微生物环境因子　出处：《干旱地区农业研究》2017年04期 　论文类型：期刊论文

【摘要】：以不同砂龄(砂田覆盖年限分别为1、6、12、19 a和25 a)的砂田为研究对象,对砂田土壤混合层、根系密集层、淋溶层和钙积层的土壤微生物区系及影响土壤微生物的因素进行研究。结果表明:(1)砂田土壤微生物组成中,以细菌为主,放线菌次之,真菌最少;随土壤剖面深度的增加,土壤微生物总数迅速减少,这主要是由于细菌数量迅速减少所致;受根系分布的影响,根系密集层的微生物数量高于只有少量根系分布的混合层。(2)细菌和放线菌的数量在作物生长期高于作物非生长期,而真菌的数量则相反。(3)细菌和真菌在砂龄约为6~12 a的砂田中最多,随砂田覆盖时间的增加,砂田逐渐老化,数量逐渐减少;而放线菌的数量反之,在砂龄约为6~12 a的砂田中最少,随砂田覆盖时间的增加而增加。(4)砂田土壤微生物数量与土壤水分含量、pH值和覆盖时间有很好的相关性,土壤养分中的全C含量是限制砂田土壤微生物数量的重要因子。
[Abstract]:The sand fields with different sand ages (covering years of 1 ~ 6 ~ 1219 a and 25 a respectively) were studied. The mixed layer of soil and the dense layer of root system were studied. The microflora of soil in leached layer and calcium accumulation layer and the factors affecting soil microorganism were studied. The results showed that in the soil microbial composition of the sand field, bacteria were dominant, actinomycetes were the second, fungi were the least, and with the increase of soil profile depth, the microorganism composition of sand field was mainly bacteria, actinomycetes and fungi were the least. The rapid decrease in the total number of microbes in the soil is mainly due to the rapid decrease in the number of bacteria; affected by the distribution of roots, The number of bacteria and actinomycetes in the dense layer of roots was higher than that in the mixed layer with only a small amount of root distribution, and the number of bacteria and actinomycetes was higher in the period of crop growth than in the non-growing stage of crops. On the contrary, the number of fungi and bacteria was the most in sandy field with the age of 6 ~ 12 years. With the increase of mulching time, the sand field gradually aged and the number of actinomycetes decreased gradually, whereas the number of actinomycetes decreased, but the number of actinomycetes decreased with the increase of mulching time. In the sandy field with the age of 6 ~ 12 years, the soil microbial quantity increased with the increase of mulching time, and there was a good correlation between soil microbial quantity and soil moisture content and soil pH value and mulching time, and there was a good correlation between soil microbial quantity and soil moisture content, pH value and mulching time. The total C content in soil nutrient is an important factor to limit the soil microbial quantity in sandy field.
【作者单位】：甘肃省干旱生境作物学重点实验室;中国科学院寒区旱区环境与工程研究所;甘肃农业大学;兰州财经大学;
【基金】：甘肃农业大学盛彤笙科技创新基金(GSAU-STS-1427) 甘肃省干旱生境作物学重点实验室—省部共建国家重点实验室培育基地开放基金课题(GSCS-2012-14) 国家自然科学基金(31560356)
【分类号】：S154.3

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