The measurement of soil fungal:bacterial biomass ratios as an indicator of ecosystem self-regulation in temperate meadow grasslands
The measurement of soil fungal:bacterial biomass ratios as an indicator of ecosystem self-regulation in temperate meadow grasslands
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DOI：
10.1007/s003740050554
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发表时间：
1999-07-01
影响因子：
6.5
通讯作者：
McAlister, E
中科院分区：
文献类型：
--
作者：
Bardgett, RD;McAlister, E
人们对制定农业土地管理战略很感兴趣，这些战略旨在加强对生态系统自我调节的依赖，而不是依赖化肥和杀虫剂等人工投入。本研究测试的有效性措施的土壤微生物生物量和真菌：细菌生物量的比例作为指标的有效转换，从集约化草地系统，主要依赖于肥料作物营养，低投入系统主要依赖于自我调节，通过土壤生物途径的养分周转。从广泛的草甸草地网站在北方英格兰，沿着梯度的长期管理强度的土壤分析表明，真菌：细菌生物量的比例（磷脂脂肪酸分析测定; PLFA）是一致的，显着高于未施肥的草地。也有一些证据表明，微生物生物量，氯仿熏蒸和总PLFA测量，是在未施肥的草地比施肥。还发现，无机氮（N）的水平，特别是硝酸盐-N，显着高于施肥比未施肥的草地。然而，微生物活性，测量基础呼吸，没有不同的网站。进行了现场操作试验，以确定是否恢复传统的管理改良中营养草地，多年来，导致类似的变化，在土壤微生物群落。结果发现，无论是停止施肥，也不改变切割和放牧管理显着影响土壤微生物生物量或真菌：细菌生物量的比例。这表明，缺乏对土壤微生物群落的影响可能与高残留肥力所造成的肥料氮在土壤中的保留。在这些结果的基础上，建议恢复低投入管理后，土壤真菌：细菌生物量的比例显着增加的测量，也许总微生物生物量，可能是一个成功的转换到草地系统依赖于自我调节的指标。
There is much interest in the development of agricultural land management strategies aimed at enhancing reliance on ecosystem self-regulation rather than on artificial inputs such as fertilisers and pesticides. This study tested the usefulness of measures of soil microbial biomass and fungal:bacterial biomass ratios as indicators of effective conversion from an intensive grassland system, reliant mainly on fertilisers for crop nutrition, to a low-input system reliant mainly on self-regulation through soil biological pathways of nutrient turnover. Analysis of soils from a wide range of meadow grassland sites in northern England,along a gradient of long-term management intensity, showed that fungal:bacterial biomass ratios (measured by phospholipid fatty acid analysis; PLFA) were consistently and significantly higher in the unfertilised than the fertilised grasslands. There was also some evidence that microbial biomass, measured by chloroform fumigation and total PLFA, was higher in the unfertilised than in the fertilised grasslands. It was also found that levels of inorganic nitrogen (N), in particular nitrate-N, were significantly higher in the fertilised than in the unfertilised grasslands. However, microbial activity, measured as basal respiration, did not differ between the sites. A field manipulation trial was conducted to determine whether the reinstatement of traditional management on an improved mesotrophic grassland, for years, resulted in similar changes in the soil microbial community. It was found that neither the cessation of fertiliser applications nor changes in cutting and grazing management significantly affected soil microbial biomass or the fungal:bacterial biomass ratio. It is suggested that the lack of effects on the soil microbial community may be related to high residual fertility caused by retention of fertiliser N in the soil. On the basis of these results it is recommended that following the reinstatement of low-input management, the measurement of a significant increase in the soil fungal:bacterial biomass ratio, and perhaps total microbial biomass, may be an indicator of successful conversion to a grassland system reliant of self-regulation.