Spatial distribution and successional pattern of microbial activity and micro-faunal populations on decomposing barley roots
Spatial distribution and successional pattern of microbial activity and micro-faunal populations on decomposing barley roots
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腐烂大麦根上微生物活动和微型动物种群的空间分布和演替模式
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
S. Christensen
中科院分区：
文献类型：
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作者：
R. Rønn;B. Griffiths;F. Ekelund;S. Christensen
1.随着目前农业实践中增加本地和添加的有机物质在土壤肥力建设中的重要性的趋势，需要更好地了解有机资源周围的分解活动的动态。在这项研究中，微生物的活动和原生动物和线虫的种群的变化，其次是在分解大麦根材料埋在土芯，并在三个土壤组分与根材料的距离增加。2.呼吸活动是最大的，在第一周，并在整个实验中下降，并在最后一次采样后392天没有显着影响的根呼吸。3.根除了微生物活性（脱氢酶活性和潜在的反硝化速率）迅速增加，在根材料和土壤中的根1.8毫米。4天后微生物活性达到峰值，2周后原生动物数量达到峰值，6周后线虫数量达到峰值。4.细菌的生长潜力，如在潜在的反硝化测定过程中的酶合成所示，并且平均细菌细胞大小在根上比在土壤中更大，这表明在该部分中更活跃的细菌生物量。5.根系效应非常局部，主要限于根系附近的土壤部分;距离根系1.8-5.4 mm的土壤和距离根系5.4 mm以上的土壤几乎不受资源影响。6.这些结果表明，不同的演替模式的微生物食物网与人口发展的顺序，从微生物到原生动物和线虫。
1. With the current trend in agricultural practice to increase the importance of indigenous and added organic matter in the build-up of soil fertility, a better understanding of the dynamics of decomposition activity around organic resources is required. In this study the changes in microbial activity and populations of protozoa and nematodes were followed in decomposing barley root material buried in soil cores, and in three soil fractions with increasing distance from the root material. 2. Respiratory activity was maximal during the first week and decreased throughout the experiment, and at the last sampling after 392 days no significant effect of the roots on respiration was observed. 3. Following root addition microbial activity (dehydrogenase activity and potential denitrification rate) increased rapidly in the root material and in soil up to 1.8 mm from the roots. Microbial activity peaked after 4 days followed by a peak in protozoan numbers after 2 weeks and a peak in the number of nematodes after 6 weeks. 4. Growth potential of bacteria, as indicated by enzyme synthesis during a potential denitrification assay, and average bacterial cell size was larger on the roots than in the soil suggesting a more active bacterial biomass in this fraction. 5. The root effect was very local, and was limited mainly to the soil fraction adjacent to the roots; soil 1.8-5.4 mm from the roots and soil more than 5.4 mm from the roots was hardly affected by the resource. 6. These results demonstrate distinct successional patterns in the microbial food web with a sequence of population development from micro-organisms to protozoa and nematodes.