Effect of microbial activity on penetrometer resistance and elastic modulus of soil at different temperatures.
Effect of microbial activity on penetrometer resistance and elastic modulus of soil at different temperatures.
复制标题
DOI：
10.1111/ejss.12440
复制
发表时间：
2017-07
影响因子：
4.2
通讯作者：
Whalley WR
中科院分区：
文献类型：
--
作者：
Gao W;Muñoz-Romero V;Ren T;Ashton RW;Morin M;Clark IM;Powlson DS;Whalley WR
探讨了根系分泌物刺激的微生物活动对土壤的电阻率和弹性模量的影响。这一点很重要，因为它是土壤机械强度的量度，并且与根的伸长速率密切相关。一个桑迪土壤培养与合成根分泌物在不同的温度下，不同的时间长度和选择性抑制真菌或细菌。用合成渗出物孵育的土壤中贯入仪阻力的温度响应形状是典型的变温温度响应。电阻率计电阻和小应变剪切模量在25至30°C之间具有最大值。在20°C或更低的温度下，用合成根分泌物孵育对小应变剪切模量的影响很小，尽管在此范围内（4-20°C），应变计电阻确实随温度增加。这表明，在该温度范围内，电阻率计电阻的增加与更大的塑性变形阻力有关。在更高的温度（> 25°C）下，示温计电阻降低。DNA序列数据的分析表明，在25°C下，链霉菌（革兰氏阳性菌）的数量增加，但真菌或细菌的选择性抑制表明真菌在细菌耐药性方面具有更大的作用。人工根系分泌物刺激微生物活性对力学性能的影响。我们比较了微生物群落的弹性模量的测量和估计。土壤的针入度电阻表现出变温温度响应。真菌对针入度计阻力的影响可能大于细菌。
We explore the effect of microbial activity stimulated by root exudates on the penetrometer resistance of soil and its elastic modulus. This is important because it is a measure of the mechanical strength of soil and it correlates closely with the rate of elongation of roots. A sandy soil was incubated with a synthetic root exudate at different temperatures, for different lengths of time and with selective suppression of either fungi or bacteria. The shape of the temperature response of penetrometer resistance in soil incubated with synthetic exudate was typical of a poikilothermic temperature response. Both penetrometer resistance and small strain shear modulus had maximum values between 25 and 30°C. At temperatures of 20°C and less, there was little effect of incubation with synthetic root exudate on the small strain shear modulus, although penetrometer resistance did increase with temperature over this range (4–20°C). This suggests that in this temperature range the increase in penetrometer resistance was related to a greater resistance to plastic deformation. At higher temperatures (> 25°C) penetrometer resistance decreased. Analysis of the DNA sequence data showed that at 25°C the number of Streptomyces (Gram‐positive bacteria) increased, but selective suppression of either fungi or bacteria suggested that fungi have the greater role with respect to penetrometer resistance. Effect of microbial activity stimulated by synthetic root exudates on the mechanical properties. We compared penetrometer measurements and estimates of elastic modulus with microbial community. Penetrometer resistance of soil showed a poikilothermic temperature response. Penetrometer resistance might be affected more by fungi than bacteria.
登录
查看更多内容
影响因子：
9.7
作者：
Benizri, Emile;Nguyen, Christophe;Philippot, Laurent
通讯作者：
Philippot, Laurent
影响因子：
2.9
作者：
Gao, W.;Ren, T.;Whalley, W. R.
通讯作者：
Whalley, W. R.
影响因子：
6.5
作者：
Whalley, W. R.;Jenkins, M.;Attenborough, K.
通讯作者：
Attenborough, K.
影响因子：
9.7
作者：
Cosentino, Diego;Chenu, Claire;Le Bissonnais, Yves
通讯作者：
Le Bissonnais, Yves
影响因子：
4.9
作者：
Hirsch, Penny R.;Jhurreea, Deveraj;Clark, Ian M.
通讯作者：
Clark, Ian M.