The effects of compaction and soil drying on penetrometer resistance
The effects of compaction and soil drying on penetrometer resistance
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DOI：
10.1016/j.still.2012.07.006
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发表时间：
2012-09-01
影响因子：
6.5
通讯作者：
Whalley, W. R.
中科院分区：
文献类型：
--
作者：
Gao, W.;Watts, C. W.;Whalley, W. R.
贯入阻力被广泛用于测量根系在干燥或压实土壤中所经历的机械阻抗。然而，有相对较少的模型来预测土壤容重计电阻，可以应用没有详细的知识，土壤质地，有机质含量，土壤水分状况，密度或其他土壤变量。很少有模型能以简单的方式预测管理对土壤电阻率计电阻的影响。如果能够预测结构、压实和土壤干燥对土壤电阻的影响，这将是有用的。我们设计了一个实验室实验，以探讨压实和随后的土壤干燥如何影响三种土壤：一个壤土和两个粉质粘土土壤具有非常不同的有机碳含量的电阻。通过假设应变计电阻与小应变剪切模量G成比例，我们能够开发一个经验模型来解释压实和土壤干燥对应变计电阻的影响。模型的参数是通过将其拟合到实验室收集的实验数据来确定的。利用感测的基质势数据和实测土壤密度数据对该模型进行了测试。模型预测与早期模型获得的结果进行了比较。这两种方法解释了约60%的方差在测得的流量计数据。这种方法的未来应用进行了讨论。(C)2012爱思唯尔有限公司版权所有。
Penetrometer resistance is widely used as a measure of the mechanical impedance that roots experience in either drying or compacted soil. However, there are relatively few models to predict penetrometer resistance that can be applied without detailed knowledge of soil texture, organic matter content, soil water status, density or other soil variables. Few models allow the effects of management on penetrometer resistance to be predicted in a simple way. It would be useful if it were possible to predict the effects of structure, compaction, and soil drying on penetrometer resistance. We designed a laboratory experiment to explore how compaction and subsequent soil drying affected the penetrometer resistance of three soils: a loamy sand and two silty clay soils with very different organic carbon contents. By assuming that penetrometer resistance is proportional to the small strain shear modulus, G, we were able to develop an empirical model to explain the effects of compaction and soil drying on penetrometer resistance. The parameters of the model were determined by fitting it to experimental data collected in the laboratory. The model was tested on field data using sensed matric potential data and measured soil density data. Model predictions were compared with those obtained with an earlier model. Both approaches explained approximately 60% of the variance in the measured penetrometer data. The future application of this approach is discussed. (C) 2012 Elsevier B.V. All rights reserved.