The Use of Electromagnetic Induction to Monitor Changes in Soil Moisture Profiles beneath Different Wheat Genotypes
The Use of Electromagnetic Induction to Monitor Changes in Soil Moisture Profiles beneath Different Wheat Genotypes
复制标题
DOI：
10.2136/sssaj2014.09.0360
复制
发表时间：
2015-03-01
影响因子：
2.9
通讯作者：
Watts, Christopher W.
中科院分区：
文献类型：
--
作者：
Shanahan, Peter W.;Binley, Andrew;Watts, Christopher W.
最近，人们对使用地面部署的地球物理方法来估计土壤水分剖面感兴趣。本研究应用多线圈、频域、电磁感应(EMI)地球物理测量方法测定了4个冬小麦(Triticum aestivum L.)根区的电导率(Sigma)分布。在四个重复的随机区组实验中生长的基因型。在两种不同土壤质地上进行了表观电导率(Sa)的野外测量。我们使用累积灵敏度模型来预测EMI电导率数据，该数据来自我们调查的地块的子集上用电阻率层析成像(ERT)测量的电导率剖面。在EMI数据的反演过程中，所有地块的电导率都进行了调整，以便与ERT数据保持一致。将田间土壤电导率的变化与土壤水分的测量变化进行了比较，其中深度是由EMI数据反演计算的深度。实验室测量证实了电导率与土壤水分之间的正相关关系。在作物出苗到成熟之间，不同小麦基因型的水分提取使水分含量减少了30%。通过比较出苗后不久测定的参考剖面与作物成熟后后期的电导率剖面之间的变化，我们能够使用电磁干扰随深度和时间远程监测不同小麦基因型的根的水分提取。
There has been recent interest in the use of surface-deployed geophysical methods to estimate soil moisture profiles. In this study, we applied multi-coil, frequency domain, electromagnetic induction (EMI) geophysical surveys to determine electrical conductivity (sigma) profiles of the root zone of four winter wheat (Triticum aestivum L.) genotypes grown in a randomized block experiment with four replicates. Field measurements of apparent electrical conductivity (sa) were obtained at sites with two different soil textures. We used the cumulative sensitivity model to predict EMI conductivity data from the conductivity profile measured with electrical resistivity tomography (ERT) on a subset of the plots we investigated. During the inversion of the EMI data, conductivities were adjusted on all plots so that they were consistent with the ERT data. Changes in electrical conductivity of field soil, with depth computed from inversion of the EMI data, during the growth period were compared with measured changes in soil water content. Laboratory measurements confirmed a positive correlation between electrical conductivity and soil water content. Between crop emergence and maturity, water extraction by the different wheat genotypes reduced the water content by up to 30% Comparing changes in electrical conductivity between reference profiles determined shortly after crop emergence and electrical conductivity profiles at later dates as the crop matured, we were able to use EMI to remotely monitor moisture extraction by the roots of different wheat genotypes with depth and time.