USE AND ACCURACY OF THE FILTER-PAPER TECHNIQUE FOR MEASUREMENT OF SOIL MATRIC POTENTIAL
USE AND ACCURACY OF THE FILTER-PAPER TECHNIQUE FOR MEASUREMENT OF SOIL MATRIC POTENTIAL
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DOI：
10.1111/j.1365-2389.1995.tb01831.x
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发表时间：
1995-06-01
影响因子：
4.2
通讯作者：
TOWNEND, J
中科院分区：
文献类型：
--
作者：
DEKA, RN;WAIRIU, M;TOWNEND, J
本文详细介绍了一种可用于测量田间土壤基质势的滤纸法。当使用一批校准的滤纸时，其精度受到单个滤纸之间的变异性和称量到最接近的毫克的限制。绝对精度也受到用于校准的仪器的限制。同一类型滤纸的批间一致性较好，表明该方法适用于Whatman No.42滤纸，当滤纸的电位大于或等于-2. 5 MPa时，滤纸需与土壤平衡6 d。为了在较低电位下达到相同的精度，需要较长的平衡时间。结果表明，该技术应该是有效的，至少-100 MPa，如果土壤被允许完全平衡的文件。校准线的决定系数（r（2））均大于或等于0.92。在-1 kPa ~-10 MPa的电位范围内，用滤纸法测得的对数（-基质电位）与用张力计和干湿球湿度计测得的对数（-基质电位）进行回归，得到r（2）值为0.995。
A filter-paper technique that can be used to measure the matric potential of field soil is described in detail, When a calibrated batch of filter papers is used, the precision is limited by the variability between individual papers and the limitation of weighing to the nearest mg. The absolute accuracy is also limited by the instruments used for calibration. There was reasonable agreement between batches of the same type of paper, suggesting that our generalized calibration curves can be used for Whatman No. 42 filter papers where accuracy is not paramount.For potentials greater than or equal to - 2.5 MPa, papers need to be equilibrated with the soil for 6 d. To achieve the same accuracy at lower potentials longer equilibration periods are required. Results suggest that the technique should be effective down to at least - 100 MPa if soils are allowed to equilibrate fully with the papers. Coefficients of determination (r(2)) for the calibration lines were all greater than or equal to 0.92. A regression of log(- matric potential) measured by the filter paper technique against measurements made using tensiometers and a psychrometer over a range of potentials between -1 kPa and -10 MPa gave an r(2) value of 0.995.