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Effect of assumptions on accuracy of analytical results and liming recommendations when testing a volume or weight of soil

 

作者: W. van Lierop,  

 

期刊: Communications in Soil Science and Plant Analysis  (Taylor Available online 1989)
卷期: Volume 20, issue 1-2  

页码: 121-137

 

ISSN:0010-3624

 

年代: 1989

 

DOI:10.1080/00103628909368073

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

The objective of this study was to examine the effects of weighing and scooping soil samples on the accuracy of soil test results, fertilizer and lime requirement recommendations using the metric, British and American measurement systems. Although, it is well Known that BO values of mineral soils vary easily by 100Z (values vary by as much as 1000% when including Histosols) from an average assumed value, one of the most widely held delusion in North American soil testing circles is that a defined constant weight of soil can be measured volumetrically. Analytical results can only be extrapolated accurately to a furrow layer of defined weight when samples are weighed for analysis. Analytical results ought then be reported as ppm, μg gram‐1, or mg kg‐1soil. Unfortunately a furrow layer of defined weight is likely to have an undefined depth. Several scoop sizes are being used to measure an assumed weight of soil, it is suggested that laboratories following this practice report analytical results in pounds acre‐1or kg ha‐1, but also display their assumed soil density (ASD) to facilitate analytical comparisons and eventual standardization. Ultimately, erroneous assumptions can be avoided by defining the acre and hectare furrow layers as being volumes having depths of 20 cm and containing 0.81 and 2‐million liters of soil, respectively. Plant nutrient concentrations of 1 μg in 0.89 or 1.0 mL soil then represent two pounds acre‐1or two kilograms ha‐1, respectively. Reporting analytical results in pg mL‐1soil is suggested as the correct form for those that have adopted the metric system. Procedures are developed to convert LR values from furrow weight to furrow volume, for the American, British, and metric system of measurements

 

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