A Study on Temperature and Time Conditions of Colorimetric Method in Measuring Soil Available Phosphorus
A Study on Temperature and Time Conditions of Colorimetric Method in Measuring Soil Available Phosphorus
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DOI：
10.4028/www.scientific.net/amr.838-841.2047
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发表时间：
2013-11
期刊：
影响因子：
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通讯作者：
Pan Pu;Miao Zhang;Li Zhang
中科院分区：
文献类型：
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作者：
Pan Pu;Miao Zhang;Li Zhang
钼蓝比色法是测定土壤有效磷的标准方法之一，对指导变量施肥具有重要意义。然而，在实际应用中，我们发现显色温度和稳定时间会影响测试结果。为了保证精度，本文在温度10°C ~ 40°C，显色反应后时间0 ~ 80 min的范围内进行了综合实验，并对单次校准模式和重复校准模式下的测试结果进行了比较。最后分别优化了两种不同校准模式下的温度和测试时间条件。在最佳条件下，用我国主要农作物产区的55个土样进行了验证试验。试验结果与标准结果的线性相关性较好（R2 = 0.97），平均相对误差较小（MRE = 0.047），能够满足变量施肥的精度要求。
Molybdenum blue colorimetric method is one of the standard methods of detecting soil available phosphorus and is crucial to guide variable fertilization. In practice, however, we find that color-developing temperature and stable time could affect test results. To ensure precision, in this paper we conducted a comprehensive experiment under the temperature range from 10°C to 40°C and time range from 0 to 80 minutes after color reaction and compared the test results in single calibration mode with that in repetitive calibration mode. Eventually we optimized temperature and testing time conditions in the two different calibration modes respectively. Under the optimum conditions we conducted a verification test using 55 soil samples which were collected from main crop-growing regions of China. The test results had a better linear correlation with standard results (R2 = 0.97) and a small mean relative error (MRE = 0.047), which could meet the accuracy requirement of variable fertilization.