The prediction of C and N content and their potential mineralisation in heterogeneous soil samples using Vis-NIR spectroscopy and comparative methods
The prediction of C and N content and their potential mineralisation in heterogeneous soil samples using Vis-NIR spectroscopy and comparative methods
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DOI：
10.1023/a:1020612319014
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发表时间：
2002-10-01
期刊：
影响因子：
4.9
通讯作者：
Fystro, G
中科院分区：
文献类型：
--
作者：
Fystro, G
开发一种快速、准确和经济的方法来预测与土壤氮供应有关的成分是很重要的。研究了利用可见光（Vis）和近红外（NIR）光谱（400-2500 nm）作为这种方法的潜力。利用80个来源相当不均匀的草地土壤样品，对有机碳（C-org）和全氮（N-tot）含量及其潜在矿化进行了可见光-近红外校准。使用“外卖-四”验证策略（48个样本）测试预测准确性。在所调查的变量中，参考数据的标准差与偏差校正预测的标准误差（RPD）的比值在1.7 (r(2) = 0.65和2.7 （r(2) = 0.87）以内。各变量间Vis-NIR预测精度的明显差异部分是由于参考值误差造成的。解冻的湿样品往往比干燥的样品更准确地预测，并且没有受益于研磨筛（4毫米）和干燥的样品。使用两种不同的系统对样品进行Vis-NIR分析，预测精度没有差异。C-org和N-tot及其潜在矿化进行了比较预测，使用了4个验证策略和简单的线性回归，以着火损失（LOI）值和热KCl提取的NH4-N （N-hotKCl）值作为预测因子。同样，C-org和N-tot的参考值也被用作相互预测和潜在的C和N矿化成分的预测因子。对所研究成分的Vis-NIR预测精度一般等于或优于这些比较方法所获得的预测精度。Vis-NIR方法对土壤氮供应的重要变量提供了有希望的预测。
The development of a rapid, accurate and cost-effective method for the prediction of constituents related to soil nitrogen (N) supply is considered important. The potential of using visible (Vis) and near infrared reflectance (NIR) spectroscopy (400-2500 nm) as such a method was investigated. Vis-NIR calibrations were performed for organic carbon (C-org) and total N (N-tot) content and their potential mineralisation using 80 grassland soil samples of rather heterogeneous origin. Prediction accuracy was tested using a 'take-out-four' validation strategy (48 samples). Within investigated variables a ratio of standard deviation of reference data to standard error of bias corrected prediction (RPD) within 1.7 (r(2) = 0.65 and 2.7 (r(2) = 0.87) were achieved. Apparent differences in Vis-NIR prediction accuracy among the variables were partly due to errors in the reference values. Thawed moist samples tend to be more accurately predicted than dried samples, and no benefit was derived from the grinding of sieved (4 mm) and dried samples. Prediction accuracy did not differ using two different systems for sample presentation to the Vis-NIR analyses. Comparative predictions of C-org and N-tot and their potential mineralisations were performed using the take-out-four validation strategy and simple linear regression to loss on ignition (LOI) values and hot KCl extracted NH4-N (N-hotKCl) values as predictors. Likewise, the reference values of C-org and N-tot were also used as predictors for each other and for the potential C and N mineralisation constituents. Accuracy obtained for the Vis-NIR predictions of investigated constituents was in general equal or better than prediction accuracy obtained by these comparative methods. The Vis-NIR method provided promising predictions of variables important for the soil N supply.