褐潮土的光谱特性及用土壤反射率估算有机质含量的研究

本文通过ASDFR便携式光谱仪对132个风干土壤样品的光谱反射率进行了实验室测定。根据土样光谱反射率变化,获得了褐潮土土壤剖面的不同诊断层反射光谱特征。结果表明,在400～1200nm范围之间,土壤有机质含量与土壤光谱反射率有较好的相关性。利用导数光谱方法建立了预测土壤有机质含量的方程,提出了预测北京地区褐潮土有机质光谱的最佳波段。在波长447nm处采用反射率和A值(反射率倒数的对数)所建立的预测方程的预测精度较高。采用反射率的一阶微分建立的预测方程的最佳波段在516nm处。而A值一阶微分光谱在615nm处相关性最好。作为一项参考指标用光谱分析法评价土壤中有机质含量,以期对精准农业中土壤养分或肥力的预测具有一定的指导作用。

Spectral Characteristics of Brown-Humid Soil and Estimation of Soil Organic Matter Content by Soil Reflectivity

Soil spectral reflectance of 132 samples were measured with ASD FR radiometer. According to the variation of soil spectral reflectance, spectral reflectance properties of different soil diagnostic horizons of a Brown-humid soil were aquired. Soil organic matter content and it's spectral reflectance have good correlation with the wavelength range of 400-1200nm. Using the first derivative of spectral reflectance, models for soil organic matter content estimation were established, and the best wavelength for the brown-humid soil organic content estimation were determined. At 447nm wavelength, estimation precision is the highest when using spectral reflectance and "A" value. When using the first derivative of spectral reflectance for estimation, 516nm is the best wavelength. For the first derivative of the A value, the best estimation was obtained at 615nm. Soil spectral analysis is meaningful for the prediction of soil fertility.