选取中国北方潮土作为研究对象,探索利用近红外光谱分析技术分析土壤参数的可行性和可能性。从一块试验麦田共采集了150个土样,土样在采集回试验室后,在保持其原始状态的条件下利用傅里叶变换近红外光谱仪迅速测定了其近红外光谱。近红外光谱变量为原始吸收光谱和一阶微分光谱,分析的土壤参数有土壤水分、有机质和全氮的含量。对于土壤水分,在相关分析的基础上建立了一元线性模型,所采用的波长为1920nm,模型的相关系数达到0.937,模型可以直接用于土壤水分的实时预测。对于有机质和全氮含量建立了多元回归模型,有机质预测模型所采用的波长是1870和1378nm,全氮预测模型所采用的波长则是2262和1888nm。分析结果表明土壤有机质和全氮含量可以利用田间土样的近红外光谱特性进行分析和检测,建立的线性模型是有效的。
The grey-brown alluvial soil in northern china was selected as research object, and the feasibility and possibility of real-time analyzing soil parameter with NIR spectroscopic techniques were explored. One hundred fifty samples were collected from a winter wheat farm. NIR absorbance spectra were rapidly measured under their original conditions by a Nicolet Antaris FT-NIR analyzer. Three soil parameters, namely soil moisture, SOM (soil organic mater) and TN (total nitrogen) content, were analyzed. For soil moisture content, a linear regression model was available, using 1 920 nm wavelength with correlation coefficient of 0. 937, so that the results obtained could be directly used to real-time evaluate soil moisture. SOM content and TN content were estimated with a multiple linear regression model, 1 870 and 1 378 nrn wavelengths were selected in the SOM estimate model, and 2 262 and 1 888 nm wavelengths were selected in the TN estimate model. The results showed that soil SOM and TN contents can be evaluated by using NIR absorbance spectra of soil samples.