摘要
为满足大田土壤钾素养分在线检测的迫切需要,设计了一种基于激光诱导击穿光谱原理的土壤养分在线检测的系统平台装置,并开展了土壤养分快速测定的实验研究,对采用激光诱导击穿光谱定量分析土壤钾素养分含量的可行性与准确度进行了探索。实验表明,土壤钾元素的特征谱线在波长766.49 nm和769.90 nm处,钾素养分含量与特征谱线强度呈正相关,但当钾素质量分数大于0.3%时,存在明显自吸收现象,谱线强度与样本质量分数呈非线性关系。为了消除土壤光谱检测的基体效应,选定土壤样本锂元素为内标元素,对土壤钾元素等离子光谱特征谱线进行内标校正处理。利用土壤样本钾元素的敏感特征波长766.49 nm和769.90 nm处的光谱强度对土壤钾元素含量进行二元线性建模分析,建模曲线拟合效果良好,模型决定系数达到0.933 7,相对均方根误差仅为0.276 1。利用该实验系统,土壤钾素养分最低检测限为212μg/g,初步具备土壤钾素养分在线检测的要求。
Regarding to the inadequacy of traditional soil nutrition detecting techniques,a new soil nutrition on-line detecting equipment based on laser induced breakdown spectroscopy theory is developed.The experiments to analyze feasibility and accuracy of detecting soil potassium nutrient content is carried out with this equipment.Experimental results show that characteristic lines of potassium are 766.49 nm and 769.90 nm respectively,and the relationship of soil potassium nutrient content and characteristic peak value is positive correlation.However,once potassium content in samples is above 0.3%,the relationship of potassium nutrient content and characteristic spectral intensity becomes nonlinear because of the existence of emission spectrum self-absorption phenomenon.To eliminate the detecting matrix effects,lithium element in soil samples is selected to be a internal standard element for correcting potassium element characteristic lines.Using spectral intensity of sensitive characteristic wavelength766.49 nm and 769.90 nm to estimate soil potassium nutrient content by binary linear model,the determination coefficient（R2） of model reaches 0.9337,and the relative root mean square error（RRMSE）is only 0.276 1.With current testing conditions,the lowest detection limit of soil potassium content is212 μg /g.This result indicates that the detecting system can satisfy the requirements of soil potassium nutrient on-line detection preliminarily,but needs to be further improved.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2014年第10期294-299,共6页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家高技术研究发展计划(863计划)资助项目(2012AA101902)
国家重点基础研究发展计划(973计划)资助项目(2012CB723704)
'十二五'国家科技支撑计划资助项目(2012BAF07B04)
山东自主创新资助项目(2013CXC90205)
土壤植物机器系统技术国家重点实验室开放课题资助项目(2011-SKL-4)
关键词
土壤
钾素
激光诱导击穿光谱
多元线性回归
内标法
Soil Potassium nutrient Laser induced breakdown spectroscopy Multiple linear regression Internal standard method
