基于LIBS的果园土壤矿物源农药残留纵向分布和时变规律研究

Laser-induced breakdown spectroscopy, a kind of effective analysis technique, is used for detecting pesticide residues in soil. The universal test parameters were lacked in existing LIBS detection of pesticide residues in soil. The existing research focused on analysing the contents of pesticide residues, and the distributions and changes of pesticide residues in the soil needed to be intensively studied. In this project, the elements of copper, chlorine, sulfur, arsenic, zinc and others in the pesticide residues of orchard soil will be considered as the research carriers. And LIBS technique combined with theoretical analysis and mathematical modeling will be employed to accurately detect the contents of mineral pesticide residues, as well as to ascertain the vertical distribution and time-dependent rules in orchard soil. Firstly, to obtain universal test parameters, the single and multi-factor analysis methods will be planed to investigate the LIBS test parameters which can influence the characteristics of laser-induced plasma of pesticide residues in orchard soil. Secondly, to reckon the contents of pesticide residues in orchard, the LIBS detection models of pesticide residues in different plough layers and the time series LIBS analysis methods will be establised. Thirdly, the data mining methods will be selected to reveal the vertical distribution and time-dependent rules.of mineral pesticide residues in orchard soil. The research results provide theoretical foundation for developing the diagnosis, repair and prevention technology of pesticide residues in orchard soil, and offer technical support for scientific spraying and precision management in agricultural production.

激光诱导击穿光谱（LIBS）是一种有效的土壤农药残留检测技术。现有LIBS检测土壤农药残留缺乏普适的测试参数，仅分析土壤农药残留含量，并未深入研究其在土壤中的分布和变化。本项目拟以果园土壤矿物源农药残留中铜、氯、硫、砷、锌等元素为研究载体，以LIBS技术为手段，结合理论分析和数学建模，旨在准确检测果园土壤矿物源农药残留含量，并探明其在土壤中纵向分布和时变规律。拟通过单、多因素分析不同测试参数对果园土壤矿物源农药残留的LIBS谱线特性影响，优化得到普适的LIBS测试参数；拟运用单波段特征谱线定标和多元化学计量学方法，构建不同耕层和时间序列的果园土壤矿物源农药残留含量LIBS检测模型和方法，反演得到准确的果园土壤矿物源农药残留含量；拟通过数据挖掘方法，探明矿物源农药残留在果园土壤中纵向分布和时变规律。这为研发土壤农药残留诊断、修复和防治技术和方法奠定理论基础，也为农业生产科学施药提供技术支撑。

激光诱导击穿光谱（LIBS）是一种有效的土壤重金属检测技术。现有LIBS技术检测土壤元素缺乏普适的测试参数，仅分析土壤农药残留含量，并未深入研究其在土壤中的分布和变化。本项目以果园土壤矿物源农药残留中铜、铅、镉等元素为研究载体，以LIBS技术为手段，结合理论分析和数学建模，旨在准确检测果园土壤重金属元素含量，并探明其在土壤中纵向分布和时变规律。主要的研究内容有：.（1）以果园土壤中主要元素的LIBS谱线特性为评价指标，通过单因素分析，分别探讨LIBS系统参数以及土壤性状参数对激光诱导土壤等离子体谱线特性；运用多因素响应面分析法，分析主要测试参数交互作用对土壤等离子体谱线特性的影响规律，优化得到土壤矿物源农药残留普适的LIBS测试条件；.（2）运用LIBS技术结合定标曲线法以及偏最小二乘回归实现土壤的金属元素Al，Fe，Mg，Ca，Na，K的定量分析，研究不仅为精准农业中土壤成分检测的起指导作用，还为开发便携式土壤LIBS检测仪提供了理论基础；.（3）利用LIBS技术结合定标曲线法和化学计量学方法对土壤中重金属铅（Pb）和镉（Cd）元素进行定量分析，为开发实时便携式LIBS土壤重金属检测仪提供了理论基础；借助LIBS技术对土壤重金属铅（Pb）和镉（Cd）元素定量分析的方法和思路，完成了对果园土壤矿物源农药残留铜（Cu）元素含量的定量分析，以及初步探明了重金属铜元素在土壤的纵向分布和随时间变化状态；.（4）通过深入了解LIBS技术定量分析方法中的自由定标法（Calibration free，CF）的计算原理及过程，设计基于LIBS技术的自由定标法（CF-LIBS）计算软件，提高使用CF-LIBS进行元素定量分析的效率，为后期的研究设计提供经验。以上研究结果为研发土壤农药残留诊断、修复和防治技术与方法奠定理论基础，也为农业生产科学施药提供技术支撑。