干旱区研究 ›› 2024, Vol. 41 ›› Issue (6): 1069-1078.doi: 10.13866/j.azr.2024.06.15

• 农业生态 • 上一篇    下一篇

基于无人机高光谱影像的冬小麦叶片氮浓度遥感估测

孙法福1,2,3(), 赖宁1,2, 耿庆龙1,2, 李永福1,2, 吕彩霞1,2, 信会男1,2, 李娜1,2, 陈署晃1,2()   

  1. 1.新疆农业科学院土壤肥料与农业节水研究所,新疆 乌鲁木齐 830091
    2.新疆农业科学院农业遥感中心,新疆 乌鲁木齐 830091
    3.新疆农业大学资源与环境学院,新疆 乌鲁木齐 830052
  • 收稿日期:2023-12-01 修回日期:2024-04-20 出版日期:2024-06-15 发布日期:2024-07-03
  • 通讯作者: 陈署晃. E-mail: chensh66@163.com
  • 作者简介:孙法福(1997-),男,硕士研究生,主要从事农业遥感相关研究. E-mail: 18253289263@163.com
  • 基金资助:
    农业科技创新稳定支持专项(xjnkywdzc-2023002);农业科技创新稳定支持专项(xjnkywdzc-2023007-3);新疆小麦产业技术体系(XJARS-01);新疆维吾尔自治区重大专项(2022A02011-2)

Estimation of nitrogen contentration in winter wheat leaves based on hyperspectral images of UAV

SUN Fafu1,2,3(), LAI Ning1,2, GENG Qinglong1,2, LI Yongfu1,2, LV Caixia1,2, XIN Huinan1,2, LI Na1,2, CHEN Shuhuang1,2()   

  1. 1. Institute of Soil, Fertilizer and Water Saving Agriculture Xinjiang Academy of Agricultural Sciences, Urumqi 830091, Xinjiang, China
    2. Agricultural Remote Sensing Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, Xinjiang, China
    3. College of Resources and Environmental Sciences, Xinjiang Agricultural University, Urumqi 830052, Xinjiang, China
  • Received:2023-12-01 Revised:2024-04-20 Online:2024-06-15 Published:2024-07-03

摘要:

叶片氮浓度(LNC)是反应作物光合作用、营养状况和长势的重要指标,为精准高效地估测不同生育期冬小麦叶片氮浓度,以新冬22为研究对象,利用无人机搭载Pika L高光谱相机获取4个关键生育期冬小麦冠层反射率数据。基于波段优化算法和相关性分析筛选LNC敏感光谱指数,结合逐步回归、多元线性回归和偏最小二乘回归建立关键生育期冬小麦叶片氮浓度估测模型,并与单变量估测模型进行比较。结果表明:基于波段优化算法筛选的组合光谱指数与LNC的相关性优于传统植被指数,且达到极显著性相关;在单变量LNC估测模型中,组合光谱指数构建的模型精度优于传统植被指数,其中,扬花期差值光谱指数(DSI(R940、R968))建立的估测模型最好,R2为0.789;多变量估测模型精度均优于单变量估测模型,其中,基于偏最小二乘回归构建的LNC估算模型最好,孕穗期和扬花期拟合效果较优,模型决定系数均为0.923,均方根误差为0.082、0.084。本研究结果可以作为冬小麦LNC估测和长势监测的科学依据。

关键词: 冬小麦, 叶片氮浓度, 无人机, 高光谱, 偏最小二乘回归, 组合光谱指数

Abstract:

Established leaf nitrogen concentration (LNC) is the response of crop photosynthesis, an important index of nutrition and growth. To accurately and efficiently estimate different growth period of winter wheat LNC, with the new winter 22 as the research object, using the (UAVs) Pika L hyperspectral cameras for four key growth period of winter wheat canopy reflectance data. The LNC-sensitive spectral index was screened based on the band optimization algorithm and correlation analysis. Stepwise regression, multiple linear regression, and partial least squares regression were combined to establish the estimation model of winter wheat LNC in each key growth stage, which was compared with the single variable estimation model. The results showed that (1) the correlation between the combined spectral index screened using the band optimization algorithm and LNC was stronger than that obtained using the traditional vegetation index and was extremely significant; (2) the combined spectral index in the single variable LNC estimation model allowed to obtain a more accurate model compared with the traditional vegetation index, including Yang flowering DSI(R940, R968) estimate model is set up, best R2 of 0.789. The multi-variable estimation models were more accurate than the single variable estimation models and, among them, the LNC estimation model based on partial least squares regression was the best, and the fitting effect of the booting and flowering stages was better. This model had a coefficient of determination of 0.923 and root-mean-square errors of 0.082 and 0.084. The results of this study provide a theoretical basis and technical support to estimate the LNC of winter wheat and monitor its growth.

Key words: winter wheat, leaf nitrogen content (LNC), unmanned aerial vehicle (UAV), hyperspectral, partial leastsquares regression, combination of spectral index