Estimation of Potato Above-Ground Biomass Using UAV Multispectral Imagery and Biomass Allocation Patterns
ZHANG Zi-tai1, 2, LI Zhen-hai1*, FAN Yi-guang2, MA Yan-peng2, GUO Li-xiao2, FAN Jie-jie2, CHEN Ri-qiang2, BIAN Ming-bo2, LIU Yang2, FENG Hai-kuan2, 3*
1. College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China
2. Key Laboratory of Quantitative Remote Sensing in Agriculture of Ministry of Agriculture and Rural Affairs, Information Technology Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
3. National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
Abstract：Above-ground biomass (AGB) is an important indicator for assessing crop growth and guiding agricultural management. Accurately estimating potato AGB is crucial for growth monitoring and yield prediction. Traditional methods of measuring AGB cannot meet the need for large-scale, rapid monitoring. Remote sensing technology is quick, efficient, and non-destructive, making it a valuable tool for crop monitoring. However, remote sensing vegetation indices lose sensitivity in areas with high vegetation coverage, leading to a “saturation effect” that limits AGB accuracy. Most previous studies focused on improving remote sensing indices for AGB estimation. However, these methods still lack clear explanations for how potato growth affects AGB changes. In this study, we analyze the growth process of potatoes and consider the characteristics of different growth stages. We use UAV multispectral data to examine how plant parts, like stems and leaves, contribute to biomass accumulation. We develop a model to track the ratio of leaf biomass (Leaf Ground Biomass, LGB) to AGB throughout the growing season, using effective accumulated temperature (Growing Degree Days, GDD) as an independent variable. By estimating LGB through remote sensing, we can indirectly estimate potato AGB. We built a dynamic AGB allocation model using field measurements. We applied three methods—correlation analysis, variable importance projection (VIP), and random forest feature importance evaluation (FIM)—to select vegetation indices related to LGB. We then used Random Forest (RF), Gaussian Process Regression (GPR), and Partial Least Squares Regression (PLSR) to estimate AGB over the entire growing season. The results showed that: (1) the best vegetation index combination, including MTVI1, MTVI2, NDVI, GNDVI, RVI, and TVI, was selected based on R, VIP, and FIM evaluations; (2) combining the AGB dynamic allocation model with machine learning improved AGB estimation accuracy; (3) the model combining AGB dynamic allocation with random forest achieved the highest accuracy, with a training set R2 of 0.80, RMSE of 256.73 kg·ha-1, and NRMSE of 9.91%. For the validation set, R2 was 0.76, RMSE was 211.91 kg·ha-1, and NRMSE was 11.46%.
Key words：Leaf biomass;Growing degree days (GDD);Multispectral remote sensing;Above-ground biomass (AGB);Potato
[1] Liu Y, Feng H, Yue J, et al. Computers and Electronics in Agriculture, 2022, 198: 107089.
[2] Yue J, Yang H, Yang G, et al. Computers and Electronics in Agriculture, 2023, 205: 107627.
[3] Liu Y, Feng H, Yue J, et al. Computers and Electronics in Agriculture, 2024, 219: 108808.
[4] David R M, Rosser N J, Donoghue D N M. Remote Sensing of Environment, 2022, 282: 113232.
[5] Estévez J, Salinero-Delgado M, Berger K, et al. Remote Sensing of Environment, 2022, 273: 112958.
[6] Tian L, Wu X, Tao Y, et al. Forests, 2023, 14(6): 1086.
[7] Shu M, Bai K, Meng L, et al. European Journal of Agronomy, 2023, 144: 126754.
[8] Mutanga O, Masenyama A, Sibanda M. ISPRS Journal of Photogrammetry and Remote Sensing, 2023, 198: 297.
[9] Gnyp M L, Miao Y, Yuan F, et al. Field Crops Research, 2014, 155: 42.
[10] Jiang Y, Wu F, Zhu S, et al. Agronomy, 2024, 14(8): 1610.
[11] Han L, Yang G, Dai H, et al. Plant Methods, 2019, 15(1): 10.
[12] Feng H, Fan Y, Yue J, et al. Computers and Electronics in Agriculture, 2025, 232: 110122.
[13] Liu Y, Yang F Q, Yue J B, et al. Computers and Electronics in Agriculture, 2024, 227: 109678.
[14] Liu Y, Feng H, Yue J, et al. Computers and Electronics in Agriculture, 2025, 231: 109984.
[15] Yang J, Du L, Gong W, et al. PLoS ONE, 2018, 13(1): e0191068.
[16] LIU Yang, SUN Qian, HUANG Jue, et al(刘 杨，孙 乾，黄 珏，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2021, 41(8): 2549.
