Scientia Agricultura Sinica ›› 2026, Vol. 59 ›› Issue (1): 41-56.doi: 10.3864/j.issn.0578-1752.2026.01.004

• TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY • Previous Articles     Next Articles

Estimation of Rice Grain Protein Content Using Fusion Imagery from UAV-based Multi-Sensors

FEI YaoYing1(), WANG Di2, TANG WeiJie3,4, GUO CaiLi1, ZHANG XiaoHu1, QIU XiaoLei1, CHENG Tao1, YAO Xia1,4, JIANG ChongYa1, ZHU Yan1, CAO WeiXing1, ZHENG HengBiao1,4,*()   

  1. 1 College of Agriculture, Nanjing Agricultural University/National Engineering and Technology Center for Information Agriculture/ Engineering Research Center of Smart Agriculture, Ministry of Education/Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs/Jiangsu Key Laboratory for Information Agriculture, Nanjing 210095
    2 Huaiyin Institute of Agricultural Sciences in Xuhuai Region of Jiangsu, Huaian 223001, Jiangsu
    3 Institute of Germplasm Resources and Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014
    4 Zhongshan Biological Breeding Laboratory, Nanjing 210014
  • Received:2025-06-12 Accepted:2025-10-22 Online:2026-01-07 Published:2026-01-07
  • Contact: ZHENG HengBiao

Abstract:

【Objective】Grain protein content (GPC) is a crucial indicator for evaluating rice quality and its commercial value. Establishing a rapid and non-destructive method for estimating rice GPC was established, so as to provide theoretical foundations and technical support for smart breeding and precision crop management. 【Method】This study employed a drone equipped with both an RGB camera and a multispectral camera to collect RGB and multispectral imagery, along with ground-measured grain protein content (GPC) data, from the heading to maturity stages of 522 rice breeding material accessions from 2022 to 2023. The Gram-Schmidt image fusion method was applied to process the RGB and multispectral images for generating fused images. Spectral and texture features extracted from the original multispectral images were combined with fused image features, and three machine learning regression algorithms—Random Forest (RF), Extreme Gradient Boosting (XGBoost), and Gradient Boosting Regression (GBR)—were employed to construct GPC estimation models. 【Result】The R-band of the RGB images contained richer image information. Vegetation indices derived from the fused R-band exhibited higher correlations with GPC than those calculated from the original multispectral data. The mean texture (Mean) appeared most frequently in texture index construction (accounting for 63.16%), with the MEA560-MEA840 index showing certain correlations with GPC across different rice types (Huaian conventional japonica: |r2|=0.28; Rugao hybrid japonica: |r2|=0.20). Using a combination of multispectral image features, texture features, and fused image features as input parameters, the GPC estimation models for rice breeding materials achieved higher accuracy at the heading stage (R2 cal=0.64) and maturity stage (R2 cal=0.70) than at the filling stage model (R2 cal=0.53). Incorporating fused image features improved GPC estimation accuracy (ΔR2 cal=0.08-0.26) over using original image features. The interannual model of RF outperformed those of XGBoost and GBR in accuracy(RF: R2 val=0.74, RMSE=0.21%; XGBoost: R2 val=0.58, RMSE=0.23%; GBR: R2 val=0.42, RMSE=0.23%). 【Conclusion】The integration of UAV image fusion technique and machine learning methods could effectively enhance the estimation accuracy of the grain protein content (GPC) in rice breeding materials. These findings provided a theoretical reference and practical approaches for the precise estimation of rice quality parameters on a large scale.

Key words: unmanned aerial vehicle (UAV), multi-source imagery, feature fusion, machine learning, rice, grain protein content (GPC), non-destructive estimation

Fig. 1

Location of the experimental site"

Table 1

Overview of the field experiment"

地点
Site
播种时间
Sowing time
品种
Variety
株行距
plant and row spacing
面积
Area (m2)
小区个数
Number of plots
如皋 Rugao 2022-05-15 常规粳稻 Conventional Japonica rice
杂交粳稻 Hybrid Japonica rice
20 cm×20 cm 3.60 240
2023-05-10 常规粳稻 Conventional Japonica rice
杂交粳稻 Hybrid Japonica rice
20 cm×30 cm 5.20 240
淮安 Huaian 2023-05-10 常规粳稻 Conventional Japonica rice 20 cm×20 cm 10.75 297

Table 2

Parameters of the UAV sensors"

相机
Camera
影像大小
Image size (pixel)
波段
Band
视场角
Field of view
飞行高度
Flight height (m)
像素大小
Pixel size (cm)
实物图
Product photo
禅思P1
DJI Zenmuse P1
8192×5460 R(620-750 nm)、G(500-570 nm)、B(450-495 nm) 38°×31° 30 0.38
RedEdge-MX 1280×960 475±20、560±20、668±10、717±40、840±10 nm 47.2°×20.9° 30 2.17

Table 3

Spectral parameters used in this study"

光谱参数
Spectral parameter
名称
Name
公式
Formula
参考文献
Reference
NDRE 归一化差值红边指数
Normalized difference red-edge index
$\mathrm{NDRE}=\frac{\mathrm{R}_{840}-\mathrm{R}_{717}}{\mathrm{R}_{840}+\mathrm{R}_{717}}$ [22]
CIrededge 红边叶绿素指数
Red-edge chlorophyll index
$\mathrm{CI}_{\text {rededge }}=\frac{\mathrm{R}_{840}}{\mathrm{R}_{717}}-1$ [23]
CIgreen 绿度叶绿素指数
Green chlorophyll index
$\mathrm{CI}_{\text {green }}=\frac{\mathrm{R}_{717}}{\mathrm{R}_{560}}-1$ [23]
NDYI 归一化差值黄度指数
Normalized difference yellowness index
$\mathrm{NDYI}=\frac{\mathrm{R}_{560}-\mathrm{R}_{475}}{\mathrm{R}_{560}+\mathrm{R}_{475}}$ [24]
EVI2 增强型植被指数2
Enhanced vegetation index 2
$\mathrm{EVI} 2=\frac{2.5 \times\left(\mathrm{R}_{840}-\mathrm{R}_{717}\right)}{\mathrm{R}_{840}+6 \times \mathrm{R}_{668}-7.5 \times \mathrm{R}_{475}+1}$ [25]
MCARI 修正型叶绿素吸收反射指数
Modified chlorophyll absorption reflectance index
$M C A R I=\left[\left(R_{717}-R_{668}\right)-0.2 \times\left(R_{717}-R_{560}\right)\right] \times\left(\frac{R_{717}}{R_{668}}\right)$ [26]
SAVI 土壤调节植被指数
Soil adjusted vegetation index
$\mathrm{SAVI}=\frac{1.5 \times\left(\mathrm{R}_{840}-\mathrm{R}_{668}\right)}{\mathrm{R}_{840}+\mathrm{R}_{668}+0.5}$ [27]
DATT 达特指数
Datt vegetation index
$\mathrm{DATT}=\frac{\mathrm{R}_{840}-\mathrm{R}_{717}}{\mathrm{R}_{840}-\mathrm{R}_{668}}$ [28]
DVI 差值植被指数
Difference vegetation index
$\mathrm{DVI}=\mathrm{R}_{840}-\mathrm{R}_{668}$ [29]
GNDVI 绿度归一化差值植被指数
Green normalized difference vegetation index
$\text { GNDVI }=\frac{R_{840}-R_{560}}{R_{840}+R_{560}}$ [30]
OSAVI 优化型土壤调节植被指数
Optimized soil adjusted vegetation index
$\text { OSAVI }=\frac{R_{840}-R_{668}}{R_{840}+R_{668}+0.16}$ [31]
SIPI 结构不敏感色素指数
Structure-intensive pigment index
$\text { SIPI }=\frac{R_{840}-R_{475}}{R_{840}+R_{668}}$ [32]
SRPI 简单比值色素指数
Simple ratio pigment index
$\mathrm{SRPI}=\frac{\mathrm{R}_{475}}{\mathrm{R}_{668}}$ [32]

Table 4

Dataset partition"

模型 Model 年份 Year 类型 Type 数据集描述 Dataset description 样本数量 Number
机器学习
Machine learning
2023 常规粳稻 Conventional Japonica Rice 训练集 Training set 105
验证集 Validation set 45
杂交粳稻 Hybrid Japonica Rice 训练集 Training set 80
验证集 Validation set 34
交叉验证
Cross validation
2023 常规粳稻 Conventional Japonica Rice 训练集 Training set 103
验证集 Validation set 44
杂交粳稻 Hybrid Japonica Rice 训练集 Training set 60
验证集 Validation set 26
年际验证
Inter-annual validation
2022 杂交粳稻 Hybrid Japonica Rice 训练集 Training set 200
2023 杂交粳稻 Hybrid Japonica Rice 验证集 Validation set 200

Table 5

Descriptive statistics of rice GPC across different years and regions"

类型
Type
地点
Site
年份
Year
均值
Mean
最大值
Max
最小值
Min
中位数
Median
标准差
Standard
deviation
变异系数
Coefficient of variation (%)
常规粳稻
Conventional Japonica rice
如皋 Rugao 2022 6.64 7.80 5.67 6.62 0.58 0.09
淮安 Huaian 2023 7.11 8.02 6.07 7.14 0.47 0.07
如皋 Rugao 2023 8.61 10.41 6.97 8.49 0.98 0.11
杂交粳稻
Hybrid Japonica rice
如皋 Rugao 2022 7.04 10.38 5.40 6.83 0.97 0.14
2023 9.08 11.97 6.70 9.12 1.21 0.13

Fig. 2

Information entropy based on different bands of RGB"

Table 6

Comprehensive evaluation of fusion images based on R and G band"

时期
Period
波段
Band
峰值信噪比
PSNR
结构相似性指数
SSIM
归一化均方根误差NRMSE 空间频率
SF
标准差
SD
平均梯度
AG
抽穗期
Heading
红 Red 12.09 0.70 0.26 32.06 31.39 18.36
绿 Green 8.44 0.59 0.39 15.04 14.43 8.42
灌浆初期
Early filling
红 Red 9.86 0.62 0.36 16.12 15.75 8.85
绿 Green 8.92 0.41 0.32 16.34 15.82 8.80
灌浆中期
Middle filling
红 Red 12.09 0.61 0.26 32.06 31.39 18.36
绿 Green 9.73 0.49 0.33 13.01 12.84 7.29
成熟期
Maturity
红 Red 10.05 0.67 0.34 18.61 17.44 10.64
绿 Green 9.55 0.58 0.32 18.31 15.25 9.31

Fig. 3

Correlation between vegetation indices and GPC among different rice varieties (Rugao experimental site)"

Fig. 4

Correlation between vegetation indices and GPC in conventional japonica rice (Huaian experimental site)"

Fig. 5

Schematic diagrams of texture combinations across different bands for conventional japonica rice"

Fig. 6

Schematic diagram of different band texture combinations for hybrid japonica rice"

Table 7

Modeling and validation accuracy of GPC at single growth stage"

生育时期
Period
参数
Parameter
R2 RF XGBoost GBR
淮安
Huaian
如皋
Rugao
淮安
Huaian
如皋
Rugao
淮安
Huaian
如皋
Rugao
抽穗开花期
Heading
植被指数、纹理指数
Vegetation index、Texture index
建模R2 cal Calibration R2 cal 0.54 0.49 0.55 0.68 0.48 0.34
验证R2 val Validation R2 val 0.29 0.39 0.54 0.67 0.38 0.08
融合指数、纹理指数
Fusion index、Texture index
建模R2 cal Calibration R2 cal 0.56 0.78 0.64 0.64 0.63 0.60
验证R2 val Validation R2 val 0.41 0.73 0.33 0.55 0.42 0.46
灌浆初期
Early filling
植被指数、纹理指数
Vegetation index、Texture index
建模R2 cal Calibration R2 cal - 0.44 - 0.79 - 0.26
验证R2 val Validation R2 val - 0.42 - 0.74 - 0.21
融合指数、纹理指数
Fusion index、Texture index
建模R2 cal Calibration R2 cal - 0.76 - 0.62 - 0.41
验证R2 val Validation R2 val - 0.74 - 0.58 - 0.40
灌浆中期
Middle filling
植被指数、纹理指数
Vegetation index、Texture index
建模R2 cal Calibration R2 cal 0.42 0.42 0.46 0.80 0.30 0.13
验证R2 val Validation R2 val 0.28 0.32 0.20 0.65 0.18 0.08
融合指数、纹理指数
Fusion index、Texture index
建模R2 cal Calibration R2 cal 0.44 0.78 0.53 0.73 0.45 0.62
验证R2 val Validation R2 val 0.33 0.74 0.37 0.66 0.31 0.49
成熟期
Maturity
植被指数、纹理指数
Vegetation index、Texture index
建模R2 cal Calibration R2 cal 0.31 0.47 0.32 0.75 0.30 0.42
验证R2 val Validation R2 val 0.26 0.44 0.28 0.72 0.23 0.14
融合指数、纹理指数
Fusion index、Texture index
建模R2 cal Calibration R2 cal 0.46 0.76 0.70 0.62 0.48 0.53
验证R2 val Validation R2 val 0.29 0.75 0.51 0.51 0.33 0.37

Table 8

Modeling and validation accuracy of GPC with multi-temporal images"

参数
Parameter
R2 RF XGB GBR
淮安
Huaian
如皋
Rugao
淮安
Huaian
如皋
Rugao
淮安
Huaian
如皋
Rugao
植被指数、纹理指数
Vegetation index、Texture index
建模R2 cal Calibration R2 cal 0.41 0.48 0.42 0.46 0.30 0.69
验证R2 val Validation R2 val 0.26 0.35 0.32 0.38 0.28 0.48
融合指数、纹理指数
Fusion index、Texture index
建模R2 cal Calibration R2 cal 0.47 0.76 0.62 0.64 0.51 0.53
验证R2 val Validation R2 val 0.34 0.74 0.39 0.58 0.35 0.42

Fig. 7

1:1 relationship between measured and predicted GPC values of conventional japonica rice in the Huaian experimental area"

Fig. 8

Validation of the hybrid japonica rice GPC estimation model across different years in the Rugao experimental area"

Fig. 9

Accuracy evaluation of RF, XGB, and GBR machine learning models Bar charts represent R², dot-line charts represent RMSE"

[1]
FU Z P, YU S S, ZHANG J Y, XI H, GAO Y, LU R H, ZHENG H B, ZHU Y, CAO W X, LIU X J. Combining UAV multispectral imagery and ecological factors to estimate leaf nitrogen and grain protein content of wheat. European Journal of Agronomy, 2022, 132: 126405.

doi: 10.1016/j.eja.2021.126405
[2]
FAN Y G, FENG H K, YUE J B, JIN X L, LIU Y, CHEN R Q, BIAN M B, MA Y P, SONG X Y, YANG G J. Using an optimized texture index to monitor the nitrogen content of potato plants over multiple growth stages. Computers and Electronics in Agriculture, 2023, 212: 108147.

doi: 10.1016/j.compag.2023.108147
[3]
LI R, WANG D L, ZHU B, LIU T, SUN C M, ZHANG Z J. Estimation of nitrogen content in wheat using indices derived from RGB and thermal infrared imaging. Field Crops Research, 2022, 289: 108735.

doi: 10.1016/j.fcr.2022.108735
[4]
王宇唯, 马旭, 谭穗妍, 贾兴娜, 陈嘉盈, 秦亦娟, 胡希红, 郑惠文. 无人机遥感与地面观测的多模态数据融合反演水稻氮含量. 农业工程学报, 2024, 40(18): 100-109.
WANG Y W, MA X, TAN S Y, JIA X N, CHEN J Y, QIN Y J, HU X H, ZHENG H W. Inverting rice nitrogen content with multimodal data fusion of unmanned aerial vehicle remote sensing and ground observations. Transactions of the Chinese Society of Agricultural Engineering, 2024, 40(18): 100-109. (in Chinese)
[5]
LI W Y, WU W X, YU M L, TAO H Y, YAO X, CHENG T, ZHU Y, CAO W X, TIAN Y C. Monitoring rice grain protein accumulation dynamics based on UAV multispectral data. Field Crops Research, 2023, 294: 108858.

doi: 10.1016/j.fcr.2023.108858
[6]
ZHANG M Z, CHEN T E, GU X H, KUAI Y, WANG C, CHEN D, ZHAO C J. UAV-borne hyperspectral estimation of nitrogen content in tobacco leaves based on ensemble learning methods. Computers and Electronics in Agriculture, 2023, 211: 108008.

doi: 10.1016/j.compag.2023.108008
[7]
LONGMIRE A R, POBLETE T, HUNT J R, CHEN D, ZARCO-TEJADA P J. Assessment of crop traits retrieved from airborne hyperspectral and thermal remote sensing imagery to predict wheat grain protein content. ISPRS Journal of Photogrammetry and Remote Sensing, 2022, 193: 284-298.

doi: 10.1016/j.isprsjprs.2022.09.015
[8]
LONGMIRE A, POBLETE T, HORNERO A, CHEN D, ZARCO- TEJADA P J. Estimation of grain protein content in commercial bread and durum wheat fields via traits inverted by radiative transfer modelling from Sentinel-2 timeseries. ISPRS Journal of Photogrammetry and Remote Sensing, 2023, 206: 49-62.

doi: 10.1016/j.isprsjprs.2023.10.018
[9]
JAY S, GORRETTA N, MOREL J, MAUPAS F, BENDOULA R, RABATEL G, DUTARTRE D, COMAR A, BARET F. Estimating leaf chlorophyll content in sugar beet canopies using millimeter- to centimeter-scale reflectance imagery. Remote Sensing of Environment, 2017, 198: 173-186.

doi: 10.1016/j.rse.2017.06.008
[10]
QIU Z C, MA F, LI Z W, XU X B, GE H X, DU C W. Estimation of nitrogen nutrition index in rice from UAV RGB images coupled with machine learning algorithms. Computers and Electronics in Agriculture, 2021, 189: 106421.

doi: 10.1016/j.compag.2021.106421
[11]
TANAKA T S T, GISLUM R. Prediction of winter wheat nitrogen status using UAV imagery, weather data, and machine learning. European Journal of Agronomy, 2025, 164: 127534.

doi: 10.1016/j.eja.2025.127534
[12]
ZHANG S H, DUAN J Z, QI X H, GAO Y Z, HE L, LIU L R, GUO T C, FENG W. Combining spectrum, thermal, and texture features using machine learning algorithms for wheat nitrogen nutrient index estimation and model transferability analysis. Computers and Electronics in Agriculture, 2024, 222: 109022.

doi: 10.1016/j.compag.2024.109022
[13]
张良培, 沈焕锋. 遥感数据融合的进展与前瞻. 遥感学报, 2016, 20(5): 1050-1061.
ZHANG L P, SHEN H F. Progress and future of remote sensing data fusion. National Remote Sensing Bulletin, 2016, 20(5): 1050-1061. (in Chinese)

doi: 10.11834/jrs.20166243
[14]
XU S Z, XU X G, BLACKER C, GAULTON R, ZHU Q Z, YANG M, YANG G J, ZHANG J M, YANG Y A, YANG M, XUE H Y, YANG X D, CHEN L P. Estimation of leaf nitrogen content in rice using vegetation indices and feature variable optimization with information fusion of multiple-sensor images from UAV. Remote Sensing, 2023, 15(3): 854.

doi: 10.3390/rs15030854
[15]
LI X W, SU X X, LI J, ANWAR S, ZHU X Q, MA Q, WANG W H, LIU J K. Coupling image-fusion techniques with machine learning to enhance dynamic monitoring of nitrogen content in winter wheat from UAV multi-source. Agriculture, 2024, 14(10): 1797.

doi: 10.3390/agriculture14101797
[16]
YANG Q, SHI L S, HAN J Y, CHEN Z W, YU J. A VI-based phenology adaptation approach for rice crop monitoring using UAV multispectral images. Field Crops Research, 2022, 277: 108419.

doi: 10.1016/j.fcr.2021.108419
[17]
刘吉凯, 王伟强, 苏祥祥, 李军, 年颖, 祝雪晴, 马强, 李新伟. 基于无人机多光谱影像和机器学习的水稻产量与氮素利用率预测. 农业工程学报, 2025, 41(20): 127-138.
LIU J K, WANG W Q, SU X X, LI J, NIAN Y, ZHU X Q, MA Q, LI X W. Prediction of rice yield and nitrogen use efficiency based on UAV multispectral imaging and machine learning. Transactions of the Chinese Society of Agricultural Engineering, 2025, 41(20): 127-138. (in Chinese)
[18]
ZHENG H B, CHENG T, LI D, YAO X, TIAN Y C, CAO W X, ZHU Y. Combining unmanned aerial vehicle (UAV)-based multispectral imagery and ground-based hyperspectral data for plant nitrogen concentration estimation in rice. Frontiers in Plant Science, 2018, 9: 936.

doi: 10.3389/fpls.2018.00936 pmid: 30034405
[19]
EUGENIO F C, GROHS M, SCHUH M, VENANCIO L P, SCHONS C, BADIN T L, MALLMANN C L, FERNANDES P, PEREIRA DA SILVA S D, FANTINEL R A. Estimated flooded rice grain yield and nitrogen content in leaves based on RPAS images and machine learning. Field Crops Research, 2023, 292: 108823.

doi: 10.1016/j.fcr.2023.108823
[20]
KANG S Y, ZHANG Q L, WEI H R, SHI Y. An efficient multiscale integrated attention method combined with hyperspectral system to identify the quality of rice with different storage periods and humidity. Computers and Electronics in Agriculture, 2023, 213: 108259.

doi: 10.1016/j.compag.2023.108259
[21]
WANG D L, LI R, LIU T, LIU S P, SUN C M, GUO W S. Combining vegetation, color, and texture indices with hyperspectral parameters using machine-learning methods to estimate nitrogen concentration in rice stems and leaves. Field Crops Research, 2023, 304: 109175.

doi: 10.1016/j.fcr.2023.109175
[22]
FITZGERALD G, RODRIGUEZ D, O’LEARY G. Measuring and predicting canopy nitrogen nutrition in wheat using a spectral index: The canopy chlorophyll content index (CCCI). Field Crops Research, 2010, 116(3): 318-324.

doi: 10.1016/j.fcr.2010.01.010
[23]
GITELSON A A, GRITZ Y, MERZLYAK M N. Relationships between leaf chlorophyll content and spectral reflectance and algorithms for non-destructive chlorophyll assessment in higher plant leaves. Journal of Plant Physiology, 2003, 160(3): 271-282.

doi: 10.1078/0176-1617-00887 pmid: 12749084
[24]
SULIK J J, LONG D S. Spectral considerations for modeling yield of canola. Remote Sensing of Environment, 2016, 184: 161-174.

doi: 10.1016/j.rse.2016.06.016
[25]
JIANG Z Y, HUETE A R, DIDAN K, MIURA T. Development of a two-band enhanced vegetation index without a blue band. Remote Sensing of Environment, 2008, 112(10): 3833-3845.

doi: 10.1016/j.rse.2008.06.006
[26]
DAUGHTRY C S T, WALTHALL C L, KIM M S, DE COLSTOUN E B, MCMURTREY J E. Estimating corn leaf chlorophyll concentration from leaf and canopy reflectance. Remote Sensing of Environment, 2000, 74(2): 229-239.

doi: 10.1016/S0034-4257(00)00113-9
[27]
HUETE A R. A soil-adjusted vegetation index (SAVI). Remote Sensing of Environment, 1988, 25(3): 295-309.

doi: 10.1016/0034-4257(88)90106-X
[28]
DATT B. A new reflectance index for remote sensing of chlorophyll content in higher plants: tests using Eucalyptus leaves. Journal of Plant Physiology, 1999, 154(1): 30-36.

doi: 10.1016/S0176-1617(99)80314-9
[29]
RICHARDSONS A J, WIEGAND A. Distinguishing vegetation from soil background information. Photogrammetric Engineering and Remote Sensing, 1977, 43: 1541-1552.
[30]
GITELSON A, MERZLYAK M N. Spectral reflectance changes associated with autumn senescence of Aesculus hippocastanum L. and Acer platanoides L. leaves. spectral features and relation to chlorophyll estimation. Journal of Plant Physiology, 1994, 143(3): 286-292.

doi: 10.1016/S0176-1617(11)81633-0
[31]
STEVEN M D. The sensitivity of the OSAVI vegetation index to observational parameters. Remote Sensing of Environment, 1998, 63(1): 49-60.

doi: 10.1016/S0034-4257(97)00114-4
[32]
PENUELAS J, FREDERIC B, FILELLA I. Semi-empirical indices to assess carotenoids/chlorophyll-a ratio from leaf spectral reflectance. Photosynthetica, 1995, 31: 221-230.
[33]
ZHENG H B, MA J F, ZHOU M, LI D, YAO X, CAO W X, ZHU Y, CHENG T. Enhancing the nitrogen signals of rice canopies across critical growth stages through the integration of textural and spectral information from unmanned aerial vehicle (UAV) multispectral imagery. Remote Sensing, 2020, 12(6): 957.

doi: 10.3390/rs12060957
[34]
WAINER J, CAWLEY G. Nested cross-validation when selecting classifiers is over Zealous for most practical applications. Expert Systems with Applications, 2021, 182: 115222.

doi: 10.1016/j.eswa.2021.115222
[35]
李树涛, 李聪妤, 康旭东. 多源遥感图像融合发展现状与未来展望. 遥感学报, 2021, 25(1): 148-166.
LI S T, LI C Y, KANG X D. Development status and future prospects of multi-source remote sensing image fusion. National Remote Sensing Bulletin, 2021, 25(1): 148-166. (in Chinese)

doi: 10.11834/jrs.20210259
[36]
HE J Y, ZHANG N, SU X, LU J S, YAO X, CHENG T, ZHU Y, CAO W X, TIAN Y C. Estimating leaf area index with a new vegetation index considering the influence of rice panicles. Remote Sensing, 2019, 11(15): 1809.

doi: 10.3390/rs11151809
[37]
REN D Y, DING C Q, QIAN Q. Molecular bases of rice grain size and quality for optimized productivity. Science Bulletin, 2023, 68(3): 314-350.

doi: 10.1016/j.scib.2023.01.026
[38]
SHENDRYK Y, SOFONIA J, GARRARD R, RIST Y, SKOCAJ D, THORBURN P. Fine-scale prediction of biomass and leaf nitrogen content in sugarcane using UAV LiDAR and multispectral imaging. International Journal of Applied Earth Observation and Geoinformation, 2020, 92: 102177.

doi: 10.1016/j.jag.2020.102177
[39]
LI D L, SONG Z Y, QUAN C Q, XU X B, LIU C. Recent advances in image fusion technology in agriculture. Computers and Electronics in Agriculture, 2021, 191: 106491.

doi: 10.1016/j.compag.2021.106491
[40]
刘骁驰, 黄向阳, 金明, 李思齐, 唐子竣, 向友珍, 李志军, 张富仓. 融合无人机多光谱与纹理特征解析开花期大豆叶片氮浓度的垂直分布. 农业工程学报, 2025, 41(14): 174-183.
LIU X C, HUANG X Y, JIN M, LI S Q, TANG Z J, XIANG Y Z, LI Z J, ZHANG F C. Integrating UAV-derived multispectral and texture features for vertical distribution of nitrogen concentration in soybean leaves during flowering. Transactions of the Chinese Society of Agricultural Engineering, 2025, 41(14): 174-183. (in Chinese)
[41]
PULLANAGARI R R, DEHGHAN-SHOAR M, YULE I J, BHATIA N. Field spectroscopy of canopy nitrogen concentration in temperate grasslands using a convolutional neural network. Remote Sensing of Environment, 2021, 257: 112353.

doi: 10.1016/j.rse.2021.112353
[42]
LI D, CHEN J M, YU W G, ZHENG H B, YAO X, CAO W X, WEI D D, XIAO C C, ZHU Y, CHENG T. Assessing a soil-removed semi-empirical model for estimating leaf chlorophyll content. Remote Sensing of Environment, 2022, 282: 113284.

doi: 10.1016/j.rse.2022.113284
[43]
FAN Y G, FENG H K, LIU Y, FENG H, YUE J B, JIN X L, CHEN R Q, BIAN M B, MA Y P, YANG G J. Transferability of models for predicting potato plant nitrogen content from remote sensing data and environmental variables across years and regions. European Journal of Agronomy, 2024, 161: 127388.

doi: 10.1016/j.eja.2024.127388
[44]
LI D, TIAN L, WAN Z F, JIA M, YAO X, TIAN Y C, ZHU Y, CAO W X, CHENG T. Assessment of unified models for estimating leaf chlorophyll content across directional-hemispherical reflectance and bidirectional reflectance spectra. Remote Sensing of Environment, 2019, 231: 111240.

doi: 10.1016/j.rse.2019.111240
[45]
FÉRET J B, BERGER K, DE BOISSIEU F, MALENOVSKÝ Z. PROSPECT-PRO for estimating content of nitrogen-containing leaf proteins and other carbon-based constituents. Remote Sensing of Environment, 2021, 252: 112173.

doi: 10.1016/j.rse.2020.112173
[1] WANG ZhongNi, LEI Yue, LI JiaLi, GONG YanLong, ZHU SuSong. Functions of ABC Transporter OsARG1 in Rice Heading Date Regulation [J]. Scientia Agricultura Sinica, 2026, 59(1): 1-16.
[2] DONG GuiChun, WANG ZiHan, WANG ShuShen, LI Jie, HUO XiaoQing, YANG Rui, ZHOU Juan, SHU XiaoWei, LI Yan, CAO LiangJing, WANG ZiRui, YAO YouLi, HUANG JianYe. Technical Approaches for Enhancing Rice Yield and Nitrogen Use Efficiency with Sulfur-Coated Controlled-Release Fertilizers [J]. Scientia Agricultura Sinica, 2026, 59(1): 57-77.
[3] WANG AiDong, LI RuiJie, FENG XiangQian, HONG WeiYuan, LI ZiQiu, ZHANG XiaoGuo, WANG DanYing, CHEN Song. Multi-Angle Imaging and Machine Learning Approaches for Accurate Rice Leaf Area Estimation [J]. Scientia Agricultura Sinica, 2025, 58(9): 1719-1734.
[4] WEI Ping, PAN JuZhong, ZHU DePing, SHAO ShengXue, CHEN ShanShan, WEI YaQian, GAO WeiWei. The Function of OsDREB1J in Regulating Rice Grain Size [J]. Scientia Agricultura Sinica, 2025, 58(8): 1463-1478.
[5] LIU JinSong, WU LongMei, BAO XiaoZhe, LIU ZhiXia, ZHANG Bin, YANG TaoTao. Effects of a Short-Term Reduction in Nitrogen Fertilizer Application Rates on the Grain Yield and Rice Quality of Early and Late-Season Dual-Use Rice in South China [J]. Scientia Agricultura Sinica, 2025, 58(8): 1508-1520.
[6] WANG Bin, WU PengHao, LU JianWei, REN Tao, CONG RiHuan, LU ZhiFeng, LI XiaoKun. Water Demand Characteristics of Rice-Oilseed Rape Rotation System in the Middle Reaches of the Yangtze River [J]. Scientia Agricultura Sinica, 2025, 58(7): 1355-1365.
[7] XIONG JiaNi, LI ZongYue, HU HengLiang, GU TianYu, GAO Yan, PENG JiaShi. Influence of Expressing OsNRAMP5 Under the Driving of the OsLCT1 Promoter on Cadmium Migration to Rice Seeds [J]. Scientia Agricultura Sinica, 2025, 58(7): 1259-1268.
[8] JIN YiDan, HE NiQing, CHENG ZhaoPing, LIN ShaoJun, HUANG FengHuang, BAI KangCheng, ZHANG Tao, WANG WenXiao, YU MinXiang, YANG DeWei. Screening and Identification of Pigm-1 Interaction Proteins for Disease Resistance of Rice Blast [J]. Scientia Agricultura Sinica, 2025, 58(6): 1043-1051.
[9] JIN YaRu, CHEN Bin, WANG XinKai, ZHOU TianTian, LI Xiao, DENG JingJing, YANG YuWen, GUO DongShu, ZHANG BaoLong. Generation of Low-Glutelin Rice (Oryza sativa L.) Germplasm Through Long Fragment Deletion Using CRISPR/Cas9-Mediated Targeted Mutagenesis [J]. Scientia Agricultura Sinica, 2025, 58(6): 1052-1064.
[10] XIAO ChangChun, WEI XinYu, ZENG YueHui, HUANG JianHong, XU XuMing. Accumulation Characteristics of Anthocyanins in Black Rice Under Different Sowing Dates and Its Relationship with Meteorological Factors [J]. Scientia Agricultura Sinica, 2025, 58(5): 890-906.
[11] XU YuanYuan, JIA DongSheng, BIN Yu, WEI TaiYun. PGRP6 Negatively Regulates Symbiotic Bacteria to Prevent the Transovarial Transmission of RDV in Nephotettix cincticeps [J]. Scientia Agricultura Sinica, 2025, 58(5): 907-917.
[12] CHEN Ge, GU Yu, WEN Jiong, FU YueFeng, HE Xi, LI Wei, ZHOU JunYu, LIU QiongFeng, WU HaiYong. Effects of Fallow Weeds Returning to the Field on Photosynthetic Matter Production and Yield of Rice [J]. Scientia Agricultura Sinica, 2025, 58(4): 647-659.
[13] WANG ShaoHua, SHEN NianQiao, CHU TianRan, WU YongHan, LI KangNing, SHI YanXia, XIE XueWen, LI Lei, FAN TengFei, LI BaoJu, CHAI ALi. Effects of Tomato-Rice Rotation on Physicochemical Properties and Microbial Communities of Soil with Continuous Cropping Obstacles in Cangnan, Zhejiang [J]. Scientia Agricultura Sinica, 2025, 58(4): 692-703.
[14] LI Lu, XIE Zhuang, XIE KeYing, ZHANG Han, ZHAO ZhuoWen, XIANG AoNi, LI QiaoLong, LING YingHua, HE GuangHua, ZHAO FangMing. Construction of Single and Dual-Segment Substitution Lines from Rice CSSL-Z492 and Genetic Dissection of QTL for Grain Size [J]. Scientia Agricultura Sinica, 2025, 58(3): 401-415.
[15] ZHUANG LiHua, LUO Lei, ZHAO ChunFang, WANG JiZhong, ZHANG YaDong, HE Lei. Identification and Gene Mapping of Rice Grain Shape Mutant sgd13 [J]. Scientia Agricultura Sinica, 2025, 58(24): 5097-5109.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!