夏莎莎^1,,
张聪³,
李佳珍²,
李红军²,
张玉铭^2,,,
胡春胜²
1.中国科学院生态环境研究中心 北京 100085
2.中国科学院遗传与发育生物学研究所农业资源研究中心/中国科学院农业水资源重点实验室/河北省节水农业重点实验室 石家庄 050022
3.华北制药集团爱诺有限公司 石家庄 050000
基金项目: 国家重点研发计划项目2016YFD0200307
河北省科技计划项目14227423D
渤海粮仓现代农业区域科技示范项目KFJ-STS-ZDTP-001

详细信息

作者简介:夏莎莎, 研究方向为分析化学。E-mail:ssxia@rcees.ac.cn

通讯作者:张玉铭, 研究方向为农田生态系统养分循环。E-mail:ymzhang@sjziam.ac.cn

中图分类号:S126;S512

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出版历程

收稿日期:2017-12-15
录用日期:2018-02-01
刊出日期:2018-04-01

Study on nitrogen nutrition diagnosis and fertilization recommendation of winter wheat using canopy digital images from cellphone camera

XIA Shasha^1,,
ZHANG Cong³,
LI Jiazhen²,
LI Hongjun²,
ZHANG Yuming^2,,,
HU Chunsheng²
1. Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
2. Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences/Key Laboratory of Agricultural Water Resources, Chinese Academy of Sciences/Hebei Key Laboratory of Water-saving Agriculture, Shijiazhuang 050022, China
3. North China Pharmaceutical Group Aino CO., LTD, Shijiazhuang 050000, China
Funds: the National Key Research and Development Plan of China2016YFD0200307
the Science and Technology Project of Hebei Province14227423D
the Science and Technology Demonstration of Modern Agriculture in Bohai Granary Region of ChinaKFJ-STS-ZDTP-001

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Corresponding author:ZHANG Yuming, E-mail:ymzhang@sjziam.ac.cn

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摘要
摘要:本文利用不同型号手机、通过不同拍摄角度获取冬小麦拔节期冠层图像，并对其图像进行色彩参数的提取、处理与分析，与传统小麦氮素营养指标进行相关性分析，筛选出敏感色彩参数，对二者进行拟合建模，建立了冬小麦氮素营养诊断指标体系和推荐施肥指标体系，为作物精准施肥提供参考。研究结果表明，在获取冬小麦冠层图像时，适宜从逆光俯视的角度拍摄，不同型号的手机拍照获取的冠层图像色彩参数没有明显差异，冠层图像色彩参数中可见光大气阻抗植被指数（VARI）及红光标准化值[R/（R+G+B）]与传统诊断指标叶片SPAD值、茎基部硝酸盐浓度均有显著的相关关系；其中VARI最为敏感，可作为冬小麦氮素营养诊断的色彩参数指标，诊断方程为冬小麦茎基部硝酸盐浓度=1.481×10⁶×VARI^4.987，依据此给出了不同VARI值下的冬小麦营养状况以及推荐施氮量。并基于此研究成果进行了手机软件开发，建立了一款针对冬小麦氮素营养诊断与推荐施肥的软件，为基于手机相机开展冬小麦氮素营养诊断与推荐施肥技术的推广与应用提供了技术支撑。
关键词:冬小麦/
精准施肥/
手机相机/
冠层图像/
色彩参数/
氮素营养诊断
Abstract:Digital cameras have been successfully used in nutrition diagnosis of crops. Few researches were reported on the application of cellphone cameras on nutrition diagnosis and precision fertilization of crops, though the cellphone cameras have various advantages, such as portability, handleability and universality. In this study, we used Samsung and Xiaomi smart cellphones to photograph winter wheat canopy at jointing stage from four shooting angles, frontlighting looking down, frontlighting overlooking, backlighting looking down and backlighting overlooking. The color parameters of achieved winter wheat canopy images were extracted, processed and analyzed. And their correlations with traditional nitrogen nutrition indexes were analyzed. According to the statistical analysis of the correlation, appropriate color parameters were selected, and the nutrition diagnosis model was established with color parameters and nitrogen nutrition index. Then the model was fitted to establish indicator systems of diagnosis of nitrogen nutrition and recommendation system of fertilization for winter wheat. The aim of the study was to provide references for application of smart cellphone on precision fertilization of crops. The results showed that there was no remarkable difference in the color parameters of canopy images taken with different types of smart cellphones. However, a certain difference was observed in color parameters of canopy images taken from different shooting angles. More than half of color parameters of canopy images taking from the view of backlighting overlooking were significantly correlated with traditional nutrient indexes. Furthermore, the results indicated that the color parameters VARI[(G-R)/(G+R-B)] and R/(R+G+B) both had outstanding correlations with leaf SPAD and stem nitrate concentration. And VARI was found to be the best, and therefore, selected as the sensitive color parameter for winter wheat nitrogen nutrition diagnosis. The diagnosis model was stem nitrate concentration=1.481×10⁶×VARI^4.987. According to the equation, the nitrogen nutrition status of winter wheat was normal when VARI was between 0.201 3 and 0.250 9. The nitrogen application rates under different VARI values were calculated for different target yields of winter wheat. The results were applied to develop cellphone software for nitrogen nutrition diagnosis and fertilization recommendation of winter wheat. In summary, it was possible and applicable to take photographs of canopy from the view of backlighting overlooking with smart cellphone and extract VARI color parameter to diagnosis nitrogen nutrition status. The results provided technical support for the diagnosis of nitrogen nutrition and recommendation of fertilization of winter wheat based on cellphone camera.
Key words:Winter wheat/
Precision fertilization/
Cellphone camera/
Canopy image/
Color parameters/
Diagnosis of nitrogen nutrition

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图1不同拍摄角度智能手机拍摄的冬小麦冠层图片
Figure1.Illustrations of winter wheat canopy photographs taken from different angles with smart cellphone


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图2三星和小米智能手机从不同拍摄角度获得的冬小麦冠层图像色彩参数的相关性
^**表示三星和小米手机图像的色彩参数间在P < 0.01水平显著相关。
Figure2.Correlations between Samsung and Xiaomi smart cellphones in color parameters of wheat canopy photographs taken from different shooting angles
"^**" means significant correlations at P < 0.01 between photographs taken with Samsung and Xiaomi smart cellphones.


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图3智能手机获得的不同拍摄方式下冬小麦冠层图像VARI与R/(R+G+B)的线性相关性
Figure3.Linear correlation between VARI and R/(R+G+B) of winter wheat canopy photographs taken from different shooting angles with smart cellphone


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图4智能手机逆光俯视角度拍摄的冬小麦冠层图像VARI与茎基部硝酸盐浓度的拟合曲线
Figure4.Fitted curve of VARI of winter wheat canopy photographs taken at backlighting overlooking view with smart cellphone and stem sap nitrate concentration of winter wheat


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图5小麦、玉米智能手机拍照进行氮素营养诊断与推荐施肥的软件界面
Figure5.Interfaces of the smart cellphone software for diagnosis of nitrogen nutrition and recommended topdressing amount of nitrogen fertilizer based on wheat and corn canopy photographs taken with smart cellphone


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表1智能手机的拍摄方式对冬小麦冠层图像色彩参数的影响
Table1.Color parameters of winter wheat canopy photographs taken from different shooting angles with smart cellphone

色彩参数 Color parameter	顺光向下Frontlighting looking down				顺光俯视Frontlighting overlooking				逆光向下Backlighting looking down				逆光俯视Backlighting overlooking
	平均值 Average	标准差 Std.	变异系数 CV		平均值 Average	标准差 Std.	变异系数 CV		平均值 Average	标准差 Std.	变异系数 CV		平均值 Average	标准差 Std.	变异系数 CV
R	105.131b	7.999	0.076		100.671a	14.686	0.146		89.23c	11.023	0.124		98.65a	15.611	0.158
G	146.933b	8.028	0.055		134.35a	13.461	0.100		135.661a	6.769	0.050		134.044a	12.804	0.096
B	77.830b	15.244	0.196		71.142a	5.955	0.084		48.169c	12.593	0.261		68.48a	6.259	0.091
R/(R+G+B)	0.314a	0.024	0.076		0.324a	0.025	0.078		0.318a	0.027	0.086		0.321a	0.025	0.078
G/(R+G+B)	0.475a	0.032	0.068		0.472a	0.023	0.048		0.532b	0.044	0.082		0.48a	0.025	0.052
B/(R+G+B)	0.212a	0.046	0.219		0.205a	0.032	0.154		0.15b	0.05	0.334		0.198a	0.032	0.159
G/R	1.573a	0.134	0.085		1.528a	0.161	0.105		1.767b	0.233	0.132		1.574a	0.172	0.109
VARI	0.244a	0.051	0.208		0.212b	0.058	0.271		0.268a	0.060	0.225		0.223b	0.059	0.262
同行中平均值后不同字母表示不同拍摄角度下获得的数字图像色彩参数差异显著(P < 0.05)。Different lowercase letters in the same line after the average values mean significant differences among the color parameters of photograph taking from different shooting angles (P < 0.05).

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表2不同型号手机对冬小麦冠层图像色彩参数的影响
Table2.Color parameters of winter wheat canopy photographs taken with different types of smart cellphone

色彩参数平均值 Average of color parameter	顺光向下 Frontlighting looking down			顺光俯视 Frontlighting overlooking			逆光向下 Backlighting looking down			逆光俯视 Backlighting overlooking
	三星手机 Samsung	小米手机 Xiaomi		三星手机 Samsung	小米手机 Xiaomi		三星手机 Samsung	小米手机 Xiaomi		三星手机 Samsung	小米手机 Xiaomi
R	103.289a	106.918a		91.727a	107.492b		89.553a	87.312a		91.834a	105.466b
G	141.766a	151.943b		122.437a	144.686b		132.712a	138.227b		124.248a	143.841b
B	88.596a	67.390b		73.104a	70.097b		58.661a	38.050b		71.199a	65.761b
R/(R+G+B)	0.306a	0.321b		0.316a	0.328a		0.312a	0.320a		0.315a	0.328a
G/(R+G+B)	0.446a	0.502b		0.452a	0.490b		0.493a	0.574b		0.460a	0.501b
B/(R+G+B)	0.248a	0.177b		0.232a	0.183b		0.196a	0.106b		0.225a	0.172b
G/R	1.507a	1.636b		1.489a	1.581b		1.644a	1.921b		1.522a	1.627b
VARI	0.249a	0.240a		0.224a	0.210a		0.269a	0.276a		0.231a	0.216a
同一拍摄角度下同一行中不同字母表示两种手机间色彩参数存在显著差异(P < 0.05)。Different lowercase letters in the same line under the same shooting angle mean significant differences between color parameters of photograph took by two types of smart cellphones (P < 0.05).

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表3智能手机获得的不同拍摄方式下冬小麦冠层图像色彩参数与氮素营养指标的关系
Table3.Correlation coefficients (R²) between nitrogen nutrient indexes and color parameters of wheat canopy photographs taken from different shooting angles with smart cellphone

色彩参数Color parameter	顺光向下Frontlighting looking down			顺光俯视Frontlighting overlooking			逆光向下Backlighting looking down			逆光俯视Backlighting overlooking
	SPAD	植株硝酸盐Plant nitrate concentration		SPAD	植株硝酸盐Plant nitrate concentration		SPAD	植株硝酸盐Plant nitrate concentration		SPAD	植株硝酸盐Plant nitrate concentration
R	0.431**	0.308**		0.198**	0.146*		0.490**	0.495**		0.700**	0.510**
G	0.264*	0.208*		0.063	0.026		0.045	0.085		0.386**	0.148
B	0.276**	0.170		0.492**	0.274*		0.086	0.065		0.031	0.017
R/(R+G+B)	0.784**	0.629**		0.559**	0.461**		0.552**	0.635**		0.875**	0.726**
G/(R+G+B)	0.001	0.003		0.013**	0.025		0.026	0.015		0.231*	0.140
B/(R+G+B)	0.265**	0.139		0.348**	0.141		0.094	0.085		0.103	0.062
G/R	0.674**	0.420**		0.427**	0.374**		0.400**	0.347**		0.866**	0.653**
VARI	0.816**	0.718**		0.509**	0.447**		0.571**	0.655**		0.888**	0.759**
*和**分别表示P < 0.05和P < 0.01水平显著相关。*and ** mean significant correlations at P < 0.05 and P < 0.01, respectively.

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表4基于智能手机获得的冠层图像VARI的冬小麦氮素营养诊断指标与推荐追肥指标
Table4.Nitrogen diagnosis and recommended topdressing amounts of nitrogen fertilizer for winter wheat under different VARI ranges of canopy photographs of smart cellphone

VARI	< 0.201 3	0.201 3~0.218 4	0.218 4~0.231 3	0.231 3~0.241 9	0.241 9~0.250 9	> 0.250 9
营养状况 Nitrogen nutrition status	极低 Very low	低 Low	中 Moderate	高 High	较高 Higher	极高 Very high
目标产量 Yield target (t·hm-2)	推荐施氮量 Recommended topdressing amount of nitrogen fertilizer [kg(N)·hm-2]
7.50~8.25	178	139~178	99~139	60~99	21~60	21
6.75~7.50	162	126~162	90~126	55~90	19~55	19
6.00~6.75	153	119~153	84~119	50~84	17~50	17
5.25~6.00	146	114~146	81~114	50~81	15~50	15
4.50~5.25	104	80~104	56~80	31~56	7~31	7

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