Study on Multi-parameter Detection System of Plant Nutrient Uptake Under Hydroponic Environment

doi:10.13304/j.nykjdb.2022.0211

Abstract

Abstract:

The kinetics of nutrient uptaking by plant roots under hydroponic environment has been studied mainly by conventional depletion curve and series concentration methods， and because of relying on a manual interval sampling process， it is not only labor-intensive but also affects the efficiency. To solve this problem， the ion concentration and phenotype area of plant roots during nutrient uptake in hydroponic environment were measured using ion selective electrode and image sensor， respectively. Michaelis-Menten equation was combined to obtain plant kinetic characteristics parameter. The system hardware took STM32F407ZGT6 microprocessor as the main control unit， and signal conditioning and data acquisition circuit with precision electrochemical sensor interface was given. The data communication， calibration and modeling processing were done in the upper computer system. The experimental results showed that the energy-strength slope conversion rates of different valence ions after solution calibration were above 80% or 90%， respectively. The linear correlation between the root phenotypic area by proposed system and WinRHIZO root analysis software was 0.97. The system obtained the characteristic parameters such as the critical concentration of uptake （C_min）， the maximum uptake rate （I_max）， and the Michaelis constant （K_m） of the whole root system of the plant stably， which could be used for scientific research on crop nutrition and nutrient uptake under hydroponic environment technical support for monitoring.

Key words: ion selective electrode, kinetic characteristics parameters, depletion curve method, Michaelis-Menten equation, data acquisition

摘要：

在水培环境下对植物根系养分吸收的动力学主要利用耗竭曲线和系列含量法进行研究，而依靠人工间隔性的采样过程不但耗费人力而且影响效率。为解决这一问题，利用离子选择电极和图像传感器分别测定植物根系在水培环境下养分吸收时的离子含量和根系表面积，结合Michaelis-Menten方程获得植物动力学特征参数；系统硬件以STM32F407ZGT6微处理器作为主控单元，给出具有精密电化学传感器接口的信号调理与数据采集电路；在上位机系统中完成数据通讯、校准以及建模处理等。经测试表明，溶液校准后不同价态离子的能斯特斜率转换率分别在80%或90%以上；该系统与WinRHIZO获得的根系表面积相比，2组数据的线性相关性为0.97。该系统能够稳定的获取植株全根系的吸收临界浓度（C_min）、最大吸收速率（I_max）、米氏常数（K_m）等特征多参数，可为农作物营养的科学研究及水培环境下的养分吸收监测提供技术支撑。

关键词: 离子选择电极, 耗竭曲线法, 动力学特征参数, Michaelis-Menten方程, 数据采集

CLC Number:

S126

Xiaoding FENG, Cheng WANG, Xiaotong JIN, Hongtu DONG, Bin LUO, Xiaodong WANG. Study on Multi-parameter Detection System of Plant Nutrient Uptake Under Hydroponic Environment[J]. Journal of Agricultural Science and Technology, 2023, 25(8): 106-114.

冯小鼎, 王成, 金晓彤, 董宏图, 罗斌, 王晓冬. 水培环境下的作物养分吸收多参数检测系统研究[J]. 中国农业科技导报, 2023, 25(8): 106-114.

Figures/Tables 11

Fig. 1 Design of the system

Fig. 2 Two-electrode system potential measurement

Fig. 3 Electrode signal conditioning circuit

Fig. 4 AD7192 analog-to-digital conversion circuit

Fig. 5 Power conversion circuit

Fig. 6 Root imaging deviceNote： 1—Camera partition bracket； 2—lens； 3—Camera； 4—Industrial control computer； 5—Background baffle； 6—Hydroponic box； 7—Backplane light source.

Fig. 7 Flow of root image processing and surface area measurement

Table 1 Nernst linear slope correction test

离子种类 Ion type	标定液Calibration solution			斜率（两/三点） Slope （two/three points）	理论斜率Theoretical slope	转换率（两/三点） Conversion rate （two/three points）
离子种类 Ion type	C1/mV	C2/mV	C3/mV	斜率（两/三点） Slope （two/three points）	理论斜率Theoretical slope	转换率（两/三点） Conversion rate （two/three points）
$N O 3 -$	330.86	273.81	213.17	-57.05/-58.85	-59.16	0.96/0.99
Cl^-	157.00	95.90	40.70	-58.15/-57.60	-59.16	0.98/0.97
K⁺	-125.12	-69.34	-13.79	55.78/55.67	59.16	0.94/0.94
Ca²⁺	-256.47	-231.57	-209.21	24.9/23.63	29.58	0.84/0.80

Table 1 Nernst linear slope correction test

离子种类 Ion type	标定液Calibration solution			斜率（两/三点） Slope （two/three points）	理论斜率Theoretical slope	转换率（两/三点） Conversion rate （two/three points）
离子种类 Ion type	C1/mV	C2/mV	C3/mV	斜率（两/三点） Slope （two/three points）	理论斜率Theoretical slope	转换率（两/三点） Conversion rate （two/three points）
$N O 3 -$	330.86	273.81	213.17	-57.05/-58.85	-59.16	0.96/0.99
Cl^-	157.00	95.90	40.70	-58.15/-57.60	-59.16	0.98/0.97
K⁺	-125.12	-69.34	-13.79	55.78/55.67	59.16	0.94/0.94
Ca²⁺	-256.47	-231.57	-209.21	24.9/23.63	29.58	0.84/0.80

Table 2 Comparison of root surface area parameter test

发育时间 Development time/d	WinRHIZO		本文测量程序Proposed measurement software
发育时间 Development time/d	表面积Surface area/cm²	投影面积Shadow area /cm²	表面积Surface area/cm²	投影面积Shadow area /cm²
5	3.969 8	12.132 6	3.776 8	11.971 3
7	4.001 2	12.243 6	4.213 7	13.237 7
9	4.630 4	14.539 4	4.713 7	14.801 0
11	5.121 3	16.712 7	5.371 4	16.874 7
13	5.961 3	18.727 9	5.777 9	18.143 6

Fig. 8 Comparison of the results between proposed measurement software and WinRHZIO

Table 3 Ion absorption kinetic characteristics parameters

离子Ion	C_min/ （mmol·L^-1）	K_m	I_max/ （mmol·cm^-2·s^-1）	C₀/ （mmol·L^-1）	电势E/mV
K⁺	4.34	4.52	0.0686	4.35	-3.69
Ca²⁺	7.97	8.41	0.122	8.07	-14.7
NO $3 -$	2.83	3.34	0.192	2.83	165.7
Cl^-	87.5	87.7	0.516	129	79.3

Table 3 Ion absorption kinetic characteristics parameters

离子Ion	C_min/ （mmol·L^-1）	K_m	I_max/ （mmol·cm^-2·s^-1）	C₀/ （mmol·L^-1）	电势E/mV
K⁺	4.34	4.52	0.0686	4.35	-3.69
Ca²⁺	7.97	8.41	0.122	8.07	-14.7
NO $3 -$	2.83	3.34	0.192	2.83	165.7
Cl^-	87.5	87.7	0.516	129	79.3

References 18

1	李道亮.农业4.0——即将到来的智能农业时代[J].农学学报,2018,8(1):207-214.
	LIN D L. Agriculture 4.0-the coming era of smart agriculture [J]. J. Agric., 2018,8(1):207-214.
2	晏琼,刘晓宇,虞昊安,等.植物无土栽培技术研究进展[J].中国农业大学学报,2022,27(5):1-11.
	YAN Q, LIU X Y, YU H A, et al.. Research progress of plant soilless culture technology [J]. J. China Agric. Univ., 2022, 27(5):1-11.
3	赵倩,王利春,郭文忠,等.水培营养液硝态氮浓度在线标测系统研究[J].农业机械学报, 2018, 49(8):203-209.
	ZHAO Q, WANG L C, GUO W Z, et al.. Research on online mapping system of nitrate nitrogen concentration in hydroponic nutrient solution [J]. Trans. Chin. Soc. Agric. Machinery, 2018, 49(8):203-209.
4	徐诺,董雪,任李,等.观赏类水培植物对盐离子的吸收动力学[J].浙江农业科学,2021,62(9):1789-1793.
	XU N, DONG X, REN L, et al.. Uptake kinetics of salt ions by ornamental hydroponic plants [J]. J. Zhejiang Agric. Sci., 2021, 62(9):1789-1793.
5	韩振海,王永章,王倩.植物的离子吸收动力学研究的现状和前景(综述)[J].北京农业大学学报, 1994(4):381-387.
	HAN Z H, WANG Y Z, WANG Q. Current status and prespectibes of ion aborption kinetics in research on crop and fruit nutrition (review) [J]. Acta Agric. Univ. Pekinensis, 1994(4):381-387.
6	李诗奇,张彦浩,李政,等.大叶藻对氮磷营养盐的吸收动力学特征[J].植物生态学报, 2020, 44(7): 78-87.
	LI S Q, ZHANG Y H, LI Z, et al.. Kinetic characteristics of nitrogen and phosphorus uptake by kelp algae [J]. Chin. J. Plant Ecol., 2020, 44(7):78-87.
7	SANSOULET J, CABIDOCHE Y M, CATTAN P. Absorption and transport of nitrate and potassium in an andosol under banana (Guadeloupe,French West Indies) [J]. Eur. J. Soil Sci., 2007, 58:478-489.
8	张熙灵,王立新,刘华民,等.芦苇、香蒲和藨草3种挺水植物的养分吸收动力学[J].生态学报,2014, 34(9):2238-2245.
	ZHANG X L, WANG L X, LIU H M, et al.. Kinetic characteristics of nitrogen and phosphorus uptake by kelp algae [J]. Acta Ecol. Sin., 2014, 34(9):2238-2245.
9	康亮,梁琼月,姚一华,等.不同氮效率木薯品种根系形态、构型及氮吸收动力学特征[J].植物营养与肥料学报, 2019, 25(11): 1920-1928..
	KANG L, LIANG Q Y, YAO Y H, et al.. Root morphology, configuration and nitrogen uptake kinetics of cassava varieties with different nitrogen efficiencies [J]. J. Plant Nut. Fertil., 2019, 25(11): 1920-1928.
10	蒋廷惠,郑绍建,石锦芹,等.植物吸收养分动力学研究中的几个问题[J].植物营养与肥料学报,1995(2):11-17.
	JIANG T H, ZHENG S J, SHI J Q, et al.. Several problems in the study of plant nutrient uptake kinetics [J]. J. Plant Nutr. Fertil., 1995(2):11-17.
11	常会庆,李娜,徐晓峰.三种水生植物对不同形态氮素吸收动力学研究[J].生态环境, 2008(02): 511-514.
	CHANG H Q, LI N, XU X F, Study on the uptake kinetics of nitrogen in different forms by three aquatic plants [J]. Ecol. Environ. Sci., 2008(2):511-514.
12	CHO W J, KIM H J, JUNG D H, et al.. On-site ion monitoring system for precision hydroponic nutrient management [J]. Comp. Electron. Agric., 2018,146: 51-58.
13	李彦峰,王春耀,王跃东,等.水果表面缺陷检测研究——基于NI Vision Assistant和IMAQ Vision[J].农机化研究,2013,35(7):62-65.
	LI Y F, WANG C Y, WANG Y D, Research on detection of fruit surface defects—based on NI Vision Assistant and IMAQ Vision [J]. J. Agric. Mechanization Res., 2013, 35(7):62-65.
14	梁丽秀,裴玖玲,孙少杰,等.植物根系图像的预处理方法研究[J].科学技术创新, 2021(25): 17-18.
	LIANG L X, PEI J L, SUN S J, et al.. Research on preprocessing method of plant root image [J]. Sci. Technol. Innov., 2021(25):17-18.
15	冯小鼎,王晓冬,罗斌,等.基于LabVIEW的植物离子吸收多参数检测系统软件研发[J].农业大数据学报,2021,3(2):16-23.
	FENG X D, WANG X D, LUO B, et al.. Software research and development of a multi-parameter detection system for plant ion absorption based on LabVIEW [J]. J. Agric. Big Data, 2021, 3(2):16-23.
16	张合心,黄承和,常春荣.不同铵硝配比下不同硅效应水稻的硅吸收动力学特征[J].中国土壤与肥料, 2017(6):122-126.
	ZHANG H X, HUANG C H, CHANG C R. Characteristic of silicon uptake kinetic with different ratio of ammonium and nitrate in different silicon-efficiency rice [J]. Soil Fertil. Sci. China, 2017(6):122-126.
17	周宝宣.土壤重金属含量检测系统及其预测模型的研究[D].海口:海南大学, 2016.
	ZHOU B X. Studies on detection system and prediction model of heavy metal in the soils [D]. Haikou: Hainan University, 2016.
18	唐艺璇,郑洁敏,楼莉萍,等.3种挺水植物吸收水体 N H 4 + 、 N O 3 - 、 H 2 P O 4 - 的动力学特征比较[J]. 中国生态农业学报, 2011, 19: 614-618.
	TANG Y X, ZHENG J M, LOU L P, et al.. Comparisons of N N H 4 + , N O 3 - and H 2 P O 4 - uptake kinetics in three different macrophytes in waterlogged condition [J]. Chin. J. Eco-Agric., 2011, 19: 614-618.

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