Cargando…

Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers

To meet the demand of intelligent irrigation for accurate moisture sensing in the soil vertical profile, a soil profile moisture sensor was designed based on the principle of high-frequency capacitance. The sensor consists of five groups of sensing probes, a data processor, and some accessory compon...

Descripción completa

Detalles Bibliográficos
Autores principales: Gao, Zhenran, Zhu, Yan, Liu, Cheng, Qian, Hongzhou, Cao, Weixing, Ni, Jun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5981356/
https://www.ncbi.nlm.nih.gov/pubmed/29883420
http://dx.doi.org/10.3390/s18051648
_version_ 1783328030723145728
author Gao, Zhenran
Zhu, Yan
Liu, Cheng
Qian, Hongzhou
Cao, Weixing
Ni, Jun
author_facet Gao, Zhenran
Zhu, Yan
Liu, Cheng
Qian, Hongzhou
Cao, Weixing
Ni, Jun
author_sort Gao, Zhenran
collection PubMed
description To meet the demand of intelligent irrigation for accurate moisture sensing in the soil vertical profile, a soil profile moisture sensor was designed based on the principle of high-frequency capacitance. The sensor consists of five groups of sensing probes, a data processor, and some accessory components. Low-resistivity copper rings were used as components of the sensing probes. Composable simulation of the sensor’s sensing probes was carried out using a high-frequency structure simulator. According to the effective radiation range of electric field intensity, width and spacing of copper ring were set to 30 mm and 40 mm, respectively. A parallel resonance circuit of voltage-controlled oscillator and high-frequency inductance-capacitance (LC) was designed for signal frequency division and conditioning. A data processor was used to process moisture-related frequency signals for soil profile moisture sensing. The sensor was able to detect real-time soil moisture at the depths of 20, 30, and 50 cm and conduct online inversion of moisture in the soil layer between 0–100 cm. According to the calibration results, the degree of fitting (R(2)) between the sensor’s measuring frequency and the volumetric moisture content of soil sample was 0.99 and the relative error of the sensor consistency test was 0–1.17%. Field tests in different loam soils showed that measured soil moisture from our sensor reproduced the observed soil moisture dynamic well, with an R(2) of 0.96 and a root mean square error of 0.04. In a sensor accuracy test, the R(2) between the measured value of the proposed sensor and that of the Diviner2000 portable soil moisture monitoring system was higher than 0.85, with a relative error smaller than 5%. The R(2) between measured values and inversed soil moisture values for other soil layers were consistently higher than 0.8. According to calibration test and field test, this sensor, which features low cost, good operability, and high integration, is qualified for precise agricultural irrigation with stable performance and high accuracy.
format Online
Article
Text
id pubmed-5981356
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-59813562018-06-05 Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers Gao, Zhenran Zhu, Yan Liu, Cheng Qian, Hongzhou Cao, Weixing Ni, Jun Sensors (Basel) Article To meet the demand of intelligent irrigation for accurate moisture sensing in the soil vertical profile, a soil profile moisture sensor was designed based on the principle of high-frequency capacitance. The sensor consists of five groups of sensing probes, a data processor, and some accessory components. Low-resistivity copper rings were used as components of the sensing probes. Composable simulation of the sensor’s sensing probes was carried out using a high-frequency structure simulator. According to the effective radiation range of electric field intensity, width and spacing of copper ring were set to 30 mm and 40 mm, respectively. A parallel resonance circuit of voltage-controlled oscillator and high-frequency inductance-capacitance (LC) was designed for signal frequency division and conditioning. A data processor was used to process moisture-related frequency signals for soil profile moisture sensing. The sensor was able to detect real-time soil moisture at the depths of 20, 30, and 50 cm and conduct online inversion of moisture in the soil layer between 0–100 cm. According to the calibration results, the degree of fitting (R(2)) between the sensor’s measuring frequency and the volumetric moisture content of soil sample was 0.99 and the relative error of the sensor consistency test was 0–1.17%. Field tests in different loam soils showed that measured soil moisture from our sensor reproduced the observed soil moisture dynamic well, with an R(2) of 0.96 and a root mean square error of 0.04. In a sensor accuracy test, the R(2) between the measured value of the proposed sensor and that of the Diviner2000 portable soil moisture monitoring system was higher than 0.85, with a relative error smaller than 5%. The R(2) between measured values and inversed soil moisture values for other soil layers were consistently higher than 0.8. According to calibration test and field test, this sensor, which features low cost, good operability, and high integration, is qualified for precise agricultural irrigation with stable performance and high accuracy. MDPI 2018-05-21 /pmc/articles/PMC5981356/ /pubmed/29883420 http://dx.doi.org/10.3390/s18051648 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Gao, Zhenran
Zhu, Yan
Liu, Cheng
Qian, Hongzhou
Cao, Weixing
Ni, Jun
Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers
title Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers
title_full Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers
title_fullStr Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers
title_full_unstemmed Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers
title_short Design and Test of a Soil Profile Moisture Sensor Based on Sensitive Soil Layers
title_sort design and test of a soil profile moisture sensor based on sensitive soil layers
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5981356/
https://www.ncbi.nlm.nih.gov/pubmed/29883420
http://dx.doi.org/10.3390/s18051648
work_keys_str_mv AT gaozhenran designandtestofasoilprofilemoisturesensorbasedonsensitivesoillayers
AT zhuyan designandtestofasoilprofilemoisturesensorbasedonsensitivesoillayers
AT liucheng designandtestofasoilprofilemoisturesensorbasedonsensitivesoillayers
AT qianhongzhou designandtestofasoilprofilemoisturesensorbasedonsensitivesoillayers
AT caoweixing designandtestofasoilprofilemoisturesensorbasedonsensitivesoillayers
AT nijun designandtestofasoilprofilemoisturesensorbasedonsensitivesoillayers