scholarly journals CALIBRAÇÃO DE SONDA CAPACITIVA EM NITOSSOLO VERMELHO LATOSSÓLICO EUTROFÉRRICO CULTIVADO COM FORRAGEIRAS IRRIGADAS

Irriga ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 38-45
Author(s):  
Arthur Carniato Sanches ◽  
Débora Pantojo de Souza ◽  
Fernanda Lamede Ferreira de Jesus ◽  
Rodolfo Guertas Maffei ◽  
Fernando Campos Mendonça ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Sao Paulo ◽  
São Paulo ◽  
Depth Level ◽  
Capacitive Probe ◽  
Probe Calibration ◽  
E Mail

CALIBRAÇÃO DE SONDA CAPACITIVA EM NITOSSOLO VERMELHO LATOSSÓLICO EUTROFÉRRICO CULTIVADO COM FORRAGEIRAS IRRIGADAS   ARTHUR CARNIATO SANCHES1*; DÉBORA PANTOJO DE SOUZA2; FERNANDA LAMEDE FERREIRA DE JESUS3; RODOLFO GUERTAS MAFFEI4; FERNANDO CAMPOS MENDONÇA5 E JOSÉ RICARDO MACEDO PEZZOPANE6   1Professor Doutor, Faculdade de Ciências Agrárias, Universidade Federal da Grande Dourados, Rod. Dourados-Itahum, km 12 – Cidade Universitária, 79804-970, Dourados, MS, Brasil, e-mail: [email protected] 2Doutoranda em Engenharia de Sistemas Agrícolas, Departamento de Engenharia de Biossistemas, ESALQ/USP, Avenida Pádua Dias, 11, 13418-900, Piracicaba, São Paulo, Brasil, e-mail: [email protected] 3Professora Doutora, Departamento de Engenharia Agrícola, Universidade Federal Rural da Amazônia, Campus Tomé-Açu, Rod. PA 140, km 03, 68680-000, Tomé-Açu, PA, Brasil, e-mail: [email protected] 4Graduando em Agronomia, Departamento de Engenharia de Biossistemas, ESALQ/USP, Avenida Pádua Dias, 11, 13418-900, Piracicaba, São Paulo, Brasil, e-mail: [email protected] 5Professor Doutor, Departamento de Engenharia de Biossistemas, ESALQ/USP, Avenida Pádua Dias, 11, 13418-900, Piracicaba, São Paulo, Brasil, e-mail: [email protected]   6Pesquisador, Embrapa Pecuária Sudeste, Rod. Washington Luiz, Km 234 s/nº, 13560-970, São Carlos, SP, Brasil, e-mail: [email protected]        1 RESUMO   O conhecimento do teor de água no solo é importante para o manejo adequado da irrigação, pois permite estimar a quantidade necessária de água a ser aplicada no tempo correto. Sensores de capacitância são uma alternativa de quantificação do teor de água do solo (θ, m3 m-3), provendo leituras em profundidade de forma prática e rápida. Uma sonda capacitiva foi calibrada em um Nitossolo vermelho Eutroférrico Latossólico cultivado com forrageiras tropicais na área experimental da ESALQ/USP na cidade de Piracicaba (SP), Brasil. Quatro tubos de acesso foram instalados e, a cada duas semanas, foram coletadas amostras com três repetições para cada nível de profundidade, até o final de oito semanas, partindo do θsaturado. Efetuaram-se leituras com o equipamento para cada 0,1 m de solo até 0,7 m de profundidade, juntamente com a coleta das amostras de solo para a determinação de θ em laboratório. Uma equação de potência foi desenvolvida para cada profundidade estudada, como também para todo o perfil do solo. A curva geral de calibração proposta (SF = 0,256*θatual0,3422), ajustada por análise de regressão, foi significativamente relacionada às medidas do equipamento, com alta correlação (r2 = 0,87) e erro-padrão de 0,022 cm3 cm-3. A calibração para cada profundidade tem mostrado maiores coeficientes de correlação nas profundidades menores, minimizando o erro dasestimativas. A calibração feita no local permitiu melhor acurácia do monitoramento da água no solo e assim, proporcionar um melhor manejo da irrigação.   Palavras-chave: sensor, manejo da irrigação, umidade do solo, reflectometria no domínio da frequência.           SANCHES, A. C.; DE SOUZA, D. P.; DE JESUS, F. L. F.; MAFFEI, R. G.; MENDONÇA, F. C.; PEZZOPANE, J. R. M. CAPACITIVE PROBE CALIBRATION IN EUTROFERRIC LATOSOL RED NITOSOL CULTIVATED WITH IRRIGATED FORAGES     2 ABSTRACT   Knowledge of soil water content is important for proper irrigation management because it allows estimating the required amount of water to be applied at the correct time. Capacitance sensors are an alternative for quantification of soil water content (θ, cm3 cm-3), providing depth readings in a practical and fast way. A capacitive probe was calibrated in a Eutroferric Red Nitosol cultivated with irrigated forages at the experimental area of ESALQ/USP in the city of Piracicaba - SP, Brazil. Four access tubes were installed and every 2 weeks samples were collected with 3 replicates for each depth level, for 8 weeks starting from θsaturated. Readings were taken with the equipment for every 0.1 m of soil up to 0.7 m of depth, together with the collection of soil samples for the determination of θ in laboratory. A power equation was developed for each depth studied as well as for the whole soil profile. The proposed general calibration curve (SF = 0.256*θcurrent0.3422), adjusted by regression analysis, was significantly related to the measurements of the equipment, with high correlation (r2 = 0.87), and standard error of 0.022 cm3 cm-3. The calibration for each depth has shown higher correlation coefficients at lower depths, minimizing the error of estimates. On-site calibration allowed better accuracy of soil water monitoring and, thus, better irrigation management.   Keywords: sensor, irrigation management, soil moisture, frequency domain reflectometry.

scholarly journals COMPARAÇÃO ENTRE CURVAS DE RETENÇÃO DE ÁGUA OBTIDAS EM LABORATÓRIO E A CAMPO

Irriga ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 125-142
Author(s):  
Rafael Gotardo ◽  
Adilson Pinheiro ◽  
Vander Kaufmann ◽  
Gustavo Antonio Piazza ◽  
Edson Torres
Keyword(s):  
Linear Regression ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Field Measurements ◽  
Sao Paulo ◽  
Time Domain Reflectometry ◽  
Native Forest ◽  
São Paulo ◽  
Land Uses

COMPARAÇÃO ENTRE CURVAS DE RETENÇÃO DE ÁGUA OBTIDAS EM LABORATÓRIO E A CAMPO     RAFAEL GOTARDO1; ADILSON PINHEIRO2; VANDER KAUFMANN3; GUSTAVO ANTONIO PIAZZA4 E EDSON TORRES5   1Eng. Agrônomo, Doutor, Programa de Pós-Graduação em Engenharia Ambiental (PPGEA), Fundação Universidade Regional de Blumenau (FURB), Rua São Paulo, n° 3250, Itoupava Norte, Blumenau-SC, Brasil,  [email protected]. 2Eng. Civil, Doutor, Programa de Pós-Graduação em Engenharia Ambiental (PPGEA), Fundação Universidade Regional de Blumenau (FURB), Rua São Paulo, n° 3250, Itoupava Norte, Blumenau-SC, Brasil. [email protected]. 3Químico, Biólogo, Doutor, Programa de Pós-Graduação em Engenharia Ambiental (PPGEA), Fundação Universidade Regional de Blumenau (FURB), Rua São Paulo, n° 3250, Itoupava Norte, Blumenau-SC, Brasil. [email protected]. 4Eng. Ambiental, Doutor, Programa de Pós-Graduação em Engenharia Ambiental (PPGEA), Fundação Universidade Regional de Blumenau (FURB), Rua São Paulo, n° 3250, Itoupava Norte, Blumenau-SC, Brasil. [email protected]. 5Químico, Mestre, Departamento de Engenharia Ambiental, Fundação Universidade Regional de Blumenau (FURB), Rua São Paulo, n° 3250, Itoupava Norte, Blumenau-SC, Brasil. [email protected].     1 RESUMO   O objetivo do estudo foi comparar dados do conteúdo de água do solo obtidos por técnicas laboratoriais (Extrator de Pressão de Richards) e por técnicas de determinação em campo (tensiômetros e TDR) em diferentes usos do solo. Os usos do solo estudados foram: agricultura, floresta nativa (Bioma Mata Atlântica), reflorestamento e pastagem. O conteúdo de água no solo determinado pelas curvas de retenção foi menor na camada superficial do solo, com aumento gradativo em relação a profundidade. Com o TDR, os valores do conteúdo de água alternaram nas profundidades e para os diferentes usos. Este resultado foi associado ao fato de que curvas de retenção ficam restritas a pressões máximas de 916 kPa em períodos de restrição hídrica. O método de Richards subestimou os valores de umidade nas áreas de agricultura, pastagem, reflorestamento, e superestimou os valores na área de floresta. O método de Richards também apresentou ineficiência na saturação (θs) das amostras e no equilíbrio hidráulico da umidade residual (θr). Apesar de alguns valores terem sido subestimados, a regressão linear do conteúdo médio de água no perfil do solo obtido pelos diferentes métodos apresentou correlação positiva para as áreas de agricultura e floresta e baixa correlação para as áreas de pastagem e reflorestamento. Estes resultados foram confirmados na regressão linear da variação diária de armazenamento de água ao longo do perfil.   Palavras-chave: Reflectometria no Domínio do Tempo (TDR), Richards, tensiometria.     GOTARDO, R.; PINHEIRO, P.; KAUFMANN, V.; PIAZZA, G. A.; TORRES, E. COMPARISON OF WATER RETENTION CURVES OBTAINED IN LABORATORY AND FIELD MEASUREMENTS       2 ABSTRACT   The aim of this study was to compare soil water content data obtained by laboratory techniques (Richards Pressure Extractor) and field measurements (tensiometers and TDR) in different land uses. The land uses analyzed in this study were agriculture, native forest (Atlantic Forest), reforestation and pasture. The soil water content determined by the retention curve was lower in the soil surface with  gradual increase in dept. With TDR, the values of water content​ ​alternated in depths and for different uses. This result was associated to the fact that retention curves are restricted to maximum pressures of 916 kPa in periods of water restriction. Richards’ method underestimated moisture values ​​in agriculture, pasture and reforestation areas, and overestimated these values ​​in  forest area.  Richards’ method also showed inefficiency to calculate  saturation of  samples (θs) and hydraulic balance of residual moisture (θr). Despite the underestimation, the linear regression of  average water content in the soil profile obtained by these methods showed a positive correlation for agriculture and forestry, and negative to pasture and reforestation. These results were confirmed by the linear regression of daily variation water storage along the profile.   Keywords: Time Domain Reflectometry (TDR), Richards, tensiometers.  

Time series outlier and intervention analysis: Irrigation management influences on soil water content in silty loam soil

2012 ◽  
Vol 111 ◽  
pp. 105-114 ◽  
Author(s):  
Basem Aljoumani ◽  
Jose A. Sànchez-Espigares ◽  
Nuria Cañameras ◽  
Ramon Josa ◽  
Joaquim Monserrat
Keyword(s):  
Time Series ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Intervention Analysis ◽  
Silty Loam ◽  
Loam Soil

Laboratory and field evaluation of five soil water sensors

2004 ◽  
Vol 84 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Q. Huang ◽  
O. O. Akinremi ◽  
R. Sri Rajan ◽  
P. Bullock
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Field Evaluation ◽  
Soil Bulk Density ◽  
Laboratory Evaluation ◽  
Engineering Sciences ◽  
Probe Calibration

Accurate in situ determination of soil water content is important in many fields of agricultural, environmental, hydrological, and engineering sciences. As numerous soil water content sensors are available on the market today, the knowledge of their performance will aid users in the selection of appropriate sensors. The objectives of this study were to evaluate five soil water sensors in the laboratory and to determine if laboratory calibration is appropriate for the field. In this study, the performances of five sensors, including the Profile Probe™ (PP), ThetaProbe™ , Watermark™, Aqua-Tel™, and Aquaterr™ were compared in the laboratory. The PP and ThetaProbe™ were more accurate than the other soil water sensors, reproducing soil water content using factory recommended parameters. However, when PP was installed on a loamy sand in the field, the same soil that was used for the laboratory evaluation, it overestimated field soil water, especially at depth. Another laboratory experiment showed that soil water content readings from the PP were strongly influenced by soil bulk density. The higher the soil bulk density, the greater was the overestimation of soil water content. Two regression parameters, a0 and a1, which are used to convert the apparent dielectric constant to volumetric water content, were found to increase linearly with the soil bulk density in the range of 1.2 to 1.6 Mg m-3. Finally, the PP was calibrated in the field and a good calibration function was obtained with an r2 of 0.87 and RMSE of 2.7%. The values of a0 and a1 obtained in the field were different from factory recommended parameters (a0 = 2.4 versus 1.6 while a1 = 12.5 versus 8.4) and were independent of soil depth, bulk density, and texture. As such, individual field calibration will be necessary to obtain precise and accurate measurement of soil water content with this instrument. Key words: Soil water content, Profile Probe, calibration, soil water content sensor

scholarly journals Evaluation of Improved Model to Accurately Monitor Soil Water Content

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3441
Author(s):  
Jingyu Ji ◽  
Junzeng Xu ◽  
Yixin Xiao ◽  
Yajun Luan
Keyword(s):  
Organic Matter ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Texture ◽  
Irrigation Management ◽  
Clay Fraction ◽  
Organic Matter Content ◽  
Matter Content ◽  
Improved Model

The accurate monitoring of soil water content during the growth of crops is of great importance to improve agricultural water use efficiency. The Campbell model is one of the most widely used models for monitoring soil moisture content from soil thermal conductivities in farmland, which always needs to be calibrated due to the lack of adequate original data and the limitation of measurement methods. To precisely predict the water content of complex soils using the Campbell model, this model was evaluated by investigating several factors, including soil texture, bulk density and organic matter. The comparison of the R2 and the reduced Chi-Sqr values, which were calculated by Origin, was conducted to calibrate the Campbell model calculated. In addition, combining factors of parameters, a new parameter named m related to soil texture and the organic matter was firstly introduced and the original fitting parameter, E, was improved to an expression related to clay fraction and the organic matter content in the improved model. The soil data collected from both the laboratory and the previous literature were used to assess the revised model. The results show that most of the R2 values of the improved model are >0.95, and the reduced Chi-Sqr values are <0.01, which presents a better matching performance compared to the original. It is concluded that the improved model provides more accurate monitoring of soil water content for water irrigation management.

scholarly journals Soil water potential during different phenological phases of coffee irrigated by center pivot

2013 ◽  
Vol 33 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Adão W. P. Evangelista ◽  
Luiz A. Lima ◽  
Antônio C. da Silva ◽  
Carla de P. Martins ◽  
Moisés S. Ribeiro
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Soil Water Potential ◽  
Field Capacity ◽  
Limiting Factor ◽  
Center Pivot ◽  
Phenological Phases

Irrigation management can be established, considering the soil water potential, as the limiting factor for plant growth, assuming the soil water content between the field capacity and the permanent wilting point as available water for crops. Thus, the aim of this study was to establish the soil water potential interval during four different phenological phases of coffee irrigated by center pivot. The experiment was set at the experimental area of the Engineering Department at the Federal University of Lavras, in Brazil. The coffee variety planted is designated as Rubi, planted 0.8 meters apart, with rows spaced 3.5 meters apart. The treatments corresponded to the water depths applied based on different percentages of Kc and reference evapotranspiration (ET0) values. Sensors were used to measure the soil water potential interval, installed 25 centimeters depth. In order to compare the results, it was considered as the best matric potential the one that was balanced with the soil water content that resulted in the largest coffee productivity. Based on the obtained results, we verified that in the phases of fruit expansion and ripening, the best results were obtained, before the irrigations, when the soil water potential values reached -35 and -38 kPa, respectively. And in the flowering, small green and fruit expansion phases, when the values reached -31 and -32 kPa, respectively.

Calibration and evaluation of a capacitance probe in agricultural soils in northeast Brazil

2020 ◽  
Author(s):  
Ceres Duarte Guedes Cabral de Almeida ◽  
Lais Barreto Franco ◽  
José Ediclécio Barbosa dos Santos ◽  
Brivaldo Gomes de Almeida ◽  
Giuseppe Provenzano
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Agricultural Soils ◽  
Irrigation Management ◽  
Clay Loam ◽  
Sandy Clay Loam ◽  
Sandy Clay ◽  
Disturbed Soil ◽  
Capacitance Probe

&lt;p&gt;Soil water content is an important parameter for irrigation management. Among the indirect methods to determine soil water content (SWC), there are electronic sensors, that need site-specific calibration to increase the accuracy of the measurements. In this research, a capacitance probe (Diviner 2000&amp;#174;, Sentek Pty Ltda., Australia) was calibrated for two agricultural soils. The experiment was carried out in a protected environment at the Federal Rural University of Pernambuco (UFRPE), Brazil. The textural classes of soils were sandy clay loam (66% sand) and sandy (95% sand). Undisturbed and disturbed soil samples were collected in the soil top layer (0-30 cm). The disturbed soil samples were initially air-dried, passed through a 4.75 mm mesh sieve, and then introduced to fill eight vessels (four replications for each soil). These vessels, equipped with drainage holes, have lower and upper diameters of 15 cm and 25 cm, respectively, and height of 22.5 cm (4.66 L). In each pot, a 5 cm layer of gravel with an average diameter of 2 cm covered with bidim&amp;#174; geotextile was disposed before introducing the soil. During filling, the soil was compacted to reach the same bulk density measured on the undisturbed samples (sandy clay loam: 1.54 g cm&lt;sup&gt;-3&lt;/sup&gt; and sandy: 1.50 g cm&lt;sup&gt;-3&lt;/sup&gt;). In the center of each pot, a PVC access tube was installed. According to the manufacturer's recommendation, during calibration, the probe normalization was performed. The pots were wetted by capillary rise and, once saturated, they were placed on a bench for drainage. After this process stopped each pot was daily weighed at a fixed time (8 a.m.), and the sensor reading was acquired until when the daily mass variations became negligible. Data were used for regression analysis to fit the site-specific calibration equation and to evaluate the mean error. Linear calibration equations, characterized by R&lt;sup&gt;2&lt;/sup&gt;=0.931 and 0.986, were obtained for the sandy clay loam and the sandy soil, respectively. The mean errors (ME) associated with the manufacturer&amp;#8217;s equation resulted in -0.05 and -0.01 for sandy clay loam and for sandy soil and decreased after calibration. The results confirmed the suitability of the manufacturer's equation in sandy soils. On the other hand, the manufacture&amp;#8217;s equation slightly underestimated SWC, in sandy clay loam soil, especially in the range above 0.26 m&lt;sup&gt;3&lt;/sup&gt; m&lt;sup&gt;-3&lt;/sup&gt;. The Diviner 2000 probe can be therefore successfully used to support irrigation management in irrigated areas with soils similar to those investigated because it is easy to operate and allows fairly accurate estimations of soil water content.&lt;/p&gt;

scholarly journals Evaluation of Soil Water Content Measurements with Capacitance Probes to Support Irrigation Scheduling in a “Red Beaut” Japanese Plum Orchard

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1757
Author(s):  
Sandra Millán ◽  
Carlos Campillo ◽  
Antonio Vivas ◽  
María José Moñino ◽  
Maria Henar Prieto
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Irrigation Scheduling ◽  
Successful Implementation ◽  
Stem Water Potential ◽  
Japanese Plum

Advances in electromagnetic sensor technologies in recent years have made automated irrigation scheduling a reality through the use of state-of-the-art soil moisture sensing devices. However, correct sensor positioning and interpretation of the measurements are key to the successful implementation of these management systems. The aim of this study is to establish guidelines for soil moisture sensor placement to support irrigation scheduling, taking into account the physiological response of the plant. The experimental work was carried out in Vegas Bajas del Guadiana (Extremadura, Spain) on a drip-irrigated experimental orchard of the early-maturing Japanese plum cultivar “Red Beaut”. Two irrigation treatments were established: control and drying. The control treatment was scheduled to cover crop water needs. In the drying treatment, the fruit trees were irrigated as in control, except in certain periods (preharvest and postharvest) in which irrigation was suspended (drying cycles). Over 3 years (2015–2017), a series of plant parameters were analyzed in relation to the measurements provided by a battery of frequency domain reflectometry probes installed in different positions with respect to tree and dripper: midday stem water potential (Ψstem), sap flow, leaf stomatal conductance, net leaf photosynthesis and daily fraction of intercepted photosynthetically active radiation. After making a comparison of these measurements as indicators of plant water status, Ψstem was found to be the physiological parameter that detected water stress earliest. The drying cycles were very useful to select the probe positions that provided the best information for irrigation management and to establish a threshold in the different phases of the crop below which detrimental effects could be caused to the crop. With respect to the probes located closest to the drippers, a drop in the relative soil water content (RSWC) below 0.2 would not be advisable for “non-stress” scheduling in the preharvest period. When no deficit irrigation strategies are applied in the postharvest period, the criteria are similar to those of preharvest. However, the probes located between the dripper at 0.15 and 0.30 m depth provide information on moderate water stress if the RSWC values falls below 0.2. The severe tree water stress was detected below 0.1 RSWC in probes located at 60 cm depth from this same position.

Effect of Initial Soil Water Content on Output Parameters of Sirmod Software Under Types of Different Irrigation Management

2019 ◽  
Vol 68 (4) ◽  
pp. 740-752
Author(s):  
Ali Javadi ◽  
Behrouz Mostafazadeh‐Fard ◽  
Mohammad Shayannejad ◽  
Hamed Ebrahimian
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Initial Soil

scholarly journals Correcting Inaccurately Recorded Data due to Faulty Calibration of a Capacitance Water Content Probe

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Mohammad N. ElNesr ◽  
A. A. Alazba ◽  
Mohammad A. El-Farrah
Keyword(s):  
Mathematical Method ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Structure ◽  
Acceptable Accuracy ◽  
Substantial Error ◽  
Recorded Data ◽  
Probe Calibration

Measuring soil water content by capacitance probes requires rigorous calibration to achieve acceptable accuracy. Some of the capacitance probes' users might take several readings using the default device calibrations or other prestored calibrations by mistake. This can lead to logging of faulty readings for periods of up to months or years. This study aimed to (1) study the importance of probe calibration and the level of error that results from using flawed calibrations and (2) to develop a mathematical method to correct the faulty recorded data. This research involved studying eleven scenarios of faulty calibrations including errors in the air/water calibration and in the in-soil calibration. A mathematical method was developed to correct the faulty recorded data and comparisons were made for the data after and before correction. Results indicated that using the manufacturer's default calibration within the software resulted in substantial error values especially for heavy textured soils. It is recommended that users and especially researchers should perform rigorous in-soil calibration wherever the probe is installed, and they should repeat the calibrations whenever the soil structure changed.

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