scholarly journals DESENVOLVIMENTO DE SENSOR DE UMIDADE DO SOLO UTILIZANDO O PRINCÍPIO DA RESISTÊNCIA ELÉTRICA

Irriga ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 29-41
Author(s):  
Francisco Aécio de Lima Pereira ◽  
José Francismar de Medeiros ◽  
Nildo da Silva Dias ◽  
Francisco Vanies da Silva Sá ◽  
Suedêmio de Lima Silva ◽  
...  

DESENVOLVIMENTO DE SENSOR DE UMIDADE DO SOLO UTILIZANDO O PRINCÍPIO DA RESISTÊNCIA ELÉTRICA     FRANCISCO AÉCIO DE LIMA PEREIRA1; JOSÉ FRANCISMAR DE MEDEIROS2; NILDO DA SILVA DIAS2; FRANCISCO VANIES DA SILVA SÁ2; SUEDÊMIO DE LIMA SILVA3 E MIGUEL FERREIRA NETO2   1Departamento de Ciência e Tecnologia, Universidade Federal Rural do Semi-Árido, Campus Caraúbas, (Avenida Universitária Leto Fernandes, Sítio Esperança II, CEP: 59780-000, Caraúbas/RN – Brasil), [email protected]. 2Centro de Ciências Agrárias, Universidade Federal Rural do Semi-Árido, Campus Mossoró (Av. Francisco Mota, 572, Bairro Costa e Silva, CEP: 59.625-900, Mossoró/RN, Brasil), [email protected]; [email protected]; [email protected]; [email protected] 3Centro de Engenharias, Universidade Federal Rural do Semi-Árido, Campus Mossoró (Av. Francisco Mota, 572, Bairro Costa e Silva, CEP: 59.625-900, Mossoró/RN, Brasil), [email protected]     1 RESUMO   A determinação do teor de água do solo é usada para decisões de manejo de irrigação. Com isso, objetivou-se avaliar tipos de eletrodos e materiais de enchimento e encapsulamento no desempenho de sensores de umidade do solo. Com base no princípio da resistência elétrica, diferentes sensores foram confeccionados e avaliados em um delineamento de blocos casualizados em esquema fatorial de 2 x 5, com dois eletrodos (20 x 5 e 15 x 5 mm) e cinco materiais de enchimento e encapsulamento (areia grossa + gesso com 30% pó de mármore, areia fina + gesso com 30% pó de mármore, lã de vidro + gesso com 30% pó de mármore, areia fina + gesso com 30% areia fina e areia grossa + gesso com 30% areia fina), com quatro repetições. Os resultados indicaram que os eletrodos de anéis concêntricos de tela de inox fixados com resina de poliéster mantêm uniforme as leituras de condutividade elétrica na medição da tensão da água no solo. Os eletrodos de 20 x 5 preenchidos com areia fina e encapsulado com gesso + pó de mármore foram mais sensíveis às baixas tensões e com leituras mais precisas da umidade do solo.   Palavras-chave: agricultura de precisão, eficiência do uso da água, manejo da irrigação.     PEREIRA, J. A. L; MEDEIROS, J. F.; DIAS, N. S.; SÁ, F. V. S.; SILVA, S. L.; FERREIRA NETO, M. DEVELOPMENT OF SOIL MOISTURE SENSOR USING THE PRINCIPLE OF ELECTRIC RESISTANCE     2 ABSTRACT   The determination of soil water content is used for irrigation planning decisions. This study aimed to evaluate electrode types and filling and encapsulation materials on the performance of soil moisture sensors. Based on the principle of electric resistance, different sensors were made and evaluated in a randomized block design in a 2 x 5 factorial scheme with two electrodes (20 x 5 and 15 x 5 mm) and five filling and encapsulation materials (coarse sand + gypsum with 30% marble powder, 30% fine sand + 30% marble sand, 30% sand and gypsum with 30% sand) with four replicates. The results indicated that the concentric stainless steel mesh ring electrodes fixed with polyester resin keep the electrical conductivity readings uniform in the measurement of soil water tension. The 20 x 5 electrode filled with fine sand and encapsulated with gypsum + marble powder were more sensitive to low voltages and with more accurate readings of soil moisture.   Keywords: precision agriculture, water use efficiency, irrigation management.

2016 ◽  
Vol 37 (3) ◽  
pp. 1189
Author(s):  
Karen Marcelle de Jesus Silva ◽  
Ignacio Aspiazú ◽  
Arley Fiqueiredo Portugal ◽  
Renato Mendes de Oliveira ◽  
Polyanna Mara de Oliveira ◽  
...  

Culturing of sweet sorghum is being considered as an excellent option for ethanol production, from an agronomical and industrial point of view. At present, information regarding the best soil water tension for beginning sweet sorghum irrigation is not available; hence, this study aimed to determine the adequate soil water tension under field conditions for beginning irrigation of four cultivars of sorghum. Two experiments were conducted at Nova Porteirinha, MG, in a randomized block design with sub-subdivided plots having four replications. Each experiment comprised six treatments of soil water tension (plots)-20, 40, 60, 80, 100, and 120 kPa-for resuming sweet sorghum irrigation, and four sweet sorghum cultivars (subplots)-BRS 508, BRS 509, BRS 511, and CMSXS647. After planting, the soil water level in the plots was elevated to field capacity (10 kPa), and then the treatments were applied. During treatment application, irrigation was resumed when the soil water tension reached the limit established in order to elevate the soil water tension to 10 kPa. The amount of water replaced during each irrigation was determined by generating a soil water retention curve for the experimental area. The following parameters were evaluated: green mass production, juice volume, soluble solids (Brix), and tons of Brix per hectare (TBH). The different soil water tensions and cultivars, agricultural year, and interaction between tension and year significantly affected (p ? 0.05) the characteristics evaluated, according to the F test. The agronomical characteristics of the evaluated cultivars showed linear relationship with water supply in the soil. According to TBH, irrigation of sweet sorghum needs to be performed when the soil tension reaches 20 kPa. The TBH values did not differ significantly among the four cultivars at the 5% significance level according to Tukey test.


Author(s):  
Gleice A. de Assis ◽  
Myriane S. Scalco ◽  
Rubens J. Guimarães ◽  
Alberto Colombo ◽  
Anderson W. Dominghetti ◽  
...  

Irrigation associated to reduction on planting spaces between rows and between coffee plants has been a featured practice in coffee cultivation. The objective of the present study was to assess, over a period of five consecutive years, influence of different irrigation management regimes and planting densities on growth and bean yield of Coffea arabica L.. The treatments consisted of four irrigation regimes: climatologic water balance, irrigation when the soil water tension reached values close to 20 and 60 kPa; and a control that was not irrigated. The treatments were distributed randomly in five planting densities: 2,500, 3,333, 5,000, 10,000 and 20,000 plants ha-1. A split-plot in randomized block design was used with four replications. Irrigation promoted better growth of coffee plants and increased yield that varied in function of the plant density per area. For densities from 10,000 to 20,000 plants ha-1, regardless of the used irrigation management, mean yield increases were over 49.6% compared to the non-irrigated crop.


Author(s):  
A. Wahab ◽  
H. Talleyrand ◽  
M. A. Lugo-López

Grain and stover yields of RS 671 grain sorghum were measured at Barranquitas in an Oxisol and at Corozal in an Ultisol. Measurements were made of weather factors, soil moisture content and tension, plant growth, water deficits and rooting depths. At each site a plot was irrigated as often as necessary to maintain a soil water tension of less than 1 bar. Nonirrigated plots at Corozal were watered whenever necessary to prevent plants from wilting permanently. During a prolonged drought and at grain filling, sorghum extracted water in the Oxisol to a depth of 120 cm. Plants became water stressed after the soil water tension at a depth of 90 cm reached 15 bars. In the Ultisol, sorghum plants were unable to effectively extract available soil moisture at depths below 45 cm. Both plant growth and grain yield were greater in the Oxisol than in the Ultisol. The relative soil compaction of the Ultisol was greater than that of the Oxisol.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2761
Author(s):  
Misheck Musokwa ◽  
Paramu L. Mafongoya ◽  
Paxie W. Chirwa

Maize production under smallholder systems in South Africa (RSA) depends on rainfall. Incidences of dry spells throughout the growing season have affected maize yields negatively. The study examined water distribution and water use efficiency (WUE) of maize rotated with two-year pigeonpea fallows as compared to continuous maize without fertilizer. A randomized complete block design, replicated three times, was used with four treatments, which included continuous unfertilized maize, natural fallow-maize, pigeonpea + grass-pigeonpea-maize, and two-year pigeonpea fallow-maize. Soil water mark sensors were installed 0.2; 0.5; and 1.2 m on each plot to monitor soil water tension (kPa). Soil samples were analyzed using pressure plates to determine water retention curves which were used to convert soil water tension to volumetric water content. Maize rotated with two-year pigeonpea fallows had higher dry matter yield (11,661 kg ha−1) and WUE (20.78 kg mm−1) than continuous maize (5314 kg ha−1 and 9.48 kg mm−1). In this era of water scarcity and drought incidences caused by climate change, maize rotated with pigeonpea fallows is recommended among smallholder farmers in RSA because of its higher WUE, hence food security will be guaranteed.


1989 ◽  
Vol 19 (5) ◽  
pp. 575-579
Author(s):  
Marcel Prévost ◽  
Jean Stein ◽  
André P. Plamondon

A soil water budget was established to estimate the water loss from the 0- to 60-cm layer as a result of evapotranspiration in a forest tree nursery. Estimated evapotranspiration totaled 69% of potential evapotranspiration (as estimated by the Penman equation) for 36 selected periods from May 15 to July 30, 1975. The root zone (0- to 15-cm layer) supplied 58% of the total evapotranspired water from the soil profile. Evapotranspiration from this layer was found to be a good predictor of total water loss. Evapotranspiration from the root zone, expressed as a percentage of potential evapotranspiration, was related to soil water tension at 3 cm depth. This relationship, combined with a knowledge of soil hydrodynamic properties, can be used to estimate evapotranspiration from the 0- to 60-cm soil profile, which in turn can be used to predict irrigation needs. For practical purposes, a relationship using net radiation instead of potential evapotranspiration can also be used. Depending on the available information, either of these two relationships may be used for irrigation planning.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Elisha Otieno Gogo ◽  
Annah Wanjala Mnyika ◽  
Simon Muti Mbuvi

Production of eggplant (Solanum melongena L.) is influenced by limited soil water and fertility conditions that affect its growth and yield. The use of superabsorbent polymer (SAP), also known as slush powder and rabbit manure are among the strategies that can improve soil conditions, hence growth and yield of crops. The objective of the study was to evaluate the effects of SAP and rabbit manure on soil moisture, growth and yield of eggplant. The study was conducted at Pwani University, Kilifi, Kenya. A randomized complete block design with three replications was used. The treatments were SAP, rabbit manure, SAP plus rabbit manure and control (without SAP or rabbit manure). Soil moisture, growth and yield parameters were determined. Superabsorbent polymer and/or rabbit manure improved soil moisture, growth and yield of eggplant compared with the control. Use of SAP had a better soil moisture retention, growth and yield comparable to SAP combined with rabbit manure. The finding demonstrates that use of SAP and/or rabbit manure may help in better soil water and nutrient management particularly in arid and semi-arid areas to improve growth and yield of eggplant.


2020 ◽  
Author(s):  
Sofia Melo Vasconcellos ◽  
Masato Kobiyama ◽  
Aline de Almeida Mota

Abstract. The objective of the present study was to determine the spatial behaviour of the Soil Water Index (SWI) by applying a distributed version of the Tank Model (D-Tank Model) to the Araponga river basin (5.26 ha) in southern Brazil and to verify its reliability through the comparison to soil moisture estimated with the measured water-tension values and the water retention curve. The study area has a monitoring system for rainfall, discharge (5-min interval), and soil-water tension (10-min interval). The simulation results showed that the D-Tank Model has a reliable performance. The correlation between SWI and HAND was reasonable (r = 0.6) meanwhile that between SWI and the Topographic Wetness Index was high (r = 0.88). The comparison between the spatially distributed values of the SWI and soil moisture confirmed the high potential of the SWI derived from the D-Tank Model to be applied for predictions related to hydrological and environmental sciences.


Irriga ◽  
2011 ◽  
Vol 16 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Marcio José De Santana ◽  
Uander Da Costa Pereira ◽  
José Daniel Cambraia Beirigo ◽  
Stefany Silva De Souza ◽  
Talita Mendes Campos ◽  
...  

1 RESUMO Um dos métodos de manejo da irrigação mais utilizado é o tanque classe A, necessitando dos valores dos coeficientes de cultura para cálculo da evapotranspiração. O objetivo deste trabalho foi determinar os coeficientes de cultura (Kc) do tomateiro irrigado para a região de Uberaba, MG. Os dados do balanço de água no solo foram obtidos em uma área experimental com a cultura em tratamentos envolvendo níveis de reposição de água no solo (40%, 70%, 100%, 130%, 160% e 190% da lâmina necessária para elevar a umidade do solo para a condição equivalente à capacidade de campo). Os dados de tensão de água no solo foram coletados nas parcelas de 100% de reposição. A evapotranspiração de referência foi obtida pelo método do tanque classe A e a evapotranspiração da cultura por meio do balanço da água no solo. Concluiu-se que os valores de Kc para as fases inicial, desenvolvimento, intermediário, final e colheita foram, respectivamente, de 0,37; 0,72; 1,03; 1,10 e 0,75. UNITERMOS: Lycopersicon esculentum L., coeficiente de cultura, déficit hídrico.  SANTANA, M.J.; PEREIRA, U.C.; BEIRIGO, J.D.C.; SOUZA, S.S.; CAMPOS, T.M.;VIEIRA, T.A. CROP COEFFICIENT FOR IRRIGATED TOMATO  2 ABSTRACT One of the most utilized irrigation management methods is the class A Pan, which requires crop coefficients to estimate crop evapotranspiration. The objective of this work was to determine crop coefficients  (Kc) of irrigated tomato in the region of Uberaba, MG. Soil water balance data were obtained in an experimental area with the culture under six levels of soil water replacement (40%, 70%, 100%, 130%, 160% and 190% of the depth necessary to raise the soil moisture to the field capacity condition). The soil water tension data were collected in plots of 100% replacement. The reference evapotranspiration was obtained by the class A Pan method and culture evapotranspiration was obtained utilizing soil water balance. Kc values for the initial, development, intermediate, final, and harvest phases were respectively of  0.37; 0.72; 1.03; 1.10 and 0.75. KEY- WORDS: LycopersiconesculentumL., crop coefficient, water deficit.


2020 ◽  
Author(s):  
Vassilios Pisinaras ◽  
Cosimo Brogi ◽  
Heye Bogena ◽  
Harrie-Jan Hendricks-Franssen ◽  
Olga Dombrowski ◽  
...  

<p>The H2020 ATLAS project (www.atlas-h2020.eu/) aims to develop an open, flexible and distributed platform that will provide services for the agricultural sector based on the seamless interconnection of sensors and machines. Two interconnected services that will be included in the platform are the soil moisture monitoring and the irrigation management services. The soil moisture monitoring service will integrate both invasive (wireless sensor network (SoilNet)) and non-invasive soil moisture monitoring methods (cosmic-ray neutron sensors (CRNS)). Ultimately, a model will be developed that combines SoilNet and CRNS measurements to predict soil moisture time series. Soil water potential sensors will be incorporated as well.</p><p>Data provided by the above described service will be incorporated in an irrigation management service which will be based on hydrological modelling. The fully distributed, deterministic Community Land Model (CLM, version 5) will be applied which incorporates physically-based simulation of soil water balance and crop growth. Two different levels of application will be considered, namely the farm and watershed scale, which will be combined to weather forecast in order to provide irrigation scheduling advice. The farm scale application will take advantage of soil moisture monitoring data and provide farm specific irrigation scheduling, while the watershed scale application will provide a more generic irrigation advice based on the average cultivation practices. Furthermore, the CLM model will be coupled to a groundwater flow model in order to connect irrigation to groundwater availability. By doing so, it will be possible to support the efficient and sustainable groundwater management as well as competent water uses in an area that suffers from water scarcity.</p><p>These services will be implemented in the area of Pinios Hydrologic Observatory, located in central Greece. Three pilot orchards will be established introducing different soil moisture monitoring setups, while the boundaries of the Observatory will be used for the pilot implementation of irrigation management service on the watershed scale. Furthermore, two pilot vineyards located in northern Greece will be established in order to further test the services functionality on the farm scale.</p>


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