An Integrated Framework for Optimal Irrigation Planning Under Uncertainty: Application of Soil, Water, Atmosphere and Plant Modeling

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.

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

Irriga ◽

10.15809/irriga.2021v26n1p29-41 ◽

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 ◽

...

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Precision Agriculture ◽

Block Design ◽

Irrigation Management ◽

Fine Sand ◽

Electric Resistance ◽

Irrigation Planning ◽

Soil Water Tension ◽

Marble Powder

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.

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Establishing relationship between measured and predicted soil water characteristics using SOILWAT model in three agro-ecological zones of Nigeria

10.5194/gmd-2016-165 ◽

2016 ◽

Author(s):

OrevaOghene Aliku ◽

Suarau O. Oshunsanya

Keyword(s):

Soil Water ◽

Soil Texture ◽

Irrigation Planning ◽

Ecological Zones ◽

Available Water ◽

Water Characteristics ◽

Permanent Wilting Point ◽

Predicted Values ◽

Wilting Point ◽

Agro Ecological Zones

Abstract. Soil available water (SAW) affects soil nutrients availability and consequently affects crop performance. However, field determination of SAW for effective irrigated farming is laborious, time consuming and expensive. Therefore, experiments were initiated at three agro-ecological zones of Nigeria to compare the measured laboratory and predicted soil available water using SOILWAT model for sustainable irrigated farming. One hundred and eighty soil samples were collected from the three agro-ecological zones (Savannah, Derived savannah and rainforest) of Nigeria and analysed for physical and chemical properties. Soil texture and salinity were imputed into SOILWAT model (version 6.1.52) to predict soil physical properties for the three agro-ecological zones of Nigeria. Measured and predicted values of field capacity, permanent wilting point and soil available water were compared using T-test. Predicted soil textural classes by SOILWAT model were similar to the measured laboratory textural classes for savannah, derived savannah and rainforest zones. However, bulk density, maximum water holding capacity, permanent wilting point and soil available water were poorly predicted as significant (p < 0.05) differences existed between measured and predicted values. Therefore, SOILWAT model could be adopted for predicting soil texture for savannah, derived savannah and rainforest zones of Nigeria. However, the model needs to be upgraded in order to accurately predict soil water characteristics of the aforementioned locations for sustainable irrigation planning.

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Evaluation of the soil water regime of an irrigated maize field

Acta Agronomica Hungarica ◽

10.1556/aagr.53.2005.2.5 ◽

2005 ◽

Vol 53 (2) ◽

pp. 161-175 ◽

Cited By ~ 10

Author(s):

◽

A. Hagyó ◽

E. Tóth ◽

J. Szabó ◽

T. Németh

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Regime ◽

Irrigation Planning ◽

Double Ring ◽

Soil Water Regime ◽

Capacitance Probe ◽

Moisture Conditions ◽

Monitoring Stations

This study was carried out to evaluate the soil hydrophysical properties and soil water regime of two irrigated maize fields in order to support irrigation planning and management. The experimental sites were located in Mezohegyes (MZH) and Hódmezovásárhely (HMV) in SE Hungary. In total 11 monitoring stations were chosen, using information from a previously developed, GIS-based agro-geoinformation system. In 2003 and 2004 soil sampling and in situ measurements were performed to determine the soil hydrophysical properties and soil water content dynamics. The hydraulic conductivity of the topsoil was evaluated from double ring infiltrometer measurements. A previously calibrated TDR 300 instrument and a 3T-M capacitance probe were used for quantifying the soil water content. Both types of equipment were found to require calibration and testing under field conditions before use. It was concluded that the study fields could be considered relatively homogeneous in relation to both soil hydrophysical properties and soil water regime. Thus, monitoring stations established for one or two carefully selected soil profiles could provide enough data to ensure proper decisions on irrigation. The results indicate that the soil management system and irrigation strategy used in the experimental fields ensured satisfactory soil and soil moisture conditions.

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