scholarly journals METODOLOGIA PARA AVALIAÇÃO DA SALINIDADE DO SOLO EM AMBIENTE PROTEGIDO

Irriga ◽  
2009 ◽  
Vol 14 (3) ◽  
pp. 383-397 ◽  
Author(s):  
Sergio Oliveira Pinto de Queiroz ◽  
Roberto Testezlaf ◽  
Edson Eiji Matsura

METODOLOGIA PARA AVALIAÇÃO DA SALINIDADE DO SOLO EM AMBIENTE PROTEGIDO  Sérgio Oliveira Pinto de Queiroz1; Roberto Testezlaf2; Edson Eiji Matsura21Departamento de Tecnologia e Ciências Sociais, Universidade do Estado da Bahia, Juazeiro, BA,  [email protected]. 2Faculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas, SP  1 RESUMO Em condições de ambiente protegido a irrigação é essencial e a fertirrigação um agente facilitador do manejo da água e fertilização do solo; todavia, o uso contínuo e nem sempre adequado pode elevar a salinidade do solo, comprometendo o processo produtivo. Este trabalho objetivou avaliar uma metodologia para caracterizar a ocorrência de salinização em cultivos protegidos, usando diferentes métodos para determinação da condutividade elétrica do solo. Em laboratório foram avaliados os equipamentos Sensor Sigma Probe EC1, da Delta-T e extratores de solução do solo à vácuo. Os equipamentos foram utilizados em três solos com diferentes texturas e sob cinco níveis de salinidade: 0, 2, 4, 8 e 12 dS. m-1 a 25° C. Os resultados obtidos pelos métodos avaliados foram comparados ao método do extrato de saturação. O equipamento Sigma Probe EC1, por apresentar melhor correlação com o método de referência na fase laboratorial, foi utilizado nas visitas as propriedades, sob produção em ambiente protegido, na macrorregião de Campinas, revelou ser mais eficiente. A aplicação do questionário associada às leituras de condutividade elétrica do solo com o sensor Sigma Probe permitiu diagnosticar a deficiência no manejo da água e condutividade elétrica nas propriedades avaliadas. Os valores obtidos de condutividade elétrica no extrato de saturação do solo para as propriedades visitadas, não caracterizam solos salinos, mas podem afetar a produção de flores e outras plantas sensíveis à salinidade. UNITERMOS: manejo da irrigação; fertirrigação.  QUEIROZ, S. O. P. de.; TESTEZLAF, R.; MATSURA, E. E. METHODOLOGY FOR SOIL SALINITY EVALUATION IN GREENHOUSE  2 ABSTRACT Under controlled environmental conditions, irrigation is essential and the use of fertigation becomes a facilitator agent for water and fertilization management. However, the intensive use of fertigation in this type of productive process can increase soil salinity, and affect productive process. This work objective was to evaluate a methodology in order to characterize the salinization process occurrence of in greenhouse farms using different methods to determine soil electric conductivity l. Sigma Probe EC1, manufactured by Delta-T and vacuum solution manufactured extractors were evaluated under laboratory conditions. The equipment was used in three different soil textures, under five salinity levels: 0, 2, 4, 8 and 12 dS. m-1 at 25° C. The obtained results of electric conductivity were compared to the saturation extract method. The Sigma Probe EC1 equipment was used in farm visits, with controlled environmental production inCampinas macro region. Among the used equipment in the laboratorial part, the sigma Probe EC1 presented the best results for soil electrical conductivity determination, when compared to saturation extract, in saline and non saline soils. Using the questionnaire for electric conductivity determinations using Sigma Probe sensor it was possible to verify the deficiency in the soil moisture and electrical conductivity management. The obtained results for electric conductivity using the saturation extract methods do not characterize saline soils on the visited farms, but they showed that the salinity levels in the soil could affect flower production and other crops sensitive to salinity. KEYWORDS: irrigation management, fertigation.

Irriga ◽  
2005 ◽  
Vol 10 (3) ◽  
pp. 279-287 ◽  
Author(s):  
Sérgio Oliveira Pinto de Queiroz ◽  
Roberto Testezlaf ◽  
Edson Eiji Matsura

AVALIAÇÃO DE EQUIPAMENTOS PARA DETERMINAÇÃO DA CONDUTIVIDADE ELÉTRICA DO SOLO.  Sérgio Oliveira Pinto De Queiroz1; Roberto Testezlaf2; Edson Eiji Matsura21Departamento de Tecnologia e Ciências Sociais, Universidade do Estado da Bahia, Juazeiro, BA, 2Departamento de Água e Solo, Faculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas, SP  1 RESUMOA salinização de solos representa um dos graves problemas da agricultura irrigada. Sob condições de ambiente protegido, a irrigação é essencial e a fertirrigação um agente facilitador do manejo da irrigação e fertilização. Todavia o seu uso intensivo no processo produtivo, acresce ao potencial de salinização da água, aquele inerente aos fertilizantes. O presente trabalho objetivou avaliar diferentes métodos para determinação da condutividade elétrica do solo, quando comparados ao método do extrato de saturação. Em laboratório foram avaliados os equipamentos Sensor Sigma Probe EC1 da Delta-T e extrator de solução à vácuo. Os equipamentos foram utilizados em três solos com diferentes texturas e sob cinco níveis de salinidade: 0, 2, 4, 8 e 12 dS. m-1 a 25° C. Os resultados obtidos foram avaliados  por análise de regressão e variância. Dentre os equipamentos avaliados na fase laboratorial [U1], o sigma Probe EC1 apresentou o melhor resultado na determinação da condutividade elétrica do solo, quando comparado ao extrato de saturação, em solos não salinos e salinos, todavia os resultados obtidos não permitem recomendar o uso dos mesmos para determinação da condutividade elétrica em solos salinos.  UNITERMOS: condutividade elétrica, fertirrigação.  QUEIROZ, S. O. P. de; TESTEZLAF, R.; MATSURA E. E. EVALUATION OF EQUIPMENTS FOR  SOIL  ELECTRIC CONDUCTIVITY DETERMINATION  2 ABSTRACT Soil salinization represents one of the most serious problems of irrigated agriculture. Under controled environmental conditions, irrigation is essential and the use of fertigation becomes a facilitator agent for the irrigation and fertilization management. However, the intensive use of fertigation in this type of productive process increases water salinization potential, which is inherent to the fertilizers. The objective of the present study was to evaluate different methods to determine electric conductivity of the soil, when compared to the saturation extract. Sigma Probe EC1, manufactured by Delta-T, and vacuum solution manufactured extractors were evaluate under laboratory conditions. This equipment was used in three different texture soils, under five levels of salinity: 0, 2, 4, 8 and 12 dS. m-1 at 25° C. The obtained results were evaluated by regression analysis. Among the used equipment in laboratory,  the sigma Probe EC1 presented better results in soil electrical conductivity determination, when compared to saturation extract, in saline and non-saline soils; however the obtained results show that its use is not recommended to determine electric conductivity in saline soils. KEYWORDS: electric conductivity, fertigation.


2020 ◽  
Author(s):  
Maria Catarina Paz ◽  
Mohammad Farzamian ◽  
Ana Marta Paz ◽  
Nádia Luísa Castanheira ◽  
Maria Conceição Gonçalves ◽  
...  

Abstract. Lezíria Grande of Vila Franca de Xira, located in Portugal, is an important agricultural system where soil faces the risk of salinization, being thus prone to desertification and land abandonment. Soil salinity can be assessed over large areas by the following rationale: (1) use of electromagnetic induction (EMI) to measure the soil apparent electrical conductivity (ECa, dS m−1); (2) inversion of ECa to obtain electromagnetic conductivity images (EMCI) which provide the spatial distribution of the soil electrical conductivity (σ, mS m−1); (3) calibration process consisting of a regression between σ and the electrical conductivity of the saturated soil paste extract (ECe, dS m−1), used as a proxy for soil salinity; and (4) conversion of EMCI into salinity maps using the obtained calibration equation. In this study, EMI surveys and soil sampling were carried out between May 2017 and October 2018 at four locations with different salinity levels across the study area of Lezíria de Vila Franca. A previously developed regional calibration was used for predicting ECe from EMCI. This study aims to evaluate the potential of time-lapse EMCI and the regional calibration to predict the spatiotemporal variability of soil salinity in the study area. The results showed that ECe was satisfactorily predicted, with a root mean square error (RMSE) of 3.22 dS m−1 in a range of 52.35 dS m−1 and a coefficient of determination (R2) of 0.89. Results also showed strong concordance with a Lin’s concordance correlation coefficient (CCC) of 0.93, although, ECe was slightly overestimated with a mean error (ME) of −1.30 dS m−1. Soil salinity maps for each location revealed salinity fluctuations related to the input of salts and water either through irrigation, precipitation or groundwater level and salinity. Time-lapse EMCI has proven to be a valid methodology for evaluating the risk of soil salinization, and can further support the evaluation and adoption of proper agricultural management strategies, especially in irrigated areas, where continuous monitoring of soil salinity dynamics is required.


2021 ◽  
Author(s):  
Maria Catarina Paz ◽  
Mohammad Farzamian ◽  
Ana Marta Paz ◽  
Nádia Luísa Castanheira ◽  
Maria Conceição Gonçalves ◽  
...  

<p>Electromagnetic conductivity imaging (EMCI) is a state-of-the-art methodology for soil salinity assessment over large areas. It involves the following rationale: (1) use of the electromagnetic induction (EMI) geophysical technique to measure the soil apparent electrical conductivity (EC<sub>a</sub>, mS m<sup>−1</sup>) over an area; (2) inversion of EC<sub>a</sub> to obtain EMCI, which provides the spatial distribution of the soil electrical conductivity (σ, mS m<sup>−1</sup>); (3) calibration process consisting of a regression between σ and the electrical conductivity of the saturated soil paste extract (EC<sub>e</sub>, dS m<sup>−1</sup>), used as a proxy for soil salinity; and (4) conversion of EMCI into salinity maps using the obtained calibration equation.</p><p>In this study, we applied EMCI and a regional calibration in Lezíria Grande de Vila Franca de Xira, located in Portugal. The study area is an important agricultural system where soil faces the risk of salinization due to climate change, as the level and salinity of groundwater are likely to increase as a result of the rise of the sea water level and consequently of the estuary. These changes can also affect the salinity of the irrigation water which is collected upstream of the estuary.</p><p>EMI surveys and soil sampling were carried out between May 2017 and October 2018 at four locations with different salinity levels across the study area. A regional calibration was developed and its ability to predict EC<sub>e</sub> from EMCI was evaluated. The validation analysis showed that EC<sub>e</sub> was predicted with a root mean square error of 3.14 dS m<sup>−1</sup> in a range of 52.35 dS m<sup>−1</sup>, slightly overestimated (−1.23 dS m<sup>−1</sup>), with a strong Lin’s concordance correlation coefficient of 0.94 and high linearity between measured and predicted data (R<sup>2</sup> = 0.88). It was also observed that the prediction ability of the regional calibration is more influenced by spatial variability of data than temporal variability of data.</p><p>Because of the transient nature of data, it was also possible to perform a preliminary qualitative analysis of soil salinity dynamics in the study area, revealing salinity fluctuations related to the input of salts and water either through irrigation, precipitation, or level and salinity of groundwater.</p>


2021 ◽  
Vol 13 (10) ◽  
pp. 1875
Author(s):  
Wenping Xie ◽  
Jingsong Yang ◽  
Rongjiang Yao ◽  
Xiangping Wang

Soil salt-water dynamics in the Yangtze River Estuary (YRE) is complex and soil salinity is an obstacle to regional agricultural production and the ecological environment in the YRE. Runoff into the sea is reduced during the impoundment period as the result of the water-storing process of the Three Gorges Reservoir (TGR) in the upper reaches of the Yangtze River, which causes serious seawater intrusion. Soil salinity is a problem due to shallow and saline groundwater under serious seawater intrusion in the YRE. In this research, we focused on the temporal variation and spatial distribution characteristics of soil salinity in the YRE using geostatistics combined with proximally sensed information obtained by an electromagnetic induction (EM) survey method in typical years under the impoundment of the TGR. The EM survey with proximal sensing method was applied to perform soil salinity survey in field in the Yangtze River Estuary, allowing quick determination and quantitative assessment of spatial and temporal variation of soil salinity from 2006 to 2017. We developed regional soil salinity survey and mapping by coupling limited laboratory data with proximal sensed data obtained from EM. We interpreted the soil electrical conductivity by constructing a linear model between the apparent electrical conductivity data measured by an EM 38 device and the soil electrical conductivity (EC) of soil samples measured in laboratory. Then, soil electrical conductivity was converted to soil salt content (soil salinity g kg−1) through established linear regression model based on the laboratory data of soil salinity and soil EC. Semivariograms of regional soil salinity in the survey years were fitted and ordinary kriging interpolation was applied in interpolation and mapping of regional soil salinity. The cross-validation results showed that the prediction results were acceptable. The soil salinity distribution under different survey years was presented and the area of salt affected soil was calculated using geostatistics method. The results of spatial distribution of soil salinity showed that soil salinity near the riverbanks and coastlines was higher than that of inland. The spatial distribution of groundwater depth and salinity revealed that shallow groundwater and high groundwater salinity influenced the spatial distribution characteristics of soil salinity. Under long-term impoundment of the Three Gorges Reservoir, the variation of soil salinity in different hydrological years was analyzed. Results showed that the area affected by soil salinity gradually increased in different hydrological year types under the impoundment of the TGR.


2018 ◽  
pp. 41-57 ◽  
Author(s):  
M. V. Konyushkova ◽  
S. Alavipanah ◽  
A. Abdollahi ◽  
S. Hamzeh ◽  
A. Heidari ◽  
...  

The study is focused on the pattern of soil salinity at the young loamy coastal plains of the Caspian Sea in Russia and Iran which were released from water less than 300 years ago. At two key sites of 45×30 m (Russia) and 25×20 m (Iran), the soil sampling with 1 to 5 m grid was performed to the depth of 1 m. The electrical conductivity (1 : 2.5) was measured in soil samples and soil sa-linity maps were compiled. Soils are represented by solonchaks with 2–3% of salts in the top layer or highly saline soils partly leached in the upper 5–10 cm. The ground water table is shallow (2–2.5 m). The studied sites are different in terms of climate, microtopography, and vegetation cover but spatial differentiation of soil salinity is quite similar what is evidenced from the similar distributions (mean values and variance) of electrical conductivity in almost all studied depths. The redistribution of salts is mainly observed in the upper 50 cm with the maximal manifestation in the upper 5 cm.


Author(s):  
Faris Mohammed SUHAIL ◽  
Imad Adnan MAHDI

We carried out two factorial experiments in pots (capacity 4 kg) in order to increase the salt tolerance  of  one  of  our  important  plant -  onion,  using  inoculation  with  mycorrhizal  fungi  (Glomus fasciculatum) and magnetized water under conditions of salinity stress. The first experiment aims the interaction  between  fungus  inoculation  and  four  levels  of  saline  drainage  water  (0.66,  5.0,  7.5,  10.0 ds/m)  and  the  second  experiment  aims  the  interaction  between  the  inoculation  factor  and  the  water magnetic and two soils with different salinity (5.6, 13.4 ds/m). The results showed that the inoculation with  the  mycorrhizal  fungi  led  to  a  significant  increase  in  height,  fresh  weight  and  dry  weight  of onions  to  all  levels  of  salinity  compared  with  no  addition  of  inoculation,  while  led  to  a  significant reduction in electrical conductivity and the percentage of AM colonization of all levels of salts water. The  treatment  with  inoculation  and  magnetized  water  when  the  salinity  was  13.4  ds.m-1  recorded significant  increase  for  plants  height,  fresh  weight  and  dry  weight  (38.46%,  60.0%,  92.30%) respectively compared to the variant without inoculation, only with addition of water non-magnetized at  the  same  soil  salinity.  The  addition  of  mycorrhizal  fungi  (Glomus  fasciculatum)  and  magnetized water impact significant in reducing the electric conductivity (Ec) in soil salinity (13.4 ds/m) while it affects significantly the percentage of AM colonization in both two soils.


1986 ◽  
Vol 66 (2) ◽  
pp. 315-321 ◽  
Author(s):  
N. C. WOLLENHAUPT ◽  
J. L. RICHARDSON ◽  
J. E. FOSS ◽  
E. C. DOLL

This study presents a method for calibrating electromagnetic induction instrument readings with saturated paste electrical conductivity (ECe) for field mapping purposes. Each meter reading represents an integration of the apparent soil electrical conductivity (ECa) over the meter’s response depth. To correlate the meter readings with measured ECe within soil depth increments, several pedons representing a range of soil salinity for the survey area were sampled in 30-cm increments to a depth corresponding to the meter response. A weighting procedure based on the meter response-depth function was developed to condense the multiple ECe by depth measurements into a single weighted area specific value. These values were correlated with the apparent soil electric conductivity from the electromagnetic induction instrument by simple linear regression. This technique is designed for soil association of similar parent materials. The resulting regression equation yields a quick reliable equation that avoids complex mathematics and converts the instrument readings into weighted forms of commonly used saturated paste electrical conductivity values. Key words: Soil survey, electrical resistance


Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 73
Author(s):  
Lorenzo De Carlo ◽  
Gaetano Alessandro Vivaldi ◽  
Maria Clementina Caputo

This paper focused on the use of electromagnetic induction measurements in order to investigate soil salinization caused by irrigation with saline reclaimed water. An experimental activity was carried out during the growing season of tomato crop in order to evaluate expected soil salinization effects caused by different saline agro-industrial wastewaters used as irrigation sources. Soil electrical conductivity, strictly related to the soil salinity, has been monitored for three months by means of Electromagnetic Induction (EMI) measurements, and evident differences in the soil response have been observed. The study highlighted two aspects that can improve soil investigation due to the utilization of geophysical tools. First, EMI data can map large areas in a short period of time with an unprecedented level of detail by overcoming practical difficulties in order to massively sample soil. At the same time, repeated measurements over time allow updating real-time soil salinity maps by using accurate correlations with soil electrical conductivity. This application points out how integrated agro-geophysical research approaches can play a strategic role in agricultural saline water management in order to prevent soil salinization risks in medium to long-term periods.


2018 ◽  
Vol 48 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Valéria Fernandes de Oliveira Sousa ◽  
Caciana Cavalcanti Costa ◽  
Genilson Lima Diniz ◽  
João Batista dos Santos ◽  
Marinês Pereira Bomfim

ABSTRACT Melon is one of the most important vegetables for the Brazilian foreign trade. However, in semi-arid areas, the irregular rainfall, excessive use of fertilizers and, especially, poor quality water contribute to the soil salinization, becoming a limiting factor and damaging the photosynthetic apparatus, as well as affecting yield. This study aimed to evaluate the physiological behavior of melon cultivars submitted to soil salinity. For that, an experiment was conducted in a greenhouse, using a randomized block experimental design, in a 3 x 5 factorial scheme, with the first factor related to melon cultivars (Iracema, Goldex and Natal) and the second one related to soil salinity levels (0.3 dS m-1, 1.3 dS m-1, 2.3 dS m-1, 3.3 dS m-1 and 4.3 dS m-1 of electrical conductivity), with four replications. For soil salinization, a saturation extract with initial soil salinity of 0.3 dS m-1 was obtained, while the other levels were prepared by adding NaCl to the soil. The physiology of melon plants is negatively affected by the increased salinity in the soil. The evaluated cultivars do not show differences in tolerance for the physiological response to soil saline stress.


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