scholarly journals Soil Salinity and Its Management

2021 ◽  
Author(s):  
Muthuraman Yuvaraj ◽  
Kasiviswanathan Subash Chandra Bose ◽  
Prabakaran Elavarasi ◽  
Eman Tawfik
Keyword(s):  
Soil Fertility ◽  
Toxic Effect ◽  
Water Uptake ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Crop Yields ◽  
Root Zone ◽  
Negative Impact ◽  
Saline Soil ◽  
Negative Effect

Soil salinity is a growing threat all over the world due to its toxic effect to reduce soil fertility and water uptake in the crops. An average of 418 million ha soil is saline in nature. Various climatic, geomorphic and rainfall pattern causes which involved in saline soil formation. To reduce the toxic effect proper management of saline soil is required. Irrigation water also a major concern regarding soil salinity management. Saline irrigation water enhances and maintains the severity soil salinity. Crop production aspects root zone salinity provides a strong negative impact on soil fertility. Salinity causes the reduction in nutrient ion, and water uptake has a significant negative effect on crop yields. Soil and water salinity interactions and their influence on crop growth and management of salinity are deliberated in this chapter.

scholarly journals Impact of Drought and Changing Water Sources on Water Use and Soil Salinity of Almond and Pistachio Orchards: 2. Modeling

Soil Systems ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 58
Author(s):  
Sarah A. Helalia ◽  
Ray G. Anderson ◽  
Todd H. Skaggs ◽  
Jirka Šimůnek
Keyword(s):  
Water Uptake ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Root Zone ◽  
Root Water Uptake ◽  
Water Salinity ◽  
Saline Irrigation ◽  
Secondary Salinization ◽  
Irrigation Water Salinity ◽  
Soil Hydraulic

California is increasingly experiencing drought conditions that restrict irrigation deliveries to perennial nut crops such as almonds and pistachios. During drought, poorer quality groundwater is often used to maintain these crops, but this use often results in secondary salinization that requires skilled management. Process-based models can help improve management guidelines under these challenging circumstances. The main objective of this work was to assess seasonal soil salinity and root water uptake as a function of irrigation water salinity and annual rain amounts. The manuscript presents a comparison of three-year experimental and numerically simulated root zone salinities in and below the root zone of almond and pistachio drip-irrigated orchards at multiple locations in the San Joaquin Valley (SJV), California, with different meteorological characteristics. The HYDRUS-1D numerical model was calibrated and validated using field measurements of soil water contents and soil solute bulk electrical conductivities at four root zone depths and measured soil hydraulic conductivities. The remaining soil hydraulic parameters were estimated inversely. Observations and simulations showed that the effects of rain on root zone salinity were higher in fields with initially low salinities than in fields with high salinities. The maximum reduction in simulated root water uptake (7%) occurred in response to initially high soil salinity conditions and saline irrigation water. The minimum reduction in simulated water uptake (2.5%) occurred in response to initially low soil salinity conditions and a wet rain year. Simulated water uptake reductions and leaching fractions varied at early and late times of the growing season, depending on irrigation water salinity. Root water uptake reduction was highly correlated with the cumulative effects of using saline waters in prior years, more than salt leaching during a particular season, even when rain was sufficient to leach salts during a wet year.

A simple numerical model to estimate water availability in saline soils

Soil Research ◽  
2018 ◽  
Vol 56 (3) ◽  
pp. 264 ◽  
Author(s):  
Mohammad Hossein Mohammadi ◽  
Mahnaz Khataar
Keyword(s):  
Numerical Model ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Weighting Function ◽  
Water Salinity ◽  
Irrigation Water Salinity ◽  
Evapotranspiration Rate

We developed a numerical model to predict soil salinity from knowledge of evapotranspiration rate, crop salt tolerance, irrigation water salinity, and soil hydraulic properties. Using the model, we introduced a new weighting function to express the limitation imposed by salinity on plant available water estimated by the integral water capacity concept. Lower and critical limits of soil water uptake by plants were also defined. We further analysed the sensitivity of model results to underlying parameters using characteristics given for corn, cowpea, and barley in the literature and two clay and sandy loam soils obtained from databases. Results showed that, between two irrigation events, soil salinity increased nonlinearly with decreasing soil water content especially when evapotranspiration and soil drainage rate were high. The salinity weighting function depended greatly on the plant sensitivity to salinity and irrigation water salinity. This research confirmed that both critical and lower limits (in terms of water content) of soil water uptake by plants increased with evapotranspiration rate and irrigation water salinity. Since the presented approach is based on a physical concept and well-known plant parameters, soil hydraulic characteristics, irrigation water salinity, and meteorological conditions, it may be useful in spatio-temporal modelling of soil water quality and quantity and prediction of crop yield.

scholarly journals Soil salinization risk assessment owing to poor water quality drip irrigation: A case study from an olive plantation at the arid to semi-arid Beit She'an Valley, Israel

2020 ◽  
Author(s):  
Vladimir Mirlas ◽  
Yaakov Anker ◽  
Asher Aizenkod ◽  
Naftali Goldshleger
Keyword(s):  
Water Quality ◽  
Soil Fertility ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Drip Irrigation ◽  
Field Experiments ◽  
Soil Salinization ◽  
Treated Wastewater ◽  
Economic Damage ◽  
Study Objective

Abstract. Salinization causes soil degradation and soil fertility reduction. The main reasons for soil salinization are poor irrigation water quality and incorrect irrigation management. Soil salinization is accelerated owing to irrigation with treated wastewater with elevated salt concentration. The study area is located in the Beit She'an Valley, one of the most important agricultural regions in Israel. The combination of soil salinization and poor drainage conditions impedes plant development and is manifested in economic damage to crops. Without clear irrigation criteria, an increase in soil salinity and steady damage to soil fertility might occur. The study objective was to provide an assessment of soil salting processes as a result of low-quality irrigation water at the Kibbutz Meirav olive plantation. This study combined various research methods, including soil salinity monitoring, field experiments, remote sensing (FDEM), and unsaturated soil profile saline water movement modeling. The assessment included the salinization processes of chalky soil under drip irrigation by water with various qualities. With a drip irrigation regime of water with a dissolved salt content of 3.13 dS/m, the salinization process is characterized by salts accumulation in the upper root zone of the trees. The modeling results showed that there is a soil salinization danger in using brackish water and that irrigation with potable water helps to reduce soil salinization.

scholarly journals Modeling the Relationship between Water Uptake by Cucumber and NaCl Accumulation in a Closed Hydroponic System

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 802-807 ◽  
Author(s):  
Dimitrios Savvas ◽  
Gerasimos Meletiou ◽  
Spiridoula Margariti ◽  
Ioannis Tsirogiannis ◽  
Anastasios Kotsiras
Keyword(s):  
Water Uptake ◽  
Irrigation Water ◽  
Root Zone ◽  
Drainage Water ◽  
Hydroponic System ◽  
Reverse Pattern ◽  
Nacl Concentration ◽  
Water Rate ◽  
Using Data ◽  
Experimental Treatments

In a completely closed hydroponic system, Na and Cl commonly accumulate in the root zone, at rates depending on the concentration of NaCl in the irrigation water (rate of Na and Cl inlet) and the Na to water and Cl to water ratios at which they are taken up by the plants (rates of Na and Cl outlet). However, while the concentration of NaCl in the irrigation water is commonly a constant, the Na to water and Cl to water uptake ratios are variables depending on the concentrations of Na and Cl in the root zone and, hence, on the rates of their accumulation. To quantify this feed-back relationship, a differential equation was established, relating the rate of Na (or Cl) accumulation to the rate of water uptake. This equation was solved according to the classical Runge-Kutta numerical method using data originating from a cucumber experiment, which was conducted in a fully automated, closed-loop hydroponic installation. Four different NaCl concentrations in the irrigation water, 0.8, 5, 10 and 15 mm, were applied as experimental treatments. The theoretically calculated curves followed a convex pattern, with an initially rapid increase of the Na and Cl concentrations in the root zone and a gradual leveling out as the cumulative water consumption was rising. This was ascribed to the gradual approaching of the Na to water and Cl to water outlet ratios via plant uptake, which were increasing as NaCl was accumulating in the root zone, to the constant NaCl to water inlet ratio (NaCl concentration in irrigation water). The model could predict the measured Na and Cl concentrations in the drainage water more accurately at 10 and 15 mm NaCl than at 0.8 and 5 mm NaCl in the irrigation water. Possible explanations for these differences are discussed. Plant growth and water uptake were restricted as salinity was increasing, following a reverse pattern to that of Na and Cl accumulation in the root zone. The leaf K, Mg and P concentrations were markedly restricted by the increasing salinity, while that of Ca was less severely affected.

scholarly journals Impact of Drought and Changing Water Sources on Water Use and Soil Salinity of Almond and Pistachio Orchards: 1. Observations

Soil Systems ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 50 ◽  
Author(s):  
Sarah A. Helalia ◽  
Ray G. Anderson ◽  
Todd H. Skaggs ◽  
G. Darrel Jenerette ◽  
Dong Wang ◽  
...  
Keyword(s):  
Soil Salinity ◽  
Irrigation Water ◽  
Root Zone ◽  
Temporal Distribution ◽  
Water Shortages ◽  
Low Salinity ◽  
Irrigation Water Salinity ◽  
Electrical Conductivities ◽  
Leaching Fraction ◽  
The Impact

Soil salinity increases when growers are forced to use higher salinity irrigation waters due to water shortages. It is necessary to estimate the impact of irrigation water on soil properties and conditions for crop growth to manage the effects of salinity on perennial crops. Therefore, in this study, we monitored root zone salinity in five almond and pistachio orchards in eastern and western San Joaquin Valley (SJV), California (CA). Volumetric soil water contents and bulk electrical conductivities were measured at four root-zone depths. Evapotranspiration was measured by eddy covariance along with three other types of data. The first is seasonal precipitation and irrigation patterns, including the temporal distribution of rains, irrigation events, and irrigation water salinity. The second is soil chemistry, including the initial sodium adsorption ratio (SAR) and soil solute electrical conductivity (ECe). The third type is the physical properties, including soil type, hydraulic conductivity, and bulk density. As expected, we found low salinity at the eastern sites and higher salinity at the western sites. The western sites have finer textured soils and lower quality irrigation water; measured actual ET was about 90% of modeled crop ET. Across the three western sites, the annual average apparent leaching fraction ranged from 11 to 28%. At the eastern sites, measured ET almost exactly matched modeled crop ET each year. Apparent leaching fractions in the eastern sites were approximately 20%.

scholarly journals Farmers' Knowledge Is the Basis for Local Level Agro-Forestry Management: The Case of Lemo Woreda in Hadiya Zone, Ethiopia

2021 ◽  
Vol 5 ◽  
Author(s):  
Yohannes Horamo ◽  
Munyaradzi Chitakira ◽  
Kowiyou Yessoufou
Keyword(s):  
Soil Fertility ◽  
Tree Species ◽  
Crop Yields ◽  
Local Level ◽  
Forestry Management ◽  
Negative Effect ◽  
Questionnaire Surveys ◽  
Development Workers ◽  
Agro Forestry

This research was designed to investigate the hypothesis that farmers practising traditional agro-forestry which dates back for centuries have accumulated immense knowledge of agro-forestry, which can be captured and incorporated into formal development programmes to improve it. Farmers' knowledge must be documented, valued and integrated in order to maximise its importance for planning and decision-making. This research aimed to investigate and document farmers' knowledge of managing agro-forestry and the contribution to sustainable management of natural resources. Accordingly, questionnaire surveys were conducted in six villages from three peasant associations. In total, 73 households were selected for interview and the data collected were analysed using SPSS (Statistical Package for Social Science) version 26. The findings revealed tree species that contribute to crop yield improvement and the important role agro-forestry trees play with regard to soil fertility. Farmers' strategies to associate trees and shrubs in their farmlands were revealed. Tree species with a negative effect on crop yields were identified and recorded. Farmers reported and ranked in the order of importance, opportunities and constraints in the management of agro-forestry. Farmers' accumulated knowledge of tree–crop and tree–animal interactions, the role of trees in soil fertility, crop and livestock improvement, revealed in the study can significantly enhance the stainability of agriculture. If local knowledge is not documented, it remains largely inaccessible to development workers seeking solutions to locally defined problems.

scholarly journals Simulation of Water and Salt Dynamics in the Soil Profile in the Semi-Arid Region of Tunisia—Evaluation of the Irrigation Method for a Tomato Crop

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1594
Author(s):  
Sabri Kanzari ◽  
Issam Daghari ◽  
Jiří Šimůnek ◽  
Anis Younes ◽  
Riadh Ilahy ◽  
...  
Keyword(s):  
Water Uptake ◽  
Crop Yields ◽  
Root Zone ◽  
Root Water Uptake ◽  
Coefficient Of Determination ◽  
Silty Clay ◽  
Water Requirements ◽  
Tomato Crop ◽  
Soil Matrix ◽  
Irrigation Method

In Tunisia, water used for irrigation is often saline, increasing the risk of salinization for soils and crops. In this study, an experiment was conducted on a tomato crop cultivated on a silty-clay soil irrigated with three different water qualities: 0, 3.5, and 7 dS·m−1. Experimental data were then used to calibrate and validate the Hydrus-1D model, which simulates water flow and salt transfer in soils. The successfully-calibrated and validated model was then used to study the combined effects of the soil osmotic and soil matrix potentials on root water uptake. The values of the root mean square error (RMSE), the coefficient of determination (CD), the modeling efficiency (EF), and the coefficient of residual mass (CRM) were close to their optimal values for both soil water content and soil electrical conductivity profiles, indicating the reliability of the model to reproduce water and salt dynamics. Relative yields (Yr), indirectly estimated using actual and potential root water uptake (transpiration), indicated that the multiplicative stress response model (using the S-shape model) satisfactorily simulates measured yields and reproduces the effects of irrigation with saline waters on crop yields. An alternative scenario using a reduction of water requirements by 50% was investigated to assess an irrigation method with considerable water savings. As the results show that relative yields, Yr, were only slightly reduced, the crop water requirements estimated by CROPWAT 8.0 must have been overestimated. The variation of the soil salinity in the root zone highlighted a high salinization risk in the short-term when water of 7 dS·m−1 is used for irrigation.

PD-L1 and survival in oral cavity squamous cell carcinoma

2020 ◽  
Vol 25 (4) ◽  
pp. 287-294
Author(s):  
S. I. Kutukova ◽  
N. P. Beliak ◽  
G. A. Raskin ◽  
M. S. Mukhina ◽  
Yu. V. Ivaskova ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Oral Cavity ◽  
Cell Carcinoma ◽  
Tumor Cells ◽  
Squamous Cell ◽  
Immune Cells ◽  
Negative Impact ◽  
Progression Free Survival ◽  
Negative Effect ◽  
Effect Of Pd

Relevance. Prognostic value of PD-L1 expression in oral cavity squamous cell carcinoma (OCSCC) and its effect on survival is still controversial. It should be to determine the prognostic role of PD-L1 expression on tumor and immune cells of OCSCC and assess their effect on overall survival (OS) and progression-free survival (PFS).Materials and methods. A prospective study included 145 patients, first diagnosed with OCSCC. PD-L1 expression on tumor and immune cells, infiltrating tumor and its microenvironment, was assessed in all tumor samples by IHC, CPS was calculated. Cut-off values were determined by ROC analysis for identification of PD-L1 expression effect on OS and PFS.Results. Most patients with oral mucosa squamous cell carcinoma showed positive expression of PD-L1 on tumor (77.2%) and immune cells (92.4%). The median PD-L1 expression on tumor cells was 13.5% [1.0-40.0], the median PD-L1 expression on immune cells was 5.0% [1.0-11.0], and the median CPS – 18.0 [3.0-7.8]. Univariate and multivariate analyses revealed a significant negative effect of PD-L1 expression on immune cells ≤ 7% on OS (HR 0.66; 95% CI 0.45-0.93; p = 0.0498); PD-L1 expression in tumor cells ≤ 15% (HR 0.65; 95% CI 0.43-0.98; p = 0.0416) and CPS ≤ 21 (HR 0.62; 95% CI 0.44-0.92; p = 0.0183) for PFS. PD-L1 expression in tumor cells ≤ 6% (HR 0.71; 95% CI 0.47-1.08; p = 0.1096) and CPS ≤ 7 (RR 0.67; 95% CI 0.44-1.01; p = 0.0575) had a confident tendency to negative impact on OS.Conclusion. Positive PD-L1 expression in tumor and immune cells as well as CPS are effective additional factors in the prognosis of the disease course, OS and PFS in patients with OCSCC.

ВОДНЫЙ РЕЖИМ ОРОШАЕМЫХ СОЛОНЦОВЫХ КОМПЛЕКСНЫХ ПОЧВ И ОСОБЕННОСТИ ЕГО РЕГУЛИРОВАНИЯ

2020 ◽  
Author(s):  
Valery Yashin
Keyword(s):  
Soil Moisture ◽  
Ground Water ◽  
Irrigation Water ◽  
Surface Runoff ◽  
Root Zone ◽  
Irrigation Methods ◽  
Salt Flats

Представлены материалы исследований формирования режима влажности и динамики грунтовых вод орошаемых солонцовых комплексных почв при различных способах полива, проведенные в Волгоградском Заволжье. Установлена значительная неравномерность распределения влажности почвы при поливах дождеванием. Отмечается поверхностный сток по микрорельефу до 30% от поливной нормы, что приводит к недостаточности увлажнения корневой зоны на солонцах и переувлажнению почв в понижениях микрорельефа и потере оросительной воды на инфильтрационное питание грунтовых вод.The article presents the materials of research on the formation of the humidity regime and dynamics of ground water of irrigated saline complex soils under various irrigation methods, conducted in the Volgograd Zavolzhye. A significant unevenness in the distribution of soil moisture during irrigation with sprinkling has been established. There is a surface runoff on the microrelief of up to 30% of the irrigation norm, which leads to insufficient moisture of the root zone on the salt flats and waterlogging of the soil in the microrelief depressions and loss of irrigation water for infiltration feed of ground water.

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