scholarly journals Evaluation of salinization and sodification in irrigated areas with limited soil data: Case study in southern Portugal

2018 ◽  
Vol 8 ◽  
Author(s):  
Carlos Alexandre ◽  
Teresa Borralho ◽  
Anabela Durão
Keyword(s):  
Soil Salinity ◽  
Irrigation Water ◽  
Soil Salinization ◽  
Soil Survey ◽  
Water Salinity ◽  
Irrigated Agriculture ◽  
Sodic Soils ◽  
Irrigated Area ◽  
Southern Portugal

Due to its high land productivity, irrigated agriculture has an increasing role in food production. In the Alentejo region (southern Portugal) the irrigated area has grown since the completion of the Alqueva dam in 2002. Climatic change patterns foreseen for the Mediterranean region (more heat extremes, less precipitation and river flow, increasing risk of droughts and decrease in crop yields) are prone to soil salinization and sodification in irrigated areas in the region. The Roxo dam has some of the higher records of water salinity and sodicity in Portugal, which makes the Roxo irrigated area (RIA) a very interesting case study. This paper aimed at two main objectives for the RIA: (i) evaluate soil salinization and sodification, and make spatial predictions of soils susceptibility to these degradation types; (ii) monitor current salinity and sodicity of the water, and simulate the effect of empirical based scenarios of water salinity and sodicity. The RIA (8250 ha) extends ~20 km along the Roxo river (northern Aljustrel), in Cenozoic sedimentary formations. Main soils mapped are: Luvisols (~40%), Fluvisols and Regosols (~20%), Gleysols and Planosols (~20%) and Vertisols (~10%). However, there are only five soil profiles with detailed analytical data from a more recent soil survey with 83 profile descriptions in the RIA and surrounding area. Irrigation water of the Roxo dam and drainage water of the Roxo river were monitored almost monthly during Jul/2014-Nov/2015 and Jun/2016-Jan/2017, for determination of electrical conductivity (EC), sodium adsorption ratio (SAR), and other parameters. Soil salinity was not a significant problem in the RIA but a potential abundance of sodic soils was found that need future confirmation. A qualitative soil salinity index applied to the RIA suggests that soils most susceptible to salinity occur to a much smaller extent when this index is obtained from the soil profile data (approach B) than when it is based on information of the soil map (approach A). During the monitoring periods, both the water of the Roxo dam and of the Roxo river were slight to moderate saline for crop growth, with no restrictions for soil infiltration. The Roxo dam received water from the Alqueva dam for the first time between June and September 2016, and a small, though regular, decrease of the water EC (0.99 to 0.76 dS m<sup>-1</sup>) was observed during the same period. Three scenarios of irrigation water, identified by Low/High EC-SAR (L-L, H-H, L-H) were simulated with the Watsuit model. Low EC water (L-L and L-H) represent wet years and show no risk of soil salinity in the rootzone. However, the risk of waterlogging increases in sodic soils, especially with the scenario (L-H). High EC water (H-H) represents dryer years and results in severe saline conditions in the rootzone. In all three scenarios, prosodic and sodic soils are most sensible to degradation by salinization, sodification or both.

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.

Classification and Mitigation of Soil Salinization

2017 ◽  
Author(s):  
Tibor Tóth
Keyword(s):  
Soil Salinity ◽  
Soil Classification ◽  
Soil Salinization ◽  
Classification Systems ◽  
Salt Accumulation ◽  
Soil Taxonomy ◽  
Sodic Soils ◽  
Water Rates ◽  
Irrigated Lands ◽  
The Right

Soil salinity has been causing problems for agriculturists for millennia, primarily in irrigated lands. The importance of salinity issues is increasing, since large areas are affected by irrigation-induced salt accumulation. A wide knowledge base has been collected to better understand the major processes of salt accumulation and choose the right method of mitigation. There are two major types of soil salinity that are distinguished because of different properties and mitigation requirements. The first is caused mostly by the large salt concentration and is called saline soil, typically corresponding to Solonchak soils. The second is caused mainly by the dominance of sodium in the soil solution or on the soil exchange complex. This latter type is called “sodic” soil, corresponding to Solonetz soils. Saline soils have homogeneous soil profiles with relatively good soil structure, and their appropriate mitigation measure is leaching. Naturally sodic soils have markedly different horizons and unfavorable physical properties, such as low permeability, swelling, plasticity when wet, and hardness when dry, and their limitation for agriculture is mitigated typically by applying gypsum. Salinity and sodicity need to be chemically quantified before deciding on the proper management strategy. The most complex management and mitigation of salinized irrigated lands involves modern engineering including calculations of irrigation water rates and reclamation materials, provisions for drainage, and drainage disposal. Mapping-oriented soil classification was developed for naturally saline and sodic soils and inherited the first soil categories introduced more than a century ago, such as Solonchak and Solonetz in most of the total of 24 soil classification systems used currently. USDA Soil Taxonomy is one exception, which uses names composed of formative elements.

scholarly journals Relationship between Soil Salinization and Groundwater Hydration in Yaoba Oasis, Northwest China

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 175 ◽  
Author(s):  
Guoqing Cui ◽  
Yudong Lu ◽  
Ce Zheng ◽  
Zhiheng Liu ◽  
Jiamei Sai
Keyword(s):  
Water Quality ◽  
Spatial Distribution ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Surface Soil ◽  
Soil Salinization ◽  
Irrigation Water Quality ◽  
Ion Content ◽  
Soil Salt ◽  
The Relationship

Precipitation is scarce and evaporation is intense in desert areas. Groundwater is used as the main water source to develop agriculture in the oases. However, the effects of using groundwater on the ecological environment elicit widespread public concern. This study investigated the relationship between soil salinity and groundwater characteristics in Yaoba Oasis through in situ experiments. The relationship of the mineral content, pH, and main ion content of groundwater with soil salt was quantitatively evaluated through a gray relational analysis. Four main results were obtained. First, the fresh water area with low total dissolved solid (TDS) was usually HCO3− or SO42− type water, and salt water was mostly Cl− and SO42−. The spatial distribution of main ions in groundwater during winter irrigation in November was basically consistent with that during spring irrigation in June. However, the spatial distribution of TDS differed in the two seasons. Second, soil salinization in the study area was severe, and the salinization rate reached 72.7%. In this work, the spatial variability of soil salinization had a relatively large value, and the values in spring were greater than those in autumn. Third, the soil in the irrigated area had a high salt content, and the salt ion content of surface soil was higher than that of subsoil. A piper trilinear diagram revealed that Ca2+ and K+ + Na+ were the main cations. SO42−, Cl−, and HCO3− were the main anions, and salinization soil mainly contained SO42−. Fourth, the changes in soil salt and ion contents in the 0–10 cm soil layer were approximately similar to those of irrigation water quality, both of which showed an increasing trend. The correlation of surface soil salinity with the salinity of groundwater and its chemical components was high. In summary, this study identified the progress of irrigation water quality in soil salinization and provided a scientific basis for improving the oasis ecosystem, maintaining the healthy development of agriculture, managing oasis water resources, and policy development. Our findings can serve as a reference for other, similar oasis research.

scholarly journals Past, Present, and Future of Irrigation on the U.S. Great Plains

2020 ◽  
Vol 63 (3) ◽  
pp. 703-729 ◽  
Author(s):  
Steven R. Evett ◽  
Paul D. Colaizzi ◽  
Freddie R. Lamm ◽  
Susan A. O’Shaughnessy ◽  
Derek M. Heeren ◽  
...  
Keyword(s):  
Water Use ◽  
Great Plains ◽  
Irrigation Water ◽  
Water Productivity ◽  
Irrigated Agriculture ◽  
Crop Water ◽  
Irrigation Technology ◽  
Irrigated Area ◽  
Irrigation Water Use ◽  
The U.S

Highlights Irrigation is key to the productivity of Great Plains agriculture but is threatened by water scarcity. The irrigated area grew to &gt;9 million ha since 1870, mostly since 1950, but is likely to decline. Changes in climate, water availability, irrigated area, and policy will affect productivity. Adaptation and innovation, hallmarks of Great Plains populations, will ensure future success. Abstract. Motivated by the need for sustainable water management and technology for next-generation crop production, the future of irrigation on the U.S. Great Plains was examined through the lenses of past changes in water supply, historical changes in irrigated area, and innovations in irrigation technology, management, and agronomy. We analyzed the history of irrigated agriculture through the 1900s to the present day. We focused particularly on the efficiency and water productivity of irrigation systems (application efficiency, crop water productivity, and irrigation water use productivity) as a connection between water resource management and agricultural production. Technology innovations have greatly increased the efficiency of water application, the productivity of water use, and the agricultural productivity of the Great Plains. We also examined the changes in water stored in the High Plains aquifer, which is the region’s principle supply for irrigation water. Relative to other states, the aquifer has been less impacted in Nebraska, despite large increases in irrigated area. Greatly increased irrigation efficiency has played a role in this, but so have regulations and the recharge to the aquifer from the Nebraska Sand Hills and from rivers crossing the state. The outlook for irrigation is less positive in western Kansas, eastern Colorado, and the Oklahoma and Texas Panhandles. The aquifer in these regions is recharged at rates much less than current pumping, and the aquifer is declining as a result. Improvements in irrigation technology and management plus changes in crops grown have made irrigation ever more efficient and allowed irrigation to continue. There is good reason to expect that future research and development efforts by federal and state researchers, extension specialists, and industry, often in concert, will continue to improve the efficiency and productivity of irrigated agriculture. Public policy changes will also play a role in regulating consumption and motivating on-farm efficiency improvements. Water supplies, while finite, will be stretched much further than projected by some who look only at past rates of consumption. Thus, irrigation will continue to be important economically for an extended period. Sustaining irrigation is crucial to sustained productivity of the Great Plains “bread basket” because on average irrigation doubles the efficiency with which water is turned into crop yields compared with what can be attained in this region with precipitation alone. Lessons learned from the Great Plains are relevant to irrigation in semi-arid and subhumid areas worldwide. Keywords: Center pivot, Crop water productivity, History, Sprinkler irrigation, Subsurface drip irrigation, Water use efficiency.

scholarly journals Delineating reclamation zones for site-specific reclamation of saline-sodic soils in Dushak, Turkmenistan

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256355
Author(s):  
Elif Günal
Keyword(s):  
Soil Salinity ◽  
Land Development ◽  
Soil Salinization ◽  
Accurate Information ◽  
Soil Reaction ◽  
Target Area ◽  
Sodic Soils ◽  
Spatial Trend ◽  
Soil Layers ◽  
Best Management

Soil salinization is the widespread problem seriously affecting the agricultural sustainability and causing income losses in arid regions. The major objective of the study was to quantify and map the spatial variability of soil salinity and sodicity. Determining salinity and sodicity variability in different soil layers was the second objective. Finally, proposing an approach for delineating different salinity and sodicity zones was the third objective. The study was carried out in 871.1 ha farmland in Southeast of Dushak town of Ahal Province, Turkmenistan. Soil properties, including electrical conductivity (EC), soil reaction (pH), sodium adsorption ratio (SAR), calcium carbonate and particle size distribution (clay, silt and sand fractions) in 0–30, 30–60, 60–90 and 90–120 cm soil layers were recorded. The EC values in different soil layers indicated serious soil salinization problem in the study area. The mean EC values in 0–90 cm depth were high (8 dS m-1), classifying the soils as moderate to strongly saline. Spatial dependence calculated by the nugget to sill ratio indicated a strong spatial autocorrelation. The elevation was the primary factor affecting spatial variation of soil salinity in the study area. The reclamation of the field can be planned based on three distinct areas, i.e., high (≥12 dS m-1), moderate (12–8 dS m-1) and low (<8 dS m-1) EC values. The spatial trend analyses of SAR values revealed similar patterns for EC and pH; both of which gradually decreased from north to the south-west. The amount of water needed to leach down the salts from 60 cm of soil profile is between 56.4–150.0 ton ha-1 and the average leaching water was 89.8 tons ha-1. The application of leaching water based on the amount of average leaching water will result in higher or lower leaching water application to most locations and the efficiency of the reclamation efforts will be low. Similar results were recorded for sulfur, sulfuric acid and gypsum requirements to remediate sodicity. The results concluded that the best management strategy in planning land development and reclamation schemes for saline and sodic soils require accurate information about the spatial distribution of salinity and sodicity across the target area.

scholarly journals Soil Salinity and Sodicity in Drylands: A Review of Causes, Effects, Monitoring, and Restoration Measures

2021 ◽  
Vol 9 ◽  
Author(s):  
Ilan Stavi ◽  
Niels Thevs ◽  
Simone Priori
Keyword(s):  
Soil Salinity ◽  
Agricultural Land ◽  
Anthropogenic Activities ◽  
Soil Salinization ◽  
Management Tool ◽  
Irrigated Agriculture ◽  
Saline Soils ◽  
Chemical Restoration ◽  
Irrigation Technologies ◽  
Over Time

Soil salinization and sodification are common processes that particularly characterize drylands. These processes can be attributed either to natural conditions or anthropogenic activities. While natural causes include factors such as climate, lithology, topography, and pedology, human causes are mostly related to agricultural land-use, and specifically, to irrigated agriculture. The objective of this study was to thoroughly review this topic, while highlighting the major challenges and related opportunities. Over time, the extent of saline, sodic, and saline-sodic croplands has increased, resulting in accelerated land degradation and desertification, decreased agricultural productivity, and consequently jeopardizing environmental and food security. Mapping and monitoring saline soils is an important management tool, aimed at determining the extent and severity of salinization processes. Recent developments in advanced remote sensing methods have improved the efficacy of mapping and monitoring saline soils. Knowledge on prevention, mitigation, and recovery of soil salinity and sodicity has substantially grown over time. This knowledge includes advanced measures for salt flushing and leaching, water-saving irrigation technologies, precision fertilizer systems, chemical restoration, organic and microbial remediation, and phytoremediation of affected lands. Of a particular interest is the development of forestry-related means, with afforestation, reforestation, agroforestry, and silvopasture practices for the recovery of salt-affected soils. The forecasted expansion of drylands and aggravated drying of existing drylands due to climatic change emphasize the importance of this topic.

scholarly journals Effects of Irrigation Water Salinity on Soil Properties, N2O Emission and Yield of Spring Maize under Mulched Drip Irrigation

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1548 ◽  
Author(s):  
Chenchen Wei ◽  
Fahu Li ◽  
Peiling Yang ◽  
Shumei Ren ◽  
Shuaijie Wang ◽  
...  
Keyword(s):  
Irrigation Water ◽  
Brackish Water ◽  
Drip Irrigation ◽  
Maize Yield ◽  
N2o Emission ◽  
Soil Salinization ◽  
Irrigation District ◽  
Water Salinity ◽  
Irrigation Water Salinity ◽  
Salinity Levels

Brackish water has been widely used to irrigate crops to compensate for insufficient freshwater water supply for agricultural use. The goal of this research was to determine an efficient brackish water use method to increase irrigation efficiency and reduce N2O emission. To this end, we conducted a field experiment with four salinity levels of irrigation water (1.1, 2.0, 3.5, and 5.0 g·L−1 with drip irrigation) at Hetao Irrigation District (Inner Mongolia, China) in 2017 and 2018. The results show that irrigation with 3.5–5.0 g·L−1 water salinity increased the soil salinity compared with irrigation using 1.1–2.0 g·L−1 water salinity. The soil water content with 5.0 g·L−1 brackish water irrigation was significantly higher than with 1.1–3.5 g·L−1 water salinity due to the effect of salinity on crop water uptake. The overall soil pH increased with the increase in irrigation water salinity. Saturated soil hydraulic conductivity decreased with the increase in irrigation water salinity. These results indicate that brackish water irrigation aggravates the degree of soil salinization and alkalization. The soil N2O cumulative flux resulting from irrigation with 5.0 g·L−1 water salinity was 51.18–82.86% higher than that resulting from 1.1–3.5 g L−1 water salinity in 2017, and was 32.38–44.79% higher than that resulting from 1.1–2.0 g·L−1 in 2018. Irrigation with brackish water reduced maize yield, and the reduction in yield in 2018 was greater than that in 2017, but irrigation with 2.0 g·L−1 brackish water did not significantly reduce maize yield in 2017. These results suggest that reducing the salinity of irrigation water may effectively reduce soil N2O emission, alleviate the degree of soil salinization, and increase crop yield.

Effect of irrigation water salinity on transpiration and on leaching requirements: A case study for bell peppers

2008 ◽  
Vol 95 (5) ◽  
pp. 587-597 ◽  
Author(s):  
Alon Ben-Gal ◽  
Eviatar Ityel ◽  
Lynn Dudley ◽  
Shabtai Cohen ◽  
Uri Yermiyahu ◽  
...  
Keyword(s):  
Irrigation Water ◽  
Water Salinity ◽  
Irrigation Water Salinity ◽  
Bell Peppers

scholarly journals Irrigated Agriculture on Saline Soils: A Perspective

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1630
Author(s):  
Anna Tedeschi
Keyword(s):  
Soil Salinity ◽  
Cropping Systems ◽  
Local Population ◽  
Crop Productivity ◽  
Soil Salinization ◽  
Irrigated Agriculture ◽  
Secondary Salinization ◽  
Crop Tolerance ◽  
Living Organisms ◽  
The Impact

Approximately 6.5% of the world’s arable and marginal soils are either saline or sodic. The situation will worsen due to climate change. Regardless of the cause that generated the salinity, i.e., whether primary or secondary, the effect of soil salinization on plant growth and on living organisms will be severe. To mitigate such impacts, several studies have been carried out over the years with the aim of providing technical or management solutions to deal with the multiple consequences of soil salinity. A review by Cuevas et al. proposes a new approach looking for solutions through soil-improving cropping systems (SICSs). The SICSs have to prevent, mitigate or remediate the negative impacts of soil salinization. The efforts of Cuevas et al. were to organize the analyses by focusing on SICSs that would: (1) prevent or halt secondary salinization; (2) cope with salinization; (3) reverse salinization. The study is concluded by an effort to assess the impacts of each SICS and of the combined SICSs application in terms of agronomic, economic, and environmental aspects. Both economic constraints and the collective willingness of stakeholders to innovate are taken into in the evaluation of feasibility. It is important to put into practice and/or identify a number of sustainable actions, at low environmental input, to improve crop tolerance to water deficit and high salinity as well as to preserve biodiversity and mitigate the impact of climate changes. At the same time, these actions would ensure crop productivity in the area, thus guaranteeing environment and social benefits to the local population, and thus weakening the motivation to abandon the land. The aim of this editorial is to propose a broader perspective on the review by Cuevas et al. “A Review of Soil-Improving Cropping Systems for Soil Salinization”. In the review, the authors go through several soil-improving cropping systems (SICSs) by considering them separately or in combination with the aim to provide guidelines towards resolving, counteracting or mitigating soil salinity. I tried to highlight the strengths of the study by Cuevas et al., while suggesting related topics that may deserve further attention by the community.

Sign in / Sign up

Export Citation Format

Share Document