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Combating Strategies
Published in Ajai, Rimjhim Bhatnagar, Desertification and Land Degradation, 2022
Here are a few pointers with regards to the prevention of salinity:Routine monitoring of groundwater levels and salt in land and water. Piezometers can be used for monitoring groundwater. For soil, salinity is measured through electrical conductivity. The conductivity values range from 0.1 dS/m (low salinity hazard) to 9.0 dS/m (very high) (https://www.qld.gov.au/environment/land/management/soil/salinity/management)Protect deep-rooted native perennial vegetationAvoid dam construction in regions of high water tableAdopt sustainable agricultural management practices
Soil salinity
Published in Willem F. Vlotman, Lambert K. Smedema, David W. Rycroft, Modern Land Drainage, 2020
Willem F. Vlotman, Lambert K. Smedema, David W. Rycroft
Under normal conditions, the salinity in the upper soil layers is quite moderate and the occurrence of high soil salinity (salty soils) is the exception rather than the rule. When the high soil salinity is directly related to the soil’s parent material and its formation, it is referred to as primary or residual salinity. The salinity of marine soils is a special case of residual salinity. Marine deposits may remain saline from past geological periods up to the present time in situations where there is very little leaching (arid climates, poor drainage). The most common cause of high soil salinity in agricultural land, however, is salinisation, i.e., the accumulation of salts in the upper layers of the soil. Frequently, salinisation involves a reversal of the leaching process i.e., the return of the leached salt (therefore often termed secondary salinity). A great deal of contemporary salinisation is caused by man’s activities, especially by irrigation development (Chapter 15), but may originate from different circumstances as well (Box 14.1). Atmospheric fall-out may be a significant source of salt in coastal land and near deserts (annual salt loads of up to 100–200 kg per ha have been reported).
Description of Effects and Sources of Salt Water Intrusion
Published in S. F. Atkinson, G. D. Miller, D. S. Curry, S. B. Lee, Salt Water Intrusion, 2018
S. F. Atkinson, G. D. Miller, D. S. Curry, S. B. Lee
Soil salinity in the plant root zone is measured by the U.S. Department of Agriculture Salinity Laboratory as electrical conductivity, which is directly proportional to the salt concentration in the soil water. Two commonly used methods provide reliable measurements: one involves sampling the soil within the root zone, preparing a saturated extract, and measuring the electrical conductivity of the extracted soil water; the other uses a recently developed instrument that, when inserted into the soil, directly measures the electrical conductivity of the soil water. Since soil salinity usually increases with depth, measurements are taken at several depths within the root zone, and the values averaged (Maas, 1984). When the electrical conductivity of a saturated soil extract is measured, the units are decisiemens per meter (dS/m), where IdS/m is approximately equivalent to 640 mg/1 salt. Table 1 shows the salt tolerance of agricultural crops as determined by the U.S. Department of Agriculture Salinity Laboratory (Maas, 1984).
Adaptive physio-anatomical modulations and ionomics of Volkameria inermis L. in response to NaCl
Published in International Journal of Phytoremediation, 2023
Nair G. Sarath, Asseema Manzil Shackira, Jos T. Puthur
The acceleration of climate change on a global scale has devastating effects on the ecosystem, and it is currently getting people’s attention worldwide. Numerous environmental challenges, including harsh temperatures, drought, and flooding, affect the development and cultivation of crops. Among the different abiotic factors, soil salinity is a major issue affecting plant growth and metabolism, thus agriculture and food security. More than 424 million hectares of topsoil (0–30 cm) and 833 million hectares of subsoil (30–100 cm) have been eroded by salt, according to the data collected from 118 nations that account for 85% of the world’s geographical area (FAO 2021). Inadequate agricultural practices, lack of precipitation, and irrigation with saline water contribute to soil salinization. In many countries, seawater intrusion into agricultural land due to changes in sea level results in a negative impact on food security (Khong et al. 2018). About 90% of our food is provided by thirty crop species, and the crop yield of these species is getting reduced drastically even under moderate salinity (EC 4–8 dS m−1). According to Kromdijk and Long (2016), approximately 87% of food production must be increased to feed the increasing population by 2050. However, it is estimated that an average of 2000 km2 of irrigated land in about 75 countries is unremittingly degraded due to salinity (Reddy et al. 2017).
Environmental and human health impacts of geothermal exploitation in China and mitigation strategies
Published in Critical Reviews in Environmental Science and Technology, 2023
Yuanan Hu, Hefa Cheng, Shu Tao
Exploitation of geothermal resources alters local landscape and geo-environment, and thus impacts the biodiversity of ecosystems due to the changes in indigenous microorganism, plant, and animal populations (Bayer et al., 2013). The construction of geothermal power plants, and the operations of their extraction wells and cooling towers could disturb wildlife (Soltani et al., 2021). The dissolved salts and toxic elements released into local soil and surface water, as well as the gaseous pollutants emitted into the air, could deteriorate the quality of local environment, and thus alter the habitats of native wildlife, vegetations, and aquatic organisms (Loppi et al., 2006; Sayed et al., 2021; Soltani et al., 2021). Biomonitoring showed that the air pollutants emitted from geothermal power plants, particularly H2S, were primarily responsible for the reduction in biodiversity of local epiphytic lichens (Loppi et al., 2002). Increase in soil salinity reduces the uptake of water and nutrients by plants due to the elevated osmotic potential, and thus negatively affects vegetation growth. Salinity is also a key factor shaping soil bacterial diversity and composition (Wang et al., 2022), and the activity of soil bacteria and fungi is reduced with increasing salinity, which negatively affects soil biochemical processes and nutrient cycling (Yang et al., 2021). Chronic exposure to toxic elements has adverse effects on plant growth and soil microbial communities, and is well known to pose a significant threat to biodiversity (Hernandez & Pastor, 2008; Xie et al., 2016).
Long-term effects of using controlled drainage on: Crop yields and soil salinity in Egypt
Published in Water Science, 2020
Eman Mostafa Foda, Mohamed Mohamed Foad Sobeih, Gehan Abd El - Hakeem Salam, Ashraf Fathy Saber Ellayn, Yasser Mohamed Atta
Soil salinity is defined as an undesirable amount of dissolved inorganic soluble salts in the soil profile Rhoades (1990). Water tables rising and geologic erosion could form salts. These salts precipitate by evapo-concentration process. Typically, salts accumulate in the topsoil layers and leach progressively into lower layers of the soil profile. In arid regions, lack of rainfall and dry climatic conditions increase both evaporation and upward capillary flow causing minimal leaching which increases the salinity of the top soil layers. In agricultural and land management applications proper irrigation practices are important to control salinization. Under-irrigation minimizes the net downward movement of water that helps leach salts from the surface of the soil and the plants’ root zone area. Also, over-irrigation causes a rise in the groundwater table, where salts in the shallow groundwater precipitate and accumulate Rhoades (1992).