How Does Salt Impact The Growth Of Plants?

Salinity is a major environmental factor that inhibits plant growth through ionic imbalance, osmotic stress, oxidative stress, and reduced nutrient uptake. Plants have evolved with adaptation strategies at both morphological and molecular levels to cope with this issue. This article examines how salinity directly affects plant growth and soil health, exploring its root causes, its varied effects, and effective solutions to promote it.

Excessive salt concentration (100 and 200 mM) has been found to significantly impact growth and physiological characteristics. Salinity is a major environmental problem that negatively affects crop productivity by impairing plant growth and development via water stress and cytotoxicity due to excessive uptake of salts in the soil.

Salinity severely limits plant performance and crop yield and is a major abiotic constraint on agricultural food production worldwide. The accumulation of salts in the soil can produce nutritional and hormonal imbalances, ion imbalances, and ion-related diseases. This chapter presents an overview of the salinity imposed effects on crops, and employs agronomic approaches, seed priming, and plant growth promoting.

Salinity affects production in crops, pastures, and trees by interfering with nitrogen uptake, reducing growth, and stopping plant reproduction. Some ions, particularly chloride, are toxic to plants, and as their concentration increases, they can poison and die.

Water salinity can significantly affect plant growth by disturbing their water balance, causing ionic imbalances, and inducing toxicity. Excessive salt above what plants need limits plant growth and productivity and can lead to plant death. Root exposure to high sodium concentrations causes wilted foliage and stunted plant growth.

How do plants cope with salinity?

Plants, being sessile, have developed mechanisms to adapt to high-salt environments, such as regulating ion homeostasis, activating the osmotic stress pathway, and mediating plant hormone signaling. Understanding these physiological and biochemical responses could provide strategies to improve agricultural crop yields. Common responses include increased osmotic adjustment, changes in cell wall elasticity, and an increase in apoplastic water, which minimizes saline effects by maintaining foliar turgidity.

Compounds involved in osmotic regulation include carbohydrates, nitrogen molecules, and organic acids. Proline and glycine betaine are essential and efficient compatible solutes, minimizing salt-stress effects and improving plant growth. Plant metabolic plasticity is also crucial in regulating salt stress response. Nosek et al. found that salinity stress is required for stress-dependent crassulacean acid metabolism (CAM) photosynthesis and maintaining its functioning.

Research on salt stress and soil pollution mitigation is essential to increase agricultural productivity and feed the world’s growing population. As global hunger and salinity stress intensify, there is a growing interest in ecologically sustainable solutions for salt tolerance. Alternative approaches for developing salt-tolerant crops include developing halophytes, using interspecific hybridization, utilizing existing crop varieties, introducing variation within existing crops through genetic approaches, or improving salt-tolerant varieties.

What is the effect of high salinity?

Salinity has a significant impact on agricultural crops, affecting their productivity, economic returns, and ecological balance. It affects various aspects of plant development, including seed germination, vegetative growth, and reproductive development. Soil salinity imposes ion toxicity, osmotic stress, nutrient deficiency, and oxidative stress on plants, limiting water uptake from soil. Plants sensitive to certain elements, such as sodium, chlorine, and boron, may be affected at relatively low salt concentrations if the soil contains enough toxic elements.

High salt levels in the soil can disrupt the nutrient balance in the plant or interfere with the uptake of some nutrients. Salinity also affects photosynthesis through a reduction in leaf area, chlorophyll content, and stomatal conductance, and to a lesser extent through a decrease in photosystem II efficiency. Salinity adversely affects reproductive development by inhabiting microsporogenesis and stamen filament elongation, enhancing programed cell death in some tissue types, ovule abortion, and senescence of fertilized embryos.

To assess the tolerance of plants to salinity stress, growth or survival of the plant is measured because it integrates the up- or down-regulation of many physiological mechanisms occurring within the plant. Osmotic balance is essential for plants growing in saline medium, and failure of this balance results in loss of turgidity, cell dehydration, and ultimately, cell death. Ion toxicity is the result of replacement of K+ by Na+ in biochemical reactions, and Na+ and Cl− induced conformational changes in proteins.

The adverse effects of salinity on plant development are more profound during the reproductive phase. Wheat plants stressed at 100–175 mM NaCl showed a significant reduction in spikelets per spike, delayed spike emergence, reduced fertility, and poor grain yields. However, Na+ and Cl− concentrations in the shoot apex of these wheat plants were below 50 and 30 mM, respectively, which is too low to limit metabolic reactions.

Salinization can be restricted by leaching salt from the root zone, changed farm management practices, and use of salt tolerant plants. Irrigated agriculture can be sustained by better irrigation practices such as adoption of partial root zone drying methodology, drip or micro-jet irrigation, and re-introducing deep-rooted perennial plants that continue to grow and use water during seasons that do not support annual crop plants.

Farming systems can change to incorporate perennials in rotation with annual crops (phase farming), in mixed plantings (alley farming, intercropping), or in site-specific plantings (precision farming).

However, implementation of these approaches to sustainable management can be limited due to cost and availability of good water quality or water resources. Evolving efficient, low-cost, easily adaptable methods for abiotic stress management is a major challenge, and extensive research is being carried out worldwide to develop strategies to cope with abiotic stresses, such as developing salt and drought-tolerant varieties, shifting crop calendars, and resource management practices.

How does salinity affect plant growth osmosis?

Excess salt levels in the soil root zone hinder plant roots’ ability to absorb soil water, causing osmotic flow from low to higher salt concentrations. Saline and alkali soils reverse this osmotic potential. To improve salt-effected soils, agricultural solutions include “leaching” salts using water, allowing plants to grow normally. However, not all salts are equally mobile in water, with table salt being more soluble in water than baking soda due to differences in polarity, bond types, and compound size. The Great Basin Rangelands Research Unit in Reno, NV, conducted the Plant Growth and Osmotic Potential project.

What happens if salinity increases?

The density of seawater increases in accordance with salinity, thereby modifying the temperature-density relationships that prevail in such a medium. Furthermore, the salt content of seawater affects the freezing point, potentially impeding the formation of sea ice in oceans with elevated salinity, as observed by Fofonoff and Millard in 1983.

Does salinity affect plant growth?

Salinity impacts crop production by reducing nitrogen uptake, reducing growth, and stopping plant reproduction. Toxic ions, particularly chloride, poison plants and cause death. Dryland salinity significantly impacts fresh rivers, affecting water quality for drinking and irrigation, with economic, social, and environmental consequences for rural and urban communities. High salt levels can affect the taste of drinking water, with chloride having a low taste threshold. Sodium and magnesium sulfate levels in drinking water may also cause laxative effects and reduce the suitability of water supply for grazing animals.

What is the effect of salinity on plant morphology?

This study aimed to screen for walnut salt-tolerant rootstocks by treating Juglans microcarpa L. seedlings in different NaCl concentrations (0, 50, 100, 200, and 300 mmol/L). The results showed that after salt stress, the external morphology of seedlings displayed salt injury, manifesting as yellowing, withering, curling, and falling off of leaves. High concentrations and long-term stress led to more serious damage, with numerous leaves undergoing withering and shedding.

Salt stress significantly inhibited the growth of seedlings, reducing chlorophyll content and photosynthetic parameters, increasing relative electrical conductivity and malondialdehyde, increasing superoxide dismutase, peroxidase, and catalase activities, accumulating proline, and increasing or decreasing soluble sugar content. It promoted the production of abscisic acid (ABA) and inhibited the synthesis of indole-3-acetic acid (IAA), gibberellic acid 3, and zeatin riboside (ZR).

J. m icrocarpa L. seedlings were more tolerant under 100 mmol/L salt stress, while the damage to growth was more severe at 200 mmol/L to 300 mmol/L salt stress. Soil salinization is a global resource and environmental problem, with 20 of arable lands and 50 of irrigated lands affected by it. In China, the vast saline soil is considered an important reserve land resource, and its rational development and use are of great significance for ecological environmental protection and sustainable development of the country’s agriculture and forestry economy.

How does salinity affect plant available water?

Salinity impedes plant access to soil water by enhancing the osmotic strength of the soil solution, which becomes increasingly concentrated as the soil dries.

How does salinity affect plant growth?

Salinity impacts crop production by reducing nitrogen uptake, reducing growth, and stopping plant reproduction. Toxic ions, particularly chloride, poison plants and cause death. Dryland salinity significantly impacts fresh rivers, affecting water quality for drinking and irrigation, with economic, social, and environmental consequences for rural and urban communities. High salt levels can affect the taste of drinking water, with chloride having a low taste threshold. Sodium and magnesium sulfate levels in drinking water may also cause laxative effects and reduce the suitability of water supply for grazing animals.

What happens if salinity is too high?

Salinity levels that are either too high or too low can have a detrimental impact on the tank inhabitants, resulting in impaired growth, loss of coloration, and incomplete polyp expansion. The optimal salinity range is 33-35 ppt. It has been observed that species such as leather corals, acroporids, and gorgonians exhibit a rapid response to elevated salinity levels. It is recommended that the salinity be adjusted by means of a partial water change, with the density being monitored on a regular basis.

How does salinity affect plant transpiration?

The study found that higher salinity stress led to decreased transpiration areas and a lower transpiration rate for severe salinity treatment (S7) compared to slight salinity and salt-free stress treatments (S3 and S0). The study also found that cookies are used by the site, and all rights are reserved for text and data mining, AI training, and similar technologies. Open access content is licensed under Creative Commons terms.

How do plants adapt to salinity?

Plants respond to salinity exposure by increasing solute concentration, adjusting osmotic pressure, modifying cell wall elasticity, decreasing tissue water content, and increasing water percentage in the apoplast. This helps maintain salinity by reducing damage. ScienceDirect uses cookies and copyright © 2024 Elsevier B. V. All rights reserved, including those for text and data mining, AI training, and similar technologies. Open access content is licensed under Creative Commons terms.