Magnetic Water Treatment: An Eco-Friendly Irrigation Alternative to Alleviate Salt Stress of Brackish Water in Seed Germination and Early Seedling Growth of Cotton (Gossypium hirsutum L.)

Abstract

Magnetized water has been a promising approach to improve crop productivity but the conditions for its effectiveness remain contradictory and inconclusive. The objective of this research was to understand the influences of different magnetized water with varying quality on seed absorption, germination, and early growth of cotton. To this end, a series of experiments involving the seed soaking process, germination test, and pot experiment were carried out to study the effects of different qualities (fresh and brackish water) of magnetized water on seed water absorption, germination, seedling growth, photosynthetic characteristics, and biomass of cotton in 2018. The results showed that the maximum relative water absorption of magnetized fresh and magnetized brackish water relatively increased by 16.76% and 19.75%, respectively, and the magnetic effect time of brackish water was longer than fresh water. The relative promotion effect of magnetized brackish water on cotton seed germination and growth potential was greater than magnetized fresh water. The cotton seeds germination rate under magnetized fresh and magnetized brackish water irrigation relatively increased by 13.14% and 41.86%, respectively, and the relative promoting effect of magnetized brackish water on the vitality indexes and the morphological indexes of cotton seedlings was greater than magnetized fresh water. Unlike non-magnetized water, the net photosynthetic rate (Pn), transpiration rate (Tr), and instantaneous water use efficiency (iWUE) of cotton irrigated with magnetized water increased significantly, while the stomatal limit value (Ls) decreased. The influences of photosynthesis and water use efficiency of cotton under magnetized brackish water were greater than magnetized fresh water. Magnetized fresh water had no significant effect on biomass proportional distribution of cotton but magnetized brackish water irrigation markedly improved the root-to-stem ratio of cotton within a 35.72% range. Therefore, the magnetization of brackish water does improve the growth characteristics of cotton seedlings, and the biological effect of magnetized brackish water is more significant than that of fresh water. It is suggested that magnetized brackish water can be used to irrigate cotton seedlings when freshwater resources are insufficient.

Spring irrigation with magnetized water affects soil water-salt distribution, emergence, growth, and photosynthetic characteristics of cotton seedlings in Southern Xinjiang, China

“…For example, Abedinpour and Rohani (2017) reported that the emergence and growth indices of maize were significantly improved by using magnetized saline water [ 36 ]. Zhang et al (2022) reported that, the cotton seed germination rates under magnetized fresh water and magnetized brackish water irrigation increased by 13.14% and 41.86% compared with fresh water and brackish water, respectively [ 37 ]. Zhou et al (2022) showed that compared with unmagnetized brackish water, cotton yield was increased by 31.3% under magnetized brackish water irrigation [ 33 ].…”

Irrigation with Magnetized Water Alleviates the Harmful Effect of Saline–Alkaline Stress on Rice Seedlings

“…Previous studies have reported that irrigation with magnetized water can increase crop tolerance to stresses, such as salt stress and drought stress [ 24 , 25 , 26 ]. For instance, Zhang et al (2022) found that magnetic water treatment reduces the saline stress of brackish water at the onset of cotton seedling development [ 27 ]. Selim et al (2019) demonstrated that the application of magnetic water increased wheat growth and cereal yield under drought stress [ 28 ].…”

Effects of Irrigation Using Activated Brackish Water on the Bacterial Community Structure of Rhizosphere Soil

“…Activated water technology involves physically treating irrigation water to significantly change its physical and chemical properties, so as to improve the activity of irrigation water (Wang et al 2019). Recently, irrigation water activation technology, like magnetization and oxygenation, are simple techniques that have low-energy consumption and low input costs and are pollution-free and efficient for treating water, thus making them a hot research topic (Zhang et al 2022;Zhu et al 2021). Improving the physical and chemical characteristics of irrigation water boosts its physiological efficacy, which further enhances the efficient transmission capacity of irrigation water from the soil to crops (Wei et al 2022).…”

“…The magnetic field can change the infrared and ultraviolet absorption intensity of irrigation water (Pang and Deng 2008), which subsequently affects the macroscopic characteristics of water, like surface tension, pH, viscosity, electrical conductivity, oxygen content, and salt solubility (Moosavi and Gholizadeh 2014). Studies have shown that as compared with ordinary fresh water, magnetized freshwater irrigation significantly increased the seed germination rate, promoted seedling growth (Morejón et al 2007;Zhang et al 2022), and improved the nutrient absorption and utilization of crops (Radhakrishnan and Ranjitha 2012). Furthermore, it can enhance photosynthesis by increasing the leaf photosynthetic pigments to significantly improve the crop yield and quality (Hozayn et al 2016(Hozayn et al , 2019.…”

“…However, nitrogenase, essential for rhizobial N fixation, could only function under low-oxygen conditions. Magnetization or oxygenation treatment could increase the dissolved oxygen concentration in the irrigation water (Zhang et al 2022;Zhu et al 2021), which might affect the soil bacterial activity and consequently the soil N transformation process. For example, magnetized irrigation water could change the soil bacterial community structure, especially increase the relative abundance of Proteobacteria, Firmicutes, and Bacteroidetes, and was closely related to the contents of soil ammonium N, nitrate N, and organic matter (Cui et al 2020).…”