Laboratory Investigation of magnetism intensity and organic matter effect on water and characteristics of moisture front movement in porous medium

The study of moisture patterns under a single dropper is necessary for the design, management, and implementation of drip irrigation systems. The proper design of these systems should be a desirable combination of dropper discharge, soil characteristics, application time and type of used water that affect the water dynamics in the soil under surface dropper. However, less attention has been paid to the effect of water type, especially magnetic water, on the dynamics of water in the soil. Magnetic fields, while changing the physical and chemical properties of water, lead to changes in the characteristics of water movement in the porous medium. The purpose of this study was laboratory investigation of combined and separate effect of magnetism and organic matter on the distribution of moisture in layered soils.

The experiments were carried out in a 50*50*50 cm box of transparent plexiglass to observe the movement of the moisture front in the soil. Also, the experimental model of the present study includes water resource, plastic pipe, magnets set for applying magnetic field to water and dropper with a constant discharge rate of 4 liters per hour. In this study, four permanent pairs of magnets were applied with two specific magnets (three pairs of magnets with 0.2 T, and a pair of magnet of 0.3 T magnitude). The Porous media treatments of this study includes two samples of sandy loam soil (74% sand, 11% clay and 15% silt) and clayey soil (15.5% sand, 52.5% clay and 32% silt) and hydroponics porous media (peat moss organic matter). Soil and hydroponic treatments were prepared in the form of homogeneous mixture of soil (80%) with organic matter (20%). Also, the total thickness of the soil layer was considered 35 cm (the thickness of the coarse textured layer (SL) 25 cm and the fine textured layer (C) 10 cm) that 15 cm was kept empty from the top of box. For this purpose, the effect of plain and magnetic water in the form of eight treatments, on the moisture movement in coarse-textured, fine-textured, coarse textured mixed with peat moss, fine-textured mixed with peat moss were evaluated. Also this tests in the irrigation and drainage and Soil Laboratories were designed and implemented. Finally, the chemical properties of drainage water extracted from soil samples and samples of soil mixed with peat moss were measured by pH meter (pH meter) and electrical conductivity meter (EC meter).

The results of this study showed that due to the application of magnetism on irrigation water, electrical conductivity of drainage water was decreased in all treatments with the highest decrease to 0.875 mmho/cm in the fine-textured soil, except the fine-textured soil mixed with peat moss. Also, drainage water pH was increased in all four soil treatments, with the highest increase in the fine-textured soil to 7.6. Furthermore, Investigation about moisture dynamics showed that the significant effect of magnetic water application on certain treatments and the patterns of moisture distribution with their progressive radii were tangible. Also, for infiltration depth factor, the most general variability of magnetic water treatment was observed in T1 (increment), T7 (decrease), T3 (decrease) and T5 (increment) treatments. On the other hand, the highest influence of forward width was obtained in T7 (increment), T1 (decrease), T5 (increment) and T3 (increment) treatments. In addition, the analysis of forward curves-soil moisture distribution showed that due to the application of magnetic water for example in the horizontal direction, the maximum horizontal progression radius increased by 19.81% to 38.9 cm. Also, T7 (the fine textured soil on the coarse textured soil with magnetic water) can be described as a treatment that has the most beneficial result of magnetic water in the present study. As a result, even without using organic matter treatment and application of its fertilizers, it is possible to use the existing condition of agricultural soils with desired results, which have the same status as the present treatment and even the same treatments. In general, the results of this study were indicated that the magnetism on the chemical properties of soil water and especially the dynamic characteristics of water in the soil, including the pattern of moisture distribution and forward velocity was effective.