SoilUse and Management doi: 10.1111/sum.12140
Soil Use and Management, December 2014, 30, 588–594
Effect of magnetized water on infiltration capacity of different soil textures M. K H O S H R A V E S H -M I A N G O L E H 1 & A.-R. K I A N I 2 1
Water Engineering Department, Sari Agricultural Sciences and Natural Resources University, PO Box 578, Sari 4816118771, Iran, and 2Gorgan Agricultural and Natural Resources Research Center, Gorgan 41996-13475, Iran
Abstract The infiltration process is important in the planning and management of irrigation systems. This study was performed in Mazandaran province, Iran, to compare the effect of magnetized and non-magnetized irrigation water on cumulative infiltration and final infiltration rate of three soil textures. Magnetized water was obtained by passing the water through a strong permanent magnet installed on a feed pipeline. The results showed that the effects of soil texture and magnetized irrigation water on cumulative water infiltration and final infiltration rate was significant (P < 0.01). Cumulative water infiltration and final infiltration rates with magnetized water were greater than that of non-magnetized water. The cumulative water infiltration rate after 4 h for magnetized and nonmagnetized water was 26.4 and 12.7 cm in clay soil, 37.6 and 20 cm in silty loam soil and 40.8 and 29.3 cm in sandy loam soil, respectively. The final infiltration rates after 4 h for magnetized and nonmagnetized water were 0.05 and 0.023 cm/min in clay soil, 0.063 and 0.036 cm/min in silty loam soil and 0.076 and 0.046 cm/min in sandy loam soil, respectively. Therefore, magnetized irrigation water had most effect on the infiltration capacity of clay soil.
Keywords: Magnetization, infiltration rate, double rings
Introduction Infiltration has an effective role in the hydrologic cycle, regional ecology, run-off rate, soil erosion and degradation, solute transport and groundwater pollution (Hillel, 1998). Understanding the infiltration process is necessary for planning and management of irrigation systems (Walker & Skogerboe, 1987). From agricultural point of view, infiltration capacity is the key property of the soil. The infiltration capacity of soil is a very important factor for improving soil properties and maintenance against hazards. It has been shown that increased soil compaction induced by agricultural machineries reduces the volume of macropores contributing to water flow (Lipiec et al., 1998; Hakansson & Lipiec, 2000) and their continuity (Lipiec & Stepniewski, 1995; Arvidsson, 1997). The adverse effects of soil compaction on crop growth have been recognized for years.
Correspondence: M. Khoshravesh-Miangoleh. E-mail:
[email protected] Received November 2013; accepted after revision July 2014
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Water infiltration is strongly dependent on soil structure, and thus, the limitation of water infiltration is related to poor structure of soil (Conolly, 1998). Infiltration rate is basically affected by the capillary force, especially in the early stages of infiltration, and the force of gravity. Soil type and dryness influence difference between the initial infiltration rate and the final infiltration rate (Durner, 1994). The infiltration rate of the coarse-textured soil is greater than that of the fine-textured soil. Osuji et al. (2010) found appreciable relationships between steady infiltration rates and soil organic matter, bulk density and total porosity (r = 0.963, 0.898 and 0.899, respectively). Intermolecular hydrogen bonds lead to strong attractive forces between molecules of water. Many unusual properties of water are due to hydrogen bonding between their molecules. These bonds have sufficient power to cause the accumulation of some of the water molecules together. On the other hand, by applying relatively weak forces this intermolecular bond will break down. Magnetic water using permanent ceramic magnets can be obtained by letting water pass through a permanent magnet or electromagnet installed in or on a feeder pipeline (Higashitani et al., 1993). Otsuka & Ozeki (2006) stated that properties of pure water distilled from ultrapure water in
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Magnetized water and infiltration capacity
vacuum by magnetic treatment were not changed. But when the same magnetic treatment was carried out after the distilled water was exposed to O2, water properties such as vibration modes and electrolytic potential were changed. The degree of magnetic treatment effect on water was quantitatively evaluated by contact angle. The changes caused by the magnetic influence depend on many factors, such as strength and direction of the applied magnetic field, duration of exposure, flow rate of the solution, additives present in the system and pH (Marcus & Rashin, 1994; Baker & Judd, 1996; Parsons et al., 1997; Iwasaka & Ueno, 1998; Gabrielli et al., 2001; Chibowski et al., 2005). Magnetized water has been studied by many researchers (Iwasaka & Ueno, 1998; Yamamoto et al., 1998; Zhou et al., 2000; Inaba et al., 2004; Ghauri & Ansari, 2006; XiaoFeng & Bo, 2008; Mostafazadeh-Fard et al., 2012). Khoshravesh et al. (2011) studied the effect of magnetized water and irrigation water salinity on soil moisture distribution in trickle irrigation system. They showed that irrigation with magnetic water increased soil moisture up to 7.5% as compared to the non-magnetic water and this increase was significant (P < 0.01). Many investigations have evaluated magnetized water on soil and crop yield in Russia, Australia, Poland, Turkey, Portugal, England, United States, China and Japan (Hozayn & Qados, 2010). To date, there is little information about the effects of magnetized water on soil infiltration capacity. The objective of the present research was to investigate soil infiltration capacity using magnetized water in comparison with non-magnetized water in three soils with different textures.
Materials and methods Field layout and treatments details In this study, three different agricultural fields were selected in Mazandaran province, Iran. The primary experimental treatment was soil texture (S1 = clay, S2 = silty loam and S3 = sandy loam), and the secondary treatments were I1 = magnetized and I2 = non-magnetized irrigation water. The experimental design was complete randomized block design with three replications for each treatment. Physical properties of the soils in these fields are shown in Table 1.
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Field experiment In each field, three points were selected and a double-ring instrument was used to measure the infiltration rate. The inner and outer rings had a diameter of 25 and 50 cm, respectively. Because the objective was to measure one-dimensional (vertical) infiltration, the protective outer ring was used to prevent horizontal water leakage from the inner ring. After 4 h, infiltration rate reached almost a constant value. Using these measurements, the infiltration rate at any given moment, the final infiltration rate and also cumulative water infiltration were calculated. The average infiltration rate for an interval of time was calculated as follows: zn zn1 f ¼ : ð1Þ tn tn1 where f is the average infiltration rate (cm/min), zn is cumulative infiltrated depth at time tn (cm), zn1 is cumulative infiltrated depth at time tn1 (cm) and tn and tn1 are time (min). As initial soil moisture affects the infiltration characteristics, before running the experiments, soil moisture was measured gravimetrically by taking soil samples from 0 to 15 cm depth. Bulk density was determined for each soil using small cylinders of 5.5 cm diameter and 4.5 cm height.
Magnetization To create a magnetic field, a permanent ceramic magnet was used in the irrigation system. Magnetized water was obtained by passing of water through the magnet (Saba PoulTM; Sabaparsian, Mazandaran, Iran) and strength of 0.3 Tesla were installed on the main feed pipe (Figure 1). The north and south poles were located on the upper and the lower sides of the pipe, respectively, in that way different poles were separated only by the diameter of the pipe. The arrangement of the north and the south poles and direction of the magnetic field generated are shown in Figure 2. The device consists of a 400 mm long polycarbonate pipe and the internal diameter of main pipe was 60 mm. The permanent magnets were made of Neodymium Ferrite Boron (NdFeB). For the magnetically treated water, the irrigation water was exposed to a static non-uniform magnetic field for about
Table 1 Some physical characteristics of the selected soils
Texture Clay Sandy loam Silty loam
Clay (%)
Silt (%)
Sand (%)
Initial moisture content (% w/w)
Soil water potential (bar)
Porosity (%)
Bulk density (g/cm3)
46.5 17 18
29.5 20 76
24 63 15
14.45 10.1 11.8
8 2.2 5.4
39.24 29.81 36.98
1.61 1.86 1.67
© 2014 British Society of Soil Science, Soil Use and Management, 30, 588–594
590 M. Khoshravesh-Miangoleh & A.-R. Kiani
Main pipe
Magnet (Positive side)
Table 2 Analysis of variance for infiltration rate and cumulative water infiltrated Mean squares Parameters
Degrees of freedom
fc (cm/min)
F (cm)
2 6 1 2 6
0.000774** 0.0000119 0.00432** 0.000126ns 0.0000312
355.77** 0.196 968.00** 20.045** 0.483
S Error I S9I Error
S, soil texture; I, irrigation water; fc, final infiltration rate; F, cumulative infiltration depth. ** and ns represent significance at P = 0.01, and non-significant, respectively.
Magnet (Negative side) Figure 1 Magnetic device installed on the water pipe.
Table 3 Comparison of the measured average of final infiltration rate (fc) and cumulative water infiltration (F) for magnetized (I1) and non-magnetized (I2) water treatments Treatment
N S
Flow of water
N S
Figure 2 Magnetic device with two permanent magnets showing their north and south poles.
0.4 s by the values of the magnetic field intensity (Bx) generated by the two magnets varied from 5.9 to 285.5 mT along the axis of the pipe (centre line). The intensity was measured along the longitudinal and cross-sectional directions of the pipe using a Tesla meter (Magna-MG 701). Final infiltration rate and the cumulative water infiltration depth were analysed using Excel and SAS software. Comparison for the mean values for each treatment was performed with least significant different (LSD) test at P = 0.01 and P = 0.05 levels.
Results and discussion Analysis of variance (ANOVA) showed that the effects of soil texture and magnetized irrigation water on cumulative water infiltration and final infiltration rate of infiltration were significant at P = 0.01 level (Table 2) and these
Type of irrigation water I1 I2
fc (cm/min)
F (cm)
0.0637 a 0.0327 b
35.02 a 20.35 b
In each column, means followed by the same letter are not significantly different at P = 0.05 level.
Table 4 Comparison of the measured average of final infiltration rate (fc) and cumulative water infiltration (F) for clayey (S1), silty loam (S2) and sandy loam (S3) soil textures Treatment
fc (cm/min)
F (cm)
Soil texture S1 S2 S3
0.0365 c 0.0491 b 0.0591 a
19.56 c 28.61 b 34.88 a
In each column, means followed by the same letter are not significantly different at P = 0.05 level.
parameters for magnetized water were greater than that for non-magnetized water (Table 3). Also, Tables 3 and 4 show that final infiltration rate and cumulative water infiltrated were significantly different among all treatments (P < 0.05), and sandy loam soil had the highest values. The effect of the interaction of irrigation water and soil texture on cumulative water infiltration (Table 5) and final infiltration rate (Table 6) shows significant differences among the soil textures studied. Initial soil moisture content and bulk densities were 14.45% (w/w) and 1.61 g/cm3 for clay soil, 11.8% and
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Magnetized water and infiltration capacity
Water treatment
Soil texture S1 S2 S3 Mean
I1
I2
Mean
26.53 d 37.93 b 40.6 a 35.02
12.60 f 19.30 e 29.16 c 20.35
19.56 28.61 34.88 –
S1, Clay loam; S2, silt loam; S3, sandy loam. In each column, means followed by the same letter are not significantly different at P = 0.05 level.
1.6 Magnetized Infiltration rate (cm/min)
Table 5 The effect of the interaction of magnetized (I1) and nonmagnetized (I2) irrigation water and soil texture on cumulative water infiltration
Soil texture S1 S2 S3 Mean
0.0511 c 0.0644 b 0.0766 a 0.0640
I2
Mean
0.0211 f 0.0333 e 0.0433 d 0.0325
0.0361 0.0488 0.0599 –
In each column, means followed by the same letter are not significantly different at P = 0.05 level.
0.8
0.4
0
50
100 150 Time (min)
200
250
Figure 4 Variation of infiltration rate versus time for magnetized and non-magnetized water in silty loam soil.
2 Infiltration rate (cm/min)
I1
Non-magnetized 1.2
0
Table 6 The effect of the interaction of magnetized (I1) and nonmagnetized (I2) irrigation water and soil texture on final infiltration rate Water treatment
591
Magnetized Non-magnetized
1.6 1.2 0.8 0.4 0 0
50
100 150 Time (min)
200
250
Figure 5 Variation of infiltration rate versus time for magnetized and non-magnetized water in sandy loam soil.
1.6
Infiltration rate (cm/min)
Magnetized Non-magnetized 1.2
0.8
0.4
0 0
50
100 150 Time (min)
200
250
Figure 3 Variation of infiltration rate versus time for magnetized and non-magnetized water in clay soil.
1.67 g/cm3 for silty loam soil and 10.1% and 1.86 g/cm3 for sandy loam soil. Figures 3–5 show variation of infiltration rate with time for magnetized and non-magnetized water in different
experimental soils. The difference in infiltration rate is obvious from the early moments of the experiment. As seen in Figures 3–5, the vertical distance [the difference of infiltration rate (cm/min) between magnetized and non-magnetized water at each time] between the magnetized and non-magnetized treatments is reduced from fine-textured to coarse-textured soils. Again, this means that magnetic effect on water infiltration rate is most effective in finetextured soils. The final infiltration rates, after 4 h of running the experiments, for magnetized and non-magnetized water were equal to 0.05 and 0.023 cm/min in clay soil, 0.063 and 0.036 cm/min in silty loam soil and 0.076 and 0.046 cm/min in sandy loam soil, respectively. Figures 6–8 show variation of cumulative water infiltration with time for magnetized and non-magnetized water for the three studied soils. On these figures, the measured amount of cumulative water infiltration is shown together with the fitted Kostiakov infiltration equation (F = atb). It is clear in Figure 6 that cumulative water infiltration in magnetized water treatment is greater than that of non-magnetized water
© 2014 British Society of Soil Science, Soil Use and Management, 30, 588–594
592 M. Khoshravesh-Miangoleh & A.-R. Kiani
100
Cumulative infiltration (cm)
Magnetized
0.6934x 0.6851
Non-magnetized
y= R 2 = 0.9949
10 y = 0.425x 0.6461 R 2 = 0.9866 1
0.1 1
10
100
1000
Time (min) Figure 6 Variation of cumulative water infiltration versus time for magnetized and non-magnetized water in clay soil.
Cumulative infiltration (cm)
100
y = 1.0962x 0.6788 R 2 = 0.9892 Non-magnetized Magnetized
10
y = 0.6178x 0.6633 R 2 = 0.9907
1
0.1 1
10
100
1000
Time (min) Figure 7 Variation of cumulative water infiltration versus time for magnetized and non-magnetized water in silty loam soil.
Cumulative infiltration (cm)
100
Magnetized Non-magnetized
y = 1.6075x 0.6168 R 2 = 0.9908 y = 1.4538x 0.5839 R 2 = 0.9879
10
1
0.1 1
10
100
1000
Time (min) Figure 8 Variation of cumulative water infiltration versus time for magnetized and non-magnetized water in sandy loam soil.
treatment. This difference in infiltration is obvious from the early moments of the experiment. As seen in Figures 6–8, the vertical distance [the difference of cumulative water infiltration (cm) between magnetized and non-magnetized water at each time] between the magnetized and non-magnetized treatments is reduced from fine-textured to coarse-textured soils. This means that magnetic effect on water infiltration is most effective in fine-textured soils. The cumulative water infiltration after 4 h for magnetized and non-magnetized water was equal to 26.4 and 12.7 cm in clay soil, 37.6 and 20 cm in silty loam soil and 40.8 and 29.3 cm in sandy loam soil, respectively. There are two reasons for greater infiltration of magnetized irrigation water. First, under magnetized conditions, the water molecules, which are influenced by hydrogen bonds and Van der Waals forces and in reactions with the ions, are released and become more cohesive (Lungader Madsen, 2004). Therefore, the water molecules easily attach to the soil particles and do not move to the lower soil depths. Also, the water molecules easily penetrate into the microspaces of the soil particles rather than moving to the deeper soil depths (Jacob, 1999; Khoshravesh et al., 2011). Second, changes in structure and physical characteristics take place when water passes through a magnetic field. In the magnetized water, the existing free gases in water are reduced (Jacob, 1999). With magnetically treated water, the contact angles is extenuate due to the increase of polarized effect and the changes of distribution and clustering structure of water molecules after magnetization. The extenuation of contact angles of magnetically treated water means causes the hydrophobic materials to increase and decrease its surface tension force relative to that of well water. Thus, its hydrophobicity decreases. As a result, it causes the solubility power to increase and water molecules easily penetrate into the microspaces of the soil particles (XiaoFeng & Bo, 2008). ANOVA showed that the effect of magnetized irrigation water on correlation coefficient was significant at P = 0.05, but the effect of soil texture on correlation coefficient was not significant (Table 7). Also, this parameter for magnetized water was greater than that for non-magnetized water, and this difference was significant at P = 0.05 (Table 8). Table 9 shows that there was a significant difference for correlation coefficient between clay soil and other soil texture (P < 0.05). Table 10 shows the overall results of the coefficients of Kostiakov infiltration equation for different soils and water treatments. From this table, coefficient a and parameter F increases and exponent b decreases as the soil texture gets coarser. If greater cumulative water infiltration and final infiltration is required, then magnetized water is preferable over non-magnetized irrigation water. ANOVA for coefficients of the Kostiakov equation showed that the effects of soil texture and magnetized irrigation water were significant at P = 0.01 level (Table 11).
© 2014 British Society of Soil Science, Soil Use and Management, 30, 588–594
Magnetized water and infiltration capacity
Table 7 Analysis of variance for correlation coefficient
Parameters S Error I S9I Error
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Table 11 Analysis of variance for coefficients of Kostiakov equation
Degrees of freedom
Sums of squares R2
Mean squares R2
F-value R2
Mean squares
2 6 1 2 6
0.00004 0.000015 0.0001 0.000010 0.000059
0.00002ns 0.000002 0.0001* 0.000005ns 0.000009
2.08 0.26 11.82 0.54 –
Parameters
Degrees of freedom
a
b
2 6 1 2 6
1.283** 0.006 0.475** 0.034** 0.0004
0.006** 0.0002 0.003** 0.00002ns 0.00007
S Error I S9I Error
S, soil texture; I, irrigation water; a, b are coefficients of Kostiakov equation. ns represent significance at P = 0.01, and non-significant, respectively. * represent significance at P = 0.05.
S, soil texture; I, irrigation water; a, b are coefficients of Kostiakov equation. ** and ns represent significance at P = 0.01, and nonsignificant, respectively.
Table 8 Comparison of the average of correlation coefficient for magnetized (I1) and non-magnetized (I2) water treatments
Table 12 Comparison of the average of coefficients of Kostiakov equation for magnetized (I1) and non-magnetized (I2) water treatments
Treatment
R2
LSD
Error mean square Treatment
Type of irrigation water I1 0.991 a I2 0.986 b
9.944 9 106 9.944 9 106
0.0036 0.0036
LSD, least significant difference. In each column, means followed by the same letter are not significantly different at P = 0.05 level.
Table 9 Comparison of the average of correlation coefficient for clayey (S1), silty loam (S2) and sandy loam (S3) soil textures Treatment
R2
LSD
Error mean square
Soil texture S1 S2 S3
0.991 a 0.988 b 0.987 b
0.0023 0.0023 0.0023
2.611 9 106 2.611 9 106 2.611 9 106
LSD, least significant difference. In each column, means followed by the same letter are not significantly different at P = 0.05 level. Table 10 Coefficients of Kostiakov equation in different soil textures and irrigation water treatments Non-magnetized water
Magnetized water
Soil texture
a
b
a
b
Clay Silty loam Sandy loam
0.425 0.617 1.453
0.646 0.663 0.583
0.693 1.096 1.607
0.685 0.678 0.616
These coefficients (a and b) for magnetized water were greater than that for non-magnetized water (Table 12). Also, Tables 12 and 13 show that a and b coefficients were significantly different between treatments (P < 0.05).
Type of irrigation water I1 I2
a
b
1.151 a 0.826 b
0.655 a 0.627 b
In each column, means followed by the same letter are not significantly different at P = 0.05 level.
Table 13 Comparison of the average of coefficients of Kostiakov equation for clayey (S1), silty loam (S2) and sandy loam (S3) soil textures Treatment
a
b
Soil texture S1 S2 S3
0.590 c 0.879 b 1.495 a
0.653 a 0.667 a 0.603 b
In each column, means followed by the same letter are not significantly different at P = 0.05 level.
Nowadays, with new developments in mechanization of agriculture and also increases in size and weight of machines, soil density has been increased in agricultural practices. This increase in density is more obvious in clay soils, compared with other coarse-textured soils. As a result, the infiltration potential of these compacted soils can be improved using magnetized irrigation water. This practice has other beneficial effects such as reduction of overland run-off and soil water evaporation.
Conclusions Effect of magnetized and non-magnetized irrigation water was studied for three soil textures of clay, silty loam and sandy
© 2014 British Society of Soil Science, Soil Use and Management, 30, 588–594
594 M. Khoshravesh-Miangoleh & A.-R. Kiani loam. Cumulative water infiltration and final infiltration rate in these soils increased under magnetized irrigation water. But the effect was more pronounced in clayey soil. Therefore, using magnetized irrigation water in clay soils is recommendable to improve their water infiltration capacity.
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