Benefaction of Saline Water Irrigation in Desert Soils “Scope of Salinity Problems and New Means of Control” | ||
| Egyptian Journal of Soil Science | ||
| Article 2, Volume 53, Issue 3, September 2013, Pages 313-333 PDF (666.18 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejss.2013.170 | ||
| Abstract | ||
| EXCESSIVE salt concentration in soils and in underground water has been considered a serious problem in arid and semi-arid regions for centuries. Removal of excess salts or decreasing their activity is necessary for optimum crop production and for soil conservation. Decreasing the activity of soluble salts in irrigation water proved to correct excessive water salinity. Besides, the realization of proper ionic and nutrients balance in soil solution lead to more successful utilization of saline water irrigation. Surface soil management, induced soil stratification, proper drying cycle and application of Nile Fertile (a natural sulfur fertilizer mixture) have been suggested as efficient means for promoting saline water irrigation. Changes in salts and moisture distribution during a drying cycle of stratified soil columns, i.e., 15 cm sand over 15 cm sandy loam (S/SL) and the opposite stratification (SL/S), were evaluated. Results revealed that S/SL system has decreased capillary rise and evaporation loss and consequently limited the upward movement of salts. On the other hand, the system SL/S greatly increased evaporation but slightly increased the upward movement of salts. However, such movement in homogenous S or SL soils was much greater than that of stratified systems. Besides, longer drying cycle decreased salt accumulation in the root zone and activated upward and downward salt movement, under all conditions of the study. Recently, magnetizing saline irrigation water through a proper magnetic field has been introduced as an effective mean for soil desalination. The magnetic field causes the hydration of salt ions and colloids to slide down, leading to better salt solubility and accelerated coagulation and salt crystallization. The mode of magnetic treatment implies certain influence on the structure of water and soil solution. Besides, the required magnetic field strength depends on salt type and concentration. In this work the effectiveness of magnetizing water of different salinity, on soil salinity and alkalinity, on ionic balance and ion uptake by plant, was evaluated in a series of pot and field experiment Upward diffusion tests of different salts and fertilizers, in normal and magnetized taper, were conducted. Magnetized water increased NaCl diffusion by 50% or more; while that of KCl reached 20%. On the other hand, magnetized water has lowered the diffusion of KH2PO4, super phosphate and ZnSO4. In an olive farm irrigated with moderately saline magnetized water was shown to have 3 main effects: (1) Lowering soil alkalinity, (2) Increasing the leaching of excess soluble salts and (3) Dissolving slightly soluble salts such as phosphates and sulfates. Such effects were also demonstrated in a citrus orchard where the solubility and uptake of Ca, Mg and SO4 were accelerated while Na+ uptake was reduced to one-half, by magnetized water. | ||
| Keywords | ||
| magnetized water; Salt diffusion; Soil stratification; Drying cycle; Capillary rise; Evaporation; Nile Fertile; Salt tolerant plants | ||
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