关键词: 磁化水 , 盐碱土 , 水分入渗 , 盐分分布

Abstract: 【Objective】 Soil salinization is one of the major obstacle factors affecting crop yield in arid region, improvement of soil by using magnetized water irrigation can be traced back to the 1960s. In this study, a laboratory soil cylinder simulation experiment and a field plot experiment were conducted to investigate the effects of magnetized water irrigation on soil water infiltration and soil salt leaching. The purpose of this research is to find a novel method to reduce soil salt content and prevent soil secondary salinity in water-saving agriculture. 【Method】 In the present study, a laboratory soil cylinder simulation experiment and a field trial were carried out to investigate the impacts of magnetized water irrigation on soil infiltration, soil moisture, and salt movement in irrigation treatments with different magnetic field intensities, under given constant water head of 7.5 cm. The soil cylinder incubation experiment included 0 (Control), 100, 300, and 500 mT of magnetic field intensity, respectively. Infiltration from soil cylinder top to down, reached the entire soil cylinder 2/3, and then samplings were made. The field trial had two treatments: conventional water irrigation (CK) and magnetized water irrigation (T), and the magnetic field intensity was 300 mT. The field experiment was finished in the lysimeter, and the lysimeter area was 6.67 m2. Meanwhile, soil water leakage and salt distribution were also measured under the magnetized water drip irrigation condition. 【Result】 An obvious effect of magnetized water on accelerating soil infiltration and increasing soil moisture were observed. Compared with the control (CK), soil wetting front speed was markedly improved with 300 mT magnetized water treatment. For instance, at soil water infiltration time of 360 minute, soil wetting front reached up to 17.0 cm and 18.5 cm depth, respectively, under CK and 300 mT magnetized water irrigation. At the end of irrigation, soil EC value in 28 cm depth was 10.9 mS•cm-1 in CK and that was 12.7 mS•cm-1 in 300 mT magnetized water treatment, Cl- contents were 17.95 g•kg-1and 25.04 g•kg-1, Na+ contents were 4.61 g•kg-1 and 5.55 g•kg-1, which increased by 16.5%, 39.5%, and 20.4 % compared with the control (0 mT). Magnetized water irrigation significantly increased the amount of soil water leaching in a plot experiment. The weights of soil water leakage which collected in the first times were 18.8 kg and 21.9 kg, respectively, in CK and 300 mT magnetized water treatments, through water magnetized, the amount of soil water leaching increased by 16.9 %. At the end of irrigation, soil salt content in 0-100 cm soil layer decreased significantly, and soil salt content in 0-100 cm layer was significantly lower in magnetized water irrigation treatment than the control. Such as in soil surface layer 0-20 cm , soil salt content decreased by 13.8% in CK and 23.2% in magnetized water treatment; in soil depth layer 80-100 cm , soil salt content reduced by 11.6% and 29.8% in CK and magnetized water irrigation.【Conclusion】From the study a conclusion could be drawn that magnetized water irrigation exerted a significant role in accelerating soil water infiltration and promoting soil salt leaching in arid region, and 300 mT magnetic field intensity was optimal treatment in this experiment. In production practice, magnetized water drip irrigation as a way to improve soil salinization was very simple and efficient. The study will provide a theoretical basis and technical support for the use of magnetized water irrigation in production.

Key words: Magnetized water , saline soil , infiltration , salt distribution