【目的】土壤盐渍化是影响干旱区绿洲农业生产的主要障碍因素,磁化水灌溉改良土壤可以追溯到20世纪60年代。在室内土柱模拟及田间膜下滴灌条件下对比研究不同磁处理水灌溉对土壤水分入渗及淋盐作用的影响,旨在提出一种高效降低土壤盐分的新技术。【方法】采用室内土柱模拟和田间小区滴灌相结合的试验方法,土柱模拟试验磁感应强度设4个处理:分别为0、100、300和500 mT,采用由上向下入渗,入渗至整个土柱2/3处停水、取样,研究不同磁感应强度处理的水对土壤入渗、土壤剖面含水量及盐分运移的影响,小区试验分别为普通水滴灌(CK)、磁化水滴灌(T),磁感应强度为300 mT,试验在测坑内完成,测坑面积6.67 m^2,研究滴灌条件下磁化水灌溉对土壤水分渗漏及盐分分布的规律。【结果】土柱试验结果表明,磁化水可加快土壤水分入渗,与对照组相比,300 mT磁处理水可显著提高土壤湿润锋运移速度。在入渗时间为360 min时,0 mT和300 mT的湿润锋深度分别为17.0和18.5 cm;磁化水可加速土壤盐分向下运动,入渗结束后0 mT和300 mT处理在土层28 cm处的电导率值分别为10.9和12.7 mS·cm^-1,Cl-含量分别是17.95和25.04 g·kg^-1,Na+含量分别是4.61和5.55 g·kg^-1,300 mT处理较对照(0 mT)分别增加了16.5%、39.5%和20.4%。小区试验结果表明磁化水灌溉可显著提高土壤水分渗漏量,CK、300 mT处理(T)第一次承接的土壤渗漏液重量分别为18.8和21.9 kg,磁化水处理较对照处理增加16.5%。灌水结束后,0-100 cm土层的土壤脱盐率总体表现为磁化水处理大于对照处理,但各层脱盐率有所差别。对照和处理土壤表层0-20 cm脱盐率分别为13.8%和23.2%,深层土壤80-100 cm脱盐率为11.6%和29.8%。【结论】磁化水灌溉可加速土壤水分的向下运动,加快土壤盐分向下运移,表明磁化水灌?
[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