荒漠绿洲农田盐渍化过程中土壤环境的演变过程

土壤环境的盐渍化演变过程是盐渍化其它过程研究的基础。采用空间代替时间的方法，在干旱绿洲区选择大麦（Hordeum vulgare L.）作物地不同盐渍化阶段农田为研究对象，并以非盐渍化农田作为对照，探讨农田盐渍化过程中土壤理化特性的演变过程。结果表明，（1）随盐渍化程度的加剧，土壤颗粒组成发生变化，沙粒含量趋于增加，黏粒含量趋于减少，粉粒含量在重度和极重度盐渍化阶段完全消失。表土层土壤容重呈显著增加趋势（P〈0-05），但土壤温度没有显著性变化（P〉0-05）。（2）土壤有机碳、全氮、全磷和速效氮含量呈波动式降低趋势，而速效磷含量呈波动式增加的趋势。与未盐渍化农田相比，轻度、中度、重度和极重度盐渍化农田土壤表层有机碳和全氮含量分别减少了14.03%、26.26%、42.01%、48.03%；19-08%、35.63%、46.84%、56.88%。（3）随盐渍化程度的加剧，盐分表聚现象明显，除 HCO3-外，Na＋、Cl-、K＋、Mg2＋、SO42-、全盐含量均显著增加（P〈0-05），且随着深度的增加逐渐下降。与未盐渍化农田相比，轻度、中度、重度、极重度盐渍化农田土壤电导率、全盐，SO42-，Na＋含量分别增加了31.42%、74.42%、203.95%、693.58%，6.56%、96.38%、86.36%、414.86%，5.23%、114.58%、104.00%、430.32%，31.46%、145.22%、345.11%、1797.70%；HCO3-下降了-11-31%、2.02%、3.75%、10.94%。（4）土壤电导率、全盐、SO42-、Ca2＋、Cl-、Mg2＋、K＋、Na＋之间呈极显著正相关（P〈0.01），但与土壤含水量没有显著正负相关性，与黏粉粒含量呈显著负相关（P〈0-05）；土壤有机碳、全氮、速效氮之间呈极显著正相关（P〈0.01），但与土壤含水量没有显著正负相关性，与土壤电导率、全盐、SO42-、Ca2＋、Cl-、Mg2＋、K＋、Na＋之间呈极显著负相关（P〈0.01）。这说明，在农田盐渍化过程中，随盐渍?

Change of Soil Physico-chemical Characteristics in Farmland Salinization in Arid Oasis

The study on development process of soil environment salinization is a basis for studies of other processes in salinization. In this paper, by using the method of replacing time with space, soil physico-chemical characteristics in the process of farmland salinization （from non-saline （CK）, to lightly, moderately, heavily and to severely salinized Hordeum vulgare L. grown field） were investigated in an arid oasis in northern China. The results showed that：（1） With an increase in salinity, the content of clay decreased, but soil bulk density in surface layer presented a increasing trend （P〈0-05）. As for soil temperature, no significant change was found among the five stages （P〉0-05）. （2） Soil organic carbon （C）, total nitrogen （N）, total phosphorus （P） and available N concentrations decreased significantly with an increase in salinity, while available phosphorus （P） concentration increased significantly. Compared to the non-saline field, soil organic C and total N in lightly, moderately, heavily, severely salinized field decreased by 14.02%, 26.26%, 41.98%, 48.04%and 19-08%, 35.63%, 46.84%, 56.88%. （3） With an increase in salinity, more and more salts accumulated in surface layer. Except HCO3-, all the salt ions increased significantly with an increase in salinity （P〈0-05）, and decreased significantly with an increase in depth. Compared to the non-saline field, soil EC, total salts, SO42-, Na＋ in lightly, moderately, heavily, severely salinized field increased by 31.42%, 74.42%, 203.95%, 693.58%; 6.56%, 96.38%, 86.36%, 414.86%; 5.23%, 114.58%, 104.00%, 430.32%;31.46%, 145.22%, 345.11%, 1797.70%;HCO3-decreased by-11-31%、2.02%、3.75%、10.94%. （4） Analysis showed that there were very significant positive correlation among soil EC, TS, SO42-, Ca2＋, Cl-, Mg2＋, K＋and Na＋（P〈0.01）, but they were significantly negatively correlated with fine particle content （P〈0-05）. Analysis also showed that there were very significant positive correlati