【作者】 纪永福；

【导师】 蔺海明； 王继和；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2000， 硕士

【摘要】 试验设在甘肃河西走廊中部的临泽县小泉子治沙站大田中进行，当地土壤盐渍化的主要因素是地下水位高、水质矿化度高、地面蒸发强烈、盐分表聚明显等。本研究采用覆盖措施对当地盐渍土形成的主要因素之一的盐分表聚作用进行控制，覆盖材料选择塑料薄膜、麦草和沙子，在土壤盐分表聚最为强烈的春季土壤解冻期和夏季高温期进行覆盖，对不同覆盖材料在不同季节对土壤不同盐分离子和水分的影响进行研究分析，同时比较研究了3种覆盖材料的覆盖效果，对不同材料在不同季节的覆盖效果机理进行了初步探讨。 选择春季土壤解冻期和夏季高温期这两个土壤盐分表聚最强烈的季节，采用塑料薄膜、麦草和沙子覆盖盐渍土地面，研究表明，覆盖对土壤盐分表聚和水分蒸发损失具有明显的抑制作用。塑料薄膜采用全地面覆盖，麦草的适宜用量为2934.8kg/hm²，沙子的适宜覆盖厚度为4cm。就各种盐分离子而言，受抑制作用由强到弱的顺序是：Cl^-＞K⁺+Na⁺＞Mg²⁺＞SO4^2-＞HCO₃^-＞Ca²⁺；这是由于土壤中各种离子随水移动的能力不同所致。就各种覆盖材料而言，在春季解冻期抑制作用由强到弱的顺序是：塑料薄膜全地面覆盖＞沙子覆盖（覆沙厚度为4cm）＞麦草覆盖（麦草用量为2934.8kg/hm²），其中塑料薄膜全地面覆盖使Cl^-、K⁺+Na⁺、Mg²⁺、SO4^2-、HCO₃^-、Ca²⁺各离子含量在0—0.5cm土层分别比对照减少了59.04％、49.01％、41.04％、21.59％、14.29％、和13.25％，沙子覆盖处理当沙子厚度为4cm时，Cl^-、K⁺+Na⁺、Mg²⁺、SO4^2-、HCO₃^-、Ca²⁺各离子含量在0—0.5cm土层分别比对照减少了58.61％、44.14％、37.44％、26.35％、12.85％和9.09％，麦草覆盖处理当麦草用量达到2934.8kg/hm²时，Cl^-、K⁺+Na⁺、Mg²⁺、SO4^2-、HCO₃^-、Ca²⁺各离子含量在0—0.5cm土层分别比对照减少了36.45％、32.27％、23.38％、15.85％、13.29／ ％和 4．ZI％。在夏季高温期抑制作用由强至弱的顺序是：塑料 薄膜全地面覆盖＞麦草覆盖(麦草用量为2934．skgha勺＞沙子 覆盖（覆沙厚度为4cm），其中塑料薄膜全地面覆盖使Q、 K”＋Na“、Mg‘“、SO4‘一、HCO。一、CaZ“各离子含量在 0一0．scm 土层分别卜对照减少了99．48％、98．08％、gi．47％、65．50％、 44．89％和 19＊3％，麦草覆盖处理当麦草用量达到 2934．skRfnm‘ 时，C厂、K”＋N。”、M牙”、SO4‘一、HCO。、CaZ”各离子含 量在0一0．scm土层分另卜对照减少了96．57％、94．15％、92．47 ％、65．19％、61．64％和 9．14％，沙子覆盖处理当沙子厚度为 4cm时，CI、K”＋Na”、Mg‘“、SO4‘一、HCO。一、Ca‘”各离 子含量在 0—0．scm土层分别比对照减少了 86．27％、sl．98％、 75．17％、63．26％、41．89和 9．33％。在春季和夏季的这种不同 是有麦草和沙子对地温的影响造成的。就土层而言，盐分和水 分变化最明显的是 0—0．scm土层，其次是 0．5—10cm土层， 在10—30cm和30—50cm土层变化较弱。就春季解冻期和夏 季高温期相比，在夏季高温期覆盖盐渍土地面，对土壤盐分离 子表聚和水分蒸发损失的抑制作用更显著。更多还原

【Abstract】 The testing field was established at the farm of Linze Xiaoquanzi Desert Control Station (DCS) in the middle part of the Hexi- corridor. Using the cover measure to control formation forms accumulating on the ground surface, which is the one of the main factors of the soil salinization. The covering material are plastic film, wheat straw and sand. The spring thawing season and summer high temperature season on which salinity accumulating on the ground surface and water evaporating on are the most serious, were chosen. This thesis analysed the effect of three covering materials on the two seasons, and approached to the mechanism of coVer effect. The research shows: on the spring thawing season and summer high temperature season, covering ground surface on the salinized soil with plastic film, wheat straw and sand can control salinity accumulating effectively on the ground surface and reduce water evaporating on. And the research also shows that plastic film should cover all ground surface, the fitable quantity of wheat straw should be 2934.8kg/hm2 and the fitable thickness of sand cover should be 4.0cm. To the different salinity ions, the controled order of the different salinity ions are: CV>K +Na>Mg>>SO4> >HCO7>Ca2 To the three covering materials, in the spring thawing season, the effect of the cover all ground surface by plastic film is best, the second is sand cover of 4.0cm thickness. In the summer high temperature season, the effect of the all ground surface cover is best, the second best effect is wheat straw covering of 2934.8kg/hm2 quantity. The difference of covering effect in spring thawing season and summer high temperature season is due to the difference of soil temperature of the covering ground with sand or wheat straw. To the layer variation of soil salinity and water, the best covering effect is the surface ground, the second is 0.5-0cm layer, the 10-0cm and 30?0cm layers are less effect.更多还原