芦苇对盐碱地盐分富集及改良效应的影响

Effect of Reeds on Salt Enrichment and Improvement of Saline-Alkali Land

利用自制模拟试验装置研究芦苇不同生长阶段内盐碱土pH、电导率、离子(Ca2+、Mg2+、SO24-、CO23-、HCO3-、Na+、Cl-)含量的变化和芦苇含盐量的变化,以及芦苇生长阶段过后腐烂成腐殖质对盐碱土pH、电导率、有机质含量的影响,揭示了处于生长阶段的芦苇具有富集盐分的能力以及生长阶段过后的芦苇腐烂成腐殖质对盐碱土具有改良作用。结果表明:(1)在芦苇不同生长阶段内盐碱土pH和电导率都呈现降低趋势。土壤pH平均值由9.22降低到8.79;电导率平均值由0.96mS/cm降低到0.43mS/cm。芦苇成熟期-枯黄期,土壤电导率降低趋势平缓,基本达到稳定状态。(2)在芦苇各生长阶段土壤离子含量都缓慢降低,其中HCO3-、Cl-、SO24-、Ca2+含量变化幅度比较大。成熟期-枯黄期,土壤各离子含量降低趋势平缓,基本达到稳定状态。(3)不同生长阶段芦苇吸收盐分是不同的。展叶期-成熟期,芦苇吸收盐分量逐渐增加,成熟期达到最大值。但成熟期-枯黄期,芦苇吸收盐分逐渐减少,说明芦苇富集盐分的能力主要集中在展叶期-成熟期阶段,而成熟期-枯黄期,富集盐分的能力减弱;在不同生长阶段,芦苇的根、茎含盐量缓慢增长,叶含盐量增长速度较快,且叶含盐量比根、茎大。(4)芦苇生长阶段过后腐烂成腐殖质,通过9次取土样分析表明腐殖质能够提高土壤有机质含量。且对土壤pH、电导率也起到了降低的效果。总之,生长阶段芦苇对盐碱土盐分降低具有显著作用,同时生长阶段过后芦苇枯萎腐烂成腐殖质对盐碱土盐分降低和有机质含量提高也同样具有一定的效果。

This paper studied the change of pH,conductivity and ion（Ca2＋,Mg2＋,SO2-4,CO2-3,HCO-3,Na＋,Cl-） contents of saline-alkali soil in different growth stages of reed and salt content change of reed with growth.Meanwhile,it also researched the effect of the humus from reed stem on the pH,conductivity and organic matter of saline-alkali soil.The result reveals the ability of reeds when growing to enrich salt in soil,and the humus from reed can improve saline-alkali soil.The detail results are that：（1）pH and conductivity of saline-alkali soil were gradually decreased in different growth stages of reed.Average pH value in soil reduced to 8.79 from 9.22;average conductivity value was from 0.96 mS/cm down to 0.43 mS/cm.During maturity-brown period of reed,saline soil conductivity changed slightly and was basically in the stable state.（2）Ion contents of saline-alkali soil slowly reduced in different growth stages of reeds.And HCO-3,Cl-,SO2-4 and Ca2＋ contents changed greatly.During maturity-brown period of reed,ion contents of soil changed slightly and was basically in the stable state.（3）At different growth stages of reed,the ability to absorb salt was different.During opening leaf and maturity period,the amount of salt absorbed by reed increased gradually and reached the maximum at the maturity period.After the maturity period,the salt amount decreased gradually,which showed the ability of reed to enrich salt varied with the growth stages.And it was bigger during the opening leaf and maturity period,smaller during maturity-brown period of reed.The amount of salt in root and stem of reed increased slowly,that in leaves increased fastest.And the amount of salt in leaves was more than that in stem.（4）Humus from reed can improve soil organic matter and reduce pH and conductivity according to experimental results.Therefore,the reed when growing can reduce the salt content of saline-alkali soil by absorbing salt in soil and the humus from reed also have a great effect to reduce the salt content and increase the organic matter of saline-alkali soil.