5种植物改良河套灌区盐渍化土壤的效果研究

Salinized soil improvement by planting 5 plant species in Hetao irrigation area

在内蒙古河套灌区重度盐渍化土壤上种植湖南稷子、田菁、高丹草、草木樨、燕麦5种植物,研究其对盐渍化土壤的生物改良效果。结果表明:5种植物均能不同程度降低土壤容重,增加土壤孔隙度,且土壤容重降幅与对照差异显著。与对照相比,种植田菁、湖南稷子、高丹草土壤容重分别下降4.1%、3.4%、4.1%,土壤总孔隙度分别增加5.9%、4.0%、3.8%,毛管孔隙度分别增加7.1%、5.9%、4.2%。5种植物均能有效降低土壤盐碱化程度,提高土壤肥力水平,其中,种植田菁、高丹草、湖南稷子耕层土壤全盐、碱化度下降较为显著,土壤全盐分别下降了15.8%、18.8%、15.0%,碱化度分别下降28.6%、28.6%和26.1%;种植田菁提高土壤养分含量最为显著,土壤有机质、全氮、解氮、速效磷、速效钾分别提高了65.4%、68.4%、43.9%、43.6%、36.4%。改良效果依次为:田菁>高丹草>湖南稷子>草木樨>燕麦,建议在河套灌区重度盐渍化土壤上生物治理模式以种植田菁为主,湖南稷子和高丹草为辅。

In order to understand the biological improvement effects,we planted 5 plant species including Frumentacea,Sesbania,Sudan-grass,sweet clover and oat in moderate and severe salinized soil of Hetao irrigation area,Inner Mongolia.The results showed that,compared with the control,all plant species significantly reduced soil bulk density and increased soil porosity.The soil bulk density with Sesbania,Frumentacea and Sudan-grass treatments decreased by 4.1%,3.4%and 4.1%,the total soil porosity with Sesbania,Frumentacea and Sudan-grass treatments increased by 5.9%,4.0%and 3.8%,and capillary porosity with Sesbania,Frumentacea and Sudan-grass treatments increased by 7.1%,5.9%and 4.2%,respectively.All plant species effectively reduced soil salinization and improved soil fertility.Soil total salt and alkalinity with Sesbania,Sudan-grass and Frumentacea in plough layer decreased significantly;the total soil salt decreased by 15.8%,18.8%and 15.0%,while the alkalinity decreased by 28.6%,28.6%and 26.1%,respectively.Sesbania mostly improved soil organic matter,total nitrogen,available nitrogen,available phosphorus and available potassium by 65.4%,68.4%,43.9%,43.6%and 36.4%,respectively.The effect of 5 plant species on salinized soil improvement was in an order of Sesbania>Sudan-grass>Frumentacea>Sweetclover>oat.Planting Sesbania mainly,supplemented by Frumentacea and Sudan-grass,are encouraged in the moderately and severely salinized area.