黄河三角洲盐碱地不同利用方式土壤理化性质

为了缓解土壤盐碱性,保证土壤可持续利用,研究了黄河三角洲典型土地利用类型撂荒地、棉田、苜蓿地和梨园土壤理化性质.结果表明:棉田土壤容重较高,而孔隙度和毛管孔隙度低,由于棉田灌水压盐措施,抬高了地下水位,土壤返盐严重.苜蓿地由于管理粗放,对土壤扰动少,容重较低,孔隙度和毛管孔隙度较高,盐碱度较低;每年对苜蓿的采收显著降低了苜蓿地土壤有机质和养分含量,而豆科固氮菌的存在,使表层速效氮含量较高.梨园位于黄河三角洲土壤质地较好的区域,且有机肥料施用一定程度上缓解了土壤板结,盐碱度较低.撂荒地表层土壤理化指标均显著优于棉田,在退化土壤恢复中具有较好的效果.

Properties of saline-alkaline soil under different land use types in Yellow River Delta

n order to allviate saline-alkaline property of soils for sustainable soil utilization, the properties of soils under the four land use types of wasteland, cotton land, clover land and pear orchard were analyzed. The analysis reveals the following: 1) In cotton lands, there is increasing soil bulk density, decreasing soil porosity and capillarity porosity, and rising water tables driven by the mode of irrigation which induces heavy salt return to soil surface. 2) In clover lands, there is decreasing soil organic matter and other nutrients, and soil physical properties are better with lower salinity due to less human disturbance. On other hand, azotobacter of legume increases the available nitrogen content in surface soil. 3) In pear orchards which are usually planted in areas with better soil quality, soil physical properties are better and salinity is lower than those in cotton lands, driven by the application of organic fertilizer such as animal manure. 4) In waster lands, soil properties are better than in cotton land, land recovering from degenerating cotton lands is feasible.