盐碱草原土壤特性及生物量空间异质性研究

Soil properties and biomass spatial heterogeneity in saline-alkali grassland

土壤盐分是土壤特性中最活跃和复杂的一部分。受土壤性质、气象、地形、地下水文及长期地球化学过程等自然条件和耕作、灌溉等人类活动因子的影响,土壤水分、盐分的变异状态在一定程度上反映了土壤各层的盐渍化程度和状态。而土壤盐分与水分、土壤物理性质等有十分密切的联系,因此,运用地统计学研究采用振动深松集成技术改良盐碱化草原前后土壤水分、盐分等特性的空间变异规律,以地理信息系统ArcGIS为平台,建立土壤水分、盐分等图形数据和属性数据相结合的信息数据库,建立其空间分异模型和空间分布图,直观的表现各特性的空间变异规律。结果表明,采用振动深松集成技术后土壤盐分含量在空间上有递减,平均ρ(土壤盐)由5.60g.L-1下降到3.73 g.L-1;土壤容重、土壤硬度分别降低13%和24%,利于牧草根系生长,生物量变异结果显示,改良前后的草层高度和产量空间分布逐渐达到了均一化,牧草产量达到了2738.1 kg.hm-2,实现了植被全覆盖,盐碱化草原得到了恢复。

Soil salt is the most active and complex part in soil properties.The variation of soil moisture and salt reflect salinization condition and degree of each soil layer to a certain extent,influenced by natural conditions and human activity,such as tillage,irrigation,soil properties,meteorological,terrain,underground hydrology and long-term geochemistry process etc.Soil salt has close connection with water and soil physical properties,so applying geo-statistics to analysis spatial variation regulation of soil salt and moisture of the pre and post the improved saline-alkali grassland by vibrating deeply-loosening integration technology.ArcGIS as the platform,building information database of graphic data and attribute data of soil moisture and salt,building spatial variation model and spatial distribution graph,which can visual express spatial variation regulation of each properties.The results show that soil salt content is decreasing in space with vibrating deeply-loosening integration technology,the average soil salinity is reduced from 5.60 g·L-1 down to 3.73 g·L-1,soil bulk density,soil hardness,reduced 13% and 24%.Soil physical index is favorable to the growth of grass roots.Biomass variation shows that turf height and yield space distribution gradually reached homogenization before and after the improvement,achieved full coverage of vegetation,and recovered saline-alkali grassland.