实验年限对砒砂岩改良风沙土微观结构的影响

Influence of Planting Years on Microstructure of Sandy Soil Amended by Soft Rock

为了厘清植物种植过程对砒砂岩改良风沙土的微观结构的影响,利用扫描电子显微镜(SEM)扫描土壤团聚体并结合Sierpinski分形模型,借助砒砂岩改良土场地实验,定量研究了0年(对照组)、3年、6年、9年4个实验年限下的砒砂岩改良风沙土的微观结构特征及演变过程。结果表明:随着作物种植年限的增加,在种植第6年和第9年后的土壤微团聚体出现了较多数量的桥接状垒结、填集状垒结、包膜状垒结,粒径小于50μm颗粒显著增加,颗粒方向及颗粒形状从简单向复杂转变;改良土颗粒的Sierpinski分维值在种植9年后达到1.2048,相比于种植3年土壤增加了9.88%,表明在种植作用下土壤结构得到显著的改良。

To clarify the influencing mechanism of different planting years on the microstructure of sandy soil amended by soft rock,the evolution processes of soil microstructure under four planting periods of 0 year,3 years,6 years and 9 years are quantitatively analyzed in the experimental field by SEM(scanning electron microscope)and Sierpinski fractal model.The results show that a certain number of the soil with bridge-like barriers,filling-like barriers and envelope-like barriers appear in the micro-aggregates of the soil with crops planted for 6 years and 9 years.With the increasing planting years,the soil particles with diameter less than 50μm significantly increase and the particle orientation and particle shape vary from simple to complex.The Sierpinski distribution fractal dimension reaches 1.2048 after 9 years planting,an increase of 9.88%over that after 3 years planting.The microstructure of the soil is significantly improved due to the planting effect.