模拟机械压实对黑土微团聚体组成及稳定性的影响  

Effect of mechanical compaction on soil micro-aggregate composition and stability of black soil

作　　者：卢倩倩[1] 王恩姮[1,2] 陈祥伟[1,2] 

机构地区：[1]东北林业大学林学院,哈尔滨150040 [2]东北森林资源培育重点开放实验室,哈尔滨150040

出　　处：《农业工程学报》2015年第11期54-59,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(41271293;41302222)资助

摘　　要：采用田间模拟机械压实的方法，通过对不同深度压实土壤水稳性微团聚体组成、平均质量比表面积、分形维数和分散系数等特征指标的测定、计算与分析，研究了机械压实对黑土区耕作土壤微团聚体组成及稳定性的影响。结果表明：0～20 cm表层土壤仅12次压实时平均质量比表面积、分形维数和分散系数显著高于对照（P＜0.05）；＞20～40 cm亚表层土壤3次压实时平均质量比表面积、分形维数值显著降低，而12次压实时平均质量比表面积、分形维数和分散系数显著增加（P＜0.05）；＞40～80 cm下层土壤，平均质量比表面积、分形维数和分散系数随压实次数的增加而增大，除3次和6次压实之间外，其他处理间差异均达显著水平（P＜0.05）。可以认为，压实对黑土区耕作土壤团聚体组成及稳定性的影响表现为下层土壤的积累压实为主。Aggregates are secondary particles formed through the combination of mineral particles glued by organic and inorganic substances. Soil compaction caused by mechanical tillage practices mainly affects its structure and function by the dispersing, braking, re-proportioning, re-arranging and re-combining aggregates. Although mechanical compaction was reported to reduce the proportion of soil water stable aggregate with size smaller than 0.25 mm, how further impact of mechanical compaction on composition and stability of soil micro-aggregate is still unknown. Comparing to the study of soil macro-aggregates, research on soil micro-aggregates can contribute to a better understanding of disperse strength and structural performance of primary aggregates under particular conditions. Based on the cropland soil in the typical black soil region of Northeast China, the influence of mechanical compaction on soil micro-aggregate composition and stability was studied by measuring and analyzing the soil micro-aggregate distribution, mean weight soil specific area （MWSSA）, fractal dimension （D） and dispersion coefficient at different soil depths （0-20 cm,〉20-40 cm, and〉40-80 cm）. The results showed that mechanical compaction mainly reduced the proportion of macro-aggregate （≥0.25 mm） and increased the proportion of small-sized （〈0.002 mm） micro-aggregate in the 0-20 cm soil depth. The MWSSA,D value and dispersion coefficient were significantly higher than control condition （P〈0.05） when the number of mechanical compaction passes increased 12 times, indicating that repeated compaction could cause a significant reduction on soil micro-aggregate stability. In the soil depth〉20-40 cm, mechanical compaction primarily affected the proportion of micro-aggregates with diameter of 0.05-0.25 mm and 〈0.002 mm. The MWSSA, andD value of soil micro-aggregates decreased significantly （P〈0.05） when the mechanical compaction treatment was only 3 passes but the proportion of each size aggregate distribute

关 键 词：土壤 机械 压实 黑土 微团聚体 分形维数 分散系数 

分 类 号：S152.481[农业科学—土壤学] S156.99[农业科学—农业基础科学]