土壤团聚体稳定性与有机碳对不同年限覆膜种植的响应

Soil Aggregate Stability and Organic Carbon Response to Different Years of Mulch Planting

本试验对贵州遵义市新蒲区辣椒种植基地不同辣椒种植年限(0年、3年、5年和10年)的土壤团聚体组成与土壤有机碳(SOC)含量进行测定,发现薄膜使用形成的微塑料污染显著改变了土壤中团聚体组成分布。干筛结果表明,相比0年辣椒种植土壤,其余3组覆膜种植造成的微塑料污染均导致大于2 mm的粒径团聚体增加30%以上。与此同时,湿筛结果显示,0年、3年、5年覆膜种植土壤的平均重量直径(MWD)和几何平均直径(GMD)呈现降低趋势,即微塑料污染降低了土壤结构稳定性,并且这种消极影响随着覆膜年限增加而逐渐恶化。此外,SOC测定结果表明,微塑料污染加速了土壤有机碳的流失,导致3年辣椒种植土和5年辣椒种植土的SOC含量分别减少5.17 g/kg和9.08 g/kg。

In this study,soil samples from a chilli plantation in Xinpu District,Zunyi City,Guizhou Province,with different chilli planting years(0,3,5 and 10 years)were analysed to determine the composition of soil aggregates and soil organic carbon(SOC)content,and it was found that microplastic contamination caused by the use of films significantly altered the distribution of aggregates in the soil.The dry sieve results indicated that microplastic contamination from the remaining three groups of film planting resulted in an increase of more than 30%of aggregates with>2 mm particle size compared to the soil planted with chilli in 0 years.Meanwhile,the wet sieve results showed that the mean weight diameter(MWD)and geometric mean diameter(GMD)of the 0,3 and 5 years mulched planted soils showed a decreasing trend,microplastic contamination reduced the structural stability of the soils,and this negative effect worsened with the increase in the number of years of mulching.In addition,SOC measurements showed that microplastic pollution accelerated the loss of soil organic carbon,resulting in a decrease in SOC content of 5.17 g/kg and 9.08 g/kg in 3 years and 5 years chilli planting soils,respectively.