种植年限对植烟土壤团聚体组成与稳定性的影响

发布时间：2018-02-27 17:08

本文关键词： 烟草种植年限土壤团聚体状况团聚体稳定性　出处：《西南农业学报》2017年06期 　论文类型：期刊论文

【摘要】：【目的】揭示不同植烟年限土壤团聚体的分布特征和稳定性,探明烟草种植对土壤结构变化的影响。【方法】以冕宁县长期植烟区域土壤为研究对象,研究种植年限在3年以下、4~6年及7年以上土壤团聚体的粒级组成、机械稳定性、水稳定性、分行维数和结构破坏率的变化。【结果】(1)植烟土壤机械稳定性团聚体以0.25 mm的土壤大团聚体含量最高,所占比例在75.85%~83.56%。随植烟年限的延长,土壤机械稳定性团聚体组成逐渐呈均质化态势,这种变化主要影响到5~2和2~1 mm 2个粒级。(2)植烟土壤水稳性团聚体组成均以0.25 mm的微团聚体为优势级别,随植烟年限的延长,土壤水稳性团聚体变化较非水稳性团聚体变化更快,尤其以5 mm的粒径变化最为显著。(3)在种植初期(3年),土壤水稳性团聚体平均重量直径(MWD)、几何平均直径(GMD)最大,分形维数(D)、结构破坏率(PAD)最小,土壤团聚体稳定性最好,随种植年限的增加,MWD、GMD降低,D、PAD增大。【结论】种植年限对土壤团聚体的组成影响不大,但影响其稳定性。长期种植烟草会使土壤团聚体的水力学稳定性变差,减弱土壤的抗蚀性。
[Abstract]:[objective] to reveal the distribution and stability of soil aggregates in different tobacco planting years, and to find out the effect of tobacco cultivation on soil structure. [methods] the long-term tobacco planting soil in Mianning County was taken as the research object. The grain size composition, mechanical stability and water stability of soil aggregates grown for less than 3 ~ 6 years and more than 7 years were studied. The variation of branch dimension and structural failure rate. [results] the content of mechanical stability aggregates in tobacco planting soil was the highest in 0.25 mm soil, the proportion was 75.85% and 83.56%. The composition of soil mechanical stability aggregates was gradually homogenized, and this change mainly affected the composition of soil water-stable aggregates of 5 ~ 2 and 2 ~ (1) mm.) the composition of water-stable aggregates in tobacco planting soil was 0.25 mm, with the extension of tobacco planting years. The change of soil water-stable aggregates was faster than that of non-water-stable aggregates, especially when the diameter of soil water stable aggregates changed most significantly in the early stage of planting (3 years, the mean weight diameter of soil water-stable aggregates was greater than that of non-water-stable aggregates, and the geometric mean diameter of soil water-stable aggregates was larger than that of non-water-stable aggregates). The fractal dimension and structure damage rate were the smallest, and the stability of soil aggregates was the best. With the increase of planting years, the GMD decreased and the pad increased. [conclusion] planting years had little effect on the composition of soil aggregates. But the long-term planting of tobacco would make the hydraulic stability of soil aggregates worse and weaken the soil corrosion resistance.
【作者单位】：内江师范学院地理与资源科学学院;重庆师范大学地理与旅游学院;
【基金】：四川省教育厅项目(15ZB0273) 四川省农村发展研究中心项目(CR1628) 内江师范学院大学生项目(13NSD-1)
【分类号】：S152.4

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