秸秆焚烧对土壤微团聚体及有机无机复合体组成的影响

Effect of Straw Burning on Composition of Micro-aggregate and Organic-mineral Complex in Soil

针对东北玉米田间＂平铺式＂和＂成铺式＂2种秸秆焚烧处理方式,对秸秆焚烧前后土壤中微团聚体组成及有机无机复合体组成进行研究,结果表明：2种秸秆焚烧方式仅对0~2 cm表层土壤中团聚体组成具有影响,且成铺式焚烧对其的影响更为显著。与未焚烧相比,2种秸秆焚烧处理均有大粒级微团聚体（〉0.2 mm和0.2~0.02 mm）含量显著降低,而小粒级微团聚体（0.02~0.002 mm和〈0.002 mm）含量显著升高。秸秆焚烧后土壤分散系数也明显升高,其中成铺式焚烧提高了33.82%~58.23%,而平铺式焚烧提高了13.50%~23.01%。有机无机复合体组成中,与未焚烧相比,仅成铺式焚烧对其影响显著,表现为粘粒和细砂粒含量降低、粉粒含量升高。2种焚烧处理下,各粒级复合体中碳储量均低于未焚烧,且在粘粒和细砂粒复合体中其有机碳含量降低,而粉粒复合体中其有机碳含量升高。结果表明：成铺式焚烧对土壤团聚体组成的影响较平铺式焚烧强;秸秆焚烧会使得土壤团粒结构有向小粒级微团聚体聚集的趋势,从而破坏了土壤微团聚结构,降低了土壤的微结构水稳定性。

This study aims at the two burning treatments of＂Ping-pu burning＂and＂Cheng-pu burning＂in the corn field in Northeast China. It researched the composition of soil micro-aggregates and organic-mineral complex in the field before and after straw burning. The results showed that： two straw burning treatments only affected soil aggregate composition of 0-2 cm surface,and effect of Cheng-pu burning was more significant. Compared with non-burning,two straw burning treatments made content of large granule micro-aggregates（ 0. 2 mm and 0. 2- 0. 02 mm） significantly decrease whereas content of small granule micro-aggregates（ 0. 02-0. 002 mm and 0. 002 mm） sig-nificantly increase. After straw burning,soil dispersion coefficient significantly increased,and that of Cheng-pu burning improved by 33. 82%- 58. 23% while that of Ping-pu burning improved by13. 50%- 23. 01%. In organic-mineral complex composition,compared with non-burning,only Cheng-pu burning affected it significantly. To Cheng-pu burning,content of clay and fine sand decreased,content of silt increased. Under two kinds of burning treatments,carbon storage capacity of each graded organic-mineral complex composition was significantly lower than non-burning,and their organic carbon content in the clay and fine sand complexes reduced,while in silt complex organic carbon the content increased. These results indicate that in the impact of soil aggregates composition,Cheng-pu burning is stronger than Ping-pu burning; straw burning makes soil aggregate structure tend to accumulate for small granule micro-aggregates,thus straw burning damages structure of soil micro-aggregates,reduce microstructure water stability of soil.