摘要
利用田间试验研究了不同覆盖条件下黄土高原旱作春玉米田土壤团聚体及其有机碳分布状况。试验设无覆盖（CK）、秸秆覆盖（SM）和地膜覆盖（PM）3个处理。结果表明,与CK处理相比,PM处理提高了0~10 cm土层中〉0.25 mm粒径机械稳定性团聚体含量;SM处理提高了0~10 cm和10~20 cm土层〉0.25 mm水稳性大团聚体含量和稳定性,且降低了团聚体的破坏率;SM和PM处理均提高了0~10 cm土层水稳性团聚体的平均重量直径值。在各土层,〈0.25 mm粒径微团聚体有机碳含量在各粒径团聚体中最低。SM处理较CK处理显著提高了0~10 cm土层总有机碳和土壤团聚体各粒径有机碳含量（0.5~0.25 mm粒径除外）,PM处理较CK处理10~20 cm和20~40 cm土层总有机碳和团聚体有机碳有降低趋势。在各土层中,土壤有机碳主要储存在水稳性大团聚体中。SM处理较CK处理提高了0~10 cm和10~20 cm土层大团聚体对土壤总有机碳的贡献率,PM处理作用不显著。总体而言,秸秆覆盖对改善土壤结构及提高固碳作用均具有明显的效果,地膜覆盖仅对土壤团聚体的团聚有促进作用。
The effects of surface mulching on soil aggregate distribution and organic carbon contents were investigated in a spring corn field of the Loess Plateau dryland. Three treatments were control（without mulching）（CK）, straw mulching（SM） and plastic film mulching（PM）. The mass of mechanically stable macro-aggregate（ 0.25 mm） was higher in PM than in CK in the 0- 10 cm layer. Compared with CK, SM increased the water-stable macro-aggregate content in both 0- 10 cm and 10- 20 cm layers and decreased the destruction rate of soil aggregates（P〈0.05）. The mean weight diameter value of water-stable aggregate was higher in SM and PM than in CK in 0- 10 cm soil layer.The organic carbon content was lower in micro-aggregates（ 0.25 mm） than in other aggregates. Compared with CK,SM significantly increased the total organic carbon content and the organic carbon content in the aggregates except for0.5- 0.25 mm size aggregate in 0- 10 cm soil layer. However, both the total organic carbon and the organic carbon in aggregates tended to decline in PM compared with CK in 10- 20 cm and 20- 40 cm layers. Soil organic carbon was mainly stored in macro-aggregates in both soil layers. SM treatment increased the contribution rate of soil macro-aggregates to total soil organic carbon compared with CK, while this effect was not significant between PM treatment and CK treatment in both 0- 10 cm and 10- 20 cm soil layers. Straw mulching could improve soil aggregate structure and promote the sequestration of soil organic carbon, while plastic film mulching could only improve soil aggregates structure in the dryland corn fields.
出处
《土壤通报》
CAS
CSCD
北大核心
2016年第2期405-413,共9页
Chinese Journal of Soil Science
基金
国家自然科学基金项目(31270484
31570440)
西北大学研究生自主创新项目(YZZ13006)资助
关键词
秸秆覆盖
地膜覆盖
土壤团聚体
有机碳
Straw mulching
Plastic film mulching
Soil aggregate
Organic carbon
