不同耕作方式土壤结构季节变化  

Seasonal Variations of Soil Structures under Different Tillage Systems

作　　者：陈强[1,2] Yuriy S Kravchenko 陈帅[1,2] 李浩[1,2] 宋春雨[1] 王禹宸 张兴义[1] 

机构地区：[1]中国科学院东北地理与农业生态研究所黑土区农业生态重点实验室,哈尔滨150081 [2]中国科学院大学,北京100049 [3]Soil Science and Soil Conservation Department, National University of Life and Environmental Sciences of Ukraine

出　　处：《土壤通报》2015年第1期184-191,共8页Chinese Journal of Soil Science

基　　金：国家自然科学基金资助项目(41171230、41071201);国家科技支撑计划项目(2012BAD14B0602)资助

摘　　要：试验于2011年通过对玉米全生育期土壤容重和团聚体的测定,分析4种黑土农田耕作方式土壤结构季节变化。结果表明:从播种到收获,传统耕作平翻(MT)和旋松(Rot)在0~20 cm土层土壤容重逐渐增大。保护性耕作少耕(RT)垄沟深松后(6月)土壤容重降低且显著低于其他耕作方式,免耕(NT)土壤容重季节差异不显著。各耕作方式1~2 mm与0.25~0.5 mm粒级团聚体季节差异不显著,】2 mm团聚体平均含量表现为NT】RT】MT】Rot,且NT更容易形成】5 mm团聚体。各耕作方式】0.25 mm水稳定性团聚体数量(WR0.25)均随时间推移逐渐减少。MT土壤团聚体平均重量直径(MWD)季节差异不显著,10~20 cm土层几何平均直径(GMD)则表现为降低趋势,分形维数随时间推移表现出先增加后降低趋势。Rot的MWD和GMD季节变化均较小。在0~10 cm土层,RT的MWD与GMD先增加后降低,分形维数季节性变幅较大。NT处理8月份土壤团聚体的MWD和GMD最大,在0~20 cm土层,NT方式下WR0.25、MWD和GMD均大于其他耕作方式,而分形维数则小于其他耕作方式且季节变化差异不显著,NT土壤结构季节变化更稳定。The soil bulk densities(BD) and water stable aggregates in the ploughed layer(0- 20 cm) under no-tillage(NT), reduced tillage(RT), moldboard plow tillage(MT) and rotary tillage(Rot) were observed during crop growth season, and their seasonal variations were analyzed. Results showed BD under MT and Rot was increasing from sowing time to harvesting time; BD under MT in October was greater than in May. In RT, deep tillage of the furrow in June significantly lowered BD than other treatments. BD under NT varied slightly. There was no significant difference in seasonal variation of both 1- 2 mm and 0.25- 0.5 mm size classes between all the treatments. The contents of >2mm water stable aggregates followed the order of NT> RT> MT> Rot. And NT had more >5 mm water stable aggregates than other tillage systems. The contents of >0.25 mm water stable aggregates(WR0.25) changing over time showed a decreased tendency. The mean weight diameter(MWD) had no significant difference between different seasons, the geometric mean diameter(GMD) showed a decreased trend in the 10- 20 cm layer of soil, and the fractal dimension increased at first and decreased afterwards under MT. Rot had no significant seasonal variation in MWD and GMD. In the 0- 10 cm layer, MWD and GMD increased firstly and then decreased with time, and fractal dimension had a larger changing range under RT. MWD and GMD in NT had a highest value in August. Compared with MT and Rot, NT was higher in WR0.25, MWD and GMD, lower in fractal dimension. NT got a more stable soil structure than other treatments.

关 键 词：保护性耕作 容重 团聚体 平均重量直径 几何平均直径 分形维数 

分 类 号：S152[农业科学—土壤学]