耕作方式对土壤水分入渗、有机碳含量及土壤结构的影响

发布时间：2018-08-19 15:45

【摘要】：为探明不同耕作方式对土壤剖面结构、水分入渗过程等的作用机理,采集田间长期定位耕作措施(常规耕作、免耕、深松)试验中的原状土柱(0~100 cm)及0~10 cm、10~20 cm、…、90~100 cm环刀样、原状土及混合土样,通过室内模拟试验进行了0~100 cm土层土壤入渗过程和饱和导水率的测定,分析了不同土层的土壤有机碳含量、土壤结构特征及相互关系。结果表明:从土柱顶部开始供水(恒定水头)到水分全部入渗到土柱底部的时间为:常规耕作免耕深松;土柱土壤入渗速率和累积入渗量为:深松免耕常规耕作;土柱累积蒸发量为:常规耕作免耕深松。土壤的饱和导水率表现为:0~10 cm和50~60 cm土层,免耕深松常规耕作;20~50 cm和60~100 cm土层,深松免耕常规耕作。随土层的加深,0.25 mm水稳性团聚体含量和土壤有机碳含量均表现为先增加(10~20 cm)再降低的趋势。在0~40 cm土层和80~100 cm土层,均以深松处理0.25 mm水稳性团聚体含量最高。在60 cm以上土层,土壤有机碳含量表现为:免耕深松常规耕作,而60 cm土层以下土壤有机碳显著降低,均低于4 g·kg?1,且在70 cm以下土层,常规耕作免耕深松。综上,耕作措施能够改变土壤有机碳含量,改善土壤结构,促进土壤蓄水保墒;深松更利于水分就地入渗,而免耕则更利于有机碳的提升和水分的储存,其作用深度在0~60 cm土层。
[Abstract]:In order to find out the action mechanism of different tillage methods on soil profile structure and water infiltration process, the undisturbed soil columns (0 ~ 100 cm) and 0 ~ 10 cm ~ (10) ~ (10) ~ (10) cm ~ (10) ~ (20 cm) of soil column were collected in field long-term positioning tillage measures (conventional tillage, no-tillage, deep loosening). The infiltration process and saturated water conductivity of 0 ~ 100 cm soil layer were measured by laboratory simulation tests. The soil organic carbon content, soil structure characteristics and correlation between different soil layers were analyzed. The results showed that the time from the water supply (constant head) to the bottom of the soil column from the top of the soil column to the bottom of the soil column was as follows: the conventional tillage no-tillage deep loosening, the infiltration rate and cumulative infiltration rate of soil column soil as follows: deep loose no-tillage conventional tillage; Soil column accumulated evaporation: conventional tillage no-tillage deep loosening. The saturated water conductivity of the soil was 10 cm and 50 ~ 60 cm soil layer, 20 ~ 50 cm and 60 ~ 100 cm soil layer by conventional tillage, and conventional tillage by no-tillage method. With the deepening of soil layer, the content of water-stable aggregate and soil organic carbon increased first (10 ~ 20 cm) and then decreased. In 0 ~ 40 cm soil layer and 80 ~ 100 cm soil layer, the content of water stable aggregates was the highest in the deep loosening treatment of 0.25 mm. In more than 60 cm soil layer, the soil organic carbon content was as follows: no tillage deep loosening conventional tillage, but under 60 cm soil layer soil organic carbon decreased significantly, all were lower than 4 g kg 路kg ~ (-1), and below 70 cm soil layer, conventional tillage was deep and loose. In summary, tillage measures can change soil organic carbon content, improve soil structure, promote soil moisture storage and conservation; deep soaking is more conducive to local infiltration of water, while no-tillage is more conducive to organic carbon promotion and water storage. The depth of action is in 0 ~ 60 cm soil layer.
【作者单位】：河南省农业科学院植物营养与资源环境研究所;农业部作物高效用水科学观测实验站;
【基金】：国家自然科学基金项目(U1404404) 河南省农业科学院优秀青年科技基金(2016YQ12) 国家高技术研究发展计划(863计划)课题(2013AA102904)资助~~
【分类号】：S152;S153.6

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