吉林南部不同耕作管理下土壤水分对降雨事件的响应  

Responses of soil water content to rainfall events under different tillage management in Southern Jilin Province of China

作　　者：秦诗洁 师登峰 高伟达 Qin Shijie;Shi Dengfeng;Gao Weida(College of Land Science and Technology,China Agricultural University,Beijing 100193,China)

机构地区：[1]中国农业大学土地科学与技术学院,北京100193

出　　处：《农业工程学报》2022年第18期147-155,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目子课题(2021YFD1500802-5)。

摘　　要：土壤水分对降雨的响应特征与降水在地表和土壤中的分配密切相关。该研究为明确不同耕作方式下黑土土壤水分对降雨的响应,利用时域反射仪原位动态监测吉林南部耕作长期定位试验翻耕(CT)和免耕(NT)下玉米生育期含水率,通过7个指标量化两种耕作管理下土壤水分对降雨量大且持续时间长、降雨量小且持续时间短和降雨量较大且持续时间较短、降雨强度大的3类降雨事件的响应。结果表明:1)CT初始含水率较低,0~2.5、2.5~5和5~10 cm累积增加含水率(ASWI)显著高于NT;随土壤深度增加,CT的ASWI明显下降,而NT基本稳定。2)多数情况下,NT下相邻土层累积增加含水率之比(RSWI)大于100%,而CT低于100%。3)高降雨强度下NT相邻土层对降雨事件的响应时间(DRTlayer)平均值和异常值为负值的频率较多,说明NT下更易发生优先流。因此,极端降雨下NT土壤水分响应更剧烈,有利于降水向下层土壤渗透,减少地表径流形成。Soil water content is one of the essential indicators for crop growth.The main source of soil water is then the rainfall in the rainfed agricultural region.Among them,tillage management is one of the important factors for the distribution of rainfall above and below ground,which is closely related to the dynamics of soil water content.However,it is still unclear in the response of soil water content to rainfall events under different tillage management.The objective of this study is to determine the effect of tillage management on the response characteristics of soil water content to rainfall events on Mollisol.The long-standing tillage experiment was carried out in the spring of 2011 at the Lishu Experiment Station of China Agricultural University(43°16′N,124°26′E),located in Lishu,Jilin Province,China.The time-domain reflectometer(TDR)probes were installed in the soil depths of 2.5,5,10,20,30,40,and 50 cm under No-Tillage(NT),and Conventional Tillage(CT)treatments,in order to monitor the dynamics of soil water content.Some parameters were used to quantify the dynamic response of soil water content under NT and CT to rainfall events,including the Accumulated Soil Water Content Increment(ASWI),the ratio of accumulated soil water content increment between adjacent soil layers(RSWI),the maximum(Smax)and mean(Smean)rate or the slope of a soil water content curve under rainfall events,the difference of the soil water content response time between two adjacent soil layers(DRTlayer),the difference of the soil water content response time and rainfall onset time(DRTrainfall),and the duration of soil water response to rainfall events(DUR).According to the rainfall duration and intensity,24 rainfall events were divided into three categories with the K-means clustering:the rainfall eventsⅠwith the large rainfall(25.53±6.52 mm)and long rainfall duration(15.92 h),the rainfall eventsⅡwith the small rainfall(5.42±2.58 mm)and long rainfall duration(2.00 h),and the rainfall eventsⅢwith the large rainfall(19.22±6.49

关 键 词：土壤水分 耕作 黑土 免耕 降雨事件 

分 类 号：S152.72[农业科学—土壤学]