不同干湿交替频率对土壤速效养分、水溶性有机碳的影响  

Influence of different drying-rewetting frequencies on available soil nutrients and DOC

作　　者：李梦寻 王冬梅[1] 任远[1] 汪西林[1] LI Mengxun, WANG Dongmei , REN Yuan, WANG Xilin(School of Soil and Water Conservation, Beijing Forestry University, Key Laboratory of Soil ＆ Water Conservation ＆ Desertification Combating of Ministry of Education, Beijing 100083, Chin)

机构地区：[1]北京林业大学水土保持学院水土保持与荒漠化防治教育部重点实验室,北京100083

出　　处：《生态学报》2018年第5期1542-1549,共8页Acta Ecologica Sinica

基　　金："十二五"国家科技支撑计划课题(2012BAC16B03;2011BAC09B08-07)

摘　　要：为了探究不同干湿交替频率对速效养分、DOC的影响机理,选择北京褐土(表层0—10cm土壤)为研究对象,采用室内模拟控制实验法,控制其他变量,设计一系列不同频率的干湿交替实验,在58d内设置了10d土壤培育期和48d试验期,其中48d试验期设置0、1、2、3、4次干湿交替,试验结束(第58天)进行速效养分、水溶性有机碳(DOC,Dissolved organic carbon)等主要土壤速效养分指标测定。采用单因素方差分析与LSD多重比较法进行数据分析,研究结果显示:恒湿组的速效钾、硝态氮含量比干湿交替组高;低频率的干湿交替使得土壤速效钾含量减少,高频率可能在后期出现释钾现象,速效钾含量随着干湿交替频率增加可能会有所增加,趋近恒湿组速效钾水平,4次干湿交替频率是出现速效钾回升的临界次数;硝态氮含量随着频率增加也有增加趋势,低频率的1次干湿交替(DW1,1 drying-rewetting cycle)硝态氮含量最低,高频率的4次干湿交替(DW4,4 dryingrewetting cycles)最高,干湿交替频率增加更频繁的打破平衡,促进矿化,干湿交替组也趋近恒湿组的硝态氮水平。经过干湿交替,土壤中速效钾、铵态氮、DOC的含量下降,硝态氮含量增加,速效磷、pH的变化不明显。在固定时间内(48d),随着干湿交替的频率增加(从1次到2、3、4次),周期变短(从48d到24、16、12d),干燥与湿润的持续时间变短(从24d到12、8、6d),干湿交替组的速效钾、硝态氮含量分别趋于恒湿组的速效钾、硝态氮水平。To investigate the mechanism of influence of different drying-rewetting frequencies on available soil nutrients and DOC,in this study, we collected cinnamon soil at a depth of 0-10cm below the surface in Beijing and manipulated soil water stress in the laboratory by exposing soil to 0, 1, 2, 3, or 4 drying-rewetting cycles for 58 days, including a 10 day pre-incubation period and a 48 day treatment period. After 58 days, principal soil fertility indexes such as available nutrients and DOC were tested to observe changes as a result of different drying-rewetting frequencies. Data were analyzed using single-factor variance analysis and the Least Significant Difference method （LSD） for the dependent groups. Available K and nitrate nitrogen were lower in the drying and rewetting treatments than in the constantly moist treatment（CM）. Low drying-rewetting frequency might lead to the loss of available K, while K release might appear in the late stages of high drying-rewetting frequency conditions. As drying-rewetting frequency increased, the available K also increased. Four drying-rewetting cycles were critical for K release. Increasing the drying-rewetting frequency would result in frequent perturbations to the balance between various forms of nitrogen, and the mineralization rate would increase at the lowest drying-wetting frequency （DW1, 1 drying-rewetting cycle） and the highest drying-wetting frequency （DW4, 4 drying-rewetting cycles）. As drying-wetting frequency increased, nitrate nitrogen of drying-rewetting treatment become closer to that of constantly moist （CM）. Soil nitrate nitrogen significantly increased, while available K, ammonium nitrogen, and DOC significantly decreased, with drying-wetting frequency, and available P and pH were relatively insensitive to drying-rewetting frequency. In 48 days, with increase in drying-rewetting frequency （from 1 cycle to 2, 3, and 4 cycles） and decrease in drying-rewetting period （from 48d to 24, 16, and 12d） and the last period of each drying o

关 键 词：干湿交替 频率 速效养分 水溶性有机碳(DOC) 

分 类 号：S158[农业科学—土壤学]