摘要
取不同连作年限(连作0、3、5、7年)的土壤测定其生物和非生物环境因子,并采用盆栽的方法获取不同连作年限的马铃薯幼苗,测定其生长发育指标及抗性生理指标,以探究马铃薯不同连作年限土壤生物和非生物环境因子的变化。结果表明:随着连作年限的增加,土壤含盐量、碱解氮含量和土壤容重逐年上升,在连作7年时分别比对照高348.31%、228.57%和5.39%;在连作5年和7年时,速效磷、速效钾和有机质含量显著下降,连作7年时比对照下降27.43%、31.27%和38.30%;土壤中酚酸类化感物质含量(除对羟基苯甲酸外)显著增加;在连作5年和7年时,香草酸分别高于对照24.87%、19.82%;阿魏酸和总酚酸含量在连作7年分别达到对照的270.2%、374.9%;土壤中脲酶、过氧化氢酶、碱性磷酸酶和转化酶活性显著下降,其中转化酶活性在连作3、5、7年时其活性分别下降为对照的78.6%、70.8%和48.1%;细菌和放线菌数量显著减少,连作7年时分别比对照下降26.67%和10.85%;马铃薯幼苗叶片叶绿素含量、抗氧化酶活性、根系活力和净光合速率显著下降,MDA含量和活性氧产生速率显著升高。从整体上看马铃薯连作5年和7年幼苗生长发育受到显著抑制,说明连作障碍达到显著水平,这与上述土壤各环境因子的变化是相对应的,这可能就是连作障碍的直接原因。马铃薯连作5年和7年时,由于土壤菌类组成、关键酶活和理化性状的改变及酚酸类化感物质含量的显著增加,造成了一系列生物和非生物环境胁迫,从而导致连作障碍的发生。
This study aims to investigate the effect of potato continuous cropping on soil properties,thus clarifying factors contributing to continuous cropping obstacles,using pot culture experiments. We analyzed soil properties including microbiological compositions,fertility,physicochemical properties and contents of phenolic acid and allelochemicals of potato continuous cropping soil,and performance of potato seedlings. The results indicated that soil salinity,alkaline hydrolysis nitrogen content and soil bulk density increased,as the continuous cropping prolonged. Activities of urease,catalase,alkaline phosphatase and invertase decreased markedly when continuous cropping lasted for 5 and 7 years,while the quantity of soil＇s bacteria and actinomycetes decreased. The content of chlorophyll,activities of antioxidase,root activity and net photosynthetic rate decreased significantly when the continuous cropping lasted for 5 and 7 years. As a whole,continuous cropping obstacle was not obvious when continuous cropping lasted for 3 years. But potato continuously cropping lasted for 5 and 7 years,a series of biotic and abiotic stres-ses were triggered due to increasing of compositions of soil fungi,and the activity of key enzyme,the changes of physicochemical properties,and phenolic acid and allelochemicals contents,resulting in continuous cropping obstacle.
出处
《干旱地区农业研究》
CSCD
北大核心
2015年第4期16-23,共8页
Agricultural Research in the Arid Areas
基金
国家科技支撑计划课题(2012BAD06B03)
国家马铃薯产业技术体系(CARS-10-P18)
甘肃省科技重大专项(1102NKDM025)
甘肃省农牧厅项目(GNSW-2012-21)
关键词
马铃薯
连作障碍
土壤酶活性
土壤微生物
抗性生理
potato
continuous cropping obstacle
allelochemicals
soil enzyme activity
soil microorganism
stress physiology
