摘要
长时间序列土壤关键氮(N)转化过程和相关微生物的变化规律仍不清楚。以慈溪市滨海围垦农田土壤为研究对象,利用室内培养法研究了11个不同利用年限土壤(0~1000a)N矿化速率、硝化强度和硝化细菌数量。结果表明,随着利用年限的增加,土壤电导率和pH下降,而有机质和全氮逐渐积累,土壤性质在利用前50a内变化幅度较快;土壤N矿化速率的大小表现为:220~1000a>0~50a>60~200a;硝化强度大体随着利用年限的延长而增强,而土壤硝化细菌数量表现为在0~20a增加后逐渐降低的趋势,其中,20~60a达到最高;皮尔森相关和聚类推进树(ABT)分析表明,土壤利用年限(45%)、电导率(12%)和有机质(11%)是影响硝化强度的主控因子,土壤中NH4+-N和有效磷含量分别是影响N矿化速率(86%)和硝化细菌数量(42%)的关键限制因子。因此,海陆界面土壤在持续农业利用过程中,硝化强度及硝化细菌丰度得到一定加强,但同时受到历史条件和当代环境因素的共同影响。
【Objective】 It is still unclear how key soil nitrogen (N) transformed and how the microbes involved in the transformation evolved along a long-term chronosequences of the soil in the coastal polders in Cixi.【Method】An indoor incubation experiment was carried out using soil samples collected from coastal polders in Cixi with cultivation age varying in the range of 0~1 000 years to determine N mineralization rate (NMR), nitrification intensity (NI) and number of nitrobacteria (NN).【Result】Results show that soil conductivity (EC) and pH decreased with aging of the soil, while soil organic matter (SOM) and total N (TN) accumulated in the topsoil, and soil properties changed significantly, especially during the first 50 years of cultivation. NMR varied in the sequence of 220~1 000 a > 0~50 a > 60~200 a;NI displayed a general rising trend with the cultivation going on year after year , but NN increased in the first 20 years, and peaked during the years of 20~60 and then turned downwards gradually, Person correlation and aggregated boosted tree (ABT) analyses show that cultivation history of the soil, EC, and SOM concentration were the dominant affecting factors, explaining 45%, 12% and 11% of the variation of NI, respectively, while soil NH4 +-N and available P contents were the ones, explaining 86% and 42% of the variation of NMR and NN, respectively.【Conclusion】 Therefore, it could be concluded that during the course of sustainable agricultural utilization of the coastal polders nitrification intensity and nitrobacteria abundance increases to a certain extent, but they are subject to the joint impact of historical conditions and contemporary environmental factors.
作者
汪峰
姚红燕
陈若霞
陈贵
戴瑶璐
WANG Feng;YAO Hongyan;CHEN Ruoxia;CHEN Gui;DAI Yaolu(Ningbo Academy of Agricultural Sciences,Ningbo,Zhejiang 315040,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing210008,China;Jiaxing Academy of Agricultural Sciences,Jiaxing,Zhejiang 314016,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2019年第5期1161-1170,共10页
Acta Pedologica Sinica
基金
国家自然科学基金项目（41501279）
土壤与农业可持续发展国家重点实验室开放基金项目（Y20160013）
宁波市农业科学研究院甬苗人才项目（2016YYM003）共同资助~~
关键词
利用年限
时间序列
硝化强度
矿化速率
滨海围垦农田土壤
Utilization years
Chronosequences
Nitrification intensity
Mineralization rate
Coastalpolder farmland soil
