摘要
目前,长期退耕恢复如何影响红壤团聚体组成及其碳氮磷生态化学计量特征还不十分清楚。本研究基于湖南红壤试验站连续27年的长期定位试验,选取常规施肥耕作和退耕恢复两个处理,采集0~15 cm耕层土样,利用湿筛法探讨了土壤团聚体粒级组成及其碳氮磷含量与生态化学计量特征对长期退耕的响应规律。结果显示:相比于常规施肥耕作方式,退耕恢复处理下:①土壤水稳性大团聚体(> 0.25 mm)总量显著增加,微团聚体(0.053~0.25 mm)和矿质颗粒(<0.053 mm)含量显著降低;②土壤有机碳和全氮含量显著增加,全磷含量显著降低,其中有机碳含量在各个粒级团聚体中均显著增加,全氮含量则在大团聚体(>2和0.25~2 mm)与微团聚体(0.053~0.25 mm)中显著增加,而全磷含量在各粒级团聚体中均显著降低。另外,0.25~2 mm粒级大团聚体对土壤碳氮磷养分贡献率最高;③土壤C∶N、C∶P和N∶P显著升高,但C∶N在各粒级团聚体中表现较为稳定,而C∶P和N∶P变异性较大,在各粒级土壤团聚体中均有显著升高。综上,退耕恢复增强了耕层土壤的团聚作用,使碳、氮、磷更集中赋存于大团聚体中,对土壤结构、团聚体质量有改善作用,但对于磷素限制作用的增强值得今后注意。
It is not clear how long-term natural restoration affects soil aggregate distribution and C∶N∶P ecological stoichiometric characteristics in red soil.Soil samples(0-15 cm depth)were taken from two treatments,conventional farming(CF)and natural restoration(NR),in a27-year field experiment in Hunan Red Soil Experimental Station.The aim of this study is to investigate the response of soil aggregate distribution and the contents and stoichiometric ratios of soil organic C(SOC),total N(TN)and total P(TP)to long-term natural restoration.Compared with CF,(1)The total soil water-stable macroaggregates(>0.25 mm)in NR significantly increased,and the proportion of microaggregates(0.053-0.25 mm)and mineral particles(<0.053 mm)significantly decreased;(2)The contents of SOC and TN in bulk soil of NR significantly increased.While the SOC content significantly increased in each aggregate size class,TN content in macroaggregates(>2 and 0.25-2 mm)and microaggregates(0.053-0.25 mm)significantly increased.In contrast,TP content significantly decreased in bulk soil and each aggregate-size fraction.The 0.25-2 mm aggregate size class contributed most of nutrients in the bulk soil.(3)The ratios of C∶N,C∶P and N∶P in bulk soil of NR significantly increased.The C∶N ratio of the four aggregates remained constant,while C∶P and N∶P showed greater variability and significantly increased in each aggregate size class.In conclusion,long-term natural restoration enhances soil aggregation effect,which results in more concentrated C,N and P in macroaggregates.While natural restoration can improve soil structure and aggregate quality,attention should be paid to the exacerbated phosphorus limitation in future.
作者
宋莉群
王义东
李冬初
张会民
娄翼来
窦渤凯
尚云涛
王中良
SONG Li-qun;WANG Yi-dong;LI Dong-chu;ZHANG Hui-min;LOU Yi-lai;DOU Bo-kai;SHANG Yun-tao;WANG Zhong-liang(Tianjin Key Laboratory of Water Resources and Environment,Tianjin Normal University,Tianjin 300387,China;School of Geographic and Environmental Sciences,Tianjin Normal University,Tianjin 300387,China;Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2019年第6期1707-1715,共9页
Chinese Journal of Ecology
基金
国家自然科学基金项目(31300381)
天津市应用基础与前沿技术研究计划项目(15JCYBJC49200)资助
关键词
长期退耕
土壤团聚体
碳氮磷
生态化学计量学
红壤
long-term natural restoration
soil aggregate
carbon,nitrogen and phosphorus
ecological stoichiometry
red soil
