中国农业科学 ›› 2010, Vol. 43 ›› Issue (20): 4207-4213 .doi: 10.3864/j.issn.0578-1752.2010.20.011

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

利用最小限制水分范围评价短期免耕对黑土有机碳矿化的影响

时秀焕,张晓平,梁爱珍,杨学明,申艳,范如芹,陈学文

  

  1. (中国科学院东北地理与农业生态研究所)
  • 收稿日期:2010-04-19 修回日期:2010-06-27 出版日期:2010-10-15 发布日期:2010-10-15
  • 通讯作者: 张晓平

Effects of Short-Term No Tillage on Soil Organic Carbon Mineralization Using Least Limiting Water Range

SHI Xiu-huan, ZHANG Xiao-ping, LIANG Ai-zhen, YANG Xue-ming, SHEN Yan, FAN Ru-qin, CHEN Xue-wen
  

  1. (中国科学院东北地理与农业生态研究所)
  • Received:2010-04-19 Revised:2010-06-27 Online:2010-10-15 Published:2010-10-15
  • Contact: ZHANG Xiao-ping

摘要:

【目的】探索免耕、秋翻和垄作通过土壤物理特性对农田耕层黑土有机碳的影响。【方法】以2001年秋开始在吉林省德惠市中层黑土上进行了7年的田间定位试验小区土壤为研究对象,对免耕、秋翻和垄作3种耕作处理下耕层土壤有机碳含量进行分析。利用不同耕作方式下最小限制水分范围为评价指标来比较不同耕作处理对土壤有机碳矿化的影响。【结果】与秋翻相比,免耕显著增加了0—5 cm土层有机碳含量,但5—30 cm土层有机碳含量显著小于秋翻。免耕处理土壤有机碳分层率大于其它两种耕作方式。各年份免耕和秋翻处理下最小限制水分范围在0.129—0.170之间,随着耕作年限的增加,最小限制水分范围有减小的趋势,并表现出免耕小于秋翻的规律性。【结论】随着耕作年限的增加,覆盖于地表的秸秆在土壤有机碳表层累积过程中已经发挥了明显作用,与秋翻和垄作相比,免耕处理下土壤有机碳的分层率最大;最小限制水分范围可以用来评价免耕对土壤有机碳的影响,通过最小限制水分范围说明免耕对土壤有机碳的固定作用开始显现。

关键词: 免耕, 土壤有机碳, 最小限制水分范围, 分层率, 黑土

Abstract:

【Objective】 Effects of no-tillage (NT), mouldboard plow (MP) and ridge tillage (RT) on the content of soil organic carbon (SOC) in the plow layer (30 cm) of a black soil in Northeast China were studied. 【Method】 The tillage experiment trial was made in Dehui County, Jilin Province in 2001. The effects of the three tillage managements on SOC mineralization were compared using an indicator, least limiting water range (LLWR) under different tillage treatments. 【Result】 NT significantly increased SOC at the top soil (0-5 cm) compared with MP, but SOC content showed a notable reduction at 5-30 cm depth. SOC stratification ratio under NT was higher than that under MP and RT. The values of LLWR under different treatments throughout the study years ranged from 0.129 to 0.170, which were lower under NT than MP, and they went to decrease with the tillage operation. 【Conclusion】 The residue covered on soil surface every year led to a clear effect on SOC accumulation after 7-year field trial. The stratification ratio of SOC under NT was higher than that under MP and RT. Investigating LLWR was helpful to understand SOC fixation related to NT.

Key words: no tillage, soil organic carbon, least limiting water range, stratification ration, black soil