摘要
在昼/夜温度为35℃/25℃和30℃/20℃条件下,研究了模拟氮沉降对稗草和陆稻生长及竞争关系的影响.结果表明:35℃/25℃条件下,每年输入4g.m-2氮处理,稗草和陆稻地上部分生物量分别比对照增加29.18%和27.80%,稗草吸收氮和磷量分别增加87.33%和49.73%,而陆稻吸收氮和磷量无显著变化.在30℃/20℃条件下,每年输入2、4、6g.m-2氮处理后,稗草地上部分生物量分别比对照增加48.99%、72.68%和36.18%,分蘖数分别增加111.11%、122.22%和144.44%,稗草植株氮和磷吸收量分别增加108.88%、129.22%、134.29%和16.53%、65.05%、22.47%,而陆稻均无显著变化.在30℃/20℃条件下,氮沉降显著增加了稗草与陆稻地上部分生物量的比值,但在35℃/25℃条件下影响不显著.表明氮沉降增加可能会提高稗草而降低陆稻的竞争力,而且在温度较低的情况下,这种趋势更明显.
A greenhouse experiment was conducted to study the effects of simulated nitrogen deposition on the growth and competition of C4 weedy species （Echinochloa crusgalli var. mitis L. ） and Ca upland rice （ Oryza sativa L, ） under day/night temperature of 35℃/25℃ and 30 ℃/20℃, The resuhs.showed that under day/night temperature 35 ℃/25 ℃, 4.0 g · m^-2 · a^ -1 N deposition enhanced the shoot biomass of E. crusgalli and O. sativa by 29. 18% and 27.80%, respectively, t compared with control. The N and P uptake by E. crusgalli increased by 87.33% and 49. 73%, respectively, but no Change was found for O. sativa. Under 30 ℃/20℃, three N depositions （2, 4 and 6 g · m^ - 1· a^- 1 ） enhanced the shoot biomass, tiller number, and shoot N and P uptake of E. crusgalli by 48.99%, 72.68% and 36.18%, 111.11%, 122.22% and 144.44%, 108.88%, 129.22% and 134. 29%, and 16. 53%, 65.05% and 22.47%, respectively, but no changes were observed for O. sativa. Nitrogen deposition significantly increased the shoot biomass ratio of E. crusgalli to O. sativa under 30 ℃/20 ℃, but had no impact on this ratio under 35 ℃/ 25 ℃. It was suggested that N deposition could enhance the competition of E. crusgalli over O. sativa, especially under lower air temperature.
出处
《应用生态学报》
CAS
CSCD
北大核心
2007年第4期848-852,共5页
Chinese Journal of Applied Ecology
基金
国家杰出青年科学基金海外合作资助项目(30228005)
关键词
模拟氮沉降
陆稻
稗草
竞争
simulated nitrogen deposition
Oryza sativa L.
Echinochloa crusgalli var. mitis L.
competition.
