摘要
探讨不同养鸭数量对稻田甲烷(CH4)排放的影响,为确定稻鸭共育模式中最佳养鸭数量提供环境学支撑。运用静止箱原位采样技术测定了不同养鸭数量的稻田甲烷排放通量、稻田土壤化学性质、产甲烷细菌种群数量以及水层溶解氧含量。结果表明,不同养鸭数量稻田水层溶解氧含量间差异显著(p<0.01),养鸭数量越多,溶解氧含量越高。20只鸭/667m2稻田的水层溶解氧含量最大,与对照比,早稻增加了2.2%～68.7%,晚稻增加了11.07%～110.77%;养鸭稻田土壤还原物质含量减少,产甲烷细菌数量下降。不同养鸭数量的稻田甲烷排放量之间差异显著,养鸭数量越多,甲烷排放量越少,与对照比,早稻减少了18.22%～28.13%,晚稻减少了17.73%～34.44%。相关分析表明,甲烷排放通量与水层溶解氧含量呈极显著负相关(p<0.001),与土壤还原物质含量及产甲烷细菌数量呈显著正相关(p<0.01)。因此,稻鸭共育减排甲烷的主要原因是养鸭提高了水体和土壤中溶解氧含量,增加养鸭数量促进甲烷减排。
The study carried out different treatments consisted of different numbers of duck in the rice-duck ecosystem compared with the no-duck rice farming in an early and late season. The treatments were designed with triplication by randomized blocks. Methane emission fluxes from paddy soils were measured by the static chambers technique. The correlations between methane emission and soil physical and chemical characteristics were also analyzed. The results showed significant differences （p 〈 0.01 ） existed in the dissolved oxygen contents of water in the treatment fields, and that the more ducks, the higher the dissolved oxygen content. The dissolved oxygen content of 20 ducks per 667m^2 was higher than any other situation compared with no-duck rice farming. The oxygen dissolve increased by 2.2%-68.7% and 11.07%-110.77% in the early and late season respectively. Secondly, the soil redox matter content and methanogenic bacteria population of the rice-duck ecosystem reduced more sharply than the no-duck rice farming resulting in a lower methane production. Moreover, methane emission fluxes at different growth stages varied as the methanogenic bacteria population varied. Thirdly, the amount of methane emission differed between the treatments - the more ducks, the less methane emission. Methane emission of rice-duck ecosystem reduced by 18.22% -28.13% during the early season and by 17.73% -34.44% during the late season in comparison with no-duck rice farming. The other related analysis showed that the negative correlation was significant （p 〈 0. 001 ） between the methane emission flux and dissolution oxygen content of water body. However, CH4 emission flux had significant positive correlation （p 〈 0.01 ） with the soil redox matter content and rice field methanogenic population. Therefore, more ducks in the rice-duck ecosystem resulted in lower methane emission than the no-duck rice farming. The optimal number of duck has great effect on methane mitigation.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第5期2107-2114,共8页
Acta Ecologica Sinica
基金
国家“十一五”粮食丰产科技工程资助项目(2006BAD02A01)~~
关键词
稻-鸭
甲烷
溶解氧含量
甲烷细菌
机理
rice
number of ducks
methanogenic bacteria
methane mitigation
mechanism
