摘要
通过大田试验,研究不同灌溉模式和施氮处理对晚稻和早稻不同时期稻田N_2O排放和硝酸还原酶(NR)、亚硝酸还原酶(NiR)和羟胺还原酶(HyR)活性的影响,并分析稻田N_2O排放通量与NR、NiR和HyR活性的关系.两季试验均设3种灌溉模式[常规灌溉(CIR)、"薄浅湿晒"灌溉(TIR)以及干湿交替灌溉(DIR)]和2种施氮处理(N1:100%尿素;N2:50%尿素+50%猪粪).结果表明:N2处理下,TIR模式早稻产量较CIR模式提高20.9%,DIR模式早稻产量和两季总产量较CIR模式分别提高37.4%和21.6%.相同施氮处理下,CIR模式土壤NR和NiR活性大于DIR模式,DIR模式土壤HyR活性在分蘖期、孕穗期和乳熟期显著大于CIR模式.与N1相比,CIR模式下N2处理土壤NR和NiR活性在孕穗期分别提高12.5%-15.1%和12.2%-25.4%;TIR模式下N2处理土壤NiR活性在分蘖期和孕穗期分别提高11.9%-16.9%和17.6%-27.1%,以及土壤HyR活性在乳熟期和成熟期分别提高34.3%-40.8%和10.1%-41.8%;DIR模式下N2处理土壤NiR活性在乳熟期和成熟期分别提高18.0%-26.1%和4.9%-12.9%,以及土壤HyR活性在孕穗期提高27.2%-40.3%.DIR和N2互作显著降低分蘖期和乳熟期土壤NR活性,提高土壤HyR活性.CIR和TIR模式稻田N_2O排放主要集中在乳熟期和成熟期,不同处理两季水稻N_2O总排放量的顺序为DIR-N2>DIR-N1>TIR-N2>CIR-N2>TIR-N1>CIR-N1;两季稻田N_2O排放通量与Hy R活性显著正相关(相关系数为0.423-0.431).因此DIR和N2互作提高了稻田水稻产量、N_2O排放量以及分蘖期、乳熟期土壤HyR活性,但降低了土壤NR活性,且土壤HyR活性显著影响N_2O排放通量,其结果可为稻田N_2O减排提供依据.
The effects of different irrigation modes and nitrogen （N） treatments on N2O emission and nitrate reductase （NR）, nitrite reductase （NiR）, and hydroxylamine reductase （HyR） activities in paddy soil at different growth stages of late rice and early rice were investigated using two field experiments. The relationships between N2O emission flux and NR, NiR, and HyR activities in paddy soil were analyzed. In the present study, the experiments were conducted over two growing seasons and included three irrigation modes—conventional irrigation （CIR）, ‘thin-shallow-wet-dry’ irrigation （TIR）, and alternate wetting and drying irrigation （DIR）—and two N treatments—N1 （100% urea） and N2 （50% urea and 50% pig manure）. In comparison with the CIR mode, the TIR mode increased early rice yield in the N2 treatment by 20.9%, and the DIR mode increased early rice yield and total yield of two growing seasons in the N2 treatment by 37.4% and 21.6%, respectively. In the same N treatment, soil NR and NiR activities were higher in the CIR mode than in the DIR mode. Additionally, at the tillering, booting, and milky stages, soil HyR activity was significantly higher in the DIR mode than in the CIR mode. In comparison with the N1 treatment, the N2 treatment increased soil NR and NiR activities at the booting stage by 12.5%–15.1% and 12.2%–25.4%, respectively, under the CIR mode; enhanced soil NiR activity at the tillering and booting stages by 11.9%–16.9% and 17.6%–27.1%, respectively, and increased soil HyR activity at the milky and ripening stages by 34.3%–40.8% and 10.1%–41.8%, respectively, under the TIR mode; and enhanced soil NiR activity at the milky and ripening stages by 18.0%–26.1% and 4.9%–12.9%, respectively, and increased soil HyR activity at the booting stage by 27.2%–40.3% under the DIR mode. The interaction of DIR and N2 significantly decreased soil NR activity and enhanced soil HyR activity at the tillering and milky stages. N2O emissions from paddy field soil under the TIR and CIR modes were mainly concentrated at the milky and ripening stages, and the total N2O emissions of two growing seasons under different treatments were ranked as DIR-N2 〉 DIR-N1 〉 TIR-N2 〉 CIR-N2 〉 TIR-N1 〉 CIR-N1. The N2O emission flux from paddy field soil was significantly positively correlated with soil HyR activity （correlation coefficient of 0.423–0.431）. The interaction of DIR and N2 increased rice yield, N2O emission from paddy field soil, and soil HyR activity at the tillering and milky stages, but decreased soil NR activity. Moreover, soil HyR activity significantly affected the N2O emission flux. Our results provide a scientific basis for the reduction of N2O emissions from paddy field soil.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2017年第6期1059-1066,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(51469003)资助~~
关键词
硝酸还原酶
羟胺还原酶
N2O排放
“薄浅湿晒”灌溉
干湿交替灌溉
有机无机氮肥配施
nitrate reductase
hydroxylamine reductase
N20 emission
＂thin-shallow-wet-dry＂ irrigation
alternate wetting anddrying irrigation
combined application of organic and inorganic nitrogen fertilizers
