摘要
【目的】研究不同灌溉施氮模式对稻田甲烷(CH_(4))和氧化亚氮(N_(2)O)排放的影响,以获得降低2季稻田温室气体(GHG)排放的灌溉施氮模式。【方法】通过田间试验,测定了3种灌溉模式(常规灌溉CR、"浅湿晒"灌溉TR和干湿交替灌溉DR)和3种施氮处理下FN1(纯氮120 kg/hm^(2),ω(基肥)∶ω(分蘖肥)∶ω(穗肥)=20∶40∶40)、FN2(纯氮120 kg/hm^(2),ω(基肥)∶ω(分蘖肥)∶ω(穗肥)=50∶25∶25)、FN3(纯氮90 kg/hm^(2),ω(基肥)∶ω(分蘖肥)∶ω(穗肥)=50∶25∶25)2季稻田CH_(4)和N_(2)O通量,并计算了其全球增温潜势(GWP)和温室气体排放强度(GHGI)。【结果】FN1处理和FN3处理下DR模式2季稻产量合计较CR模式分别增加17.9%和21.1%。TR模式和CR模式下FN1处理早稻产量和2季稻产量合计较FN2处理分别增加13.4%和11.4%,以及16.1%和12.6%。DR模式下FN2处理早稻产量较FN3处理增加11.0%。DR-FN1处理2季稻产量合计最高。FN1、FN2处理和FN3处理下TR和DR模式整个生育期2季稻田CH_(4)累积排放量较CR模式分别降低17.1%~22.5%和43.0%~56.8%,但是FN1处理和FN2处理下稻田N_(2)O累积排放量较CR模式分别增加69.3%~85.2%和146.2%~160.7%。TR模式下,FN3处理整个生育期2季稻田CH_(4)和N_(2)O累积排放量分别较FN2处理降低26.8%和32.3%。TR和DR模式的GWP和GHGI低于CR模式,且DR模式GWP和GHGI最低。FN1处理和FN3处理的GHGI低于FN2处理,且FN1处理的GHGI最低。因此,不同施氮处理下,TR和DR模式代替CR模式可以降低GWP和GHGI。【结论】TR和DR模式下,采用低氮肥用量以及少施基肥和多施追肥方案来可以降低GWP和GHGI,其中DR-FN1处理是本研究合适的灌溉施氮模式,可以增加水稻产量并降低GWP和GHGI。
【Objective】Greenhouse gas emissions from agricultural soils are modulated by a multitude of abiotic and biotic factors,and the objective of this study is to elucidate how irrigation and nitrogen(N)fertilization combine to affect emissions of methane(CH_(4))and nitrous oxide(N_(2)O)from double-harvest rice field in south China.【Method】The experiment was conducted in a rice field and compared three irrigations:conventional irrigation(CK),thin-wet-dry irrigation(TR),alternate wet and dry irrigation(DR);and three N fertilizations:120 kg/hm^(2)with 20%used for basal and 80%for topdressing(FN1),120 N kg/hm^(2)with 50%for basal and 50%for topdressing(FN2),90N kg/hm^(2)with 50%for basal and 50%for topdressing(FN3).In each treatment,we measured crop yield,emission of CH_(4)and N_(2)O,and then calculated their global warming potential(GWP)and GHG emission intensity(GHGI).【Result】Compared with CK combined with FN1 or FN2,DR combined with FN1 or FN2 increased total yield of the rice at the two seasons by 17.9%and 21.1%,respectively.In contrast,combing TR or CK with FN1 increased the yield of the early rice and the yields of the rice in the two seasons by 13.4%and 11.4%,and 16.1%and 12.6%,respectively,compared with their combination with FN2.Under DR irrigation,FN3 increased the early rice yield by11.0%compared to FN2.Of all treatments,DR+FN1 was optimal in increasing total yield of the rice in the two seasons.Compared to CK,TR and DR reduced the cumulative CH_(4)emissions over the whole growth season by17.1%~22.5%and 43.0%~56.8%,respectively;but when combined with FN1 or FN2,they increased the cumulative N_(2)O emissions by 69.3%~85.2%and 146.2%~160.7%,respectively.Combing TR and FN2 reduced the cumulative CH_(4)and N_(2)O emissions by 26.8%and 32.3%,respectively,compared to its combination with FN3.【Conclusion】In terms of irrigation,TR and DR reduced both GWP and GHGI compared to CK,especially DR.In terms of N fertilization,FN1 and FN3 emitted less gases than FN2,especially FN1.Therefore,TR and DR combined with reduced N application was more effective to mitigate GWP and GHGI,especially after reducing its proportion for basal application.
作者
李熠凡
李烙布
李伏生
LI Yifan;LI Luobu;LI Fusheng(College of Agriculture,Guangxi University,Nanning 530005,China)
出处
《灌溉排水学报》
CSCD
北大核心
2021年第12期44-53,共10页
Journal of Irrigation and Drainage
基金
广西科技计划-基地和人才专项(AD17195060)
国家自然科学基金项目(51469003)。
关键词
“浅湿晒”灌溉
干湿交替灌溉
CH4和N2O排放
全球增温潜势
温室气体排放强度
“Thin-wet-dry”irrigation
alternate wetting and drying irrigation
CH_(4) and N_(2)O emission
global warming potential
greenhouse gas emission intensity
