华中地区水旱轮作模式下水稻季施氮肥对油菜季施氮肥土壤N_2O排放的影响  

Effects of nitrogen fertilization during rice growing season on N_2O emission from the subsequent rapeseed season in central China

作　　者：徐鹏[1] 蒋梦蝶 邬磊[1] 吴限 赵劲松[1] 胡荣桂[1,2] 

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]华中农业大学环境生态中心,武汉430070

出　　处：《环境科学学报》2018年第2期798-804,共7页Acta Scientiae Circumstantiae

基　　金：中央高校基本科研业务费专项资金(No.2662016PY098)~~

摘　　要：设置了水稻季与油菜季均不施用氮肥(N0-0);水稻季施用氮肥150 kg·hm-2(以N计,下同),油菜季不施用氮肥(N150-0);水稻季与油菜季均施用氮肥150 kg·hm-2(N150-150);水稻季不施用氮肥,油菜季施用氮肥150 kg·hm-2(N0-150)4种施肥处理,采用静态箱/气相色谱法对旱作油菜季N_2O的排放进行了原位观测(2016年9月—2017年4月),研究了华中地区水旱轮作模式下水稻季施肥对油菜季土壤N_2O排放的影响.结果表明,油菜季N_2O排放主要集中在施基肥后1周内.N0-0、N150-0、N150-150和N0-150处理N_2O排放通量变化范围分别为-10.81~181.26、-20.48~95.61、-8.87~638.56和-21.76~827.86μg·m-2·h-1,平均排放通量分别为4.58、3.89、21.06和27.24μg·m-2·h-1,N_2O累积排放量分别为0.20、0.17、0.92和1.19 kg·hm-2,施氮肥处理(N150-150和N0-150)N_2O排放量显著高于不施氮肥处理(N0-0、N150-0)(p<0.05).N150-150和N0-150处理N_2O排放通量与土壤孔隙充水率(WFPS)具有显著正相关关系(p<0.05);N150-150和N0-150处理N_2O排放通量与土壤可溶性有机氮(DON)和无机氮(NO-3-N和NH+4-N)具有显著正相关关系(p<0.01).以上结果表明,油菜季N_2O排放与稻季施用氮肥无关,施氮肥对土壤活性氮含量的影响是导致N_2O排放差异的主要原因,而土壤孔隙充水率也是影响油菜季N_2O排放的重要环境因子.Farmland is a main source of nitrous oxide （ N20） which is an important greenhouse gas next to carbon dioxide （ CO2 ） and methane （ CH4 ） , but the effects of agricultural measures on N20 emission are unclear. To study the effects of nitrogen fertilization during rice growing season on N20 emission from the subsequent rapeseed season in central China, a static/gas chromatography method was used by situ observation with no nitrogen fertilizer in two seasons （N0-0 ） ; nitrogen fertilizer of 150 kg. hm-： in rice season and no nitrogen fertilizer in rapeseed season （N150-0 ） ; nitrogen fertilizer of 150 kg·hm^-2 in each season （N 150-150 ） and no nitrogen fertilizer in rice season and nitrogen fertilizer of 150 kg· hm^-2 in rapeseed season （N0-150 ） four kinds of fertilization carried out in a long-term fertilization experiment platform （between September 2016 and April 2017）. The results showed that N20 emissions mainly concentrated within 1 week after basal dressing. N20 fluxes from treatments of N0-0, N150-0, N150-150 and N0-150 varied from -10.81- 181.26, -20.48-95.61, -8.87 - 638.56 and -21.76 - 827.86 μg·m^-2·h^-1 , with average fluxes of 4.58, 3.89, 21.06 and 27.24 μg · m-2. h-1 and cumulative emissions were 0.20, 0.17, 0.92 and 1.19 kgμhm-2, respectively. Cumulative N2O emissions of nitrogen treatments were significantly higher than no nitrogen treatments （p〈0.05）. N20 fluxes from N150-150 and N0-150 treatments both had a significant positive correlation （p〈0.05） with soil waterfilled pore space （WFPS） and a very significant positive correlation （p〈0.01） with soil dissolved organic nitrogen （DON） and inorganic nitrogen. The above results showed that the differences of reactive nitrogen content resulted from nitrogen fertilization in soil is the key to soil N20 emissions and the water filled pore space is also a important environmental factor affecting N20 emissions.

关 键 词：水旱轮作 N2O排放 油菜季 施肥 环境因子 

分 类 号：X17[环境科学与工程—环境科学]