减量施氮与间作大豆对华南地区甜玉米连作农田N_2O排放的影响  

Effect of reduced N application and soybean intercropping on soil N_2O emission in sweet corn fields in South China

作　　者：唐艺玲[1] 管奥湄[1] 周贤玉[1] 赖叶宁 王建武[1] 

机构地区：[1]华南农业大学热带亚热带生态研究所/农业部华南热带农业环境重点实验室/华南农业大学广东省高等学校农业生态与农村环境重点实验室,广州510642

出　　处：《中国生态农业学报》2015年第12期1529-1535,共7页Chinese Journal of Eco-Agriculture

基　　金：国家重大基础研究计划(973计划)项目(2011CB100400);国家科技支撑计划项目(2012BAD14B16-04);广东省科技计划项目(2012A020100003)资助~~

摘　　要：通过3季大田试验,采用静态箱?气相色谱法对比研究了两种施氮水平[300 kg(N)?hm?2,N0;360 kg(N)?hm?2,N1]和3种种植模式[甜玉米∶大豆按2行∶3行(S2B3)和2行∶4行(S2B4)行数比间作,甜玉米单作(SS)]对华南地区甜玉米连作农田N2O排放情况的影响。结果表明,相比常规施氮,减量施氮显著降低了土壤N2O的全球增温潜势(GWPN2O,kg?hm?2),其中S2B4-N0的减排效果最好,其3季的土壤GWPN2O依次比S2B4-N1减少66.31%、84.08%和51.31%。种植模式对GWPN2O没有显著影响;间作和减量施氮均显著降低了单位产量的GWPN2O(即N2O排放强度,GHGIN2O,kg?t?1),其中S2B4-N0的减幅最大,其3季平均的GHGIN2O分别比SS-N0和S2B4-N1降低71.60%和71.21%;减量施氮不会影响作物产量且间作系统的土地当量比(LER)均大于1。因此,减量施氮下的甜玉米||大豆间作不仅能保证作物产量,提高土地利用率,而且能降低土壤N2O的排放,其中减量施氮水平下的甜玉米||大豆2行∶4行间作模式(S2B4-N0)的效益最佳。Intercropping systems have been proved to be sustainable, boosted crop productivity and increased resource utilization. However, little has been known about the effect of intercropping on greenhouse gas emissions in field soils.Intensive mono-cropping of sweet corn along with N fertilizer overuse induces nitrous non-point pollution in South China.Cereal-legume intercropping can reduce N application while maintaining crop yield. The objective of this study was to determine the effect of sweet corn and soybean intercropping under reduced N fertilizer on soil N2 O emission and crop yield.A field experiment was conducted in South China Agriculture University during three seasons（autumn of 2013, spring of2014 and autumn of 2014）, two N fertilizer levels（N0： 300 kg·hm^-2and N1： 360 kg·hm^-2） and three planting patterns [sweet corn｜｜soybean intercropping system with line ratios of sweet corn to soybean of 2：3（S2B3） and 2：4（S2B4）, sole sweetcorn（SS）] were used. N2 O emission in the field was determined using the static chamber/gas chromatographic technique.Results showed that reduced N application significantly decreased Global Warming Potential of N2O（GWPN2O, kg·hm^-2）,with treatment of S2B4-N0 producing the lowest GWPN2 O, respectively 66.31%, 84.08% and 51.31% less than S2B4-N1 during the three seasons. However, no significant difference in GWPN2 Owas noted among different planting patterns. In addition, reduced N application did not reduce crop yield and land equivalent ratio（LER） was greater than one in every intercropping systems. As the yield of intercropping system was higher than that of mono- cropping of sweet corn and reduced N application decreased soil N2 O emission, intercropping and reduced N application significantly decreased Greenhouse Gas Intensity of N2O（GHGIN2O= GWPN2O/yield, kg·t^-1）. The lowest GHGIN2 Owas observed under S2B4-N0 treatment. During the three seasons, the average GHGIN2 Ounder S2B4-N0 treatment dropped by 71.60% and 71.21%compared with t

关 键 词：施氮水平 甜玉米||大豆间作 N2O 全球增温潜势 温室气体排放强度 

分 类 号：S151.9[农业科学—土壤学]