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1、AbstractThis paper discussed the sumlner maize field ecosystemsby usi ng t11e staticchamber sampling on different soil moisture and different fertilizationWithin 2consecutive years of observation and research on the gas e111issions i11 differentgro州11 stages，using gas chromatograplly for sanlple ana
2、iysis，we。btained t11e gasemissions rules of corn field greenhouseThe results areas foilows：(1)Seasonal change of tile summer maize soil C02 emission increases and 20esto the 1naxlnlunl within about sixty daysThen it dropsLownitrogen concenIration(N150 mgkg。1)deal with summer corn soil C02 emissions
3、by a maximum of 5137ragmz11；hlgh nitrogen concentration(N300 nag。kg。1)deal with sLlllllner com in soilC02 emission maxinlum is 5897 nlgm 2hThe change is consistent with the summermalZe growth cycle，in which the sumnler maize isusually at tile nlost exuberant stageatter growth of sixty daysThe temper
4、ature of 5cm soil，1 0cm soil and 20cm soil ofsumlll吖maize significantly correlates with seasonal changes of its C02 emission rule(孙In different growth stage of sumnler maize，tile intraday c1】a119e of C02ellllSSlOn SHOWS the sameIt increases from nightand goes to tile maxinlLull at 1 4：00Then it fall
5、sAfter applying three concentlations of nitrogenous fertilizer within a11tile growth stages-the intraday change of C02 emission shows great differelltTheresult 1S that nitrogenous fertilizer increases the C02 emission and that the alnount ofLU2 enllsSloll 1S positively proportional to tile concentra
6、tion of nitrogenous fertilizerIn the 8ame nitrogen concentrationthe an30unt of C02 emission atheading Stage ismo。e than that of Jointing stage and the amount at jointingstage is more than t11at ofmature periodFor example：under nitrogenthe jointing stage of sumnler nlaize soilCU2 enllSsIon volume val
7、ue of 3 1 52 mgm王h，tile heading stagesoil C02 emissionvolume value of 4542 mgm1hmature soil C02 emission volume value of 2821mgm-hThe amount of C02 release peaks at the heading stae(3)The intraday change of C02 emissions in different weatller conditions showssimilar with(2)All growth stages in the s
8、unny days when the soil C02 emissionsmean。espectively：seedling 1 606 mgm 211，jointing 3370 mgm211，headill2 4094mgmhTile mean of C02 emission in sunny days、cloudy days and rainv davs s110wsgreat differenceIt can be when tile weather is finesummer maize soil C02 emissionsw1儿1ncrease somewhatIn tile sa
9、nle weather conditionsthe sort of CO!emisslon indifferent growth periods is heading stagejointing stageseedling stageMeantillle，C02 release peaks at the heading stage(4)With three different soil moisture treatments，the soil C02 emissions inseedling and jointing stages have changed obviously，which is
10、 increased in themorning and then decreasedWith the condition of different soil moisture，the mean ofdifferent growth stage varies significantlyWe can conclude that at the conditionwhich is soil water content accounts for 70of the field water holding capacity，summer maize soil C02 emissions have incr
11、eased significantlySeedling stage whenthe value of 2373 mgmh，the jointing stage is 35 19 mgm2h(5)Soil C02 release in Jointing Stage and temperature of 1 0cm soil aresignificantly relatedThe linear regression equation is y=98567x+2 182，of whichR2 is O8786(P拔节期插秧期成熟期。113影响农田土壤C02排放的影响因素中圈自二一I1丛纪七I年代J：
12、始研究农fTt C02排放通量，。掘日6订的研究结论看，农11土壤C02释放受作物属性和各种环境条件的综合影响，影n向较大主要因子有：_1二壤温度、：I二壤水分、和肥料状况等I_12】。1131温度的影响在一定范围内环境温度升高可加速土壤中有机质的分解和微生物活性，从而增加土壤中C02浓度，温度是通过多种途径对C02排放量起作用的131。国外学者经过一系列观测总结出了一些定量关系。CLKucera等f141(1970)得出经验公式：Iny=m+nln(x+10)，式中：Y是土壤C02排放量；m是常数；n是温度系数(10-30时取16-23)。KMathes掣15通过试验也得出回归方程： y=m
13、+nx2，式中：Y是土壤C02排放量；x是土壤温度；1TI、n是统计常数。并且得出相对于地表温度，x值使用地表下5cm处的温度效果更好一些。我国一些学者如戴万宏(2002)16观测壤土_lJ壤温度季节变化与壤二t C02浓度季节变化得“5其两者有明显的相似性。结果表明，在土温大于5时，土壤C02浓度与土温做回归分析呈极湿著：一：次曲线棚关。刘允芬(1996)7试验结果显示，与同纬度东部平原相比西藏高原海拔高，热量条件低，但是地温高，所以二1二壤生命活动力强，生物活性增强，因此使C02排放量增高。lb于不同植被的覆盖，各环境因素与土壤C02排放量的村I关程度也各不相同，但土壤C02排放量却与空气
14、中的C02浓度呈明显负相关，与地温及气温呈明显的F相关U71 8 191。1132土壤水分的影响_【：壤水分影I Jl；J生物体的很多方面，如卜物体的有效水分含量、可溶物质的数量、土壤通气状况、pH值等，水分含量在一定的范围内，与C02排放量呈极显著相关。H-：1201。Grant等(1994)211的研究表明，一般在体积含水量占总孔隙的60的情况_卜微生物呼吸速率最大，当含水量在此之时，其呼吸速率与含水量负相关，反之lF相关。土壤呼吸的主要碳源之一是有机质中易降解的部分，持续淹水比干湿交替处理的C02排放多了近-T(Curtin et al，1998)1221。土壤水分不仅影UlfiJ：f：
15、壤中有机质的含量，还对植物根系生长、分布和呼吸有重要影响，因而导致士壤呼吸剧烈变动，使得C02排放量不断变化f23】。目前有多数学者认为，其两者之|、白j存在。科，负相关关系【：刚。1133施肥对C02排放的影响张衍华(2008)1251认为在氮肥施用量为300kghm2水ir时土壤C02排放量达最高，施氮肥量或多或少与这个量时，COz排放量均减少。在小麦拔节期施增氮肥对C02排放量影响最大，其他生育时期影响较小，并且相对于早期品种而-D+，施肥量使得现代I铺种C02排放量增加迅速。欧|jHl1(2003)261在黄淮海平原地区研究夏玉米农田土壤呼吸动态的结果表明，1二壤II乎II,XJ季节变
16、化大体与温度变化的趋势相同，施用有机肥料增加了土壤呼吸速率。秸秆因素也丌始明鼹影响I：壤的有机碳含量，如果全国的地面上秸秆还阡I比率由当日，j的1 5增加到80，则中国农阳土壤碳的平衡状态町由当6，J亏损状态(一95半107ta1)变为盈收(+8O木107ta1)山净排放C02-C(95木107ta一)转变为每年从人气吸收C02-C(8O木107ta一)。增加秸秆或动物粪肥还阳Liarlk：k产已成为加速全球变暖不容忽视的人类活动之-70】。玉米作为我国第三人粮食作物，玉米种植在粮食生产占有重要地位，且玉米播种面积在逐年增加。所以本沦文以夏K米农rf，卜态系统为主要研究对象，采用静念箱采样，对彳i同土壤湿度、不同施肥条件下的各个，L育期的：二氧化碳排放进行了连续2年的观测研究，通过气相色游法对样本进
