不同生长期盆栽大豆的土壤呼吸昼夜变化及其影响因子  

Diurnal variation of soil respiration in soil-potted with soybean (Glycine max L.) at various growth stages and its affecting factors

作　　者：杨兰芳[1] 蔡祖聪[1] 

机构地区：[1]土壤与农业可持续发展国家重点实验室

出　　处：《生态学报》2004年第12期2955-2960,共6页Acta Ecologica Sinica

基　　金：国家杰出青年基金资助项目 ( 4 0 12 5 0 0 4) ;中国科学院知识创新工程重大资助项目 ( KZCX1-SW-0 1-0 5 )~~

摘　　要：通过盆栽试验 ,用静态箱法采样 ,气相色谱测定样品 CO2 浓度 ,分别在大豆开花期、结荚期和鼓粒期测定土壤呼吸速率 ,研究大豆不同生长期土壤呼吸的昼夜变化规律及其主要影响因素。在结荚期灌水后测定土壤呼吸速率 ,以研究水分对土壤呼吸昼夜变化的影响。结果表明在大豆不同生长期中 ,土壤呼吸均具有明显的昼夜变化规律 ,且均呈单峰曲线型 ,峰值出现在 12 :0 0到 16 :0 0之间。6 :0 0～ 18:0 0的 CO2 排放占总排放的 6 1%～ 6 9% ,昼夜平均土壤呼吸速率最接近于 18:0 0～ 2 1:0 0之间的速率。如果忽略大豆生长对土壤有机质分解的激发效应 ,大豆根际呼吸占总土壤呼吸的 85 %～ 96 %。裸土土壤呼吸与温度呈极显著的指数和线性相关 ,种大豆的土壤呼吸与温度的关系因生长期而异 ,鼓粒期的相关性最好 ,结荚期最差。这些都说明大豆生长和生长阶段影响土壤呼吸及其与温度的关系。灌水后使大豆土壤呼吸昼夜变化增强 ,平均土壤呼吸速率增大。由此可见植物生长时期。The diurnal variation of soil respiration at various growth stages of soybean and the influencing factors are investigated with static dark chamber method and gas chromatograph technique in pot experiment. In the flowering, pod, and grain-filling stage, soil respiration rate was measured consecutively 3 day-nights at 2 hours internal in daytime (6:00～18:00) and 3 hours internal in night (18:00～6:00). In the course of sampling, the temperature in air, on surface, and at 5 cm depth soil were recorded. The soil respiration rate was also determined one day-night at three hours internal after watering in the pod stage. Results showed that there was a substantial diurnal variation of soil respiration rate with a single peaked rate occurring from 12:00 to 16:00 in soybean-planted soil. The maximum soil respiration rate and the averaged rate in soybean-planted treatment were higher in pod and grain-filling stage than in flowering stage. The cumulative CO_2 emission during daytime accounted up 61%～69% of total emission over a day-night. The daily average of soil respiration rate was most close to the rate between 18:00 and 21:00. Rhizosphere respiration made up 85% ～ 96% of soil respiration if the priming effect of soybean growth on decomposition of native soil organic matter were neglected. In the bare soil, the soil respiration rate was significantly correlated with temperatures exponentially, but in soybean-planted treatment, the relationships were poor and depending on growth stages. The correlation was most significant in grain-filling plumping stage and lowest in pod stage, and more significant with temperature on surface and at 5cm depth soil than with air temperature. The results suggested that the soybean growth as well as growth stage influenced soil respiration rate and the relationship with temperatures. Watering affected the magnitude and intensity of soil respiration rate and enhanced the diurnal variation of soil respiration. All the results indicated that soybean growth and growth stages, temperatu

关 键 词：大豆 土壤呼吸 生长时期 昼夜变化 温度 灌水 

分 类 号：S154[农业科学—土壤学]