【摘要】 在垄作覆盖条件下,研究了夏玉米生长季中常规灌溉(沟沟灌溉)和隔沟交替灌溉2种灌溉方式对土壤呼吸作用昼夜变化、阶段变化规律及不同水分胁迫下土壤含水量与土壤呼吸速率的相关关系.结果表明,夏玉米拔节期土壤呼吸速率最小,抽雄期最大,之后缓慢回落;昼夜动态变化呈单峰变化趋势,高峰、低谷分别在14:00和6:00左右;在同一水分条件下,交替灌溉方式土壤呼吸速率高于常规灌溉,处理间最大差异平均可达3.46μmol.m-2.s-1,交替灌溉方式下土壤呼吸速率昼夜变化幅度小于常规灌溉方式下土壤呼吸速率;不同水分胁迫条件下,土壤呼吸速率呈现出轻度亏缺处理>中度亏缺处理>重度亏缺处理;玉米生长期较高土壤含水量促使土壤呼吸增强,尤其在玉米生长中期土壤呼吸速率与耕层土壤含水量呈极显著的正相关关系.更多还原

【Abstract】 The relationships between irrigation methods and soil respiration,soil water content and soil respiration were studied systematically in a summer maize agroecosystem under conservation tillage conditions.The results showed that the slowest and quickest soil respiration rates happened at the jointing and silking stages,respectively,and then followed by a steady fall-back.Diurnal variations of soil respiration rate showed a single-peak curve,with the peak and trough time at about 14:00 and 6:00.under the same moisture condition,soil respiration rate of the alternative furrow irrigation was significantly higher than that of the conventional irrigation,with the biggest difference of averaged 3.46μmol·m-2 ·s-1 among all treatments.The diurnal variation of soil respiration rate by alternative irrigation was smaller than that by conventional irrigation.Under the different moisture conditions,the soil respiration rate changed in the following order: light water stress > moderate deficit > severe stress pattern;higher soil moisture during corn growing season could enhance the soil respiration rate,especially at mid-growth period of maize.There was a significant positive correlation between soil water content and soil respiration.更多还原