摘要
利用田间试验研究了不同覆盖条件下旱作农田冬小麦土壤呼吸及其水热状况。设4个处理,即无覆盖处理(CK)、小麦全年4500 kg/hm2秸秆覆盖(M4500)、9000 kg/hm2秸秆覆盖(M9000)和地膜覆盖(PM)。结果表明,土壤呼吸在作物生育期呈单峰曲线变化,PM处理峰值出现在拔节期,其余处理推迟至抽穗期;CK、M4500、M9000、PM处理呼吸速率均值分别为CO21.54、1.44、1.45、1.75μmol/(m2·s),其中PM与CK处理差异显著(P<0.05);生育期内土壤呼吸温度敏感性(Q10值)在1.86~2.39之间;土壤温度低于5℃时,Q10值较高,而当土温高于5℃时,土壤呼吸的温度控制作用较弱;土壤水分对土壤呼吸的限制作用不大。多元线性回归分析表明,0—5cm土层温度和水分形成的双因子模型可以更好地解释土壤呼吸速率变异,各处理的决定系数分别为CK 0.827、M45000.816、M9000 0.896、PM 0.729(P<0.01)。
A field experiment was conducted to study soil respiration and its relations with soil temperature and soil moisture in rainfed winter wheat fields in the Loess Plateau. Four treatments were included as two rates of 9000 kg/ha and 4500 kg/ha with straw mulching (M9000 and M4500), plastic film mulching (PM) and the control without mulching (CK). The results show that the dynamic tendency of soil respiration is in a single peak pattern, and the peak of PM is appeared at the jointing stage, the peaks of the other’s treatments are observed at the heading stage. The mean soil respiration rates of the CK, M4500, M9000 and PM treatments during the whole growing season are CO2 1.54, 1.44, 1.45 and 1.75 μmol/(m2·s), respectively, and the difference between the PM and CK is significant(P〈0.05). The range of the temperature sensitivities of soil respiration (Q10) is from 1.86 to 2.39 for the four treatments in the whole growing season. The Q10 values are higher when the soil temperature is lower than 5℃. On the contrary, the soil temperature affects soil respiration slightly when it is greater than 5℃. There are weak negative correlations between soil moisture and soil respiration during the whole growing season while there are no correlations for the CK and M4500. These results demonstrate that the soil moisture has a little effect on soil respiration during our studies. The regression models including both soil temperature and soil moisture could better explain 0.827, 0.816, 0.896 and 0.729 of soil respiration for the CK, M4500, M9000 and PM, respectively (P〈0.01).
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2012年第5期1103-1110,共8页
Journal of Plant Nutrition and Fertilizers
基金
教育部科技重点项目(209123)
国家自然科学基金项目(41171033
31270484)资助
关键词
土壤呼吸
覆盖条件
水热因子
Q10值
soil respiration mulching soil temperature and moisture, Q10 value