施肥对内蒙古短花针茅荒漠草原土壤呼吸的影响  

Effect of fertilization on soil respiration in the Stipa breviflora desert steppe of Inner Mongolia

作　　者：赵巴音那木拉[1] 红梅[1] 梁存柱[2] 包乌云[1] 张佳鑫[1] 

机构地区：[1]内蒙古农业大学生态环境学院,呼和浩特010019 [2]内蒙古大学生命科学学院,呼和浩特010021

出　　处：《应用生态学报》2014年第3期687-694,共8页Chinese Journal of Applied Ecology

基　　金：国家重点基础研究发展计划项目(2010CB950602);国家自然科学基金项目(31160476)资助

摘　　要：2012年在内蒙古短花针茅荒漠草原设置了3个N肥水平（2．5、5和10gN·m^-2）的不同NPK配施样地，并以未施肥样地为对照（CK），采用LI-8100土壤碳通量测量系统测定了样地中土壤呼吸速率的日动态和季节变化，分析土壤呼吸速率与环境因子的关系．结果表明：在植物生长旺盛期（8月），3个N肥水平中，10gN·m^-2处理的土壤呼吸速率显著高于其他处理，5和2．5gN·m^-2处理的土壤呼吸速率与CK无显著差异．在植物生长初期和中期（5—9月），施P肥有利于提高土壤呼吸速率．施肥并未改变荒漠草原土壤呼吸的日动态和季节变化特征．各处理日变化最高值和最低值分别出现在10：00—14：00和03：00-05：00；季节动态的峰值均出现在8月．土壤呼吸速率与5cm土壤温度及0～10cm土壤含水量显著相关，其决定系数分别在0．40—0．58和0．51～0．70，说明表层土壤含水量是制约土壤呼吸变化的主要环境因子．In 2012, a field experiment with different fertilizer treatments was conducted in the Stipa breviflora desert steppe of Inner Mongolia. The LI-8100 was used to investigate daily and seasonal variations of soil respiration rate, and the relationships between soil respiration rate and environmen- tal factors were analyzed. The results showed that： 1 ） In the rapidly growing stage （August） , the respiration rate in 10 g N.m^-2 was significantly higher than in the other treatments. No significant differences were observed among 5 g N . m-2, 2.5 g N . m-2 and CK. 2 ） During the early and middle growing stage （ May to September）, P fertilizer improved the soil respiration rate. 3 ） Fertili- zation did not change the daily and seasonal variations of soil respiration. The daily variations of soil respiration of all fertilization treatments were almost the same, with the highest values occurring within 10：00-14：00 and the lowest values occurring within 03：00-05：00. The peak of seasonal variation occurred in August. 4） The soil respiration rate was significantly related to soil tempera- ture at 5 cm depth and soil moisture at 0- 10 cm depth, and the determined coefficients were 0.40-0.58 and 0.51-0.70, respectively, indicating that soil moisture was the major factor affecting soil respiration.

关 键 词：土壤呼吸速率 施肥 环境因子 短花针茅荒漠草原 

分 类 号：S812.2[农业科学—草业科学]