土壤水分对半干旱区石灰性土壤有机碳矿化的影响  

Effect of Soil Moisture on Mineralization of Soil Carbonin Calcareous Soils in the Semi-arid Regions of China

作　　者：贾俊仙[1,2] 蔚耀洲 张健[1] 许剑敏[1] 张亚丽[1] 赵艳 洪坚平[1] 

机构地区：[1]山西农业大学,山西太谷030801 [2]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008

出　　处：《灌溉排水学报》2017年第9期62-68,共7页Journal of Irrigation and Drainage

基　　金：山西省自然科学基金项目(2012011033-7);土壤与农业可持续发展国家重点实验室开放基金课题(0812201222);山西农业大学博士后基金项目(134849);山西农业大学引进人才科研启动项目(XB2010007)

摘　　要：为明确土壤水分对我国北方半干旱区域石灰性土壤有机碳矿化的影响,采用室内恒温培育试验,以栗钙土、栗褐土、褐土为研究对象,研究了不同土壤水分条件下土壤有机碳(SOC)矿化差异。土壤含水率设置为田间持水率(WHC)的40%、70%和100%。结果表明,随着土壤含水率升高,3类土壤2种利用方式(玉米地、果园)土壤有机碳累积矿化量及矿化率增大,较高水分下的增幅(70%WHC^100%WHC)小于较低水分下的增幅(40%WHC^70%WHC);土壤有机碳矿化动态符合一级动力学方程,土壤潜在矿化碳库(Cp)为33.10~193.56 mg/kg,潜在矿化率Cp/SOC为0.41%~3.35%,Cp及Cp/SOC随土壤含水率升高而增大,Cp及Cp/SOC较高水分条件下的增幅较小;40%WHC下Cp/SOC与土壤有机碳量显著负相关,70%WHC及100%WHC下则与土壤有机碳量及黏粒量显著负相关(P<0.05)。半干旱区域石灰性土壤有机碳矿化及土壤有机碳固存能力在较低水分条件下(40%WHC^70%WHC)受土壤水分变化影响较大。This paper studied the impact of soil moisture on mineralization of organic carbon （SOC） mineralization in calcareous soils inthe semi-arid region of northern China. During the experiment, the temperature was kept at constant and the soil moisture varied from 40% to 100% of water holding capacity of the soils （WHC）. Three calcareous soils - chestnut soil, chestnut brown soil and cinnamon soil-were examined. The results showed that the cumulative mineralization and the mineralization rate of SOC in maize and orchard fields in the three calcareous soils all increased with soil moisture, but the increase in the high moisture treatments, 70%-100% WHC, was less than those in the low moisture treatments, 40%-70% WHC. The SOC mineralization was well described by the first-order kinetics, where the soil organic carbon （Cp） varied from 33.10 to 193.56 mg/kg and the mineral- ization rate （Cp/SOC） varied from 0.41% to 3.35% respectively. Both Cp and Cp/SOC increased with soil moisture. Similarly, the increase in Cp and Cp/SOC in the high moisture treatments was higher than those in the low moisture treatments. The Cp/SOC was negatively correlated with SOC and clay content （P〈0.05） under 40% and 70% and 100% of WHC. In conclusion, the soil moisture has a great impact on soil organic carbon mineralization and carbon sequestration.

关 键 词：土壤水分 土壤有机碳矿化 栗钙土 栗褐土 褐土 

分 类 号：S153.6[农业科学—土壤学]