不同垦殖年限对川西北高寒草地土壤有机碳、氮密度的影响  

Effects of Different Cultivation Years on Soil Organic Carbon,Nitrogen Storage in Alpine-cold Grassland in Northwest of Sichuan

作　　者：何剑锋 胡玉福 杨泽鹏 段皓 凌静 肖海华 舒向阳 李正青 阳帆 李玥萩 HE Jian-feng;HU Yu-fu;YANG Ze-peng;DUAN Hao;LING Jing;XIAO Hai-hua;SU Xiang-yang;LI Zheng-qing;YANG Fan;LI Yue-qiu(College of Resource and Environment,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学资源学院,四川成都611130

出　　处：《土壤通报》2018年第4期834-840,共7页Chinese Journal of Soil Science

基　　金：国家支撑计划项目(2015BAC05B01;2015BAC05B02);四川省科技支撑计划项目(2014SZ0057)资助

摘　　要：不合理的垦殖是造成土壤退化的主要原因之一。以垦殖1、3、6、10年后的天然草地为研究对象,以未垦殖天然草地为对照,研究了垦殖对川西北高寒草地土壤理化性质和有机碳氮的影响。结果表明,垦殖草地的土壤有机碳(SOC)、土壤全氮(STN)、土壤有机碳密度(SOCs)和土壤全氮密度(STNs)均显著降低;大部分SOCs和STNs减少发生在垦殖的早期阶段,随着垦殖年限的增加,SOCs和TNs的下降速率呈现降低趋势,垦殖10年后,在0~60 cm土层土壤SOCs和STNs比垦殖前的天然草地分别下降了30.97%和17.87%。随着土层深度的增加,SOCs和STNs及其损失速率呈现出下降趋势,表层土壤有机碳氮密度的损失明显高于下层土壤。在垦殖过程中SOCs的损失大于STNs,土壤碳氮比(C/N)呈现出下降趋势。Unreasonable cultivation is the main cause of soil degradation. In order to reveal the effect of cultivation on the soil organic carbon（SOC） and total nitrogen（TN） in grassland, natural grasslands cultivated for 1, 3, 6, and 10 years were used as the research objects, and the natural grassland was used as the control（CK）. The effects of cultivation on soil physicochemical properties, SOC and TN were studied. The results showed that soil water content（SWC）, SOC, TN, SOC storage（SOCs）, TN storage（STNs） significantly decreased, while soil pH and soil bulk density（BD） significantly increased. Most of the SOCs and STNs losses occurred in the early stage of cultivation. The rates of SOCs and STNs decreased with the increase of cultivation periods. After 10 years of cultivation, the SOCs and STNs in0-60 cm soil layer decreased by 30.97% and 17.87%, respectively, SWC in 0-20 cm soil layer decreased by41.72%, while the pH and BD values in 0-20 cm soil layer increased from 6.08 and 0.80 g cm^-3 to 6.56 and 0.97 g cm^-3,respectively. With the increase of soil depth, the contents of SOCs and STNs and the loss rates of SOCs and STNs showed the decreasing trend. And the losses of SOCs and STNs in surface soil were higher than that indeep soil. The SOCs loss was higher than STNs, and the soil C/N showed the decreasing trendin the process of cultivation.

关 键 词：人为垦殖 土壤有机碳氮密度 高寒草地 

分 类 号：S151.9[农业科学—土壤学] S812.2[农业科学—农业基础科学]