氮肥处理下高寒草甸土壤水稳性团聚体的季节性变化特征  

Seasonal Dynamic of Soil Water-stable Aggregates under Nitrogen Fertilization Treatments in an Alpine Meadow Ecosystem

作　　者：蒋胜竞[1] 罗佳佳 金中财[1] 石国玺 柴宇星[1] 刘永俊 冯虎元[1] JIANG Sheng-jing;LUO Jia-jia;JIN Zhong-cai;SHI Guo-xi;CHAI Yu-xing;LIU Yong-jun;FENG Hu-yuan(School of Life Sciences, Lanzhou University, Lanzhou 730000, China;College of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China;Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences / Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Ministry of Agriculture, Danzhou 571737, China;The Key Laboratory of Restoration Ecology in Cold Region of Qinghai Province, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China)

机构地区：[1]兰州大学生命科学学院,甘肃兰州730000 [2]海南大学热带农林学院,海南海口570228 [3]中国热带农业科学院热带作物品种资源研究所农业部热带作物种质资源利用重点开放实验室,海南儋州571737 [4]中国科学院西北高原生物研究所青海省寒区恢复生态省级重点实验室,青海西宁810008

出　　处：《土壤通报》2018年第2期329-335,共7页Chinese Journal of Soil Science

基　　金：国家自然科学基金(31570512;31670433)资助

摘　　要：以青藏高原东缘高寒草甸为研究样地,探究了氮肥添加下不同月份间土壤水稳性团聚体的组成差异。结果表明:各处理下土壤水稳性团聚体含量在80.78%~95.67%之间,平均重量直径(MWD)在1.41 mm^2.08 mm之间。氮肥添加仅对土壤水稳性团聚体总量有影响,对MWD与各级粒径团聚体含量影响均不显著。较氮肥添加而言,采样月份对土壤水稳性团聚体总量及其粒径分布有着更为显著的影响。6月份土壤水稳性团聚体以2~4 mm粒径团聚体为主,7、8月份则以0.25~1 mm粒径团聚体为主。土壤水稳性团聚体含量,MWD及>1 mm粒径的团聚体含量均随季节变化呈先降后升的趋势,而0.038~0.25 mm粒径水稳性团聚体含量则呈现相反的趋势。土壤有机碳和球囊霉素含量是影响土壤水稳性团聚体形成与稳定的关键土壤因子。本实验结果说明中度氮素的添加可降低土壤水稳性团聚体含量,土壤水稳性团聚体在不同采样月份间处于破解与形成的动态变化中,对青藏高原的施肥措施应充分考虑不同季节间土壤物理结构的差异。The changes of soil water-stable aggregate in different months under different nitrogen fertilization treatments were studied in an alpine meadow of eastern Qinghai-Tibetan Plateau. The results showed that the proportions of soil water-stable aggregates were between 80.78% and 95.67%, and the mean weight diameters（MWD）ranged from 1.41 mm to 2.08 mm. Nitrogen addition had no significant effects on MWD and the proportion of water-stable aggregates. The sampling season had more significant effects on soil water-stable aggregates distribution.The 2-4 mm aggregate was dominant in June, while the 0.25-1 mm aggregate was dominant in July and August.The proportion of water-stable aggregates, MWD and the 1 mm aggregate all decreased first and then increased in the sampling months, while the 0.038-0.25 mm aggregate showed the opposite trend. Soil organic C and glomalin-related protein were the key soil factors affecting the formation and stability of soil water-stable aggregates.These results indicated that the addition of moderate nitrogen fertilizer can reduce the proportion of soil water-stable aggregates. The continuous process of cracking and formation of soil aggregate in different sampling months and the differences in soil physical structure between seasons should be taken into account when applied fertilizers to the Tibetan Plateau.

关 键 词：施肥 季节变化 青藏高原 土壤团聚体 

分 类 号：S158.5[农业科学—土壤学]