不同初始pH值酸性土壤净矿化、净硝化和酸度变化分析  

An analysis on the changes of net mineralization,net nitrification and acidification of acid soil with different initial pH values

作　　者：刘莉[1] 刘丹丹[2] 乔琴[2] 李永梅[1] 何飞飞[2,3] 

机构地区：[1]云南农业大学资源与环境学院,云南昆明650302 [2]云南大学农学院,云南昆明650091 [3]湖南农业大学生物科学技术学院,湖南长沙410128

出　　处：《云南大学学报（自然科学版）》2015年第4期592-599,共8页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(31201688);中国博士后科学基金(2012M511374)

摘　　要：采集了4个不同初始pH值酸性土壤,在60%土壤持水量和25℃条件下对土壤矿化、净硝化和酸度变化进行了研究.结果表明,Ⅰ号土壤（pH=4.03,茶园土）矿化作用不明显,Ⅱ号（pH=4.81,玉米地）、Ⅳ号（pH=6.02,菜地）土壤矿化模式为Logistic方程,Ⅲ号土壤（pH=5.41,菜地）为指数方程.不加NH＋4条件下Ⅱ、Ⅲ、Ⅳ号土壤净硝化模式为一级反应方程,加NH＋4后净硝化速率增加一个数量级.培养结束后不加NH＋4条件下Ⅱ、Ⅲ、Ⅳ号土壤pH值没有变化,加NH＋4处理后pH值显著降低,同时交换性Al3＋显著增加.加NH＋4促进酸性土壤（pH=4.81~6.02）硝化和酸化,但pH值过低的土壤（pH=4.03）NO-3-N、pH值和交换性Al3＋无显著变化.A laboratory soil incubation condition with moisture content 60% WHC and temperature at 25℃ was conducted to study dynamics of net mineralization,nitrification and acidification of four acidic agricultural soils with different initial pH,which were collected from a tea garden and three cropland in Yunnan province. The results showed that the mode of time courses for NH＋4- N ＋ NO-3- N accumulation followed a logistic model for soil II（ pH 4. 81,corn field） and Ⅳ（ pH 6. 02,vegetable field）,exponential model for soil Ⅲ（ pH 5. 41,vegetable field）. No significant mineralization was found for soil Ⅰ（ pH 4. 03,tea garden field）. NO-3- N accumulation in the soil followed a first- order reaction model for soil Ⅱ,Ⅲ and Ⅳ without additional NH＋4,and an addition of NH＋4stimulated the soil nitrification significantly. By inputting NH＋4,initial pH of Ⅱ,Ⅲ and Ⅳ soil was significantly changed,resulting in a decrease in soil pH and an increase in soil exchangeable Al3 ＋content,which did not happen in soil I with or without NH＋4- input. The results indicated that for some soil with a very low pH,such as pH 4. 03,nitrification,pH and exchangeable Al3 ＋were not affected by the available NH＋4.

关 键 词：酸性土壤 净矿化 净硝化 酸化 反应方程 

分 类 号：S153.6[农业科学—土壤学]