免耕不同秸秆覆盖量对土壤可溶性氮素累积及运移的影响  

Accumulation and transport of soil extractable N affected by corn stover mulching quantity in no-tillage system

作　　者：何传瑞 全智[3] 解宏图[3] 鲁彩艳[1] 陈欣[1] 史奕[1] 

机构地区：[1]中国科学院污染生态与环境工程重点实验室,沈阳110016 [2]中国科学院大学,北京100049 [3]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《生态学杂志》2016年第4期977-983,共7页Chinese Journal of Ecology

基　　金：国家公益性行业(农业)科研专项(201303095-9);沈阳市科技计划项目(F14-231-1-41)资助;中国科学院"率先行动"计划特色研究所项目资助

摘　　要：通过田间原位试验,研究了连续8年免耕秸秆覆盖对土壤剖面NH_4^+-N、NO_3^--N和可溶性有机氮(EON)累积、垂直运移和淋溶损失的影响。试验设5个处理,分别为常规垄作对照(RT)、免耕无秸秆覆盖(NT-0)、免耕+33%秸秆覆盖(NT-33)、免耕+67%秸秆覆盖(NT-67)和免耕+100%秸秆覆盖(NT-100)。结果表明:免耕秸秆覆盖条件下,土壤可溶性氮素主要以NO_3^--N形态存在,其次是EON;免耕不同秸秆覆盖量对土壤NO_3^--N累积和垂直运移特性的影响不同;NT-33和NT-67处理中土壤NO_3^--N淋溶至40~80 cm土层,而NT-100处理淋溶至40~60 cm土层;与RT处理相比,NT-67和NT-100处理显著降低了0~20 cm土层NO_3^--N和EON库的容量,但增加了40~60 cm土层NO_3^--N库的容量;说明免耕秸秆覆盖增加了土壤NO_3^--N自耕层向深层的垂直运移和淋溶损失,但对EON和NH_4^+-N无显著影响。An 8-year field experiment was conducted to study the accumulation,vertical transport and leaching of soil NH_4^＋-N,NO_3^--N and extractable organic N（ EON） affected by corn stover mulching in no-tillage system. The experiment consisted of five treatments,including a ridge tillage as control（ RT）,no-tillage without corn stover mulching（ NT-0）,no-tillage with 33% corn stover mulching（ NT-33）,no-tillage with 67% corn stover mulching（ NT-67）,and no-tillage with 100% corn stover mulching（ NT-100）. The results showed that soil extractable N mainly existed in form of NO_3^--N,followed by EON in the no-tillage system with corn stover mulching.Corn stover mulching with different quantities significantly affected the accumulation and vertical transport of soil NO_3^--N in no-tillage system. The soil NO_3^--N was leached to the 40-80 cm soil layer in the NT-33 and NT-67 treatments,and the 40-60 cm soil layer in the NT-100 treatment.Compared to RT treatment,NT-67 and NT-100 treatments significantly decreased the capacity of NO_3^--N and EON pools in the 0-20 cm soil layer,and increased that of NO_3^--N pool in the 40-60 cm soil layer. Our results suggest that corn stover mulching increased the vertical transport and leaching loss of soil NO_3^--N pool from cultivation layer to deep soil in no-tillage system,and had no influence on the soil EON and NH_4^＋-N.

关 键 词：免耕 可溶性氮 运移 库容 淋溶损失 

分 类 号：S153[农业科学—土壤学]