摘要
为准确量化常规垄作和免耕不同量秸秆覆盖处理条件下,玉米不同生育期尿素氮来源铵态氮(NH_4^+-N)和硝态氮(NO_3^--N)在土壤剖面中的累积、垂直运移特性和淋失风险,于2016年在连续运行9年的长期免耕定位试验基地上设置田间原位^(15)N同位素示踪微区试验,试验设5个处理,分别为常规垄作(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)。研究结果表明:玉米苗期和抽雄期,0~20 cm和20~40 cm土层尿素来源NO_3^--N的累积量显著高于尿素来源的NH_4^+-N,尿素来源NO_3^--N占所施入尿素氮的比例在苗期最高,各个处理相应土层的平均值分别为24.0%和17.4%。玉米成熟期,0~100 cm土壤剖面中残留的尿素来源的矿质氮96%以上是NO_3^--N,约有7%左右的尿素氮以NO_3^--N的形态垂直运移至80~100 cm土层中,其对相应土层总的土壤NO_3^--N库的贡献比例达50%以上,说明当季作物施入氮肥的淋溶损失风险较高。与常规垄作处理相比,免耕67%和100%秸秆覆盖处理降低了尿素来源NO_3^--N在深层土壤剖面的残留,但差异未达到显著性水平。
In present study, a ^15N-labeling field micro-plot experiment was conducted in the 9-year long-term no tillage experiment station in 2016, and the objective was aimed to accurately quantify the accumulation, vertical movement and leaching risk of urea N-derived ammonium nitrogen（NH4^＋-N） and nitrate nitrogen（NO3^--N） in soil profile during different growth stage of maize under the conditions of ridge tillage and no-tillage with corn stover mulching. Five treatments were set： ridge tillage（RT）, no-tillage without corn stover mulching（NT-0）, no-tillage with33% corn stover mulching（NT-33）, no-tillage with 67% corn stover mulching（NT-67）, and no-tillage with 100%corn stover mulching（NT-100）. Results showed that the accumulation of urea N-derived NO3^--N was significantly higher than that of urea N-derived NH4^＋-N in the 0-20 cm and 20-40 cm soil layers at the seedling and tasseling stages of maize. The percentage of urea N-derived NO3^--N to applied fertilizer N was the highest at the seedling stage,and the average value was 24.0% and 17.4% in the 0-20 cm and 20-40 cm soil layers, respectively. At the ripening stage of maize, more than 96% of urea N-derived mineral N were NO3^--N in the 0-100 cm soil profile.About 7% urea N as NO3^--N migrated vertically to 80-100 cm soil layer, and it contributed more than 50% of the total soil NO3^--N in the corresponding soil layer, which suggested the high leaching risk of fertilizer N in the present maize season. Compared with RT treatment, NT-67 and NT-100 decreased the accumulation of NO3^--N derived from urea N in deep soil profile, but the difference was not significant.
作者
腾珍珍
袁磊
王鸿雁
刘亚军
张钟文
史奕
陈欣
张旭东
何红波
鲁彩艳
TENG Zhen-zhen;YUAN Lei;WANG Hong-yan;LIU Ya-jun;ZAHNG Zhong-wen;SHI Yi;CHEN Xin;ZHANG Xu-dong;HE Hong-bo;LU Cai-yan(Key Laboratory of Pollution Ecology and Environment Engineering,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,Chin;Agricultural Technical Extension Station of Lishu County,Jilin Province,Lishu 136500,Chino;University of Chinese Academy of Sciences,Beijing 100049,Chino;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《土壤通报》
CAS
北大核心
2018年第4期919-928,共10页
Chinese Journal of Soil Science
基金
"十三五"国家重点研发计划子课题(2016YFD0800103-3)
"十三五"国家重点研发计划课题(2016YFD0200307
2017YFD0200105)资助
国家自然科学基金面上项目(41671290)
