title: [Translocation and transformation characteristics of fertilizer nitrogen in paddy soil: a study with simulated soil column].
abstract: Aimed to understand the translocation and transformation characteristics of applied fertilizer nitrogen in paddy soil, a simulated soil column experiment was conducted in laboratory to study the variations of soil mineral nitrogen along the profile under the application of 360 mg x kg(-1) (3 folds of conventional application rate) of urea- and ammonium sulfate nitrogen. In the experimental period, the soil NH4(+)-N and NO3(-)-N contents in the control (no fertilization) had less change, and no significant differences among different soil layers. Applying urea- and ammonium sulfate nitrogen resulted in a significant increase of soil NH4(+)-N and NO3(-)-N in 0-50 mm layer, being 186.0-2882.1 mg x kg(-1) and 268.7-351.5 mg x kg(-1), and 4.8-242 times and 5.7-316 times of those in CK, respectively. However, the NH4(+)-N and NO3(-)-N contents below 50 mm soil depth were similar to those in CK, indicating that the translocation and transformation of applied fertilizer nitrogen mainly occurred in 0-50 mm soil layer. The translocation of fertilizer nitrogen mostly occurred in the first 14 days after fertilization. In the whole experimental period, the NH4(+)-N and NO3(-)-N contents in each soil layer under the application of ammonium sulfate were 0.7-2.0 times of those under the application of urea, and the nitrification rate was 0.9-1.4 times of that, suggesting the higher transformation rate of applied ammonium sulfate in paddy soil, as compared with applied urea.
authors.affiliation: Chinese Research Academy of Environmental Sciences, Beijing 100012, China. zhangchao@craes.org.cn
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Che
authors.forename: Zhong-Pei
authors.initials: ZP
authors.lastname: Li
mesh_terms: D003198:Computer Simulation; D005308:Fertilizers; D009566:Nitrates / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D012275:Oryza / Q000254:growth & development*; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012987:Soil / Q000032:analysis*
chemical_list: D005308:Fertilizers; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D012987:Soil; D009584:Nitrogen