文献类型： 外文期刊

作者： Li, Pei-Pei ¹ ; Han, Yan-Lai ¹ ; He, Ji-Zheng ² ; Zhang, Shui-Qing ³ ; Zhang, Li-Mei ² ;

作者机构： 1.Henan Agr Univ, Coll Resource & Environm Sci, Zhengzhou 450002, Henan, Peoples R China

2.Chinese Acad Sci, Res Ctr Ecoenvironm Sci, State Key Lab Urban & Reg Ecol, Beijing 100085, Peoples R China

3.Henan Acad Agr Sci, Inst Plant Nutr & Environm Resource Sci, Zhengzhou 450002, Henan, Peoples R China

4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China

关键词： Combined organic and reduced chemical N fertilization; Soil aggregation; Net nitrification rate; Ammonia-oxidizing bacteria and archaea; N conservation

期刊名称：GEODERMA （ 影响因子：6.114； 五年影响因子：6.183 ）

ISSN： 0016-7061

年卷期： 2019 年 338 卷

页码：

收录情况： SCI

摘要： Long-term field fertilization trials have suggested that reduced chemical nitrogen (N) plus organic fertilization can effectively reduce N loss without sacrificing crop yield, while the knowledge of how organic fertilizers regulate soil microorganisms and their function in N transformation are limited. In this study, the response of net nitrification rate and the ammonia-oxidizer community within soil aggregates to long-term combined organic N and reduced chemical N fertilization was evaluated to understand the underlying mechanism of the practice in mitigating soil N loss. The fertilization experiment included an unfertilized control; chemical N fertilizer (N), superphosphate (P) and potassium sulfate (K) fertilizer (NPK); NPK plus straw (NPKS); and NPK plus manure (NPKM). The results showed that the large macro-aggregates mass (> 2 mm) in soil significantly increased from 34.1% in NPK to 47.2% in NPKS (P < 0.05). NPKS and NPKM both had positive effects on soil moisture retention, total N (TN), soil organic carbon (SOC), ammonium (NH4+-N) and nitrate (NO3--N) accumulation, particularly within micro- (< 0.25 mm) and small macro-aggregates. Compared with the NPK treatment, soil net nitrification rate (NNR) and ammonia-oxidizing bacterial (AOB) abundance decreased by 67.1% and 40.7% respectively under NPKS (P < 0.05), and the decrease mainly appeared in large macro-aggregate and micro aggregates. The net nitrification rate was significantly correlated with ammonia-oxidizing archaea (AOA) abundance only in small macro-aggregates (r = 0.642, n = 12, P < 0.05). In contrast, NRR was positively correlated with AOB abundance within small macro- and micro-aggregate size classes (r values ranged from 0.654 to 0.813, P < 0.05). The community structure of AOB varied among different fertilization treatments, while AOA community differentiation was mainly dependent on aggregate size. The shift of the AOA and AOB communities corresponded with high moisture and lower ammonia content in the large macro-aggregates and were potentially responsible for the suppressed nitrification activity in the NPKS treatment. These results indicated that reduced chemical N plus organic fertilization is beneficial for increasing N concentration in large macro-aggregates.