Soluble organic nitrogen cycling in soils after application of chemical/organic amendments and groundwater pollution implications
| Autor: | Xilai Zheng, Feifei Tian, Jia Xin, Hui Nai, Leyun Wang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities Nitrogen Environmental pollution 010501 environmental sciences engineering.material 01 natural sciences Soil Environmental Chemistry Water Pollutants Organic Chemicals Leaching (agriculture) Fertilizers Groundwater Nitrogen cycle Soil Microbiology 0105 earth and related environmental sciences Water Science and Technology Chemistry Agriculture 04 agricultural and veterinary sciences Mineralization (soil science) Nitrogen Cycle Straw Manure humanities Humus Environmental chemistry 040103 agronomy & agriculture engineering 0401 agriculture forestry and fisheries Fertilizer Environmental Pollution |
| Zdroj: | Journal of Contaminant Hydrology. 217:43-51 |
| ISSN: | 0169-7722 |
| DOI: | 10.1016/j.jconhyd.2018.08.003 |
| Popis: | Nitrogen (N) fertilizers have been extensively used to maintain soil fertility in intensively agricultural soils, creating serious environmental pollution. In this study, a 70-day incubation experiment was conducted to investigate the effects of different N fertilizers (urea, manure, straw) on N mineralization, soluble organic nitrogen (SON) dynamics and its leaching potential in typical agricultural soils of the Shandong Peninsula. The results showed that the addition of N fertilizers affected the SON pools and soil N mineralization in different ways owing to their various properties and interaction with soils. When comparing treatments, urea application was found to decrease SON content, whereas manure and straw addition increased the SON content after long-term incubation. Considering that SON content depended on a complicated formation process and consumption process, no direct link between SON content and N mineralization capacity was observed in different treatments. Additionally, we analyzed free amino acids (FAAs) in SON and found that FAA content was negatively correlated with N mineralization, except for the straw treatment. This suggested that FAAs were important substrates of N mineralization in soils. In addition, the composition of SON was determined by 3-dimensional excitation-emission matrix and ultraviolet-visible absorbance spectrophotometer after long-term incubation. The PIII+V/PI+II+IV ratio, SUVA254, and A253/A203 ratio decreased after fertilizer application. This indicated that fertilizer addition decreased the SON humification degree and increased SON leaching. Therefore, SON should be taken into account when optimizing fertilization management and evaluating the risk of N leaching in groundwater systems. |
| Databáze: | OpenAIRE |
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