Effect of Soil Drying Intensity During an Experimental Drying-Rewetting Event on Nutrient Transformation and Microbial Community Composition
| Autor: | Dasheng Sun, Kejie Li, Xianyong Lin, Qingfang Bi, Qichun Zhang, Jun Zhu, Chong Wei Jin, Lingli Lu |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Chemistry
Soil Science Soil chemistry 04 agricultural and veterinary sciences Mineralization (soil science) 010501 environmental sciences 01 natural sciences Soil respiration Nutrient Microbial population biology Environmental chemistry Loam Soil water 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Water content 0105 earth and related environmental sciences |
| Zdroj: | Pedosphere. 28:644-655 |
| ISSN: | 1002-0160 |
| Popis: | Soil drying-rewetting (DRW) events affect nutrient transformation and microbial community composition; however, little is known about the influence of drying intensity during the DRW events. Therefore, we analyzed soil nutrient composition and microbial communities with exposure to various drying intensities during an experimental drying-rewetting event, using a silt loam from a grassland of northern China, where the semi-arid climate exposes soils to a wide range of moisture conditions, and grasslands account for over 40% of the nation's land area. We also conducted a sterilization experiment to examine the contribution of soil microbes to nutrient pulses. Soil drying-rewetting decreased carbon (C) mineralization by 9%–27%. Both monosaccharide and mineral nitrogen (N) contents increased with higher drying intensities (drying to ≤ 10% gravimetric water content), with the increases being 204% and 110% with the highest drying intensity (drying to 2% gravimetric water content), respectively, whereas labile phosphorus (P) only increased (by 105%) with the highest drying intensity. Moreover, levels of microbial biomass C and N and dissolved organic N decreased with increasing drying intensity and were correlated with increases in dissolved organic C and mineral N, respectively, whereas the increases in labile P were not consistent with reductions in microbial biomass P. The sterilization experiment results indicated that microbes were primarily responsible for the C and N pulses, whereas non-microbial factors were the main contributors to the labile P pulses. Phospholipid fatty acid analysis indicated that soil microbes were highly resistant to drying-rewetting events and that drought-resistant groups were probably responsible for nutrient transformation. Therefore, the present study demonstrated that moderate soil drying during drying-rewetting events could improve the mineralization of N, but not P, and that different mechanisms were responsible for the C, N, and P pulses observed during drying-rewetting events. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect