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Acta Prataculturae Sinica ›› 2023, Vol. 32 ›› Issue (10): 15-27.DOI: 10.11686/cyxb2022469

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Response of soil organic phosphorus mineralization to alpine meadow degradation and temperature

Hong-yu QIAN(), Yu-lin PU(), Shan-xin LANG, Yi-ran LI, Nan-ding ZHOU   

  1. College of Resources,Sichuan Agricultural University,Chengdu 611130,China
  • Received:2022-11-29 Revised:2023-02-27 Online:2023-10-20 Published:2023-07-26
  • Contact: Yu-lin PU

Abstract:

Clarification of the mineralization characteristics of organic phosphorus in degraded grassland soils at different temperatures can provide basic data and a theoretical framework for the scientific management of soil phosphorus nutrients during the ecological recovery of degraded grassland. In this research, an aerobic culture method at constant temperature and humidity was used to investigate the mineralization characteristics and temperature responses of organic phosphorus in non-degraded (ND) meadow, and lightly degraded (LD), moderately degraded (MD) and heavily degraded (HD) soils on the Zoige Plateau. It was found that the mineralization rate of organic phosphorus showed no obvious change in the early stage (0-30 d), increased rapidly in the middle stage (30-60 d), and gradually stabilized in the late stage (60-120 d) when the four types of meadow soils were cultured at 5-15 ℃. Meadow degradation had no significant effect on soil organic phosphorus mineralization at low temperature (5-10 ℃). However, soil organic phosphorus mineralization was significantly reduced in MD and HD soils at high temperature (≥15 ℃). Compared with ND, the net mineralization rate of organic phosphorus in MD and HD soils decreased by 52.8% and 56.8%, respectively, at 15 ℃, and the constant B0 of soil organic phosphorus mineralization decreased by 29.5% and 40.4%, respectively. Furthermore, the temperature sensitivity of soil organic phosphorus mineralization decreased gradually with increased severity of meadow degradation. For example, the temperature sensitivity coefficient y" of organic phosphorus mineralization in ND soil was significantly higher than that in MD and HD soils by 221.1% and 306.7%, respectively. In summary, the degradation of alpine meadow reduced the mineralization and temperature sensitivity of soil organic phosphorus, which would be predicted to result in further reduction of soil phosphorus availability, and exacerbate any problem of phosphorus limitation in degraded grassland ecosystems arising from ongoing global warming.

Key words: Zoige Plateau, meadow degradation, soil organic phosphorus mineralization, temperature sensitivity