欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2023, Vol. 32 ›› Issue (12): 36-46.DOI: 10.11686/cyxb2023054

• 研究论文 • 上一篇    下一篇

若尔盖不同退化高寒草甸土壤磷形态及其影响因素

杨志强(), 刘丹(), 廖小琴, 陈丹阳, 宋小艳, 柳杨, 王长庭   

  1. 西南民族大学青藏高原研究院,四川 成都 610041
  • 收稿日期:2023-02-20 修回日期:2023-04-10 出版日期:2023-12-20 发布日期:2023-10-18
  • 通讯作者: 刘丹
  • 作者简介:Corresponding author. E-mail: liudan_ucas@163.com
    杨志强(1999-),男,甘肃和政人,在读硕士。E-mail: 2091944761@qq.com
  • 基金资助:
    国家自然科学基金(32101348);西南民族大学优秀学生培养工程项目(2023NYXXS101)

Changes in soil phosphorus fractions and their causes under alpine meadows with different degradation status in Zoigê

Zhi-qiang YANG(), Dan LIU(), Xiao-qin LIAO, Dan-yang CHEN, Xiao-yan SONG, Yang LIU, Chang-ting WANG   

  1. Institute of Qinghai-Tibetan Plateau,Southwest Minzu University,Chengdu 610041,China
  • Received:2023-02-20 Revised:2023-04-10 Online:2023-12-20 Published:2023-10-18
  • Contact: Dan LIU

摘要:

为了明确不同退化高寒草甸土壤磷含量的变化特征,以若尔盖未退化(UD)、轻度退化(LD)、中度退化(MD)、重度退化(SD)和极度退化(ED)高寒草甸为研究对象,采用Hedley磷分级法,测定并比较不同退化程度下高寒草甸土壤磷形态含量差异,探讨影响退化高寒草甸土壤磷形态的环境因素。结果显示:1)整体上高寒草甸土壤磷形态以盐酸磷为主,稀盐酸无机磷(DHCl-Pi)、浓盐酸无机磷(CHCl-Pi)和浓盐酸有机磷(CHCl-Po)含量之和占总磷(TP)的50%以上。2)高寒草甸土壤各形态磷随退化程度加剧整体呈下降趋势。与未退化草甸相比,极度退化草甸0~10 cm土壤水溶性磷(H2O-P)、碳酸氢钠无机磷(NaHCO3-Pi)和碳酸氢钠有机磷(NaHCO3-Po)显著降低了92.51%、89.57%和85.10%,10~20 cm土壤仅NaHCO3-Po显著降低了80.32%;0~20 cm土壤氢氧化钠无机磷(NaOH-Pi)、氢氧化钠有机磷(NaOH-Po)、浓盐酸有机磷(CHCl-Po)和残余磷(residual-P)整体表现为随退化加剧而降低,最小值均在极度退化草甸且分别为12.15、7.09、21.14和26.48 mg·kg-1。3)H2O-P与土壤容重(BD)显著负相关;NaHCO3-Pi、NaHCO3-Po、NaOH-Pi、NaOH-Po、CHCl-Po和residual-P与土壤总碳(TC)和总氮(TN)显著正相关而与土壤pH和BD显著负相关;CHCl-Pi与所有环境因子相关性不显著;土壤BD、pH、含水量(SMC)、TC和TN共同解释土壤磷形态变异的78.79%,其中土壤pH的贡献率最高(52.29%)。综上,土壤各磷形态均随高寒草甸退化加剧而呈现出不同程度的降低,其中土壤有机磷的下降幅度最为明显。研究结果有望为未来若尔盖退化高寒草甸土壤养分保持及草甸恢复管理提供科学依据。

关键词: 若尔盖, 退化草甸, 土壤, 磷形态, Hedley磷分级法

Abstract:

This research investigated the variation in soil phosphorus content in alpine meadows of different degradation status, using the Hedley sequential fractionation method. Soil phosphorus fractions were measured for undegraded (UD), lightly degraded (LD), moderately degraded (MD), severely degraded (SD), and extremely degraded (ED) alpine meadow sites in Zoigê, and the environmental factors influencing soil phosphorus fractions were also explored. It was found that: 1) On the whole, the HCl extractable phosphorus (HCl-P) dominated soil phosphorus fractions in the alpine meadow, and the content of the dilute HCl extractable inorganic phosphorus (DHCl-Pi), concentrated HCl extractable inorganic phosphorus (CHCl-Pi) and concentrated HCl extractable organic phosphorus (CHCl-Po) together accounted for more than 50% of the total phosphorus (TP). 2) All categories of soil phosphorus fraction showed a decline trend with increased degradation. Compared with the undegraded meadow, the H2O extractable phosphorus (H2O-P), NaHCO3 extractable inorganic phosphorus (NaHCO3-Pi) and NaHCO3 extractable organic phosphorus (NaHCO3-Po) of ED soil were decreased (P<0.05) by 92.51%, 89.57% and 85.10%, respectively, in the 0-10 cm soil horizon. Only NaHCO3-Po decreased significantly (by 80.32%) in the 10-20 cm horizon of ED soils. The NaOH extractable inorganic phosphorus (NaOH-Pi), NaOH extractable organic phosphorus (NaOH-Po), CHCl-Po and residual-P in the 0-20 cm soil horizon decreased with increased degradation and were lowest in ED soil, with values of 12.15, 7.09, 21.14 and 26.48 mg·kg-1, respectively. 3) There was a significant negative correlation between the H2O-P and soil bulk density (BD); The NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, NaOH-Po, CHCl-Po and residual-P showed positive correlations with soil total carbon (TC) and total nitrogen (TN) but negative correlations with soil pH and BD. The CHCl-Pi exhibited no significant correlation with any of the environmental factors. Soil BD, pH, soil moisture content (SMC), TC and TN together explained 78.79% to the variation of soil phosphorus fractions, with soil pH having the largest contribution (52.29%). In conclusion, the various soil phosphorus fractions presented various patterns of decrease with increased soil degradation. Loss of soil organic phosphorus in degraded soils was relatively high. Those results are expected to provide scientific clues for future soil nutrient conservation initiatives and for planning of ecological restoration management of degraded alpine meadow in Zoigê.

Key words: Zoigê, degraded alpine meadow, soil, phosphorus fractions, Hedley sequential fractionation method