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草业学报 ›› 2020, Vol. 29 ›› Issue (1): 28-37.DOI: 10.11686/cyxb2019113

• 研究论文 • 上一篇    下一篇

祁连山东段高寒草甸土壤持水能力在小尺度不同坡面位置的分异特征

马海霞1,2, 张德罡1,*, 陈瑾2, 郭春秀1, 董永平3, 马源1, 康玉坤1, 陈璐1, 杜凯1, 陈建纲1   

  1. 1.甘肃农业大学草业学院,甘肃 兰州 730070;
    2.定西市水土保持科学研究所,甘肃 定西 743000;
    3.全国畜牧总站,北京 100125
  • 收稿日期:2019-02-28 修回日期:2019-07-08 出版日期:2020-01-20 发布日期:2020-01-20
  • 通讯作者: *E-mail: zhangdg@gsau.edu.cn
  • 作者简介:马海霞(1979-),女,甘肃定西人,工程师,在读博士。E-mail: mhx_qhdx@163.com
  • 基金资助:
    农业部全国畜牧总站“草地生态系统关键产品与服务实物量测度研究”和甘肃省草原技术推广总站“基于3S技术的草原生态监测与评价研究”资助

Change in factors influencing soil water holding capacity at microsites along a slope transect in alpine meadow in the eastern Qilian Mountains

MA Hai-xia1,2, ZHANG De-gang1,*, CHEN Jin2, GUO Chun-xiu1, DONG Yong-ping3, MA Yuan1, KANG Yu-kun1, CHEN Lu1, DU Kai1, CHEN Jian-gang1   

  1. 1.College of Pratacultural Science, Gansu Agricultural University, Lanzhou 730070, China;
    2.Institute of Soil and Water Conservation in Dingxi, Dingxi 743000, China;
    3.National Animal Husbandry Station, Beijing 100125, China
  • Received:2019-02-28 Revised:2019-07-08 Online:2020-01-20 Published:2020-01-20
  • Contact: *E-mail: zhangdg@gsau.edu.cn

摘要: 对高寒草甸不同坡面位置间土壤持水能力在小尺度下的分异特征及其主要影响因素进行了研究,以期为高寒草甸水分保持功能评价及其合理利用与保护提供参考。试验选择5个不同坡面位置,分别为2990(坡顶)、2980(坡上)、2970(坡中)、2960(坡下)、2950 m(坡脚),测定了土壤粒径、土壤湿度、土壤孔性、入渗及持水性等指标。结果表明,土壤颗粒组成中粘粒含量占8%~10%,粉粒占79%~83%,砂粒占7%~11%,坡顶到坡下以及各个土层之间变化程度均较小,而在坡脚处变化较大,砂粒含量随土层深度增加从42%增加到74%,同时粘粒和粉粒含量随土层深度的增加而减少。田间持水量与砂粒和粘粒含量呈负相关关系,与粉粒含量呈正相关关系,从坡顶到坡下,田间持水量为45%~55%,而在坡脚处由于砂粒含量较高,随土层深度的增加则从40%下降到21%。土壤总孔隙度在各坡面位置和土层间的变化趋势和田间持水量相似,其中非毛管孔隙度随坡面位置和土层的变化不明显,在总孔隙度中仅占8%。土壤入渗率从坡顶到坡脚呈增加趋势,且随土层深度的增加而减小,在坡顶,入渗试验开始5 min以后入渗率从1.2 mm·min-1(0~10 cm)减小到0.2 mm·min-1(30~40 cm),而在坡脚,则是从4.4 mm·min-1(0~10 cm)下降到2.5 mm·min-1(30~40 cm)。

关键词: 高寒草甸, 土壤颗粒组成, 田间持水量, 孔隙度

Abstract: In order to provide reference data for water conservation modelling and to determine sustainable utilization and protection criteria for alpine meadow, factors influencing soil water holding capacity were assessed for microsites at different positions along a slope transect in the eastern Qilian Mountains. Five study plots at different altitudes (slope crest, 2990 m; upper slope, 2980 m; mid slope, 2970 m; lower slope, 2960 m and slope foot, 2950 m) were selected, and the soil particle size distribution (i.e. soil texture), soil moisture, soil bulk density, soil porosity and soil permeability were measured. Soil texture varied little between the slope crest, upper, mid, and lower slope or with soil depth at those sites (typically 8%-10% clay, 79%-83% silt, and 7%-11% sand); however, at the slope foot soil had 42% sand in the 0-10 cm soil layer, increasing with depth to 74% sand in the 30-40 cm soil layer, with corresponding reductions in silt and clay components. Soil field moisture capacity was negatively correlated with sand and clay content and positively correlated with silt content and was typically in the range 45%-55% for slope crest and upper, mid and lower slope positions, and was 40% for the 0-10 cm layer reducing to 21% for the 30-40 cm layer at the slope foot where soil had a higher sand content. Total soil porosity was generally similar to soil field moisture capacity, and showed a tendency to decrease with soil depth, while non-capillary porosity was somewhat variable with slope position and soil depth, and typically less than 8%. Infiltration rate decreased with increasing soil depth, but increased moving down the slope from crest to foot. At the slope crest, infiltration rates after 5 min testing were 1.2 mm·min-1 for the 0-10 cm soil layer, decreasing to just over 0.2 mm·min-1 in the 30-40 cm soil layer, while at the slope foot they were 4.4 mm·min-1 for the 0-10 cm soil layer, decreasing to approximately 2.5 mm·min-1 in the 30-40 cm soil layer. These data will assist with modelling of soil storage and release of water after rainfall events.

Key words: alpine meadow, soil particle composition, field moisture capacity, soil porosity