徐俏,崔东,王兴磊,朱振华.冻融对伊犁草地土壤水稳性大团聚体的影响[J].干旱地区农业研究,2017,35(6):244~251 |
冻融对伊犁草地土壤水稳性大团聚体的影响 |
Effects of freezing and thawing on soil water stable aggregates in Yili grassland |
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DOI:10.7606/j.issn.1000-7601.2017.06.35 |
中文关键词: 水稳性大团聚体 草地土壤 冻融作用 湿筛法 冻融循环次数 冻结温度 |
英文关键词:water stable aggregate grassland soil freezing and thawing wet sieving method freeze-thaw cycles freezing temperature |
基金项目:伊犁师范学院污染物化学与环境治理重点实验室开放课题科研项目资助(2016HJZD05) |
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中文摘要: |
以伊犁托乎拉苏大草原土壤为研究对象,进行0~20 cm草地表层土壤混合样品多点采集,实验室内依据干筛法取得各粒级大团聚体,模拟不同含水率、冻融试验,利用湿筛法获得每种粒级的水稳性大团聚体质量,对实验数据进行统计分析,研究草地土壤在冻融环境条件下其水稳性大团聚体的特征、变化规律及其机理。研究结果表明:(1) 初始水分含量是影响土壤水稳性大团聚体的关键因素。随着土壤初始含水率的提高,>5 mm、5~4 mm、4~2 mm、2~1 mm四个粒径组水稳性团聚体,呈现出逐渐降低、或先升高后降低的变化趋势;1~0.5 mm、0.5~0.25 mm呈现先降低后增加、或先增加后降低再增加的趋势。(2) 冻融循环次数是影响土壤水稳性大团聚体的重要因素。随冻融循环次数的增加,各组粒级水稳性团聚体表现出的规律性不尽相同,>1 mm水稳性团聚体整体有降低趋势,1~0.5 mm、0.5~0.25 mm两组粒径水稳性团聚体则整体呈现增加趋势。(3) 冻结温度是影响土壤水稳性大团聚体的另一重要因素,随着冻结温度的降低,>5 mm与5~4 mm水稳性团聚体有降低的趋势,1~0.5 mm与0.5~0.25 mm水稳性团聚体有升高的趋势,4~2 mm与2~1 mm两个粒级水稳性团聚体并无显著变化。 |
英文摘要: |
This study mainly took the soil of grassland in Yili as the research object. We sampled the 0~20 cm surface soil of Tuohulasu grassland in Yining County and obtained soil aggregates in different particle fraction via dry sieving method. After simulating water rate of soil aggregates and conducting freeze-thaw tests at laboratory, the weight of different size fraction water-stable aggregates were measured via wet sieving method. The results showed that: (1) Initial moisture content is the key factor affecting soil water stable aggregates. With the increase of soil initial moisture content, four size fraction water-stable aggregates, including>5 mm, 5~4 mm, 4~2 mm and 2~1 mm, gradually declined, or declined after an increase; water stable aggregates of 1~0.5 mm and 0.5~0.25 mm size fraction showed the changing trend of increasing first and then decreasing, or increase first, then decline and then increase again. (2) The frequency of freeze-thaw cycles is an important factor affecting soil water-stable aggregates. With an increasing frequency of freeze-thaw cycles, each size fraction of water stable aggregates showed different patterns. Water stable aggregates in>1 mm size fraction had overall decreasing trend, while other two size fractions of the aggregates including 1~0.5 mm and 0.5~0.25 mm showed an increasing trend. (3) Freezing temperature is another important factor affecting soil water stability. While the temperature decreased, the water stable aggregates of >5 mm and 5~4 mm size fraction also decreased, however, water stable aggregates of 1~0.5 mm and 0.5~0.25 mm size fractions increased significantly, and water-stable aggregates of 4~2 mm and 2~1 mm size fractions had no significant changes. |
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