| 摘要: |
| 【目的】 探索具有“物理疲劳症”的设施土壤的水分蒸发特性，为设施土壤的水分管理及设施土壤的改良提供依据。【方法】 在实验室条件下，设置土壤容重分别为1.2 g/cm3(疏松)和1.5 g/cm3（紧实）2个处理，研究紧实胁迫条件下土壤水分蒸发速率随时间的动态变化特征，对蒸发过程进行分段模拟；并根据模拟模型，对各阶段的历经时间进行估算。【结果】 2种容重条件下，土壤水分的蒸发过程均具有3个明显的阶段性特征：第1阶段的蒸发速率高且相对稳定，与大气温度及空气相对湿度有关，蒸发模型用y^=y-（y为蒸发速率）表示；第2阶段的蒸发速率急剧下降，与土壤的导水能力有关，1.2和1.5 g/cm3土壤容重处理下的平均蒸发速率分别为1.1，1.3 mm/d,估算历经时间分别为25.6和28.3 d；第3阶段的蒸发速率很小；后2个阶段的蒸发模型可用y^=aeb/t(y为蒸发速率，t为时间，a、b为常数)表示。【结论】 紧实胁迫提高了土壤水分的蒸发速率，使蒸发持续时间延长，水分损失量增大，保墒性降低。 |
| 关键词: 紧实胁迫 土壤容重 水分蒸发 数学模拟 |
| DOI： |
| 分类号: |
| 基金项目:陕西省自然科学基金项目（2005C103） |
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| Soil water evaporation and its maths simulation under compaction stress condition |
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TIAN Kun1 HUANG Chi hua2 ZHANG Guang jun1 ZHENG Fen li1
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| Abstract: |
| 【Objective】 The purpose of this work was to probe into water evaporation characteristics of horticultural structure soil having physical fatigue,providing a basis for water management in horticultural structure soil and improvement of horticultural structure soil.【Method】 Under laboratory condition,two trentments of 1.2 g/cm3(loose soil) and 1.5 g/cm3(compact soil) soil bulk density were set.Dynamic changing characteristics of soil water evaporation rate with time was studied under compaction stress condition.Water evaporation processes were simulated by sectioned curve.Time for evaporation at each stage was estimated with sectioned model function.【Result】 There were three clear stages in water evaporation processe of soils having two bulk densitty treatments. At the first stage,water evaporation rate was great and stable,related to air temperature and relative air moisture,evaporation model is y^=y-（y is evaporation rate）.At the second stage,water evaporation rate dropped sharply,related to water conductivity of soil.The mean soil evaporation rate of 1.2 and 1.5 g/cm3bulk density treatment was 1.1 and 1.3 mm/d respectively.At the third stage,water evaporation rate was small.Evaporation model in latter stages was y^=aeb/t ( y is evaporation rate,t is time,a and b are constents).【Conclusion】 Compaction stress increased the water evaporation rate and water loss amount of soil,prolong evaporation time,and the ability to water retention decreased under compaction stress. |
| Key words: compaction stress soil bulk density water evaporation maths simulation |
