有机覆盖物对城市绿地土壤水分和温度的影响

为了解有机覆盖物对城市绿地土壤水分和温度的影响,文章选择城市公园绿地对地表分别进行了覆盖3cm、5cm有机覆盖物和未覆盖空白对照三种处理试验,研究了0~10cm、10~20cm、20~30cm和30~40cm不同土层的水分和温度变化。结果表明:(1)三种覆盖处理土壤含水量的季节变化趋势一致。土壤含水量在0~10cm波动最大,随着土壤深度的增加,这种波动表现得越来越弱。(2)覆盖3cm有机物处理在四个土壤层次均高于空白对照,而在10~20cm和20~30cm的增加量最多;覆盖5cm有机物处理只在0~10cm明显的高于空白对照。(3)不同覆盖处理的土壤温度的季节变化趋势一致。相对于空白对照,覆盖处理的土壤日温变化幅度要明显小于空白对照,其中覆盖3cm和5cm有机物的处理比对照区在炎热的夏季土壤温度分别降低了2.0℃和0.9℃,而在寒冷的冬季升高了0.9℃和1.4℃。同时,覆盖处理也减小了不同土层深度的温度变幅。  

Effect of Organic Mulch on Soil Moisture and Temperature in Urban Green Space

In order to study the effect of organic mulch on soil moisture and temperature in urban green space, three experimental treatments were designed in green land of urban park as the followings: 3cm mulch, 5cm organic mulch and no cover to study the change of soil moisture and temperature in the depths of 0~10cm, 10~20cm, 20~30cm and 30~40cm. The result of continual observation from March to December in 2008 shows that: (1) Seasonal variation of soil moisture displayed the same trend in the three experimental treatments,the largest fluctuation of soil moisture was found in depth of 0~10cm, and the larger the soil depth, the smaller the fluctuation; (2) 3cm mulching increased soil moisture in the four depths compared to the control, and more obvious in the depths of 10-20cm and 20-30cm; while 5cm mulching just significantly increased soil moisture in the depth of 0-10cm compared to the control; (3) Seasonal variation of soil temperature is the same in three experimental treatments. The range of diurnal-variation is smaller in the mulching than in the control, 3cm and 5cm mulching decreased daily soil temperature by 2.0℃ and 0.9℃ respectively in the summer and increased daily soil temperature by 0.9℃ and 1.4℃ respectively in the winter compared to the control. At the same time, mulching reduced the variation of soil temperature among soil depths.