套种黑麦草对桃园近地层水热环境的影响及模拟研究

The effects and simulation of peach orchard intercropped with rye grass on water and heat environments in the near soil surface:

分析了桃园套种黑麦草对近地层水热环境及其梯度的影响，并进行了模拟研究。结果表明，在热状况下，自然裸露区域桃园的空气温度日较差、日极端最高温度和２０ ｃｍ 高度处的空气平均温度均高于黑麦草套种区，空气湿度则黑麦草套种区明显大于自然裸露区。但这些差异均随着离地高度的增加而减小，自然裸露区和黑麦草套种区不同高度的空气平均温度，在阴天条件下，２０ｃｍ 高度处２ 个区域的绝对差异为０ ．７ ℃，２００ ｃｍ 高度处仅为０．１ ℃，在晴天条件下分别为１．１ ℃和０ ．２ ℃。近地层空气温度时间变化，２００ ｃｍ 高度处日最高气温和日最低气温出现的时间均比２０ ｃｍ高度处推迟２ ｈ 左右。在晴天，黑麦草套种区近地层的空气温度均随离地高度的增加而升高，但水汽压均随高度增加而减小；在自然裸露区，白天空气温度随离地高度的增加而减小，夜间温度梯度方向和白天相反。

Based on the data from field experiments,the effects of peach orchard intercropped with rye grass on air temperature,humidity and their gradient in the near soil surface were analyzed.The daily mean air temperature of 20 cm height,daily change of air temperature and daily maximum temperature in the areas without intercropping were higher or larger than those with intercropping of rye grass;the air humidity in the areas with intercropping of rye grass was higher than that without intercropping.These differences decreased obviously, with increase in height for example,under cloudy condition,the absolute differences of daily air temperature between areas without and with intercropping was 0.7℃ at the 20 cm height,only 0.1℃ at the 200 cm,under sunny condition,1.1℃ and 0 2℃ respectively.The appearing time of daily maximum and minimum value of air temperature at the 200 cm height was 2 hours later than that at 20 cm.Under sunny condition,air temperature in the areas with intercropping of rye grass increased with increase in height in the all day,but the vapor pressure decreased with increase in height;air temperature in those areas without intercropping decreased with increase in height in the day and increased in the evening.