不同沟灌方式下土壤水、热分布研究

为了阐明不同沟灌方式对土壤水、热分布的影响，开展大田分区试验，研究了玉米生长期间交替隔沟(AFI)和常规沟灌(CFI)方式下不同位置处（沟位、坡位、垄位）土壤水热变化。结果表明，在一个灌水周期内，AFI的根区土壤水分以向下和侧向入渗为主，土壤水分有利于被作物根系吸收利用，而CFI的根区土壤水分始终保持较高的水平，促进土壤水分向根区以下移动，容易发生渗漏损失；沟灌方式引起剖面土壤温度的变化，高水分区域引起低土温，1个灌水周期内AFI根区平均土温比CFI高0.56~1.78℃，但不同点位之间根区平均土温差异较CFI小。在玉米生长期间，AFI根区平均土温比CFI高0.05~2.16℃，根区平均土壤含水量比CFI低3.31%左右。土温与土壤含水量存在良好的二次曲线关系，当土壤含水量X=37.30%时，土壤温度出现最低值。因此，与常规沟灌相比，交替隔沟灌溉具有控墒调温的作用，有利于根区土壤水分的高效利用，促进根区土温的均匀分布。

The Distribution of the Water and Temperature Under Different Furrow Irrigation Methods

In order to understand effect of different furrow irrigation methods on soil water and heat distribution, variation of soil water and heat at different sites （furrow, slope and ridge） in maize field with alternative furrow irrigation （AFI） and conventional furrow irrigation （CFI） was investigated. Results showed that： most of soil water in root zone with AFI moved downward and laterally during an irrigation period. It was conductive to crop roots to uptake soil water. Soil moisture in root zone with AFI was always to maintain a high level to promote soil water to move out the root zone, increasing the probability of deep percolation. Variation of the temperature in the soil profile was caused by furrow irrigation patterns. Low value of soil temperature happened in the zone with high soil moisture. During an irrigation period, soil temperature in root zone with AFI was higher than that with CFI by 0.56-1.78℃, but the soil temperature difference among different sitesCFI by 3.31%. The relationship between soil temperature and soil moisture could be figured by a quadric equation. When soil moisture X was 37.3%, soil temperature was at its lowest. Therefore, compared with CFI, AFI had important roles to regulate soil moisture and temperature. It was beneficial to high efficiency use of soil moisture in root zone and uniform distribution of soil temperature in root zone.