亚热带花生旱坡地的水分动态特征分析

Analysis on the Feature of Soil Water Dynamics of Peanut Slope Upland in Subtropical China

为研究红壤旱坡地的水分动态特征,进行了2001—2003年田间实测。花生旱坡地水分状况随年降水周期和坡位不同变化。0￣150cm土壤贮水量大致分为盈余期、消耗期和补充期三个阶段。土壤水势变化与贮水量三阶段相对应,总体由大变小再回升,只是土壤剖面空间从上而下,水势值增大,变幅减小,100cm土层以下近乎常年稳定。在四个水势段出现频率中,水势较高的水势段出现频率越大,顺序为饱和>湿润>亏缺>干旱。饱和-湿润段出现频率比例总体上底土>心土>表土,坡下>坡上;低水势干旱段主要出现在坡上、土壤上层和伏秋干旱季节。旱坡地在雨季有壤中流产生,坡下降雨后深层出现较长时间的饱和区,而坡上深层水势出现较短时间的饱和区或未出现变化;旱季降雨对坡地水分影响较小。

The paper aimed at studying the soil moisture dynamics of red soil along slope farmland. Collected data showed that soil water status of peanut slope farmland changes along with periods of year rainfall, and location of slope farmland. The 0-150cm soil pondage is divided into three stages that are water surplus period, water consume period and water complementarities period. The soil potential is in accordance with the pondage stage the variety mutually, The soil potential of the current total from diminish to back up again greatly, just the soil layer is from the top bottom, the water potential of the current value enlarge, the water potential changes to let up, the 100 cm soil layer is as follows almost yearly stable. The higher soil water potential has, the more the frequency appears, ranking in saturation〉 wetness〉 wane〉 drought. The frequency of saturation- moist segment is ranked in the bottom soil〉 the subsoil〉 topsoil, down slope〉 up slope. The drought segment of low water potential appears on up slope, the soil surface and the dry season. Interflow appears on upland slope in rainy season. Saturation zone at deeper layer of down slope lasts longer time after a rain event while it lasts shorter or no at up slope. Rainfall has slight influence on soil moisture of upland during drought season.