地被物对土壤水分动态和水量平衡的影响研究

通过土壤水分渗漏装置试验研究了百喜草( Paspalum notatum) 及其枯落物在红壤坡地对土 壤水分动态和水量平衡的影响。结果表明, 百喜草覆盖(A) 、百喜草敷盖(B) 、裸露对照(C) 的地表径 流系数分别为1.35%、2.78%和32.74%, C 的地表径流量分别是A、B 的24.25 倍和11.78 倍。A、B、C 的月均土壤含水量变化规律显示, 地被物对土壤含水量的影响随季节的不同而不同, 不同地被物可 以增加或减少土壤水分。年均土壤含水量排列顺序是: B( 27.09%) >A( 26.46%) >C( 26.27%) 。不同处 理水量平衡各分量有较大差异。在2002 年降雨量1 808.5mm 的情况下, A、B、C 的年总径流深分别 为1 245.24、1 453.81 和1 383.23mm, 蒸散量分别为562.74、347.91 和413.82mm, 土壤蓄水年变化 量分别为0.52、6.78 和11.45mm。

A Study on Effects of Ground Cover on Dynamics of Soil Moisture and Water Balance

The effects of Bahia grass (Paspalum notatum) and its litter on dynamics of soil moisture and water balance were studied by using Lysimeter in the slopeland of red soil.The results indicated that surface runoff coefficient of Bahia grass’ coverage (A), Bahia grass’ mulching (B) and CK (C) was 1.35%, 2.78% and 32.74% respectively.Surface runoff of C was 24.25 times of A and 11.78 times of B.Changing laws of monthly mean soil moisture of A, B and C showed that the effects of ground cover on soil moisture were different because of seasons and that different ground cover could increase or decrease soil moisture.Their annual mean soil moisture was B (27.09%)>A(26.46%)>C(26.27%).There were obvious differences between every gradient of water balance.On condition that precipitation was 1 808.5mm in 2002, the total runoff depth of A, B and C was 1 245.24mm, 1 453.81mm and 1 383.23mm respectively; their evapotranspiration was 562.74mm, 347.91mm and 413.82mm respectively; their annual soil moisture variation was 0.52 mm, 6.78mm and 11.45mm respectively.