摘要
博罗县下村农场地处花岗岩类型的缓坡台地，分布的土壤为赤红壤，其表土层多属中壤土，总孔隙度因利用方式不同而略有差异，待垦荒坡一般为５０％－５５％，全垦后辟为梯地的果园则＜５０％，但由于下层的较表层的低，致使剖面的土壤透水性较低，影响降水的入渗。土壤的持水能力较强，但土壤有效水量偏低，在熟化度略高的果园土壤中可占总库容量的５５％，未开垦的则仅占３０％－３５％。在有效水量范围内，当土壤吸力为８００ｋＰａ时，可释放出总有效水量的７０％－８０％。在土壤吸力分别为５０ｋＰａ、８００ｋＰａ时，土壤水容量分别降到１０－２、１０－３数量级，所以，如果连续７—８天未下雨，则土壤容易出现干旱。
Xiacun Farm is located in gently slope granite terrace region dominated by latored soil. It is showed that the soil texture of the most epipedons is medium loam,and there are slightly differences in total porosity of different utilized soils. The total porosity is from 50% to 55% in uncultivated slope land, and <50% in orchard soils of slope land. Because the total porosity of the subsurface horizon soils is lower than that of the epipedon soils, the permeability of rainfall to the soils is usually limitted. Analytic results indicates that the water-storage capacity of the soils in gently slope terrace is higher, but the available water content is generally lower. The available water capacity is 55 % of the total water-holding content in orchard soils; 30% to 50% of the total water-holding capacity in uncultivated soils. In available water capacity range, 70% to80% of total available water is released under a suction of 800kpa.
基金
省科委攻关项目
