黄河源高寒草甸封育条件下的土壤持水能力

摘要

Taking the alpine meadow under the condition of different fencing years and grazing in Maqin, Qinghai Province as the research object, through the monitoring of soil bulk density, soil saturated water holding capacity, capillary water holding capacity and field capacity, the soil water-holding capacity and its relationship with environmental factors were analyzed.The results as follows: In the whole layer of 0～40 cm, The field capacity of different plots had an increasing tendency overall, the soil water-holding capacity in 0～10 cm soil layer was higher than 10～20 cm and 20～40 cm.After fencing 12 years, soil saturated water holding capacity, capillary water holding capacity and field capacity increased by 11.34 mm, 15.14 mm and 15.05 mm respectively, at a increase rate of 0.95 mm,1.26 mm and 1.25 mm per year respectively.Soil water storage were negatively correlated with soil bulk density significantly(P<0.01), and positively correlated with organic carbon content and underground biomass(P<0.05 or P<0.01).In the vertical direction, the surface soil water-holding capacity was higher than the deep, and in the fencing and grazing prohibition gradient, soil water-holding capacity in fencing plot was higher than grazing plot.It showed that fencing can improve the soil water-holding capacity.%以青海省玛沁县不同封育年限与自然放牧的高寒草甸为研究对象,通过对土壤容重、土壤饱和持水量、田间持水量及毛管持水量等指标监测,分析不同封育年限下高寒草甸的土壤持水能力及与环境因素的关系.结果表明:随着封育年限延长,封育样地0～40cm土层土壤持水量增加,其中0～10cm土层的土壤持水量高于10～20cm和20～40cm;封育12a后土壤饱和持水量、田间持水量、毛管持水量分别增加11.34mm、15.14mm、15.05mm,分别按0.95mm/a、1.26mm/a、1.25mm/a的速率增加;土壤饱和持水量、田间持水量和毛管持水量与容重呈极显著负相关(P<0.01),与有机质及地下生物量呈极显著或显著性正相关(P<0.05或P<0.01);土壤持水能力在垂直方向表现为表层高于深层,在封育禁牧梯度上表现为封育高于未封育.研究表明,封育能提高土壤持水能力.