原状土与填装土水分特征曲线及孔隙分布的比较研究

Comparative Study on Water Retention Curves and Pore Size Distribution of Intact and Repacked Soil

对原状土和填装土的水分特征曲线和土壤孔隙分布进行比较研究,以期为合理进行农业耕作提供依据。结果表明,原状土和填装土的测定曲线相交于pF2.7,当0≤pF<2.7时,填装土含水量大于原状土,而当2.7<pF≤4.2时,原状土含水量大于填装土。原状土破坏后,土壤水分特征曲线平滑度变差,说明土壤孔隙连续性遭到破坏;土壤导水和储水孔隙的总孔隙度增加42.3%,但由于孔隙连续性变差,仍将不利于作物有效吸水。因此,实际生产中,建议适当降低犁耕强度和频率,以保持土壤结构的连续性。

This paper studied the water retention curves and pore size distribution of intact and repacked soil.The results showed that the measured water retention curves of intact and repacked soil met at pF=2.7.When 0≤pF〈2.7,water content of the repacked soil was higher than that of the intact soil,and the reversed result was true when 2.7〈pF≤4.2.After the intact soil was disturbed,the water retention curve became less smooth,indicating that the connection of soil pores became worse;the total porosity increased by 42.3%,but the plants took up water less freely due to the worse connection of soil pore.Therefore,the tillage practice should be properly limited to keep soil natural structure.