羟丙甲纤维素对土壤水分入渗特性及水稳性团聚体的影响

通过向土壤中施加不同含量的羟丙基甲基纤维素(简称HPMC),研究了HPMC对土壤水分入渗特性及土壤水稳性团聚体的影响。结果表明:(1)土壤中施加一定量的HPMC可以显著降低土壤入渗能力,在施加量为0～1.0g/kg范围内,累积入渗量、湿润锋运移距离和入渗率均随施加HPMC含量的增加而显著减小;利用Philip方程和Kostiakov公式对实测数据进行拟合发现,两者均能较好模拟施加HPMC后土壤的入渗过程,随HPMC施加量的增加,吸渗率S、稳渗率A和经验系数K明显减小,经验指数β逐渐增大。(2)随HPMC含量的增加,0.25mm的水稳性团聚体百分比明显增大,供试土壤的分形维数逐渐减小,其平均重量直径与水稳性团聚体含量间呈显著正相关关系,表明施加HPMC之后,土壤结构更趋于稳定,土壤抗破坏和抗侵蚀能力增强。HPMC加入土壤后具有明显的减渗效果,一定程度上可以增加水稳性团聚体含量,改良土壤结构,并提高土壤的抗侵蚀能力。

Effect of Hydroxypropyl Methyl Cellulose on Soil Water Movement and Water Stable Aggregate

The effect of hydroxypropyl methyl cellulose (HPMC) on soil water movement and soil water stability aggregates was studied by applying different content of HPMC into soil. The results showed that:(1) The infiltration capacity of soil was significantly reduced by a certain amount of HPMC in soil, and the cumulative infiltration, wetting front migration distance and infiltration rate decreased significantly with the increase of HPMC in the range of 0~1.0 g/kg. The measured data fitted with the Philip formula and the Kostiakov formula respectively, and two formula could well simulate the infiltration process of the soil after the application of HPMC. With the increase of HPMC content, the infiltration rate S, the stable infiltration rate A and the empirical coefficient K decreased obviously, and the empirical index beta gradually increased. (2) With the increase of HPMC content, the percentage of water stable large aggregate of >0.25 mm increased obviously, the fractal dimension of the tested soil decreased gradually, and the average weight diameter of the soil showed a significant positive correlation with the content of water stable. This indicated that after HPMC application, the soil structure was more stable, and its ability of anti-destruction and erosion resistance was enhanced. In conclusion, HPMC has obvious effect on reducing permeability after adding into the soil, and to a certain extent, it can improve soil structure and improve soil erosion resistance.