振动深松耕作对不同类型土壤水分特征曲线影响研究

为了探讨振动深松耕作措施对不同类型土壤的水分特征曲线的影响,利用吸力平板仪和压力膜仪对黑龙江省5种典型土壤,即黑土、黑钙土、水稻土、苏打盐碱土、沙土进行了测定。得到振动深松区和对照区的原状土壤在脱湿过程中不同吸力下的土壤含水率,并利用van Genuchten数学模型对5种土壤的水分特征曲线的实测值进行数值拟合,对比研究了5种土壤水分特征曲线及模型拟合参数、土壤当量孔径、土壤水分有效性及比水容量的变化。结果表明,振动深松前后土壤水分特征曲线差异显著。同一吸力下,深松区土壤含水率高于对照区,振动深松显著提高了土壤的有效供水能力,其中效果最佳的是苏打盐碱土和黑土。振动深松通过改善土壤结构,调整了孔隙孔径的比例,进而提高了土体的有效供水能力。

Impact of Vibration-tillage of Subsoils on Their Water Retention Curves

This paper investigated the impact of vibration-tillage of subsoil on water retention curves offive different soils in Heilongjiang Province:Black soil,Chernozem soil,Paddy soil,Soda-saline soil,and sandy soil.Soil moisture under different matric potential controlled by tension table and pressure membrane apparatus was measured during both drying and wetting processes.The measured water retention curves were then fitted to the van Genuchten formula.The differences between the water retention curves,best-fitting parameters,equivalent pore size,soil moisture availability and specific water capacity of the five soils were assessed.The results showed a significant change in water retention curves of the same soil before and after the vibration-tillage.At the same matric potential,the soil water content after vibration-tillage was higher than that before the tillage.Vibrating the subsoil appeared to have significantly improved the availability of soil water,especially for the soda-saline and the black soils.Vibration-tillage of subsoil changed soil structure and increased soil porosity,thereby enhancing the ability of soil to retain and supply water.