不同机械压实条件下黑土性质及入渗特征变化研究

Characterization of Black Soil Infiltration under Different Mechanical Compaction Conditions

为探究不同机械压实条件对黑土土壤性质入渗特征的影响,以克山县典型黑土为研究对象,设置3种不同型号机械(华夏HX2104-C:154 kW、约翰迪尔554:40 kW、中国海山:19 kW)和不同压实次数(0,1,3,5,7,9次)对秋收后大豆耕地垄沟开展模拟压实,通过测定土壤容重、含水率、孔隙及土壤入渗特征,分析不同机械压实条件对土壤物理性质及土壤入渗特征的影响。结果表明:在0~10 cm土层,大型、中型、小型机械压实后土壤容重分别增加54.17%、56.25%、46.88%;总孔隙度分别减小31.58%、28.07%、29.82%;含水率分别下降19.35%、16.13%、9.68%。首次压实对土壤性质的影响最显著,容重均增加32.29%以上,土壤总孔隙度均减小15.8%以上,只有大型机械使土壤含水率显著减小9.6%。随压实次数增加,各机械压实后10~20 cm土层土壤容重从1.25 g·cm^(-3)增加至1.58 g·cm^(-3),总孔隙度从52.16%减小至38.22%,土壤含水率从27.33%下降至20.67%,其中,大型机械在首次压实使容重及孔隙特征产生显著影响,而中型及小型机械对土壤物理性质的影响主要依靠压实次数的增加对土壤起到压实的累积作用。首次压实,中型及小型机械使2 h累计入渗量分别减少87.16%、50.81%,初渗速率分别减少87.59%、70.93%,中型机械使稳渗速率显著减少92.90%;3次压实,大型机械使2 h累计入渗量、初渗速率分别显著减小73.29%、75.67%,大型及小型机械使稳渗速率分别显著减少74.07%、66.97%;至5次压实后土壤各入渗特征无显著差异。0~20 cm土层土壤容重及土壤孔隙特征均影响机械压实土壤入渗特征,其中,0~10 cm土层土壤容重是影响综合土壤入渗特征的主导因素。

To explore the soil properties and soil infiltration characteristics of black soil under different mechanical compaction conditions,taking the typical black soil of Keshan County as the research object,three types of machinery(Huaxia HX2104-C:154 kW,John Deere 554:40 kW,and China Haishan:19 kW) were set up in Keshan County to carry out 0,1,3,5,7 and 9 simulated compactions on the furrow of soybean land after autumn harvest.The effects of different mechanical compaction conditions on soil physical properties and infiltration characteristics were analyzed by measuring the soil density,water content,porosity,and soil infiltration characteristics.The results showed that in the 0-10 cm soil layer,large machinery,medium machinery and small machinery compaction bulk density increased 54.17%,56.25%,46.88%;total porosity decreased 31.58%,28.07%,29.82%;water content decreased 19.35%,16.13%,9.68%.After the first compaction,all the machinery had the most significant effect on soil prorperties,which increased the bulk density by more than 32.29% and reduced the porosity by more than 15.8%,while only the large machinery significantly reduced the soil water content by 9.6%.With the increase of compaction time,the soil bulk density of the 10-20 cm soil layer after mechanical compaction increased from 1.25 g·cm^(-3) to 1.58 g·cm^(-3),the total porosity decreased from 52.16% to 38.22%,and the water content decreased from 27.33% to 20.67%.Among all the machines,the bulk density and porosity of soil were significantly affected by the first compaction of large machinery,while the influence of medium and small machinery on the physical properties of soil was mainly due to the cumulative pressure effect.For the first compaction,the cumulative infiltration volume of 2 h was reduced by 87.16% and 50.81% by medium and small machinery.The initial infiltration rate was reduced by 87.59% and 70.93%.The stable infiltration rate was significantly reduced by 92.90% by medium machinery.After three times of compaction,the cumulative infiltration volume of 2 h and initial infiltration rate were significantly reduced by 73.29% and 75.67% by large machinery,while the stable infiltration rate was significantly reduced by 74.07% and 66.97% by large and small machinery.There was no significant difference in soil infiltration characteristics after five times of compaction.Both soil bulk density and soil pore characteristics of the 0-20 cm soil layer affect the infiltration characteristics of mechanically compacted soil,with soil bulk density of the 0-10 cm soil layer being the dominant factor affecting the integrated soil infiltration characteristics.