冬前灌溉条件下冻融作用对土壤压实的影响

Effect of Freezing and Thawing on Soil Compaction Under Pre-winter Irrigation in Northern China

在北京大兴区进行大田试验,研究冬前灌溉条件下冻融现象对土壤压实的影响。使用TN-60压实翻耕后的土地,对比研究压实与不压实地块在冬前灌溉条件下土壤容重、总孔隙度、含水率和紧实度的变化。结果表明:冬前灌溉条件下,冻融作用使压实区0～15cm土层的压实降低,总孔隙度提高;对于未压实土壤,冻融作用提高0～10cm土层的容重,降低0～10cm土层的孔隙度;冬前灌溉土壤含水量明显高于不灌溉,冬前灌溉降低0～30cm土壤紧实度。因此,北京地区的冬前灌溉有利于减轻土壤压实。

Experiment was conducted in Daxing District in Beijing to measure the effect of freezing and thawing on soil compaction under pre -winter irrigation. The compacted treatment was done by TN-60 type tractor. Three compaction treatments were used：compacted,uncompacted and random planted field after tillage. Soil samples were taken before and after winter. Three indicators were used：soil bulk density,total porosity,soil moisture content and cone index to compare the effect of freezing and thawing on soil compaction under pre-winter irrigation. Results showed freezing and thawing reduced soil bulk density and increased total porosity in 0 ～ 15 cm in compacted soil,while in uncompacted soil,freezing and thawing increased soil bulk density and reduced total porosity in 0 ～ 10cm soil layer. Soil moisture was significantly higher in pre-winter irrigation than that in non -pre-winter irrigation. Pre-winter irrigation significantly reduced soil cone index in 0 ～ 30cm soil layer.