耕作方式对冀西北高原旱沙地土壤机械组成和容重的影响

Effects of Tillage Practices on Soil Mechanical Composition and Bulk Density in Dry Sandy Field of the Northwest Plateau of Hebei Province

针对冀西北高原旱沙地农田经济与生态兼顾的要求,在免耕产量明显降低的背景下,通过研究土壤机械组成、容重等物理性质,探究保护性耕作在该类农田造成减产的原因。研究发现,该区域内土壤质地为多砾质沙土,主要风蚀物（0.01~0.25 mm颗粒）在0~5 cm土层内旋耕和翻耕处理分别比免耕高7.31%和14.64%,差异显著（P〈0.05）;5~30 cm土层内0.01~0.25 mm颗粒总量各处理间差异不显著（P〉0.05）。旋耕处理0~10 cm土层和翻耕处理0~30 cm各层土壤容重为1.34~1.52 g/cm3;免耕各层均大于1.60 g/cm3,耕作明显降低了土壤的容重。

In order to meet the demand of economic development and ecological protection in dry sandy field of the northwest plateau of Hebei province, the soil mechanical composition and bulk density were studied under the background of the yield decreased markedly with no-tillage to explore the reasons of reducing production by conservative tillage. The results showed that the soil texture was gravelly sandy soil in this region. The proportion of sand particles of the main erosion matter in 0~5 cm soil layers with 0.01~0.25 mm diameter in rotary tillage（RT） and conventional tillage（CT） were 7.31% and 14.64% higher than that in no-tillage（NT） with significant difference（P0.05）. The content of soil particles in 5~30 cm soil layers with 0.01~0.25 mm diameter in CT was 0.83% and 1.21% lower than that in NT and RT treatments with no obvious difference（P0.05） difference. The soil bulk density in 0~10 cm layer of RT and 0~30 cm layer of NT ranged from 1.34 g/cm3to 1.52 g/cm3. The soil bulk density in every layer of NT treatment was higher than 1.60 g/cm3. Therefore tillage reduced soil density significantly in this field.