机械深松对土壤容重和机械组成的影响

Effects of Mechanical Deep Loosening on Soil Bulk Density and Mechanical Composition

为探究农田耕层对机械深松不同程度的适宜性,采用田间大区试验,分别设置常规松土25cm(对照)、机械深松30cm和机械深松40cm三个处理,比较分析了各处理对农田0～20cm和20～40cm两个土层中土壤容重和土壤机械组成的影响。结果表明:与常规松土25cm相比,机械深松30cm对0～20cm土壤容重影响不显著(P<0.05),使20～40cm土壤容重显著降低了10%,而机械深松40cm使0～20cm和20～40cm土壤容重分别显著降低了12.4%和21.0%;在0～20cm和20～40cm两个土层中,与常规松土25cm相比,机械深松30cm和机械深松40cm均表现为粗砂粒(2～0.5 mm)、粉粒(0.05～0.002 mm)和粘粒(<0.002mm)含量呈现出增加的趋势,细砂粒(0.5～0.05mm)整体呈现出减少的趋势。可见,机械深松明显有利于疏松土壤,降低土壤容重,改变土壤的机械组成,增加了粗砂粒、粉粒和粘粒的比重,而相对减少细砂粒的比重。

In order to explore the suitability of farmland plough layer for different depths of mechanical subsoiling,a field regional test was carried out by setting three treatments,respectively,conventional loosening 25 cm （control） ,mechanical loosening 30 cm and mechanical loosening 40 cm. The effects of each treatment on soil bulk density and mechanical composition in two soil layers of 0-20 cm and 20-40 cm in farmland were compared and analyzed in the paper. The results showed that soil bulk density in mechanical loosening 30 cm treatment was not significant in soil layer of 0-20 cm （P〈0.05） and was significantly reduced by 10%in soil layer of 20-40 cm compared with control treatment. Soil bulk density in two soil layers of 0-20 cm and 20-40 cm in me chanical loosening 40 cm treatment decreased significantly by 12. 4Y0 and 21%,respectively,compared with control treatment. In two soil layers of 0-20 cm and 20 40 cm,the content of coarse sand（2 0.5 mm） ,silt（0.05-0.002 mm） and clay（〈0. 002 mm） showed an increasing trend and the content of line sand （0.5-0.05 mm） showed a decreasing trend in mechanical loosening 30 cm and 40 cm treatment compared with control treat ment. In conclusion,mechanical deep loosening is conducive to loosening the soil, reducing the bulk density of the soil, changing the soil mechanical composition, increasing the specific gravity of coarse sand particles, silt particles and clay particles ,and relatively reducing the proportion of line sand particles.