基于最小限制水分范围评价不同耕作方式对土壤密度的影响

Evaluating the Effects of Tillage Practices on Soil Bulk Density by Least Limiting Water Range

摘要: 利用最小限制水分范围(LLWR)来评价不同耕作方式(免耕和秋翻)对土壤密度的影响。结果表明,免耕(NT)较秋翻(MP)显著增加了5 cm~20 cm的土壤密度,计算LLWR的上限值和下限值分别由田间持水量和土壤硬度决定,NT和MP处理的LLWR值在0.155 cm³·cm^-3~0.174 cm³·cm^-3之间且表现出前者小于后者的规律性。LLWR与土壤密度呈极显著负相关,可以用来评价耕作方式对土壤密度的影响。

Abstract: Effects of tillage practice on soil bulk density were compared using the least limiting water range (LLWR). The results showed that compared with mouldboard plow (MP), no tillage (NT) increased the soil bulk density in the 5 cm~20 cm soil layers. The upper and lower limits of LLWR were determined by field capacity and soil resistance, respectively. The values of LLWR under NT and MP ranged from 0.155 cm³·cm^-3 to 0.174 cm³·cm^-3, which were lower under NT than MP treatments. There was a significant negative correlation between LLWR and soil bulk density. LLWR can evaluate the effect of no tillage on soil bulk density.