中文摘要：

为了探究东北地区水田土壤下层土与水稻根系生长及产量的关系，采用微区试验方法，研究白浆土、黑土、草甸土三种类型水田土壤下层土对水稻根系生长和产量的影响。研究结果表明：不同类型土壤间水稻根系分布密度差异显著，其中黑土〉草甸土〉白浆土，且有下层土处理〉无下层土处理；水稻总根长、根系直径、根尖数在不同类型土壤间差异极显著，不同土壤间表现规律不一致，但各类土壤均为有下层土处理高于无下层土处理；水稻根系总体积、表面积、干重、根冠比、垂直根长各项指标均与水稻产量呈正相关性；比较不同类型土壤水稻产量为：黑土〉白浆土〉草甸土，下层土对水稻产量贡献率分别为：黑土32．97％、白浆土6．32％、草甸土10．59％。

英文摘要：

The study investigated the relationship between subsoil properties of paddy field and rice root growth and/or rice yield. Micro-area experimental methods were used to study the effects of soil properties of three soils （albic soil, black soil, and meadow soil） on rice root growth and rice yield. Results showed that the root density and distribution depth differed greatly among different soil types. Black soil most facilitated root growth, followed by meadow soil and then albic soil. Additionally, the presence of subsoil enhanced root growth. The measured indexes of total root length, root diameter, and root tip numbers also differed markedly among different soils. Although the patterns of these indexes varied between the different soils, all the results was greater at the subsoil than at the top soil. The rice root total volume, root superficial areas, dry root weight, root： shoot ratio, and vertical root length all had great positive correlations with rice yield. Rice yield was the greatest in black soil, followed by albic soil and then meadow soil. The contribution of subsoil to rice yield was 32.97%, 6.32%, 10.59%, respectively, in black soil, albic soil and meadow soil. The subsoil in black soil was rich in nutrients, and the textures were conducive to rice root growth, which, in turn, increased the yield. Based on these findings, the subsoil plays an important role in rice root growth and yield.