紫花苜蓿在酸性土壤中的生长表现

以酸性紫色土(pH值5.45),粘黄壤(pH值4.99)和砂岩黄壤(pH值4.30)为供试土壤,利用盆栽试验比较分析了6个紫花苜蓿品种的生长表现。结果表明,酸性粘黄壤和砂岩黄壤显著抑制紫花苜蓿生长与结瘤,而在酸性紫色土中,紫花苜蓿生长相对良好,且能正常结瘤;3种土壤不同的pH值水平是引起紫花苜蓿生长差异的主要原因,不同紫花苜蓿品种对酸性土壤的耐受性也不同,使紫花苜蓿品种间存在较大的生长差异。酸性粘黄壤和砂岩黄壤施用一定量的石灰,可提高紫花苜蓿生长高度,增加生物量的积累,且粘黄壤中根瘤数极显著增加;酸性紫色土经石灰改良后,部分品种地上部和地下部生物量降低,所有品种的根瘤重显著下降;相比之下,酸性粘黄壤和砂岩黄壤不经改良没有种植紫花苜蓿的可能,酸性紫色土较适宜种植紫花苜蓿。

Study on Medicago sativa growth in acid soils

Three types of acid soils:acid purple soil(pH value 5.45),acid clay yellow soil(pH value 4.99),and acid sandy yellow soil(pH value 4.30),were used in a pot experiment to study the growth of 6 types of Medicago sativa.The results showed that the growth and nodulation of the M.sativa plants were significantly inhibited in clay yellow soil and sandy yellow soil,whilst in purple soil M.sativa grew well and its nodulation was unaffected.The difference in growth of M.sativa between soils was mainly caused by the difference in soil pH value.Different M.sativa varieties also had different tolerances to the acid soils.Plant height,dry shoot weight and dry root weight of M.sativa were significantly increased by liming in two types of acid yellow soils,with the nodulation in clay yellow also increased significantly.However,liming decreased the shoot and root biomass of some varieties and nodule weight of all varieties in acid purple soil.Further,it was not possible to grow M.sativa in acid clay yellow and acid sandy yellow soil without soil amendments being added.Acid purple was the most suitable to grow M.sativa.