三种植物物料对两种茶园土壤酸度的改良效果

用室内培养实验研究了稻草、花生秸秆和紫云英在 5、10 和 20 g/kg 的加入量水平下对茶园黄棕壤和茶园红壤酸度的改良效果.结果表明:除了黄棕壤加入紫云英处理会降低土壤的 pH 外,其余所有加入植物物料的处理均使土壤 pH 有不同程度的增加,使土壤交换性酸和交换性Al的数量减小,使土壤交换性盐基阳离子和盐基饱和度增加.有机物料对土壤酸度的改良效果与有机物料灰化碱和N含量有关,灰化碱和有机N的矿化使土壤 pH 升高,NH4+-N的硝化使土壤 pH 降低.3种植物物料中花生秸秆对土壤酸度的改良效果优于紫云英和稻草.加入植物物料使红壤中有毒形态Al的浓度显著减小,说明植物物料能够缓解红壤中Al对植物的毒害.

Amelioration effects of three plant materials on acid tea garden soils

The amelioration effects of rice straw, peanut straw and Chinese milk vetch shoot on the acidity of red soil and yellow brown soil from tea gardens were examined with the incubation experiments at three levels of plant materials, i.e., 5, 10 and 20 g/kg added. After the soils incubated with plant materials, soil exchangeable acid and exchangeable Al decreased while exchangeable base cations and base cation saturation increased. For yellow brown soil added with Chinese milk vetch, soil pH increased to some extent compared with control. The amelioration effects of plant materials on soil acidity depend on the ash alkalinity and N content in plant materials. The ash alkalinity and mineralization of organic N increased soil pH, while nitrification of NH4+-N decreased soil pH. The amelioration effect of peanut straw on soil acidity was greater than Chinese milk vetch shoot and rice straw. The incorporation of plant materials into soils resulted in the decline of toxic species of Al obviously in soils, which suggest that the addition of plant materials could alleviate aluminum toxicity to plants in acid soils.