茶树叶和刺槐叶对茶园土壤酸度的改良效果

通过培养实验，比较研究了茶树老叶和刺槐叶对2种酸化茶园土壤的改良效果。结果表明，在酸性茶园土壤中分别加入5、10和20g·kg^-1。茶树老叶和剌槐叶培养35d后，相对于对照，土壤pH值有不同程度的提高，土壤交换性酸减小，土壤交换性钙和镁等交换性盐基离子数量有所提高，土壤毒性铝离子的数量减少。2种树叶对土壤酸度的改良效果随其加入量的增加而增加，刺槐叶的改良效果好于茶树老叶，2种树叶对红壤的改良效果优于其对黄棕壤的改良效果。植物物料所含的灰化碱及豆科植物所含大量有机氮的矿化是导致土壤酸度下降的主要原因。

Amelioration Effect of Tea Tree Leaves and Acacia Leaves on the Acidity of Tea Garden Soils

Amelioration of two acidic soils（i.e., Uhisol and Alfisol）from tea gardens was investigated with incubation experiments using the old leaves of tea plants and acacia. The results indicated that the old leaves of tea plants and acacia increased the pH and exchangeable Ca^2＋ and Mg^2＋ of both soils. This caused the decrease in soil exchangeable acidity and toxic aluminum ions in the soils after the soils incubated with these two leaves for 35 days at the rate of 5, 10 and 20 g. kg^-1. The amelioration effect of the leaves on soil acidity increased with the increase in the amount of the leaves added. Comparing these two leaves the acacia leaves showed the greater amelioration effect than the tea tree leaves. On the other hand the amelioration effect of these leaves on acid Uhisol is greater than that on acid Alfisol. The decrease of soil acidity was ascribed to the ash alkalinity and the mineralization of organic nitrogen in these leaves.