土壤的酸碱度通常用pH值表示,它是土壤中很多化学性质的综合反应。土壤微生物的活动,有机质的转化,矿质营养元素的存在形式及保持养分的能力等,都与土壤的酸碱度有关。因此,人们常把土壤的酸碱度作为选择造林树种的重要条件。根据我国土壤酸碱度的情况及其与土壤肥力的关系,可把土壤的酸碱度划为强酸性(pH<5.0)、酸性(pH5.0～6.5)、中性(pH Soil pH is usually expressed as pH, which is a combination of many chemical reactions in the soil. Soil microbial activities, organic matter transformation, the existence of mineral nutrients and the ability to maintain nutrients, etc., are related to soil pH. Therefore, soil pH is often used as an important condition for selecting afforestation species. According to the situation of soil pH and its relation with soil fertility in our country, the soil pH can be classified as strong acid (pH <5.0), acid (pH5.0 ~ 6.5), neutral