文档介绍：土壤酸性
土壤碱性
土壤缓冲性能
土壤反应与土壤肥力和作物生长
第六章:土壤酸碱性 Chapter:Soil Reaction
中国土壤酸碱性分布规律
中国土壤的酸碱性反应,~。在地理分布上有“东南酸西北碱”的规律性。大致可以长江为界(北纬33~35),长江以南的土壤为酸性或强酸性,长江以北的土壤多为中性或碱性。我国土壤的酸碱性南北差异很大,由南向北土壤pH相差7个数量级。
如吉林、内蒙古、,而台湾省的新八仙山和广东省丁湖山、五指山的黄壤,~。
(Brady & Weil 2000)
第一节 土壤酸度 soil acidity
What is pH?
pH can be viewed as an abbreviation for power of concentration of hydrogen ion in solution
pH = - [log (H+)] in solution
kw = pH + pOH
kw = 14
14 = pH + pOH
pH = 14 - pOH
Soils are acidic, neutral or alkaline depending on parative concentrations of H+ and OH- ions
Common soil acids:
* CO2 +H20 H2CO3 (carbonic acid)
* H2CO3 H+ + HCO3- (bicarbonate)
* Sulfuric (H2SO4) and nitric acids (HNO3) are stronger but much less abundant in the soil solution
Soil pH
pH in solution
ACID if pH is < 7
BASIC if pH is > 7
Neutral if pH = 7
In soils the neutrality is not pH 7, the neutrality is a range between and
pH Scale
Figure
一、土壤酸性的类型
(一)、活性酸(Active acidity)
---游离于土壤溶液中的H+所表现出来的酸度。
---H+活度越大,活性酸度越强。
---通常用pH值表示活性酸度。