title: [Short-term changes of pH value and Al activity in acid soils after urea fertilization].
abstract: Acidic soils are widely distributed in South China, and their acidity is the major environmental stress factor limiting the growth of most crops. It is well known that soil Al solubilized at low pH is a main toxic factor for plant growth. Our study with three acidic soils showed that soil pH increased quickly, while soil exchangeable Al decreased sharply with the increasing concentrations of applied urea. The time-course experiment revealed that the increase of soil pH was short-lived, with a subsequently slow drop after reached its maximum. Urea fertilization caused a drastic change of soil pH during 2-4 weeks of the experimental period. There was a negative relationship between soil pH and soil exchangeable Al. Biological toxicity test demonstrated that applying urea to acidic soils could obviously decrease the aluminum toxicity of maize in a short-term period.
authors.affiliation: College of Resource and Environment, Hunnan Agricultural University, Changsha 410128, China. qrzeng@163.net
authors.forename: Qingru
authors.initials: Q
authors.lastname: Zeng
authors.forename: Bohan
authors.initials: B
authors.lastname: Liao
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Jiang
authors.forename: Xihong
authors.initials: X
authors.lastname: Zhou
authors.forename: Can
authors.initials: C
authors.lastname: Tang
authors.forename: Ning
authors.initials: N
authors.lastname: Zhong
mesh_terms: D000535:Aluminum / Q000032:analysis* / Q000378:metabolism; D005306:Fertilization; D006863:Hydrogen-Ion Concentration; D012987:Soil; D014508:Urea
chemical_list: D012987:Soil; D014508:Urea; D000535:Aluminum