Phase Changes of Soil Ph and Metal Availability Induced by Urea Application to Acidic Red Soils from South China

摘要

Nitrogenous fertilizers are added to the soil to increase crop yields and quality,but may also affect other soil functions and processes as well.The effect of urea fertilizer on soil pH and metal availability,in relation to the dynamics of the chemical composition of red soil solutions,was evaluated using a laboratory experiment with different urea treatments.The results revealed that addition of urea fertilizer to acidic red soils caused drastic changes in soil pH during some stages of the experiment,and these pH changes depended on time courses and the N rate of urea application.