Effect of fertilization on soil ammonia volatilization in spring corn fields

Aeration method was used to study the influence of different modes of fertilization on soil NH₃ volatilization on corn farmlands. Results show that the combination of straw soil incorporation and deep autumn fertilization significantly decreases soil NH₃ volatilization. Cumulative total NH₃ volatilizations under different autumn fertilization treatments are between 5.37kg/hm² and 6.92kg/hm², accounting for 0.28% to 1.18% of applied N through fertilization.However, no significant difference is observed among treatments. Cumulative total soil NH₃ volatilization in spring fertilization treatments is higher than that of autumn, and a significant difference is observed among spring treatments. Difference in NH₃ volatilization between spring and autumn treatments is obvious. The least difference (2.65kg/hm²) is found between spring and autumn straw mulching and the highest difference(25.58kg/hm²) is found between spring and autumn straw soil incorporation. About 1.77%～17.06% higher NH₃ volatilization occurs in spring.