Nitrogen (N) and phosphorus (P) losses from agroecosystems are dominant nonpoint pollution. To minimize the losses of N and P, the optimal depth of fertilization was explored using a soil column study with the red paddy soil as the research objects. The losses of N and P were measured under five depths of fertilization (0, 5, 7.5, 10, and 12.5 cm) as well as no fertilization. The results showed that ammonia volatilization was significantly decreased with increasing fertilization depth within 0-10 cm, and there was no significant difference among the 10 cm, 12.5 cm, and no-fertilization treatme...
