Abstract: This paper probed into the spatial distribution patterns of nitrogen (N) in the water bodies of Hubian and Shidou-Bantou reservoirs in Xiamen during winter, and analyzed the relationships of the N forms in the water bodies with environmental factors, aimed to provide scientific bases for the prevention and treatment of the water pollution of the reservoirs. The average concentrations of total N in the water bodies of Hubian reservoir and of the Shidou and Bantou sections of Shidou-Bantou reservoir were 1.36, 1.44, and 1.45 mg·L^-1, respectively, with the pollution source being exogenous for the Hubian reservoir whereas endogenous for the Shidou-Bantou reservoir. Inorganic N was the major N form in the two reservoirs, accounting for 61.7% and 58.0% of the total N in Hubian and Shidou-Bantou reservoirs, respectively. The inorganic N in Hubian reservoir was mainly NO₃^--N, and that in Shidou-Bantou reservoir was mainly NH₄⁺-N. In Hubian reservoir, the NH₄⁺-N was positively correlated with NO₃^--N but negatively correlated with DO; and in the Bantou section of Shidou-Bantou reservoir, the NH₄⁺-N was positively correlated with transparency but negatively correlated with pH.

Key words: Cultivated practice, Sloping field, Red soil, Nitrogen loss