Effects of Long-term Similated Nitrogen Deposition on Soil Nitrogen Components of Pleioblastus amarus Plantation

To find how the simulated nitrogen deposition affected the soil nitrogen components of Pleioblastus amarus plantation, nitrogen addition was initiated in the bamboo forest of Rainy Area of West China from November 2007, in the form of ammonium nitrate (NH₄NO₃).4 N treatment levels were set:control(CK,0 kg·N·hm^-2·a^-1), low-N(LN, 50 kg·N·hm^-2·a^-1), medium-N(MN, 150 kg·N·hm^-2·a^-1), and high-N(HN, 300 kg·N·hm^-2·a^-1). Samples were taken from the topsoil(0~20 cm) in November 2013, January 2014, April 2014, and July 2014. The TN, NH₄⁺-N, NO₃^--N, PON, ION content of soil were determined.Results showed that,compared with the initial nitrogen deposition, the TN content of the soil increased, and the content of NO₃^--N increased significantly under long-term nitrogen deposition treatment, while the other nitrogen components were not significantly changed, but still had some changes.