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| Effects of fertilizer application on N and P concentrations of soil water in slope land in Fuxian Lake Watersheds |
| Niu Hongyu1，Wang Keqin1，Li Taixing2，Wang Ping1，Tang Zuoxin1 |
| 1. The Faculty of Environment Science and Engineering, Southwest Forestry University,650224，Kunming; 2. Yuxi Municipal Hydrological Bureau，653100，Yuxi, Yunnan：China |
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Abstract To study the effects of fertilization and slope position on the variation of total nitrogen and total phosphorus concentrations, a field experiment was conducted in Fuxian Lake Watersheds in central Yunnan Province, Nine micro plots were arranged. Soil solution samplers of different depth were installed at different slope positions in the plots. Variation characteristics of total nitrogen and total phosphorus concentrations were studied. Results showed that: 1) With fertilizer amount increasing, average concentrations of total nitrogen and total phosphorus in soil water increased. At 1.5 times and 2 times of constant fertilization treatments, total phosphorus concentration of soil water at 0-100cm depth were 1.26 times and 1.63 times of constant fertilization. 2) Under the same fertilization treatment, total nitrogen and total phosphorus concentrations of soil water at bottom were larger than those at middle slope. Total nitrogen concentration of soil water at 0-50cm depth at slope bottom was 1.30 times of that at middle slope. Total phosphorus concentration of 0-100cm soil water at slope bottom was 2 times of that at middle slope. 3) Under the same fertilization treatment, total nitrogen concentration of soil water had a decline trend with depth deepening. Average total nitrogen concentration of soil water at 0-50，50-100cm，beneath 100cm were respectively 4.58，3.93，3.17mg/L. Total phosphorus concentration of soil water had a wavy decline trend over depth. Variation range of total phosphorus concentration was larger (0.010-0.021mg/L) at 0-100cm, smaller beneath 100cm (0.010-0.014mg/L). 4）Total nitrogen concentration should be controlled in 270.0kg/hm2, and total phosphorus concentration should be controlled in 61.2kg/hm2.
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Received: 07 March 2011
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