滇池柴河流域蔬菜地土壤施用生物炭包膜尿素与普通尿素的氮损失研究

摘要

[目的]为滇池柴河流域蔬菜种植区更科学、合理使用氮肥以及当地农业面源污染控制提供依据。[方法]通过盆栽试验，比较施用炭基包膜尿素与普通尿素对柴河周边蔬菜地土壤氨挥发和氮淋失的影响。[结果]氮损失量与施氮量呈正比，氮素淋失量均高于氨挥发量；同一施肥水平的两种肥料氨挥发、氮素淋失和氮素损失量间差异在0．05水平显著（普通尿素＞生物炭包膜尿素）；在施氮量为320和280mg/kg的水平下，生物炭包膜尿素处理比普通尿素处理氮损失低43．5%～45．5%，其中氨挥发低3．7%～21．7%，氮淋溶低49．8%～52．1%，而硝态氮是氮素淋溶的主要形式占总氮淋出的76．0%～95．7%（普通尿素处理)和51．6%～53.5%（生物炭包膜尿素处理）。[结论]生物炭包膜尿素主要通过减少硝氮淋失来控制氮损失。减量施氮并结合生物炭包膜尿素的施用，对控制该地区氮肥施用带来的水体污染具有现实指导作用。%Objective] This study aimed to provide the basis for scientific and rea-sonable application of nitrogen fertilizer and control of agricultural non-point source pol ution in vegetable-growing area at Chaihe catchment of Dianchi Lake. [Method] A pot experiment was carried out to compare the loss of nitrogen via ammonia volatilization and nitrogen leaching after application of biochar coated urea (BCU) and common urea (Urea) with different nitrogen rates (0 mg N/kg soil, 400 mg N/kg soil, 320 mg N/kg soil and 280 mg N/kg soil). [Result] The results indicated that the amount of nitrogen loss was proportional to nitrogen applied rate. Leaching nitrogen was higher than ammonia volatilization. Compare with Urea treatments, ammonia volatilization and nitrogen leaching losses were significantly lower in BCU treatments at the same nitrogen application rate. At the nitrogen application rate of 320 and 280 mg N/kg soil, nitrogen loss, ammonia volatilization and leaching nitrogen was 43.5%-45.5%, 3.7%-21.7% and 49.8%-52.1% lower in BCU treatments than in Ure-a treatments, respectively. [Conclusion] The application of BCU could minimize nitro-gen loss by reducing nitrate leaching loss. It can be concluded that the low nitrogen application rate combined with BCU have a practical influence on control ing the risk of nitrogen pol ution in Dianchi Lake.