青铜峡灌区水稻田三氮变化特征试验研究

以宁夏青铜峡灌区水稻田三氮(总氮、氨氮、硝氮)作为研究对象,从田间运移、土壤剖面中的变化以及在排水沟内受到的消解作用方面进行了分析。结果表明:(1)水稻田间,排水中总氮浓度大于其在引水中浓度;5、6月份田间积水中总氮浓度小于其在引水、排水中浓度,7、8月份刚好相反。引水中氨氮浓度小于其在田间积水、排水中浓度。5—7月排水中硝氮浓度>其在引水中浓度>其在田间积水中浓度,8月份变化没有明显规律。(2)土壤剖面中0～20cm土层三氮含量最高,随着土壤剖面加深,呈递减趋势,总氮在灌溉后的含量高于灌溉期间,氨氮、硝氮灌溉后的含量低于灌溉期间。(3)排水沟内三氮均受到消解作用,消解幅度呈氨氮>总氮>硝氮的趋势,且与植被覆盖度、沟道长度、水流速度等因素关系密切。

Experimental Research on Variation Feature of Three Kinds of Nitrogen from Paddy Field in Qingtongxia Irrigation Area

With strict controlling of point source pollution,how to understand and control non-point source pollution scientifically and effectively has become the important pressing research.Agricultural non-point source pollution due to wide application of fertilizers and pesticides is becoming the major cause of the environment deterioration.It has been researched in 1980s in our country,and now it becomes a research hotpot.An experiment was done to asses the loss of nitrogen in paddy field in Qingtongxia irrigatio...