灌区尺度氮磷的迁移转化特征分析

为了解中国土壤中残留农业面源污染物的迁移转化规律及其特征，以前郭灌区典型灌域为研究对象，通过10组试验处理与小区田间试验，在不同深度提取水样，进行水质观测和数据处理，主要对铵氮、硝氮以及磷酸盐在土壤剖面上的迁移转化规律展开分析研究。结果表明，各试验小区表层水的氨氮浓度在施肥后的一段时间内有一个峰值出现，并随后呈现衰减趋势，在灌水量和施肥量越大的情况下，随水向下迁移的铵氮量越大（灌水量NI处理比SI处理多2．2kg／hm^2，施肥量NF处理比SF处理多1．5kg／hm^2），在施肥越均匀的情况下，随水向下迁移的铵氮量越小（F1处理比F2处理少0．7kg／hm^2）；各试验小区表层水的硝氮浓度具有与铵氮相似的变化趋势，在灌水量越大、施肥量越大及施肥越不均匀的情况下，进入地下水的硝氮量皆越大（灌水量NI处理比SI处理多1．12kg／hm^2，施肥量NF处理比SF处理多0．55kg／hm^2，施肥比例F1处理比F2处理多0．4kg／hm^2），对地下水造成的污染也越大；各试验小区表层水的磷酸盐浓度在第一次施肥（底肥）呈现一个极大的峰值，然后迅速回落并持续稳定在一个较小的水平内（不超过2．5mg／L）。

Analysis on the Characteristics of Transportation and Conversion of Nitrogen and Phosphorus Irrigation-scale

In order to know China＇s agricultural non-point source pollution in the soll of the residual migration into law and special, as field trials in Qianguo Irrigation Area, and through the 10 groups of testing processing and district field experiment, extracted water samples at different depths, doing water quality observation and data processing, mainly ammonium, nitrate and phosphate in the soil profile to start on the migration and transformation of analysis. The results showed that, there was a peak which the experimental plot of ammonia concentration in surface water for some time after fertilization, and then appeared attenuation trend. The greater the amount of irrigation and fertilization in the greater volume of cases, the greater the amount of nitrogen with the downward migration of water, （in the irrigation water NI treatment than dealing with many SI2.2 kg/hm2, fertilizer treatment processing NF more than SF 1.5 kg/hm2）. In the case of fertilizer evenly, the water down the nitrogen migration ammonium was smaller （which F1 deal with less than F2 deal with 0.7 kg/hm2）. The test area of surface water and ammonium nitrate nitrogen concentration had nitrogen similar change trend, the greater the irrigation water and fertilizer in the greater the fertilizer and condition of uneven, the bigger into the groundwater nitrate nitrogen （irrigation water which NI treatment more than SI 1.12 kg/hm2, fertilizer treatment processing more than SF NF 0.55 kg/hm2, fertilizing, F1 processing proportion than F2 dealing with many 0.4 kg/hm2）, so as to the groundwater. The test area of surface water in the first fertilization phosphate concentration （e-jing-za no.3） presented a huge spike, then fell back quickly and stable in a smaller level （no more than 2.5 mg/L）.