为研究不同施氮量对茶园土壤氮淋失的影响，改良茶园土壤品质，采用室内土柱淋滤试验，研究不同施氮量对强酸性茶园土壤淋溶液pH、N H＋4‐N和NO3－‐N淋溶量的影响。氮肥采用尿素，氮肥用量分别为N0（0 kg · hm －2）、N1（150 kg · hm －2）、N2（300 kg · hm －2）、N3（450 kg · hm －2）、N4（600 kg · hm －2）。结果表明：施用氮肥降低了土壤p H和土壤淋溶液p H ，降低幅度分别为0.08～0.32和0.35～0.81个单位，促进茶园土壤酸化；N H＋4‐N和N O3－‐N的淋溶量均随施氮量的增加而提高；无机氮的淋失率为47.66％～71.31％，淋失量（Y）与施氮量（X）之间的线性回归方程为Y＝0.708X＋145.27（R2＝0.98）；在整个淋洗过程中，NH＋4‐N和NO3－‐N淋溶主要发生在前5次，且主要以NO3－‐N的形式淋失，淋失比例为73.50％～89.21％。%To improve strongly‐acidified soil quality of tea garden ,a laboratory simulation test of column‐leach was carried out to investigate the effects of applying different nitrogen rates on the pH ,ammonium nitrogen (NH+4 ‐N) and nitrate nitrogen (NO3-‐N ) of soil leachate .With urea as nitrogen fertilizer , the different applications were respectively treated with N0 (0 kg · hm -2 ) ,N1 (150 kg · hm -2 ) ,N2 (300 kg · hm-2 ) ,N3 (450 kg · hm-2 ) and N4 (600 kg · km -2 ) .The results showed that the pH values of soil leachate were be decreased by 0.08~0.32 and 0.35~0.81 with different N application rates ,resulting in more soil acidification .The leaching amounts of NH+4 ‐N and NO3-‐N were increased by increasing rates of nitrogen fertilizer ,and 47.66% ~71.31% inorganic nitrogen was lost in leaching water .The regression equation between inorganic nitrogen loss (Y ) and N application rates (X) was Y = 0.708 X + 145.27 (R2 =0.98) .The leaching of NH+4 ‐N and NO3-‐N majorly occurred at the first five times , and the leaching amounts of NO3-‐N accounted for 73.50% ~89.21% of the total leaching inorganic nitrogen .
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