不同氮肥型態對酸性紅壤硝化作用之影響

本研究旨在探討施用五種NH4^+/NO3^-比率（100/0、75/25、50/50、25/75、0/100）氮肥對酸性紅壤硝化活性的影響，試驗結果顯示，施用200 ppm氮肥後，各處理土壤有效性NH4^+/NO3^-含量比值逐日降低，施用NH4^+比率越高，則轉換成NO3^-量越多，但殘留土壤之NH4^+仍較多，施用100%銨態氮於種植非洲菊的土壤，施肥6天後之有效性氮含量中38%為NH4^(+) -N。而土壤之短期硝化活性（short-term nitrification activity，SNA）以50%銨態氮之處理最高，75%及25%銨態氮之處理次之，單獨施用銨態氮或硝態氣（以氯化銨或硝酸鈣配製）之處理土壤SNA最低；除了100%銨態氮之處理外，其餘處理在施入氮肥後第1天即有最大的SNA，施50%銨態氮之處理，於施肥後第1天之SNA顯著高於其他處理，為41.5 μg(NO2^- + NO3^-) -Ng乾土^(-1)天^(-1)，75%及25%銨態氮之處理分別為18.0及22.9 μg(NO2^- + NO3^-) -Ng乾土^(-1)天^(-1)，而施用氯化銨配製之100%銨態氮，在施肥後第1、2天之SNA均未測得正淨值，至第3天之後其SNA始有提高傾向，此或許是銨態氮或氯離子濃度較高，因而使硝化活性受到抑制之故。

關鍵字

短期硝化活性；氮肥型態；硝酸態氮；銨態氮；非洲菊

並列摘要

A pot culture experiment planted with gerbera (Gerbera jamsonii B.) was conducted to evaluate the effects of different N-form of inorganic fertilizers on the nitrification activity in acid red soil. The combination of 5 NH4^-/NO3^- percentage ratios of 100/0, 75/25, 50/50, 25/75, and 0/100, respectively, were used at equivalent N rates. Date showed that the concentration ratios of available NH4^+/NO3^- were decreased day by day in all treatments, and the available NH4^+ was varied from 67% to 38% in the cultivated soil of gerbera with 100% NH4^+ treatment in the period of 6 days after fertilization. The short term nitrification activity (SNA) was found the highest in the 50% NH4^+ treatment, and applied only with ammonium or nitrate, prepared with NH4CLl and Ca(NO3)2, had the lowest SNA. Each N-form treatment resulted in a highest SNA at the first day after fertilization, except for the 100% NH treatment. The nitrogen supplied with 100% NH4^+ did not produce a detectable SNA value at the 1st and 2nd day after fertilizing, but tend to increase the SNA at the later period under planting gerbera condition. Perhaps, this is because the high level concentration of Cl^- or NH4^+ in the 100% NH4^+ treatment to reduce the nitrification activity.

並列關鍵字

Short term nitrification activity ； N-form ； Nitrate ； Ammonium ； Gerbera

國際替代計量

不同氮肥型態對酸性紅壤硝化作用之影響

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