不同氮水平对马铃薯块茎和土壤NO_3^--N含量的影响

Effects of Different N Levels on NO_3^--N Contents in Potato Tubers and Soil

[目的]为马铃薯科学施肥提供理论依据。[方法]设置N1:传统氮肥施用量;N2:80%推荐氮肥施用量、N3:推荐氮肥施用量、N4:120%推荐氮肥施用量4个氮水平,研究不同水平对马铃薯块茎和土壤NO3--N含量的影响。[结果]马铃薯块茎内NO3--N含量随施氮量的增加而增加,但均未超标。N2处理马铃薯产量最高,块茎NO3--N为431.56 mg/L。随着施氮量的增加,氮淋失程度加深,土壤中的NO3--N含量逐渐增加。各处理土壤NO3--N含量随土层的加深有不同程度的递减。N2处理的氮素供应与马铃薯对N素的吸收基本达到了平衡。[结论]随着氮水平的提高,马铃薯块茎和土壤中的NO3--N含量均呈上升趋势。

[Objective] The study aimed to supply theoretical foundation for scientific fertilization of potato. [Method] Four N levels of traditional N fertilization amouunt （N1 ）, 80% of recommended N fertilization amount （N2）, recommended N fertilization amount （N3）, 120% of recommended N fertilization amount （N4） were set up to study the effects of different levels on NO3^- -N contents in potato tubers and soil. [Result] NO3^- -N contents in potato tubers was increased along with the increment of N fertilization amount, but didn＇ t exceed the standard. In N2 treatment, the potato yield was highest and NO3^- -N content in tuber was 431.56 mg/L. The leaching degree of N deepened and NO3^- -N content in soil was increased gradually along with the increment of N fertilization amount, The NO3^- -N contents in soil in various treatments had gradual decrement to different degrees along with the deepening of soil layers. In N2 treatment, the N supplication and the N adsorption of potato basically reached balance. [ Conclusion] The NO3^- -N contents in both potato tubers and soil showed increasing trend along with the enhancement of N level.