施氮量对多用型甘薯济薯21产量和养分吸收的影响

通过田间定位试验,设置不同施氮量处理,研究多用型甘薯济薯21的产量及养分吸收规律。结果表明：不施氮肥处理的济薯21鲜薯产量最高,各施氮处理的薯块鲜重显著下降,与不施氮处理相比,施氮处理鲜薯产量降低16.92%～20.92%,两者呈极显著负相关。增施氮肥提高了济薯21的出干率,降低了甘薯收获指数,提高了薯块和茎叶含氮量与吸氮量。当施氮量为90 kg/hm2时,济薯21的出干率、薯块含氮量与吸氮量达最大值。在土壤肥力较高的条件下,施用氮肥虽然能促进济薯21对氮的吸收,但对产量的增加没有促进作用,反而会造成减产。

Effects of Nitrogen Application Rate on Yield and Nutrient Uptake of Multiple-Use Sweet Potato Jishu 21

The field experiments were carried out by setting different nitrogen application rate treatments to study the yield and nutrient uptake rules of multiple-use sweet potato Jishu 21. The results showed that the highest fresh tuber yield of Jishu 21 was obtained under no nitrogen fertilizer treatment. The fresh tuber yield significantly decreased with the application of nitrogen fertilizer. Compared with no nitrogen fertilizer treatment,the application of nitrogen fertilizer decreased the fresh tuber yield by 16. 92% ～ 20. 92%. There was significantly negative correlation between fresh tuber yield and nitrogen application rate. Nitrogen application increased dry matter percent,nitrogen content and absorption of tubers and leaves,and decreased the harvest index. When the nitrogen application rate was 90 kg/hm2,the dry matter percent and nitrogen content and absorption of tuber reached the maximal value. Under the condition of high soil fertility,the application of nitrogen fertilizer could promote the nitrogen absorption of Jishu 21,but had no help to increase tuber yield. Instead,it would decrease tuber yield.