施氮量对木薯氮素营养特性及产量形成的影响

Effects of Nitrogen Application on Nitrogen Nutrition Characteristics and Yield Formation in Cassava

采用大田试验,研究了不同施氮水平下木薯氮素营养特性的变化及其对产量形成的影响。试验设置0、120、240、360 kg/hm24个氮水平,综合分析了各生育期木薯根、茎、叶等组织中的氮含量、氮素积累量、氮素吸收强度、氮素分配和干物质积累分配、产量品质以及经济效益等指标的变化。结果表明:施氮能显著增加木薯根、茎、叶等组织的氮含量和氮积累量,提高氮素吸收强度,并改变氮素养分的分配特性;此外,随着施氮量的增加,木薯块根干物质积累量、鲜薯产量、淀粉产量、经济效益等均显著提高。综上所述,最佳施氮量为240 kg/hm2,适宜的施入比例为:幼苗期∶茎秆分叉期∶块根形成期∶块根膨大早期∶块根膨大中期=1∶1.71∶1.33∶0.73∶0.57。

This study investigate d the effects of nitrogen rate on the nitrogen nutrition characteristics and yield formation of Cassava in field trials. We made a comprehensive analyses of the changes in nitrogen content,nitrogen accumulation amount, nitrogen absorption intensity, nitrogen distribution rate and distribution of dry matter of different parts（roots, stems and leaves） in Cassava at different growth stages under four nitrogen levels（0, 120, 240, 360 kg/hm2）, and the yield, quality and economic benefit of Cassava under the four processing were also analyzed. The results showed that nitrogen fertilization increased the nitrogen content and the nitrogen accumulation amount, improved the nitrogen absorption intensity, and changed nitrogen distribution characteristics of different parts（roots, stems and leaves） in Cassava. In addition, the content of dry matter accumulation in tuberous root, fresh tuber yield and starch yield increased significantly with the increase of the amount of nitrogen. In conclusion, the optimum nitrogen application amount was 240 kg/hm2, and the optimum proportion of nitrogen application was 1 ∶ 1.71 ∶ 1.33 ∶ 0.73 ∶ 0.57 at seedling stage, stem bifurcation stage, roottuber formation stage, first expanding roottuber growth stage and middle expanding roottuber growth stage, respectively.