水肥一体化条件下施氮量对密植春玉米茎秆抗倒伏性状的影响

在滴灌水肥一体化及分次施氮条件下,设置9个施氮水平,研究施氮量对密植玉米茎秆抗倒伏能力的影响。结果表明,在一定施氮量范围内,随着施氮量增加,玉米茎秆抗折断力、基部节间穿刺强度(RPS)和单位长度干重(DWUL)逐渐增加;当施氮量达到一定量时,茎秆抗折断力、RPS和DWUL不再增加。玉米株高、穗位高和穗位系数随施氮量增加而上升。茎秆抗折断力与株高、穗位高和穗位系数呈显著负相关,与RPS和DWUL呈显著正相关。滴灌水肥一体化及分次施氮条件下,增加施氮量通过提高玉米茎秆中干物质积累量来改善机械强度,从而提高茎秆的抗倒伏能力。

Effect of Nitrogen Application Rate on Lodging Resistance of Spring Maize Stalks under Integrated Irrigation with Water and Fertilizer

Under the condition of nitrogen split application, nine nitrogen application levels were set up to study the effect of nitrogen application rate on stalk lodging resistance of closely planted maize. The results showed that in a certain range of nitrogen application, with the increase of nitrogen application, the breaking force, rind penetration strength(RPS), and dry weight per unit length(DWUL) of maize stalk increased gradually. When nitrogen application reached a certain amount, the nitrogen application had no effect on stalk breaking force, RPS, DWUL. The plant height, ear height and ear coefficient increased with the increase of nitrogen application. Correlation analysis showed that the stalk breaking force was negatively correlated with plant height, ear height and ear coefficient, and positively correlated with RPS and DWUL. Therefore, under the split application of water and fertilizer, increasing nitrogen application can improve the mechanical strength and the lodging resistance of stalk by increasing the dry matter accumulation in maize stalk.