Effects of irrigation and urea types on n utilization, yield and quality of maize

Chinese. 【目的】研究不同灌水条件下,控释尿素与常规尿素用量对玉米氮利用及产量和品质的影响。【方法】采用随机区组设计5个施氮水平和2个水分水平,研究不同类型尿素与水耦合对玉米干物质量、叶面积指数、籽粒产量、生物产量、地上部氮素吸收和籽粒蛋白质产量的影响。【结果】相同灌水条件下,施氮处理玉米干物质量、叶面积指数均大于对照,控释尿素处理玉米的干物质量、叶面积指数大口期前低于常规尿素,开花后却显著高于常规尿素;增加施氮量可显著提高玉米吸氮量及花后籽粒吸氮量,营养器官虽可获得较大的氮素累积,但降低了向籽粒转移氮量。同一氮水平下,灌浆水提高了玉米地上部干物质量、叶面积指数和籽粒产量,降低了玉米地上部吸氮量、花后籽粒吸氮量和花前转移氮量,籽粒蛋白质含量和产量也显著降低。与常规尿素相比,控释尿素与水分对玉米氮素吸收、籽粒产量和籽粒蛋白质产量的耦合效应更显著。【结论】与常规尿素相比,不论有无灌浆水,控释尿素均能较好地协调玉米的地上部生长,具有明显的＂前控后保＂效果,利于获得高产与优质的同步,而灌浆水可以显著提高这种效果。

English. [ Objective ] The objective of this study is to investigate the effects of application rates of normal urea and controlled release urea on N utilization, yield and quality of summer maize under different irrigation levels. [Method] Five nitrogen rates and two irrigation levels were designed to investigate the effects of water-nitrogen coupling on dry matter accumulation, leaf area index, grain yield, dry matter yield, the N uptake and grain protein yield of the summer maize in a randomized design. [Result] At the same irrigation level, compared with the control, nitrogen application enhanced dry matter accumulation and leaf area index. Dry matter accumulation and leaf area index of maize applied with controlled release urea were lower than those applied with normal urea before anthesis, but the situation was just contrary after anthesis. Increasing the nitrogen fertilizer rates enhanced total N uptake of maize, and excessive nitrogen increased the proportion of vegetative organs, thereby reduced the grain quality. At the same nitrogen level, dry matter accumulation, leaf area index and yield were increased with irrigation at filling stage, while N uptake amount before and after anthesis, grain protein content and yield were decreased with irrigation at filling stage. The coupling effects of water and controlled release urea on N uptake, grain yield and protein yield of maize were obviously higher than those of water and normal urea. [Conclusion] In conclusion, compared with normal urea, whatever with or without irrigation at filling stage, controlled release urea can coordinate the growth of shoot to get higher grain yield, and increase of soil moisture is beneficial to improve the superiority of controlled release urea.