耦合效应弥补水氮减量对夏玉米养分吸收和利用的不利影响

李慧; 王旭敏; 刘朋召; 刘苗; 王小利; 王瑞; 李军

doi:10.11674/zwyf.2021619

耦合效应弥补水氮减量对夏玉米养分吸收和利用的不利影响

Interaction offset the adverse impacts of water and nitrogen reduction on nutrient accumulation and utilization of summer maize

摘要

摘要:
目的适宜的水氮管理是提高关中平原夏玉米产量的关键。研究水、氮减量及其交互作用对夏玉米养分积累和转运以及氮素利用的影响，为关中平原夏玉米高产高效栽培提供理论依据。
方法于2018—2019年，在陕西杨凌设置水、氮二因素裂区田间试验。3个灌溉处理为传统灌水量800 m³/hm² (W2)、减量50%灌水 (400 m³/hm²，W1)和无灌溉(W0)。每个灌溉量下设传统施氮量的100% (300 kg/hm², N300)、–25% (225 kg/hm², N225)、–50% (150 kg/hm², N150)、–75% (75 kg/hm², N75)和不施氮(N0) 5个水平，W2N300为传统水氮管理模式对照。分析夏玉米籽粒产量、氮磷钾养分积累与转运特征，计算氮肥利用效率。
结果与W2N300相比，W2N225、W1N225、W1N150处理的夏玉米产量和产量构成因素无显著差异。W1N225显著提高了玉米抽雄后干物质积累，显著提高了玉米抽雄后氮、磷、钾养分积累和所占比例，W2N225、W1N300则与W2N300无显著差异。与W2N300相比，W1N225处理可以显著提高干物质和氮磷钾养分转运量，分别比W2N300处理的干物质和氮磷钾转运量提高了11.67%、16.28%、19.80%、18.95%。相关分析结果表明，玉米抽雄前后氮、磷、钾素积累量与籽粒产量均呈显著或极显著正相关，且抽雄后的氮、磷、钾积累量与产量的相关性高于抽雄前。
结论在传统灌水量和施氮量基础上，减少50% 的灌水量，减少25%的氮素投入量可显著提高玉米抽雄后养分积累，促进养分转运量和抽雄后转运养分对籽粒贡献率的协同提高，进而提高了玉米产量和氮肥利用效率。综合考虑夏玉米产量，氮、磷、钾养分积累与其转运特征以及氮素利用效率等因素，在关中平原灌溉区，以灌水减量50% (即400 m³/hm²)、施氮减少25% (即 225 kg/hm²)的模式较为适宜。

Abstract:
Objectives Irrigation and nitrogen application are two key factors which sustain summer maize yield in Guanzhong plain, however, over fertilization and irrigation are common in this region. We studied the optimum water and N rate for efficient water and fertilizer use.
Methods A split plot trial of summer maize was conducted in Yangling, Shaanxi Province in 2018–2019. Three irrigation levels were traditional 800 m³/hm² (W2), 400 m³/hm² (W1) and no irrigation (W0). Under each water treatment were the five N rate treatments, 300 kg/hm² (N300), –25% (225 kg/hm²), –50% (150 kg/hm²), –75% (75 kg/hm²) and no N fertilizer (0), respectively. The W2N300 treatment under traditional irrigation mode served as control. Maize yield, accumulation and translocation of N, P, K, and nitrogen use efficiency under different water and nitrogen reduction treatments were analyzed.
Results W2N225, W1N225, and W1N150 treatments produced similar maize yields and yield components with W2N300. Compared with W2N300, W1N225 significantly enhanced the dry matter accumulation after tasseling stage, enhanced the nutrient accumulation after tasseling stage and their proportion in total uptakes, but there was no significant difference from those of W2N225 and W1N300. N and irrigation level exhibited significant interaction on dry matter remobilization and nutrient translocation. Compared to W2N300, W1N225 significantly increased dry matter and N, P, and K translocation after tasseling stage by 11.67%, 16.28%, 19.80%, and 18.95%. Correlation analysis showed significant relationship between yield and N, P and K accumulation before and after tasseling stage, and the P values after tasseling stage were higher than before tasseling stage.
Conclusions Proper water and nitrogen levels have significant interaction on the dry mater and nutrient accumulation after tasseling stage of maize, that offset the adverse impacts of reducing irrigation and nitrogen inputs, as maize yield is significantly correlated with the nutrient accumulation and translocation of N, P, K after tasseling stage, thus increases nitrogen and water use efficiency. A combination of 400 m³/hm² and N 225 kg/hm² is optimum irrigation and nitrogen rates respectively in Guanzhong Plain irrigation region.

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