| 引用本文: | 佘映军,李 平,白芳芳,等.地下水埋深与施氮水平对夏玉米生长及硝态氮量的影响[J].灌溉排水学报,2021,(4):22-28. |
| SHE Yingjun,LI Ping,BAI Fangfang,et al.地下水埋深与施氮水平对夏玉米生长及硝态氮量的影响[J].灌溉排水学报,2021,(4):22-28. |
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| 摘要: |
| 【目的】探讨华北地区夏玉米-冬小麦轮作体系下氮肥减施与地下水埋深的交互作用。【方法】借助大型地中渗透仪和Logistic作物生长模型，采用二因素完全随机区组设计：地下水埋深（G1:2.0 m、G2:3.0 m、G3:4.0 m），施氮量（N1：减氮20%、N2：常规施氮），以及不施氮不控水作为对照（WN），研究了华北地区地下水埋深和施氮水平组合对夏玉米生长、干物质量积累和硝态氮量的影响。【结果】所有处理夏玉米叶面积指数（LAI）在灌浆期最大，成熟期相同施氮水平，G1处理LAI显著高于G2、G3处理；N2水平下，G1处理玉米株高快速生长时间较G2、G3处理分别增加了3.99%、12.91%，但最大增长速率相对降低了9.69%、14.65%；N1水平下，G1处理籽粒干物质量显著高于G2和G3处理，N2水平下，G3处理籽粒干物质量显著高于G1和G2处理；N2水平下，G1处理硝态氮增量显著高于G2、G3处理，0~20 cm分别高出75.92%、90.03%，20~40 cm分别高出30.56%、130.95%。同一地下水埋深下，成熟期LAI表现为N2处理显著高于N1处理；0~20 cm与20~40 cm土层N2处理下硝态氮增量是N1处理的1.4~5.3倍和2.4~11.2倍；在G1水平下，N2处理株高快速生长期较N1处理增加了7.52%，而N1处理单株籽粒干物质量显著高于N2处理，高出9.13%；Person相关性分析表明，N2水平下，随着地下水埋深变化，0~40 cm土层硝态氮增量与产量显著负相关，R2为0.827~0.883。【结论】高氮与较浅地下水埋深组合促进了玉米营养生长，不利于玉米生殖生长和产量形成；低氮与浅地下水埋深组合有利于产量形成和减氮增效。 |
| 关键词: 地下水埋深；减氮；干物质量；硝态氮；Logistic曲线模型；产量 |
| DOI：10.13522/j.cnki.ggps.2020204 |
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| The Combined Effects of Groundwater Depth and Nitrogen Fertilization on Yield of Summer Maize and Nitrate Distribution in Soil |
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SHE Yingjun, LI Ping, BAI Fangfang, DU Zhenjie, LIANG Zhijie, QI Xuebin
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1. Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China; 2. Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China; 3. Water Environment Factor Risk Assessment Laboratory of Agricultural Products Quality and Safety, Ministry of Agriculture and Rural Affairs, Xinxiang 453002, China; 4. Agricultural Water Soil Environmental Field Research Station of Xinxiang, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China
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| Abstract: |
| 【Objective】Soil water and nutrients combine to impact crop growth and nitrogen cycling. The objective of this paper is to study how groundwater depth and nitrogen fertilization modulate yield and nitrogen use efficiency of summer maize, as well as its consequent impact on nitrate dynamics.【Method】The experiments were conducted in lysimeters under different combinations of groundwater depth and nitrogen application. We compared three groundwater depths: 2.0 m (G1), 3.0 m (G2) and 4.0 m (G3); on top of these were two nitrogen treatments: conventional nitrogen fertilization used by local farmers (N2), and reducing it by 20% (N1), with no nitrogen fertilization and water control as control (WN). During the experiment, we measured the growth traits of the summer maize and nitrate dynamics in soil in each treatment. 【Result】The leaf area index (LAI) was affected by groundwater depth but peaked at the grouting stage in all treatments. When nitrogen application was the same, LAI in G1 at mature stage was higher than that in G2 and G3 at a significant level. When groundwater depth was the same, increasing nitrogen application boosted LAI at mature stage. When nitrogen was applied at conventional level, the number of days that maize saw a rapid growth in G1 was 3.99% and 12.91% longer than that in G2 and G3, while its associated growth rate reduced by 9.69% and 14.65% respectively; G3 gave the highest yield. Reducing nitrogen application reduced the yield in G2 and G3 more significantly than in G1 due to the reduction in rapid-growth duration. Keeping nitrogen application at conventional level in G1 increased soil NO3- in top 20 cm of soil by 75.92% and 90.03%, and in 20~40 cm of soil by 30.56% and 130.95%, respectively, compared with that in G2 and G3. Reducing nitrogen application by 20% increased the grain yield per plant by 9.13% at significant level. Pearson correlation analysis showed that when nitrogen was applied at the conventional level, nitrate in 0~40 cm of soil varied with groundwater depth and was negatively correlated with the yield with R2 varying from 0.827 to 0.883. 【Conclusion】High nitrogen fertilization and shallow groundwater facilitated vegetative growth, but was unfavorable for reproductive growth thereby reducing the yield of the summer maize. Reducing nitrogen application coupled with shallowing the groundwater will benefit both yield and nitrogen use efficiency. |
| Key words: groundwater table depth; nitrogen application reduction; dry biomass matter; nitrate; Logistic; yield |
