| 引用本文: | 杨胜举,佟 玲,吴宣毅,等.玉米冠层辐射分布和产量对种植密度和水分的响应研究[J].灌溉排水学报,2021,(8):19-26. |
| YANG Shengju,TONG Ling,WU Xuanyi,,et al.玉米冠层辐射分布和产量对种植密度和水分的响应研究[J].灌溉排水学报,2021,(8):19-26. |
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| 摘要: |
| 【目的】探究玉米冠层光分布和产量对种植密度和水分条件的响应。【方法】试验选用石羊河流域普遍种植的先玉335为供试品种，设置D1（7万株/hm2）和D2（9万株/hm2）2个种植密度，以及充分灌水（W1）、轻度亏缺（W2）、中度亏缺（W3）3个水分梯度，共6个处理。观测各生育期的叶面积指数、相对叶绿素量、辐射截获率、干物质积累以及产量等指标的变化。【结果】相对叶绿素量受水分影响显著，随灌水量减少而降低，但受密度影响不显著；D2密度较D1密度有更大的叶面积指数（LAI），能显著提高玉米群体对辐射的截获率，改善群体的光能利用，增加群体的干物质积累量，促进冠层辐射利用率（RUE）的提高。2个密度下，产量均随灌水量减少而降低，但D2密度下的降幅小于D1密度。在D1密度下，充分灌溉的产量为13.39 t/hm2，轻度亏水和中度亏水分别降低2.63%和7.03%。在D2密度下，充分灌溉的产量达到了16.39 t/hm2，轻度亏水和中度亏水分别降低2.37%和6.73%。在3个水分条件下，D2密度较D1密度分别增产了22.44%、22.76%和22.84%，D2密度水分利用效率显著高于D1密度；在相同密度条件下，水分利用效率都呈W2处理>W3处理>W1处理；在低密度下轻度亏缺的收获指数最大，而高密度下，中度亏缺的收获指数要大于其他处理。【结论】适度提高种植密度有利于构建合理高效的光合群体结构，增加玉米群体干物质积累、产量和WUE。适度亏缺灌溉可以在不明显减产的情况下有效提高水分利用效率。 |
| 关键词: 种植密度；水分亏缺；冠层光结构；产量；玉米 |
| DOI：10.13522/j.cnki.ggps.2021006 |
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| Changes in Radiation in Canopy and the Yield of Maize in Response to Planting Density and Irrigation Amounts |
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YANG Shengju, TONG Ling, WU Xuanyi, CHEN Yang
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1.Center for Agricultural Water Research in China, China Agricultural University, Beijing 100083, China;
2. Wuwei Experimental Station for Efficient Water Use in Agriculture, Ministry of Agriculture and Rural Affairs, Wuwei 733000, China
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| Abstract: |
| 【Objective】 Planting density and soil moisture combine to modulate plant growth and its ultimate yield. Taking maize as an example, this paper investigates the response of light radiation in the canopy and yield of the maize to different combinations of plant density and irrigation amounts.【Method】Maize variety Xianyu 335 was used as the model plant, and we compared two planting densities: 70 000 plants/hm2 (D1) and 90000 plants/hm2 (D2). Added to each planting density were three irrigation treatments: Sufficient irrigation (W1), mild (W2), and moderate (W3) deficit irrigation. In each treatment, we measured the changes in leaf area index, chlorophyll content, radiation interception rate, dry biomass accumulation at different growth stages and the final maize yield. 【Result】Chlorophyll content was significantly affected by soil water but not by planting density, and it hence increased with irrigation amount. LAI was higher in D2 than in D1 at significant level, indicating that increasing planting density boosted radiation interception thereby improving light energy utilization and dry matter accumulation. Reducing irrigation amount in both planting densities led to a decline in yield, though the reduction in D2 was less than that in D1. Under sufficient irrigation, increasing planting density from D1 to D2 increased the yield from 3.39 t/hm2 to 16.39 t/hm2. Imposing mild or moderate deficit irrigation reduced the yield of D1 by 2.63% or 7.03%, and the yield of D2 by 22.76% or 22.84% respectively. Water use efficiency of both planting densities was contingent on irrigation, ranked in the order of W2>W3>W1. The harvest index varied with planting density and irrigation amount. Mild deficit irrigation in D1 gave the highest harvest index, while moderate irrigation in D2 worked better.【Conclusion】A moderate increase in planting density of maize can benefit photosynthesis and increase dry matter accumulation, thereby improving both yield and water use efficiency. Combining with moderate deficit irrigation can further improve water use efficiency without compromising yield. |
| Key words: planting density; water deficit irrigation; canopy light interception; yield; maize |
