Center for Agricultural Water Research in China, College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China.
National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei, China.
J Sci Food Agric. 2023 Aug 30;103(11):5300-5311. doi: 10.1002/jsfa.12602. Epub 2023 Apr 20.
Increasing crop yield per unit area by increasing planting density is essential to ensure food security. However, the optimal combination of planting density and nitrogen (N) application for high-yielding maize and its source-sink characteristics need to be more clearly understood.
A 2-year field experiment was conducted combining three planting densities (D1: 70 000 plants ha ; D2: 100 000 plants ha ; D3: 130 000 plants ha ) and three nitrogen rates (N1: 150 kg hm ; N2: 350 kg hm ; N3: 450 kg hm ). The results showed that increasing planting density significantly increased leaf area index and grain yield but negatively affected ear traits. The Richards model was used to fit the dynamic changes of dry matter accumulation of maize under different treatments, and the fitting results were good. Increasing planting density increased population yield while limiting the development of individual plants, bringing the period of rapid dry matter accumulation to an early end and accelerating leaf senescence. An appropriate nitrogen rate could prolong the period of rapid accumulation of dry matter in maize, and increase the 100-kernel weight. Increasing planting density enhanced post-silking dry matter accumulation to a lesser extent, and the source-sink relationship of the maize population gradually developed from sink limitation to source limitation with increasing planting density.
The decrease in yield due to the insufficient source strength to meet the sink demand at too high densities was the reason that limited further improvement of the optimal planting density. An appropriate nitrogen rate facilitated the realization of yield potential at high density. © 2023 Society of Chemical Industry.
通过增加种植密度来提高单位面积的作物产量对于确保粮食安全至关重要。然而，为了实现高产，还需要更清楚地了解玉米的最佳种植密度和氮（N）施用量组合及其源库特性。
本研究在大田条件下进行了为期 2 年的试验，结合 3 种种植密度（D1：70000 株/公顷；D2：100000 株/公顷；D3：130000 株/公顷）和 3 种氮素水平（N1：150 千克/公顷；N2：350 千克/公顷；N3：450 千克/公顷）。结果表明，增加种植密度显著提高了叶面积指数和籽粒产量，但对穗部性状产生了负面影响。采用 Richards 模型拟合不同处理下玉米干物质积累的动态变化，拟合效果较好。增加种植密度提高了群体产量，但限制了单株的发育，使干物质快速积累期提前结束，叶片衰老加速。适当的氮素水平可以延长玉米干物质快速积累期，增加百粒重。增加种植密度在一定程度上促进了花后干物质的积累，玉米群体的源库关系逐渐由库限制向源限制发展，随着种植密度的增加。
由于过高密度下源强度不足以满足库需求，导致产量下降，这是限制最佳种植密度进一步提高的原因。适当的氮素水平有利于实现高密度下的产量潜力。© 2023 英国化学学会。
