Seeding rate is an important factor in optimizing yield components and thus grain yield of conventional rice (Oryza sativa L.), yet limited information on its effect on organic rice production is available. A field study was conducted under organic management over 2 yr to comprehensively evaluate the effects of seeding rate (108, 161, 215, 269, 323, 376, and 431 seeds m⁻²) and rice cultivar (Presidio [inbred] and XP753 [hybrid]) on yield components, grain yield, milling quality, weed density, and economic returns. Seeding rate had significant effects on seedling stand density and dry biomass with positive linear correlations. Yield linearly increased with increasing seeding rate with the greatest yields of 3,462 kg ha⁻¹ for Presidio and 7,508 kg ha⁻¹ for XP753 at the highest seeding rate tested. Panicle number was positively correlated with seeding rate, while milling quality was not affected by seeding rate. The linear‐plateau (LP) model fit best for Presidio and the quadratic‐plateau (QP) model fit best for XP753 to estimate the ex ante economic optimum seeding rate (EOSR). The EOSR was 87 kg ha⁻¹ (340 seeds m⁻²) for Presidio and 48 kg ha⁻¹ (192 seeds m⁻²) for XP753. Using the EOSR, producers could expect a yield of 3053 kg ha⁻¹ and an economic return of US$1,288−$1,346 ha⁻¹ for Presidio, and a yield of 5,835−6,092 kg ha⁻¹ and an economic return of $1,986−$2,686 ha⁻¹ for XP753.

中文翻译：

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播种率对有机水稻的生长，产量和经济效益的影响

播种量是优化常规水稻（Oryza sativa L.）产量构成要素和谷物产量的重要因素，但有关其对有机水稻生产影响的信息尚有限。在有机管理下进行了2年的田间研究，以全面评估播种率（108、161、215、269、323、376和431种子m ^-2）和水稻品种（Presidio [近交]和XP753 [ [杂种]），包括产量构成，谷物产量，制粉质量，杂草密度和经济效益。播种量对苗木密度和干生物量具有显着影响，且呈线性正相关。产量随着播种量的增加而线性增加，其中Presidio的最大产量为3,462 kg ha ^-1，最大产量为7,508 kg haXP753在测试的最高播种速率下为^-1。穗数与播种量成正相关，而制粉质量不受播种量的影响。线性高原（LP）模型最适合Presidio，而二次高原（QP）模型最适合XP753，以估计事前经济最佳播种量（EOSR）。对于普雷西迪奥，EOSR为87 kg ha ^-1（340种子m ^-2），对于XP753，EOSR为48 kg ha ^-1（192种子m ^-2）。使用EOSR，生产者可以预期Presidio的产量为3053 kg ha ^-1，经济收益为$ 1,288− $ 1,346 ha ^-1，产量为5,835−6,092 kg ha ^-1，经济收益为$ 1,986− $ 2,686 ha ^-1 适用于XP753。