Compared with growth and yield, far less attention has been devoted to the impact of elevated CO₂ on rice grain quality. Exposure to elevated CO₂ induces numerous physiological changes in plants that can alter the chemical composition and thus the quality of rice grains. This meta-analysis was conducted to synthesize the effect of free air CO₂ enrichment (FACE, approximately 550 μmol mol⁻¹) on grain quality of rice grown under open field conditions. Factors that could modify the CO₂ effects were also investigated. They included cultivars, nitrogen applications, environmental temperatures and grain types. On average, elevated CO₂ decreased head rice percentage by 8%, which led to no increase in head rice yield, despite substantial increases of brown rice yield and white rice yield that were obtained under FACE conditions. Elevated [CO₂] increased chalky grain percentage by 26% and chalkiness degree by 30%, which significantly impaired rice appearance. However, the cooking and eating quality was improved by elevated [CO₂], as indicated by the changes in starch RVA profiles and the palatability of cooked rice. The nutritional value of FACE rice declined as shown by the 2–9% decreases in the concentrations of nitrogen, phosphorus, magnesium, sulfur, zinc, iron, copper, manganese and amino acids; meanwhile the anti-nutrient phytate and the molar ratio of phytate to zinc were increased. High nitrogen application alleviated negative effects of elevated [CO₂] on milling quality and rice appearance but further decreased the bioavailability of essential nutrients. The CO₂-induced decreases in element concentrations of white rice were generally higher than those in brown rice. In general, CO₂-induced changes on grain quality were seldom modified by rice cultivars, temperatures or experimental locations.

与生长和产量相比，人们对CO ₂升高对稻谷品质的影响关注较少。暴露于升高的 CO ₂会导致植物发生许多生理变化，这些变化可以改变化学成分，从而改变稻谷的质量。进行该荟萃分析以综合自由空气CO ₂富集（FACE，约550 μmol mol ^-1）对露地条件下生长的水稻籽粒品质的影响。还研究了可以改变 CO _{2效应的因素。}它们包括品种、施氮量、环境温度和谷物类型。平均而言，升高的 CO ₂尽管在 FACE 条件下糙米产量和白米产量大幅增加，但整粒米百分比降低了 8%，这导致整粒稻产量没有增加。升高的[CO ₂ ] 使白垩粒百分比增加26%，白垩度增加30%，显着损害稻米外观。然而，通过升高 [CO ₂]，正如淀粉 RVA 谱的变化和米饭的适口性所表明的那样。FACE 大米的营养价值下降，表现为氮、磷、镁、硫、锌、铁、铜、锰和氨基酸浓度下降 2-9%；同时提高了抗营养植酸盐和植酸盐与锌的摩尔比。高施氮量减轻了[CO ₂ ] 升高对碾米质量和稻米外观的负面影响，但进一步降低了必需营养素的生物利用度。CO ₂引起的白米元素浓度下降普遍高于糙米。一般来说，CO ₂水稻品种、温度或试验地点很少改变由谷粒质量引起的变化。