Improving rice yield potential is crucial for global food security. Taoyuan, China, is famous worldwide as a special ecosite for ultrahigh rice yield. Climatological factors affecting this phenomenon have been identified, but the potential molecular processes and environmental mechanisms promoting ultrahigh yield remain mysteries. This study identifies soil biotic factors affecting ultrahigh yield, considering soil microbial community structure and metagenomic functions during four key rice growth stages, together with results from nitrogen enrichment experiments and rice root transcriptome analysis. Our results show that Taoyuan has more diverse bacterial taxa, less diverse fungal taxa, and a 10-fold-stronger connection among microbial taxa as well as a significantly higher proportion of nutrient transport functions than a regular site. Notably, our metagenomic analysis shows that Taoyuan contains more taxa with nitrogen metabolism functions and a higher abundance of genes involved in the nitrification process (e.g., hydroxylamine oxidoreductase and nitric oxide dioxygenase), promoting effective transformation of ammonium (NH₄⁺) to nitrate (NO₃⁻) in rice fields and stimulating high expression of nitrate transporters in rice roots, leading to ultrahigh yields. Our results indicate that soil microbiota contribute to ultrahigh rice yield in Taoyuan, and indicate that nitrogen metabolism functions could be one of the mechanism for the ultrahigh yield of rice.

提高稻米单产潜力对于全球粮食安全至关重要。桃园（Taoyuan）以超高水稻产量的特殊生态基地而闻名世界。已经确定了影响这一现象的气候因素，但是促进超高产量的潜在分子过程和环境机制仍然是个谜。这项研究考虑了四个关键水稻生长阶段的土壤微生物群落结构和宏基因组功能，以及氮富集实验和水稻根转录组分析的结果，确定了影响超高产的土壤生物因子。我们的结果表明，桃园的细菌分类单元种类更多，真菌的分类单元种类更少，微生物分类单元之间的连接强度是普通站点的10倍，而且营养传输功能的比例也明显更高。值得注意的是₄ ⁺）以硝酸盐（NO ₃ ^-在稻田）和刺激在水稻根部硝酸盐转运蛋白的高表达，从而导致超高产量。我们的研究结果表明，土壤微生物群可以促进桃园的水稻超高产，并表明氮的代谢功能可能是水稻超高产的机理之一。