Security in rice production requires solving challenges of water scarcity and phosphorus (P) limitations. Reductive dissolution of ferric (III) iron bound phosphate (Fe–P) and organic P (P) mineralization are two understudied P sources for rice plants and microorganisms. Using the new water-saving alternate wetting-drying irrigation should increase P mineralization but decrease the Fe–P dissolution and thereby shift the plant and microbial preferences for P sources. Rice biomass increased two-fold under alternate wetting-drying compared to continuous flooding, but the P use efficiency of plants was independent of water regimes. Plants were more competitive for P from Fe–P by Fe(III) reduction, whereas microorganisms preferred straw-derived P (enzymatic hydrolyzation). The high contribution (∼20 %) of P from straw to the P nutrition of rice plants and microorganisms raises the significance of P mineralization, e.g. from organic fertilizers. This makes the application of organic P fertilizers highly beneficial to increase rice productivity. Plants took up 62 % more soil-derived P under alternate wetting-drying than under continuous flooding. Accordingly, alternate wetting-drying is a more efficient management to increase the use of soil legacy P and reduce the use of mineral fertilizers compared to continuous flooding.

中文翻译：

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越湿越好吗？对比灌溉下水稻种植中植物-微生物对磷源竞争的偏好

水稻生产安全需要解决水资源短缺和磷 (P) 限制的挑战。三价铁 (III) 铁结合磷酸盐 (Fe–P) 的还原溶解和有机磷 (P) 矿化是水稻植物和微生物的两个尚未研究的磷源。使用新型节水干湿交替灌溉应该会增加磷的矿化，但会减少铁磷的溶解，从而改变植物和微生物对磷源的偏好。与连续淹水相比，干湿交替条件下水稻生物量增加了两倍，但植物的磷利用效率与水分状况无关。通过 Fe(III) 还原，植物对 Fe-P 的磷更具竞争性，而微生物更喜欢秸秆衍生的磷（酶水解）。来自秸秆的磷对水稻和微生物的磷营养的高贡献（~20%）提高了磷矿化的重要性，例如来自有机肥料的磷矿化。这使得施用有机磷肥对于提高水稻产量非常有利。干湿交替条件下植物吸收的土壤来源磷比连续淹水条件下多 62%。因此，与连续淹水相比，干湿交替是一种更有效的管理方法，可以增加土壤残留磷的使用并减少矿物肥料的使用。