Next to nitrogen, phosphorus (P) is the most limiting nutrient for plant production worldwide. To secure food production, new nutrient management strategies using alternative P sources instead of mined P fertilizers need to be implemented. Struvite (MgNH₄PO₄ · 6 H₂O) is a promising example of a recycled mineral P fertilizer. Besides positive agronomic results regarding crop yields, further investigations are required to improve the use efficiency of the product and thereby increase its value. Using an automated plant phenotyping platform, we investigated the dynamic response to struvite by two plant species (lupine and maize) with diverse P acquisition strategies in an acidic sandy substrate. Although at three weeks after germination both maize and lupine had reduced leaf area in the struvite treatments compared to the commercial triple superphosphate (TSP), from week four onwards struvite plants grew larger than the TSP‐treated plants, indicating a slow release fertilizing effect. Greater P uptake efficiency (g / root length), but reduced root length were observed in the combined treatment of struvite and ammonium, in comparison to struvite and nitrate. We propose that rhizosphere acidification in response to ammonium uptake may enhance P recovery from struvite. A possible additional acidification effect by lupine root exudation might explain the higher P uptake efficiency in this species compared to maize. We conclude that struvite combined with ammonium can be used as a sustainable slow‐release P fertilizer on acidic sandy soils.

中文翻译：

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鸟粪石对磷的吸收受氮素形态的调节

除氮外，磷（P）是全球植物生产中最限制性的营养素。为了确保粮食生产，需要实施使用替代磷源替代开采的磷肥的新养分管理策略。鸟粪石（MgNH ₄ PO ₄ ·6 H ₂O）是再生矿物P肥料的一个有前途的例子。除了农作物产量方面的积极农艺结果外，还需要进一步研究以提高产品的使用效率，从而增加产品的价值。使用自动植物表型平台，我们研究了两种植物物种（羽扇豆和玉米）对鸟粪石的动态响应，以及在酸性沙质基质中采用多种磷获取策略。尽管发芽后三周玉米和羽扇豆在鸟粪石处理中的叶面积均比市售三重过磷酸钙（TSP）减少，但从第四周开始，鸟粪石植物的生长大于经TSP处理的植物，表明缓释施肥作用。更高的磷吸收效率（克/根长），但是与鸟粪石和硝酸盐相比，鸟粪石和铵盐的联合处理观察到根部长度减少。我们建议根际酸化响应铵的吸收可能会提高鸟粪石中磷的回收率。羽扇豆根分泌物可能产生的附加酸化作用可能解释了与玉米相比，该物种中较高的P吸收效率。我们得出结论，鸟粪石与铵盐结合可以用作酸性砂质土壤上的可持续缓释磷肥。