Rare earths elements (REEs) can affect plant growth positively. Besides their intentional agricultural use, REEs have also been involuntarily applied to soils through phosphate (P) fertilizers. This study aimed to evaluate the effects of REEs contained in P fertilizers on increasing legume crops yield in Brazilian agroecosystems. Field experiments were conducted with Phaseolus vulgaris L. and Glycine max (L.) Merrill with four sources of P (a pure ammonium phosphate with no REEs and three single superphosphates—SSP—with varying REEs contents) applied to the soil at four P rates (0, 17.5, 35, 70 kg ha⁻¹). Irrespectively of the rate, the SSP—Catalão (richest in total and soluble REEs among the sources tested) consistently increased the yield of common bean (~ 30%) in relation to the control (ammonium phosphate). Single superphosphate Araxá (intermediate REEs content) also increased common bean yield. For soybean, the SSP-Catalão, at the 70 kg P ha⁻¹ rate, was superior to the control (at the same level of P) and to the treatment without P addition. Our results showed that the REEs, present as impurities in phosphate fertilizers, increase their effectiveness on legume crops yield. These findings are relevant, as producers could enhance yield with REEs-rich P-fertilizers, especially in tropical agroecosystems, where high application rates are required.

稀土元素（REE）可以对植物生长产生积极影响。除了有意用于农业之外，REE还通过磷酸盐（P）肥料非自愿地应用于土壤。这项研究旨在评估含磷肥料对巴西农业生态系统中豆类农作物增产的影响。在菜豆上进行了田间试验，其中菜豆和甘氨酸美林将四种磷源（四种纯磷铵，无稀土元素和三种单一过磷酸钙（SSP），稀土元素含量不同）以四种磷比率施用到土壤中（0，17.5，35，70公斤公顷^-1）。与速率无关，SSP-Catalão（测试来源中的总REE和可溶性REE最丰富）相对于对照（磷酸铵）始终提高了普通豆的产量（〜30％）。单一的过磷酸盐Araxá（中等REEs含量）也增加了普通豆的产量。对于大豆，以70 kg P ha ^-1的比例处理的SSP-Catalão优于对照（在相同的P水平下），并且优于不添加P的处理。我们的结果表明，稀土元素作为磷酸盐肥料中的杂质存在，提高了其对豆类作物产量的有效性。这些发现是有意义的，因为生产者可以使用富含REE的P肥提高产量，特别是在需要高施用量的热带农业生态系统中。