Complementarity in phosphorus (P) acquisition from different sources and facilitation of P uptake have been implicated in yield advantages of intercropping. These beneficial interactions between crop species are expected to be particularly relevant on low-P soils.

Millet and chickpea have previously been found to differ in their ability to access different chemically bound forms of P. Here, we conducted a two-year field experiment on a low-P soil with or without P fertilization to determine whether the resulting potential for complementarity and facilitation with respect to P acquisition is associated with increased P uptake and yield of an intercrop as compared to sole crops.

Alkaline phosphatase activity and carboxylate concentration differed between millet and chickpea, indicating potential complementarity in access to different P sources. Comparison of aboveground P content in the intercrop and the pure stands showed a positive net effect for P uptake (NE_P > 0) when no P fertilizer was applied, but this positive net effect for P acquisition was not associated with a yield increase (NE_Y = 0). When P fertilizer was applied, there was no significant net increase in P uptake by the intercrop compared to sole crops (NE_P = 0), but there was a significant yield gain (NE_Y > 0).

Species trait dissimilarities for P acquisition from different sources supported complementarity in, and facilitation of P uptake by millet and chickpea in the field on a low-P soil, but this did not result in yield increase. The finding does not support the notion that complementarity in P acquisition from different sources and facilitation of P uptake are key drivers for overyielding by intercropping on low-P soil.

间作的产量优势涉及从不同来源获取磷（P）的互补性和磷吸收的便利性。预计作物品种之间的这些有益相互作用在低磷土壤上特别重要。

先前发现小米和鹰嘴豆获取不同化学结合形式的磷的能力不同。在这里，我们在有或没有磷施肥的低磷土壤上进行了为期两年的田间试验，以确定产生的互补潜力与单一作物相比，促进磷素吸收与间作作物的磷素吸收和单产增加有关。

小米和鹰嘴豆的碱性磷酸酶活性和羧酸盐浓度不同，表明在获取不同磷源方面存在潜在的互补性。间作和纯林间地上磷含量的比较表明，在不施用磷肥的情况下，对磷的吸收具有正的净效应（NE _P > 0），但是对磷的采集而言，这种正的净效应与产量增加（NE）无关。_Y = 0）。施用磷肥后，与单独作物相比，间作作物对磷的吸收没有显着的净增加（NE _P = 0），但有显着的增产（NE _Y > 0）。

从不同来源获取磷的物种性状差异支持低磷土壤田间小米和鹰嘴豆的互补性，并促进了小米和鹰嘴豆对磷的吸收，但这并未导致产量增加。这一发现不支持这样的观点，即从不同来源获取磷的互补性和促进磷的吸收是通过在低磷土壤间作而过量生产的关键驱动力。