Phosphorus (P) plays an important role in the physiological plant processes; however, in tropical soils, P is one of the most limiting nutrients for crop yield due to its low mobility, determined by the adsorption of this element to the soil. To enhance P-use and P-acquisition efficiency, this research aimed to evaluate the effect of cover crops and mycorrhizal colonization on changing soil P fractions, both organic and inorganic. A complete randomized block design was adopted in a field experiment, with four replications using four cover crops: i) pigeon pea (Cajanus cajan); ii) crotalaria (Crotalaria juncea); iii) millet (Pennisetum glaucum); iv) brachiaria (Brachiaria ruziziensis) and v) fallow, as control. The arbuscular mycorrhizal fungus colonization, the fungal spore density, soil P fractionation, and N, P, and K uptake were assessed. Our results show that cover crops affected the soil P cycling in deeper soil layers. Cover crops may increase arbuscular mycorrhizal inoculum potential for the succeeding crop in rotation or intercropping, when used as a green manure.

磷（P）在植物生理过程中起着重要作用；然而，在热带土壤中，P 是作物产量中最受限制的养分之一，因为其流动性低，这是由该元素吸附到土壤中决定的。为了提高磷的使用和磷的获取效率，本研究旨在评估覆盖作物和菌根定植对改变土壤有机和无机磷含量的影响。田间试验采用完全随机区组设计，使用四种覆盖作物进行四次重复：i) 木豆 ( Cajanus cajan )；ii) crotalaria ( Crotalaria juncea )；iii) 小米（Pennisetum glaucum）；iv) Brachiaria ( Brachiaria ruziziensis)) 和 v) 休耕，作为对照。评估了丛枝菌根真菌的定植、真菌孢子密度、土壤 P 分馏以及 N、P 和 K 吸收。我们的结果表明，覆盖作物影响了更深土壤层中的土壤磷循环。当用作绿肥时，覆盖作物可能会增加轮作或间作作物的丛枝菌根接种潜力。