Phosphorus (P) is a key element for energy transfer, and biosynthesis of nucleic acids and cell membranes. The objective of this study was to investigate and quantify P utilization by different grain—maize (Zea mays L.) and soybean (Glycine max L.)—and forage-cover crop brachiaria (Brachiaria ruziziensis) plant species in a low fertility highly weathered Oxisol. Two rates of P (25 and 50 mg kg⁻¹) were applied by water-soluble P fertilizer (triple superphosphate) to each of 12 crop cycles, together with a control (no P added). Measurements included plant biomass production and P uptake for each cycle, and analysis of soil P fractions (including labile and non-labile) and enzymes activities (acid phosphatase and β-glucosidase) were done at the beginning of the experiment and after 3, 6, and 12 cycles. Total biomass production and P uptake/removal were significantly higher for brachiaria than maize and soybean, which was reflected in the P use efficiency (PUE), being higher for brachiaria (57%), compared with maize (26%) and soybean (21%). The higher PUE by brachiaria was partly attributed to higher levels of acid phosphatase and β-glucosidase activities which indicated enhanced biological activity and P cycling under brachiaria. Data from the control treatment clearly demonstrated that all three plant species mobilized stable/occluded fractions of P throughout the experiment, however, brachiaria could produce more using less P. The findings of this study indicated the inclusion of brachiaria in crop rotations as a forage or cover crop/green manure may enhance overall P use efficiency.

磷 (P) 是能量转移以及核酸和细胞膜生物合成的关键元素。本研究的目的是调查和量化不同谷物——玉米 (Zea mays L.) 和大豆 (Glycine max L.)——以及草料覆盖作物臂形草 (Brachiaria ruziziensis) 在低肥力高度风化条件下的磷利用情况奥克西索尔。通过水溶性磷肥（三重过磷酸钙）向 12 个作物周期中的每一个施用两种比例的磷（25 和 50 mg kg ⁻¹ ），以及对照（不添加磷）。测量包括每个周期的植物生物量产量和磷吸收，以及在实验开始时和实验开始后 3、6 小时对土壤磷组分（包括不稳定和不稳定）和酶活性（酸性磷酸酶和 β-葡萄糖苷酶）进行分析。 ，和12个周期。臂形草的总生物量产量和磷吸收/去除量显着高于玉米和大豆，这反映在磷利用效率 (PUE) 上，臂形草 (57%) 高于玉米 (26%) 和大豆 (21 %）。臂形草较高的 PUE 部分归因于较高水平的酸性磷酸酶和 β-葡萄糖苷酶活性，这表明臂形草的生物活性和磷循环增强。对照处理的数据清楚地表明，在整个实验过程中，所有三种植物物种都动员了稳定/封闭的磷部分，然而，臂形草可以使用较少的磷生产更多的磷。这项研究的结果表明，臂形草可以作为饲料或作物轮作中的一部分。覆盖作物/绿肥可以提高磷的整体利用效率。