Potential shortages in the reserves of phosphorus (P) rock and low soil P availability are among the main limiting factors for agricultural development. Recent studies show that biochar plays a crucial role in regulating soil physicochemical properties and crop development. To further verify the contribution of biochar to availability of soil P and nutrient efficiency of crop P, a maize continuous cropping field trial was started in 2013 to investigate the effects of biochar (0 and 2.63 t ha⁻¹) combined with P fertilizer (0 and 26 kg ha⁻¹) on soil biologically-based P and maize P use efficiency and yield. The treatments included mineral NPK fertilizer (NPK), mineral NK fertilizer (NK), mineral NPK fertilizer in combination with biochar (NPK + BC) and mineral NK fertilizer in combination with biochar (NK + BC). The following results were obtained in 2017 and 2018: biochar increased the pH, electrical conductivity (EC), total C (TC) and total P (TP) of the soil. Biochar can increase soil biologically-based P (CaCl₂-P, enzyme-P, citrate-P and HCl-P). The grain yield of the NPK + BC treatment reached the highest point and improved maize grain yield by 4.2 %–12.5 % compared with NPK fertilization alone. Moreover, the application of biochar (2.63 t ha⁻¹) instead of phosphate fertilizer in these experimental conditions did not lead to a decrease in the yield of maize. The addition of biochar increased the contents and uptake of P in maize grains, while negatively affecting the content and uptake of P in maize stover. Increases in P fertilizer use efficiencies (PUE) (12.4 %–31.4 %) and agronomic P efficiencies (AEP) (21.6 %–51.2 %) occurred after the application of biochar. The yield of maize and PUE positively correlated with the soil biologically available P. The structural equation modeling (SEM) results suggest that the increases in maize yield could be ascribed to improvements in soil biologically-based P and soil properties. Therefore, the addition of biochar is an effective approach to enhance the yield of maize, which is not only relevant to the improvement of soil biologically-based P but also increases in P use efficiency.

磷 (P) 岩石储量的潜在短缺和土壤磷的可用性低是农业发展的主要限制因素。最近的研究表明，生物炭在调节土壤理化特性和作物发育方面起着至关重要的作用。为了进一步验证生物炭对土壤磷的有效性和作物磷养分效率的贡献，2013 年开始了玉米连作田间试验，以研究生物炭（0 和 2.63 t ha ^-1）与磷肥（0和 26 公斤公顷^-1) 对土壤生物基磷和玉米磷的利用效率和产量。处理包括矿物NPK肥料(NPK)、矿物NK肥料(NK)、矿物NPK肥料结合生物炭(NPK+BC)和矿物NK肥料结合生物炭(NK+BC)。2017 年和 2018 年获得了以下结果：生物炭提高了土壤的 pH 值、电导率 (EC)、总碳 (TC) 和总磷 (TP)。生物炭可以增加土壤生物基磷（CaCl ₂ -P、酶-P、柠檬酸盐-P和HCl-P）。NPK + BC 处理的籽粒产量达到最高点，与单独施肥 NPK 相比，玉米籽粒产量提高了 4.2%–12.5%。此外，生物炭的应用（2.63 t ha ^-1) 在这些实验条件下代替磷肥并没有导致玉米产量的下降。生物炭的添加增加了玉米籽粒中磷的含量和吸收，同时对玉米秸秆中磷的含量和吸收产生了负面影响。施用生物炭后，磷肥使用效率 (PUE) (12.4 %–31.4 %) 和农艺磷效率 (AEP) (21.6 %–51.2 %) 增加。玉米产量和 PUE 与土壤生物有效磷呈正相关。结构方程模型 (SEM) 结果表明玉米产量的增加可归因于土壤生物磷和土壤性质的改善。因此，添加生物炭是提高玉米产量的有效途径，