Abstract:An experiment was conducted to study the effects of phosphorus fertilizer combined with four kinds of biological materials (microbial fertilizer, W; biochar, S; humic acid, F; and fulhuic acid, H) on salinized soil improvement and maize yield. A total of 16 treatments including no phosphate fertilizer and no biological material treatment (CK), conventional phosphorus fertilizer (P5, 75 kg/hm2; P10, 150 kg/hm2; P15, 225 kg/hm2), and phosphorus fertilizer combined with materials (P5W, P5S, P5F, P5H, P10W, P10S, P10F, P10H, P15W, P15S, P15F, P15H, P15H) were set up in this experiment. Results show that compared with CK, soil bulk density and pH are decreased by 1.96%-14.38% and 0.11%-1.98% respectively, soil available P content are increased by 33.71%-182.39%. P accumulation in grain is the highest under 75 kg/hm2 P fertilizer application and P accumulation in stem, leaf and plant are the most significant under 150 kg/hm2 P fertilizer application. The utilization rate, agricultural efficiency and partial productivity of P fertilizer are decreased as P fertilizer amount is increased. Maize fresh weight and dry weight per plant are increased by 6.52%-34.78% and 11.54%-42.31% respectively. The 100-grain weight and yield are increased by 31.15%-40.52% and 21.81%-60.02% respectively. Principal component analysis shows that the highest comprehensive score of 150 kg/hm2 P fertilizer combined with 7 500 kg/hm2 biochar treatment is 1.255 1, and this treatment has the best comprehensive effect on soil improvement, phosphorus fertilizer utilization and maize yield increase. This study provides important theoretical and technical support for salinized soil improvement and efficient phosphate fertilizer utilization.