Effect of phosphorus application level on wheat growth, yield, and phosphorus utilization efficiency

Objective In order to investigate the effects of phosphorus application levels on wheat yield formation and fertilizer utilization efficiency.

Methods Field experiments were conducted, Four phosphorus fertilizer treatments were set, including: No phosphorus fertilizer application (P0), 75 kg/hm² phosphorus fertilizer (P1), 150 kg/hm² phosphorus fertilizer (P2) and 225 kg/hm² phosphorus fertilizer (P3). Analyze the differences in wheat growth, yield, and fertilizer utilization efficiency under different phosphorus treatments.

Results The application of phosphorus fertilizer can increase the leaf area index of wheat. The P2 phosphorus treatment had the highest leaf area index during the flowering and filling stages, significantly higher than other phosphorus treatments. The P2 phosphorus treatment increased the leaf area index during the flowering and filling stages by 4.68%−7.02% and 4.28%−7.14%, respectively, compared to other phosphorus treatments. The net photosynthetic rate of P0 without phosphorus treatment was the lowest, with net photosynthetic rates Pn of 21.80 and 22.70 mmol·m⁻²·s⁻¹ during flowering and grain filling stages, respectively. The net photosynthetic rate (Pn) between the phosphorus treatments during the flowering and grain filling stages was highest in the P2 treatment, which increased by 7.91% and 6.52% respectively compared to the P1 and P3 treatments during the flowering stage; The net photosynthetic rate Pn during the grouting period of P2 treatment increased by 10.59% and 9.07% respectively compared to P1 and P3 treatment. The dry matter accumulation of P1, P2, and P3 treatment with phosphorus during the mature stage increased by 13.91%, 28.16%, and 16.60% respectively compared to the P0 treatment. The differences in dry matter accumulation during the mature stage between each phosphorus treatment and the P0 treatment were significant. Phosphorus application increased the number of wheat ears, grains per ear, and thousand grain weight. Among them, the yield of P2 treatment was significantly higher than that of P0, P1, and P3 treatment. The yield of P2 treatment increased by 32.19%, 15.73%, and 11.28% respectively compared to P0, P1, and P3 treatment. The P2 treatment had the highest agronomic utilization efficiency of phosphorus fertilizer, increasing by 157.03% and 127.08% respectively compared to the P1 and P3 treatments.

Conclusion Under the conditions of this experiment, the P2 phosphorus treatment showed the best performance in wheat growth, yield, and fertilizer utilization efficiency, which can serve as a reference for the use of phosphorus fertilizer in field production.