Improving Wheat Yield and Phosphorus Use Efficiency through the Optimization of Phosphorus Fertilizer Types Based on Soil P Pool Characteristics in Calcareous and Non-Calcareous Soil

Irrational phosphorus (P) nutrient management practices often fail to match of P fertilizer type, soil P transformation and crop P demand, lead to increased accumulation of legacy P, reduced PUE, and pollution, affecting crop production. A pot experiment incorporating soil types and P fertilizer types (SSP, simple superphosphate; CMP, calcium magnesium phosphate; DAP, diammonium phosphate; TSP, triple superphosphate; APP, ammonium polyphosphate; CK, no P application) to establish coupling of the soil and P fertilizer types, soil P pool characteristics, crop P uptake. In calcareous soil, the available P concentrations in rhizosphere soil were higher under TSP and DAP, with the increase in NaHCO3-Pi concentration the most. In non-calcareous soil, the NaHCO3-Pi and NaOH-Pi increased the most under SSP, DAP, and TSP at anthesis. Shoot P accumulation at maturity was highest under TSP and APP, TSP and DAP, respectively, in the two soil. TSP and APP significantly increased yield and PUE in the calcareous soil, while TSP and DAP performed better in the non-calcareous soil. NaHCO3-Pi and NaOH-Po are potentially available P sources in calcareous and non-calcareous soil, which remarkably affect shoot P uptake through H2O-P. Comprehensive assessment of the relationship between soil P pool characteristics, yield and PUE, TSP and APP are recommended for application in calcareous soils and TSP and DAP for application in non-calcareous soils in wheat cropping systems.