Abstract: The effects of phosphorus optimization combined with microbial agents on tomato yield, phosphorus absorption and quality were studied, in order to provide a theoretical basis for the rational management of phosphorus in the facility vegetable field. This test was designed according to the main and secondary areas. The main area was the application of microbial agents and the non-application of microbial agents, while the secondary area was phosphorus reduction of different gradients. There were a total of 7 treatments, namely T1（phosphorus reduction 0%）, T2（phosphorus reduction 25%）, T3（phosphorus reduction 25% + microbial agent）, T4（phosphorus reduction 50%）, T5（phosphorus reduction 50% + microbial agent）, T6（phosphorus reduction 100%）, T7（phosphorus reduction 100% + microbial agent）. The results showed that the T3 treatment under microbial agents application had a good effect on tomato yield, dry matter quality of all parts, phosphorus uptake and phosphorus utilization, and in terms of fruit quality, sugar content, sugar-acid ratio and vitamin C content were improved, nitrate content was reduced, which significantly improved tomato fruit quality and reduced soil phosphorus transport to deeper layers. Under the condition of not applying microbial agents, T2 treatment has the highest yield, plant dry matter quality, tomato fruit and total phosphorus uptake, high phosphorus utilization rate, good fruit quality, and effectiveness in reducing phosphorus transport. Based on various indicators, it was found that T3 treatment with microbial agents had the best effect on improving the yield, quality, phosphorus absorption, and reducing soil phosphorus transport of greenhouse tomatoes, while T2 treatment without microbial agents had the best effect.

Key words: phosphorus reduction, microbial agent, facility tomato yield, phosphorus absorption, quality