Study on Phosphorus Uptake Utilization and Morphological Transformation in Greenhouse Soil Under the Combination of Phosphorus Reduction and Microbial Agent Application

In order to provide a theoretical basis for the rational management of phosphorus in facility vegetable fields, the dry matter quantity, phosphorus uptake and soil phosphorus morphological transformation of tomato were studied by combining phosphorus reduction and microbial agents application. This experiment was designed according to the main and secondary zones, the main zones were microbial agent application and no microbial agent, and the secondary zones were different gradient phosphorus reduction. It was arranged in stochastic order. A total of 8 treatments are used to plant tomatoes, namely T1 (base phosphorus), T2 (base phosphorus + Microbial agent), T3 (25% phosphorus reduction), T4 (25% phosphorus reduction + Microbial agent), T5 (50% phosphorus reduction), T6 (50% phosphorus reduction + Microbial agent), T7 (100% phosphorus reduction), T8 (100% phosphorus reduction + Microbial agent). The total amount of phosphate fertilizer (P₂O₅) applied was 540 kg ha^− 1, the application form was base fertilizer + topdressing, and the application amount of microbial agent was 24 kg ha^− 1, which was applied when the second ear of tomato was expanded. T4 treatment is the most effective in improving the quality of dried tomatoes and phosphorus absorption. Phosphorus fertilizer from the T4 treatment have the highest agronomic efficiency and help to convert a slow available phosphorus sources of rapid available phosphorus sources in the soil. The alkaline phosphatase activity of T4 treatment was the highest in both surface and rhizosphere soils. In the ratio of bacteria to fungi in rhizosphere soil, the proportion of bacteria is higher under T4 treatment was 1.11. The available phosphorus content in rhizosphere and non-rhizosphere soils is lowest under T5 treatment, 6.54% and 33.60% lower than T1 treatment respectively. In greenhouse tomato production, T4 treatment has the highest net income of 234.1 thousand yuan·ha^− 1. The water-soluble phosphorus content in the surface soil is highest under T4 treatment, but decreases to the lowest when reaching deep soil. On the whole, in the experiment of basal fertilizer phosphorus reduction method and applying microbial inoculants, T4 treatment had the best effect on improving the dry matter quantity of tomatoes, the absorption and utilization of phosphorus, promoting the conversion of soil phosphorus, and reducing the downward migration of soil phosphorus.