Effects Of Different Fertilization Treatments On Soil Phosphorus In Greenhouse Tomatoes And Environmental Risk Assessment Of Phosphorus

There is a shortage of phosphate fertilizer resources in my country.To meet the current needs of my country’s agricultural production,lots of phosphate fertilizer needs to be imported every year.With the current increase in vegetable planting area,ordinary farmers are influenced by traditional concepts and believe that the more fertilizers they use,the more crops can have high yield and quality.Therefore,the amount of phosphate fertilizer invested by ordinary farmers in vegetable production is gradually increasing.However,the benefit of increasing production and income of phosphate fertilizers has been declining,which has led to an increasingly obvious accumulation of soil phosphorus.In order to explore the effects of different fertilization treatments on soil phosphorus composition,soil phosphorus retention index and soil phosphorus saturation and their correlation analysis,based on the long-term positioning experiment of Shenyang Agricultural University and selects ten treatments.This experiment aims to provide a basis for the more reasonable utilization of soil and fertilizer resources and environmental protection of the tomato soil in the facility.The main research results of this experiment are as follows:1.The mixed application of phosphate fertilizer and organic fertilizer can improve the content of H₂O-P and Na HCO₃-P significantly.The content of Na OH-P can be improved by the application of phosphate fertilizer or the mixed application of phosphate fertilizer and organic fertilizer in a short time,and the application of phosphate fertilizer or phosphate fertilizer and organic fertilizer Mixed application can significantly improve the content of HCl-P.The accumulation of Residual-P in the soil can be caused by the application of organic fertilizer,and can be activated by the nitrogen and potassium fertilizers.2.Correlation analysis shows that with the conspicuously improvement of soil organic matter,water content,total phosphorus,total nitrogen,available phosphorus and acid phosphatase activity,the content of soil H₂O-P is increased,and with the increase of alkaline phosphatase activity,p H,and phytase activity,it significantly decreases.The content of Na HCO₃-P increases significantly with the increase of soil water content,organic matter content,total phosphorus,available phosphorus and total nitrogen.The content of Na HCO₃-P significantly decreases with the increase of p H.With the improvement of phytase alkaline phosphatase and phytase activity,it is Na HCO₃-Pi that will be significantly reduced.With the increase of organic matter content,water content,total phosphorus content,total nitrogen content,available phosphorus content,acid phosphatase activity in the soil,it is HCl-P content that increases significantly,and fall significantly with the improvement of p H.With the improvement of available phosphorus and total phosphorus in the soil,it is the content of soil Na OH-P that conspicuously improves,and decreases with the improvement of p H significantly.With the increase of alkaline phosphatase activity,the content of Na OH-P₀ will decrease significantly.With the increase of organic matter,water content,total phosphorus,and available phosphorus content,it is Residual-P content that significantly increases.3.Correlation analysis shows that in the soil of H₂O-P,Na HCO₃-P and Na OH-P are the main phosphorus components that promote the increase of the phosphorus content of plant stems.Na OH-P in the soil is the main phosphorus component that affects the total phosphorus content of tomato plants.In addition,it also has a significantly positive correlation with the total phosphorus content of leaves.It is H₂O-P that is the main phosphorus component which restricts tomato yield.4.Application of phosphate fertilizer can reduce soil PSI significantly,soil DPS will be significantly increased by application of phosphate fertilizer or organic fertilizer,and it is the soil PSI and DPS that will be improved by combined application of organic fertilizer and phosphate fertilizer significantly.Correlation analysis shows that soil PSI decreases significantly with the increase of Na OH-P and Na HCO₃-P₀ content,and soil DPS has a significant positive correlation with all phosphorus components.5.In general,the mixed application of organic fertilizers and NPK fertilizers can increase the total phosphorus content and yield of tomato plants.However,the DPS in the soil of each fertilization treatment in the experimental site exceeds 25%of the environmental prediction index,and the minimum is 34.61%.The DPS of the mixed application of organic fertilizer and NPK fertilizer is 156.95%,which is relatively large.It shows that the soil phosphorus is easy to lose in each fertilization treatment in this experimental site.