Optimization Of Nutrient Management Based On Metabolism Of Quality-related Compounds In The Tea Plantation

Imbalanced nutrient caused by yield targeting fertilization strategies becomes the main factors restricting sustainable production in tea plantation.The environmental pollution and degradation of crop quality caused by irrational fertilization is of increasing interest by researchers worldwide.Over many years,optimization of cultivation practices,especially nutrient management strategy,had a substantial impact on improvement of tea yield and quality.In this study,we conducted a pot simulation method to analyze the quality of tea leaves and the metabolic accumulation of quality-related components,such as polyphenols and anthocyanins,in young tea leaves under different nutrition treatments.The main results are as follow:1.There are significant differences in the accumulation of main quality components in tea plants under different nitrogen release rates: slow-released nitrogen promotes the accumulation of amino acid content in new shoots,inhibits the accumulation of tea polyphenols,further to improving the quality of tea.In addition,nitrogen slow-release improved the softness and leaf spacing in tea shoots,promoting the accumulation of NH4+-N content in the soil.2.Different phosphorus and potassium fertilizers have a significant impact on the accumulation of main quality components such as anthocyanins in tea plants: Compared with traditional non-water-soluble phosphorus and potassium fertilizers(composite fertilizers),water-soluble phosphorus and potassium fertilizers have higher efficiency on improving tea growth and tea quality.3.There are significant differences in the response of anthocyanin to phosphorus and potassium nutrient levels: insufficient supply of phosphorus and potassium fertilizer promotes the accumulation of tea polyphenol content and induces the accumulation of geranium and paeoniflorin,and the quality of tea is significantly lower than the control(optimized nutrient)treatment.Noteworthy,available phosphorus and potassium highly accumulated in the soil under excessive application of phosphorus and potassium fertilizer,while the quality of tea doesn’t improve.This could be attributed to the accumulation of anthocyanins in tea shoots,such as peonidin and cyanidin.4.To further clarify the adaptability of varieties to nutrient strategies,we compared the responses of Fudingdabai,Huangjinya,Zijuan,and Baiye 1 to nutrient optimization application.The results showed that,excessive nitrogen fertilizer application will inhibit the accumulation of anthocyanin content in new shoots of in Fudingdabai and Baiye 1 tea plants,while in Huangjinya and Zijuan tea plants,the inhibitory effect of phosphorus fertilizer on the accumulation of anthocyanin content is much higher.Compared with normal green leaf varieties(Fudingdabai),leaf color mutation(Huangjinya,Baiye1)shown special nutrient demand patterns,and their nutrient management optimization strategies need to be further improved.