镁改性生物炭对茶园土壤养分及茶叶品质和香气化合物的影响OA

[Objective]This study aimed to evaluate the effects of different magnesium-modified biochar treatments on chemical properties tea plantation soil,tea plant growth and nutrient uptake,as well as tea quality and aroma com-pounds,providing scientific guidance for improvement of tea plantation soil and tea quality.[Method]Two-year-old plants of Longjing 43 were used to perform a pot experiment.Four treatments were applied:control group without biochar(CK),treatment with magnesium chloride-modified biochar(BCL),treatment with magnesium nitrate-modified biochar(BCX),and treatment with magnesium acetate-modified biochar(BCY).After harvesting at 90 d of growth,soil chemi-cal properties,tea plant growth indicators,tea quality indicators,and volatile component contents were determined to analyze correlations between soil indicators and differential aroma substances of tea.[Result]Compared with CK,treat-ment with magnesium-modified biochar significantly increased soil pH(P<0.05),improved soil qua-lity,promoted tea plant growth,enhanced tea nutrient uptake,and elevated tea quality.Specifically,the BCY treatment elevated soil pH by 0.39,increased organic matter content by 9.5-time,raised available phosphorus and available potassium by 84.44%and 14.02%respectively,and enhanced cation exchange capacity by 75.82%,with high content of exchangeable base cations.The magnesium-modified biochar also increased soil and plant analyzer development(SPAD)values of leaves,improved tea plant growth indicators and nutrient uptake,increased the contents of tea polyphenols,free amino acids,water ex-tracts,and caffeine in leaves,while reducing the ratio of polyphenol-amino acid.Aroma component analysis revealed that the BCY treatment notably increased both the types and contents of volatile compounds in leaves,with higher accumula-tion of key odor-active substances such as octanal,(E)-2-octenal,and phenylethyl alcohol,which imparted typical flo-ral,fruity,and honey-like notes for tea.Correlation analysis results showed that most aroma substances were positively correlated with soil pH and nutrient content,while they were negatively correlated with exchangeable hydrogen,ex-changeable aluminum,and exchangeable acid content.[Conclusion]Magnesium-modified biochar synergistically amelio-rates soil acidification and enhances tea flavor quality,with the treatment with magnesium acetate-modified biochar de-monstrating the optimal improvement effects.