Abstract: To develop a new technology mode of reducing chemical fertilizers and increasing their efficiency in tea garden, a pot experiment was conducted with four treatments: mulching of pruned tea branches (T1), monoculture soybean (T2), mulching of pruned tea branches and interplanting soybean (T3), and control (CK). We examined the contents of total phosphorus (TP), available phosphorus (AP), total potassium (TK), available potassium (AK), total nitrogen (TN), alkalihydrolyzable nitrogen (AN), organic matter, pH and the activity of urease, cellulase, sucrase, catalase, acid phosphatase, aiming to explore the responses of nutrients and enzyme activities in potted tea garden soil under the interaction of mulching pruned tea branches and interplanting soybean. The results showed that the concentrations of soil TP, AP, AK, and activities of various enzymes had significant response to the interaction between mulching of pruned tea branches and interplanting soybean. The contents of TN and AN in T3 were higher than those in T1 and T2. Organic matter content and soil pH of T3 increased by 53.92% and 2.44% compared with T1, and by 25.60% and 6.03% compared with T2, respectively. The activity of sucrase and urease had similar response, showing T3 > T1 > T2 > CK, with the difference between T3 and other treatments being significant. The activities of cellulase and acid phosphatase under T3 were higher than those of other treatments. PCA results showed that T3 and CK were close to the origin of PC2 and had opposite scores on PC1; T1 and T2 were close to the origin of PC1, and had opposite scores on PC2. There was a strong correlation between phosphorus and potassium concentrations, while organic matter and nitrogen content were closely related to enzyme activity. Soil pH value was significantly positively correlated with the activities of cellulase, urease, sucrase, catalase, and the concentrations of TN and organic matter. Under the condition of pot culture, mulching of pruned tea branches and interplanting soybean had interactive effects on soil nutrient and enzyme activity, which could increase the content of nitrogen and organic matter in tea garden soil, improve soil enzyme activity, and alleviate soil acidification, providing a scientific basis for the new technology of reducing fertilizer application and increasing fertilizer efficiency in tea garden.

Key words: tea garden soil, nutrient, enzyme activity, pruned tea branch, soybean, interaction.