[Photosynthetic mechanism of tea yield and quality affected by different habitats]. / ç”Ÿå¢ƒå¯¹èŒ¶å¶å“è´¨å’Œäº§é‡å½±å“çš„å ‰åˆç”Ÿç†æœºåˆ¶.

To understand photosynthetic mechanism of tea yield and quality, an experiment was conducted with four different typical habitats, including three intercropping patterns (S1:Osmanthus-Tea, S2:Michelia-Tea, S3:Osmanthus-Michelia-Tea) and a control (CK) at Changsha Agricutural Observation Station of Chinese Academy of Sciences. The photosynthetic physiological and ecological characteristics of tea yield and quality were examined. The results showed that the habitats S1, S2, S3 reduced the leaf temperature (TL), photosynthesis active radiation flux (PAR), net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (gs), as well as the tea polyphenol content. Habitats S1, S2, S3 significantly increased leaf relative humidity (RHS), total amino-acid content of tea, and the yield and quality of tea, with a pattern of S3>S1>S2>CK. The leaves in habitats S1 and S3 could be made into high-grade green tea and famous green tea respectively. Comprehensive indicators showed that habitat S3 is an ideal intercropping pattern for high quality and high yield of tea garden.

[Effects of Long-term Fertilization on Enzyme Activities in Profile of Paddy Soil Profiles].

The enzyme activity, which is closely related to soil material cycling (mineralization, transformation, etc.), can reflect soil quality and nutrient status. In order to explore the effect of long-term fertilization on the enzyme activity in paddy soil profile (0-40 cm), soils with organic fertilizer and inorganic fertilizer, and non-fertilized soils were selected, and the carbon and nitrogen contents, and the activities of ß-1,4-glucosidase (BG), and ß-1,4-N-acetylglucosaminidase (NAG) in 10cm depths of soil were analyzed. The results showed that the activities of BG and NAG in the soils treated with inorganic fertilizer and organic fertilizer increased by 0.73-47.87 nmol·(g·h)-1 and 1.33-128.81 nmol·(g·h)-1, and 0.19-9.72 nmol·(g·h)-1 and 0.92-57.66 nmol·(g·h)-1, respectively, compared to those for non-fertilized soil. Soil enzyme activity decreased with increasing soil depth. Soil enzyme activity in soil from 0-20 cm was significantly higher than that of soil from 20-40 cm. Soil enzyme activities were significantly affected by long term fertilization at different soil depths. RDA analysis showed that soil carbon and nitrogen contents had significant positive relationships with the activities of BG and NAG in the 0-20 cm soil profiles, however, negative relationships were observed in the 20-40 cm soil profiles. The long-term application of organic fertilizer significantly increased soil biomass and enzyme activity, both of which decreased with the increase in soil depth. Long-term fertilization could increase soil nutrient contents, microbial biomass, and extracellular enzyme activities, which has important theoretical significance for optimizing farmland fertilizer management and improving soil productivity.