Crop coefficient (Kc) is one of the most significant parameters for crop water demand prediction and irrigation scheduling. However, there is a lack of knowledge about water vapor and Kc in tea plantation ecosystems. This study explored and determined the actual evapotranspiration (ETc) and Kc of two cultivars of tea (Camellia sinensis), clone variety Baiye1 (BY1) and Longjing43 (LJ43), based on lysimeter data. An estimation was made for both for ETc and adjusted ETc, and the corresponding Kc and adjusted Kc. The results showed that the adjusted ETc and Kc values revealed a minor fluctuation when compared to the ETc and Kc values during the experimental period, which indicated that the adjusted ETc and Kc values were more precise and practical to field conditions. The average adjusted Kc values were 0.71 (range of 0.43–1.02) for BY1 and 0.84 (range of 0.48–1.22) for LJ43. Additionally, heavy pruning can decrease ETc and Kc values, possibly due to the lower level of LAI after pruning. Moreover, it is clearly manifested that BY1 consistently had lower ETc and Kc values than those of LJ43 because of plant growth status differences between BY1 and LJ43. Overall, our study proposed a reliable reference of Kc in tea plantation, and illuminated the effects of pruning and plant growth differences on Kc, which could provide a strong basis for precise irrigation in tea plantations in a subtropical climate.

Rhizosphere microbes play pivotal roles in regulating the soil ecosystem by influencing and directly participating in the nutrient cycle. Evidence shows that the rhizosphere microbes are highly dependent on plant genotype and cultivars; however, their characteristics in soils with different tea (Camellia sinensis L.) cultivars are poorly understood. Therefore, the present study investigated the rhizosphere soil properties, microbial community composition, and their potential functions under four tea cultivars Huangjinya (HJY), Tieguanyin (TGY), Zhongcha No.108 (ZC108), and Zijuan (ZJ). The study found a minor impact of cultivars on rhizosphere soil properties but a significant influence on microbial community structure. Except for available potassium (AK) (HJY > TGY > ZC108 > ZJ), tea cultivars had no significant impact on other soil properties. The tea cultivars resulted in substantial differences only in the diversity of soil bacteria of lower taxonomic levels (family to species), as well as significantly changed communities’ structure of bacteria and fungi (R2 = 0.184, p = 0.013 and R2 = 0.226, p = 0.001). Specifically, Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteriota, and Firmicutes accounted for approximately 96% of the bacterial phyla in the tea soils, while Ascomycota, Mortierellomycota, Rozellomycota, Basidiomycota, and Monoblepharomycota (90% of the total) predominated the soil fungal community. Redundancy analysis (RDA) identified soil pH (14.53%) and ammonium-nitrogen (NH4+-N; 16.74%) as the key factors for the changes in bacterial and fungal communities, respectively. Finally, FAPROTAX analysis predicted significant differences in the carbon, nitrogen, and sulfur (C-N-S)-cycling among the soils with different tea cultivars, specifically, ZJ cultivar showed the highest C-cycling but the lowest N- and S-cycling, while FUNGuild analysis revealed that the pathotroph group was significantly lower in ZC108 than the other cultivars. These findings improve our understanding of the differences in microbial community characteristics among tea cultivars and provide a basis for precisely selecting and introducing excellent tea varieties in the agriculture practices.