Two nitrogen (N) sources – synthetic urea ammonium sulfate (UAS, 33-0-0) and organic bloodmeal (BM, 13-0-0) were evaluated for growing tea transplants in southeastern Louisiana. In Expt. 1, UAS and BM were applied at three rates (150, 250, and 350 lbs. N/A/year) to a 1-year-old tea field. Expt. 2 evaluated five treatments by substituting UAS with BM at 0%, 25%, 50%, 75%, and 100%, all at 350 lbs. N/A/year, applied to a 2-year-old tea field. N applications were divided into seven applications and applied every 40 days from April to October in 2023 and 2024 for a total of 11 applications. Despite periodic pruning to encourage branching for the building of a plucking table, plant growth metrics, such as leaf greenness and size index were similar across treatments in both experiments. However, tissue nitrogen concentration (N%) was consistently higher in BM-treated plants compared to UAS-treated plants at all application rates in Experiment 1. The highest tissue N% was also observed in the 100% BM treatment in Experiment 2. One year after treatment initiation, plants fertilized with UAS exhibited faster recovery after pruning compared to those treated with BM, though this difference diminished over time. In both experiments, plots treated with blood meal or more than 75% blood meal replacement resulted in less acidification compared with those treated with UAS. Further research on leaf quality (e.g., health-promoting compounds) and a more comprehensive evaluation of soil microbial activity are required to refine recommendations for nitrogen application rates and sources for tea production.
