Effects of Soil Properties and Nutrients on the Fruit Economic Parameters and Oil Nutrient Contents of Camellia oleifera

Abstract

The Camellia oleifera industry is hindered by the substandard quality of its fruits and the low yield of camellia seed oil. Although soil factors have been shown to affect the productivity of this plant, the relationship between C. oleifera characteristics and soil properties and nutrients remains unclear. Therefore, we investigated soil factors within the central distribution area of this species. Our findings revealed that this plant thrives in acidic soils with a medium cation exchange capacity. There were moderate differences in the main and medium element contents in the soils, while the variation of microelements was significant. Overall, C. oleifera cultivated soils were poor, with an uneven distribution of soil nutrients. Most of the shape characteristics of camellia fruits showed moderate variability, whereas dry kernel rate and oil content exhibited minor variability. The fatty acid profiles remained stable across different planting sites, but there were higher variations in the content of active compounds. Fruit shape characteristics were primarily influenced by soil properties, while soil nutrients mainly affected the seeds and kernels of the fruit. Minor fatty acid content could be influenced by soil properties and nutrients, except for total nitrogen (TN), which specifically affected the content of palmitic acid and oleic acid. There was no significant correlation between soil factors and sterols, polyphenols, and tocopherols, while squalene was affected by soil properties. Our study highlights the importance of considering soil properties and nutrients in the cultivation of C. oleifera and emphasizes the need for rational fertilizer application.