Implications for yield enhancement of Camellia oleifera plantation in Hunan Province: Based on distribution and yield influencing factors

Hunan Province has the largest Camellia oleifera planting area in China, yet studies on the factors affecting its distribution and yield are limited. This study analyzed the planting area, total yield, and yield per unit area of C. oleifera in Hunan Province from 2018 to 2022, and explored the key factors influencing these variables. The total planting area and yield of C. oleifera in the province were 1.5 million hectares and 1.2 million tons, representing 32.9 % and 40.2 % of the China’s national totals, respectively. The core planting area was in Hengyang City, with a yield of 0.9 t ha⁻¹. C. oleifera was mainly planted in hilly regions with red and purple soils and high annual temperature. Random forest analysis identified key environmental factors influencing the yield of C. oleifera, including mean rainfall, temperature, and solar radiation from October to December, mean annual solar radiation and temperature, mean rainfall from July to September, altitude, aspect, clay content, and cation exchange capacity (CEC). The yield per unit area of C. oleifera was positively correlated with mean rainfall, temperature, and solar radiation from October to December, soil clay content, and CEC (p < 0.05). The experimental results showed that in the C. oleifera plantation, the highest yield per plant (4.7 kg) was on the south-facing slope (Aspect = 180°). Intercropping with Arachis hypogaea and Cassiae Semen increased yields by 39.4 % and 28.1 %, respectively, compared to monoculture. These findings offer valuable insights for improving the yield of C. oleifera plantation.