Effect of different levels of potassium fertilization on nutrient accumulation and oil yield of Camellia oleifera Abel

【Objectives】 Camellia oleifera Abel is one of the major edible woody oil trees in southern China. It is very common that potassium is extremely lack in the Camellia woodlands, which affects its growth and oil yield seriously. In this paper, the effects of different levels of potassium on the accumulation of nitrogen, phosphorus, potassium and oil yield of C.oleifera Abel were studied. The results will provide scientific base for the health management of woody oil trees. 【Methods】 Seven-years-old clone strain of C. oleifera Abel was used as tested material, and a field experiment was conducted in Jiujiang City, Jiangxi Provence. Six K2O application levels: 0, 100, 200, 300, 400, 500 kg/hm2 and no fertilizer control were designed with triplicates. The contents of nitrogen, phosphorus, potassium in the leaves and fruits, the individual plant oil output were determined. 【Results】With annual addition of K2O 300 kg/hm2, the P and K contents in leaves in June, and the N, P and K contents in leaves and fruits in October were effectively improved. The fruit outputs and oil contents in the fresh fruits were increased significantly. However, the N contents in leaves of June and the oil contents in the dry kernel were not significantly different. N, P, K in fruits and N, P in leaves in October and oil yield per plant were correlated significantly. The accumulation of N and P in the fruits was the most important to the oil output, and the accumulation of N in leaves in October was less important. The contribution of nutrient to oil yield was in the following order: fruit Pfruit Nfruit Kleaf Nleaf P. 【Conclusions】 K application levels affect the N, P and K accumulation in leaves and fruits of C. oleifera Abel, consequently affect the oil outputs in fruits. Annual dosage of K2O 300 kg /hm2 is appropriate for C. oleifera Abel in the tested region.